Pull xpc-disengage into release branch
authorTony Luck <tony.luck@intel.com>
Fri, 28 Oct 2005 22:27:03 +0000 (15:27 -0700)
committerTony Luck <tony.luck@intel.com>
Fri, 28 Oct 2005 22:27:03 +0000 (15:27 -0700)
arch/ia64/sn/kernel/xpc.h
arch/ia64/sn/kernel/xpc_channel.c
arch/ia64/sn/kernel/xpc_main.c
arch/ia64/sn/kernel/xpc_partition.c
include/asm-ia64/sn/xp.h

index d0ee635..33df1b3 100644 (file)
@@ -57,7 +57,7 @@
 #define XPC_NASID_FROM_W_B(_w, _b) (((_w) * 64 + (_b)) * 2)
 
 #define XPC_HB_DEFAULT_INTERVAL                5       /* incr HB every x secs */
-#define XPC_HB_CHECK_DEFAULT_TIMEOUT   20      /* check HB every x secs */
+#define XPC_HB_CHECK_DEFAULT_INTERVAL  20      /* check HB every x secs */
 
 /* define the process name of HB checker and the CPU it is pinned to */
 #define XPC_HB_CHECK_THREAD_NAME       "xpc_hb"
 #define XPC_DISCOVERY_THREAD_NAME      "xpc_discovery"
 
 
-#define XPC_HB_ALLOWED(_p, _v) ((_v)->heartbeating_to_mask & (1UL << (_p)))
-#define XPC_ALLOW_HB(_p, _v)   (_v)->heartbeating_to_mask |= (1UL << (_p))
-#define XPC_DISALLOW_HB(_p, _v)        (_v)->heartbeating_to_mask &= (~(1UL << (_p)))
-
-
 /*
- * Reserved Page provided by SAL.
+ * the reserved page
+ *
+ *   SAL reserves one page of memory per partition for XPC. Though a full page
+ *   in length (16384 bytes), its starting address is not page aligned, but it
+ *   is cacheline aligned. The reserved page consists of the following:
+ *
+ *   reserved page header
+ *
+ *     The first cacheline of the reserved page contains the header
+ *     (struct xpc_rsvd_page). Before SAL initialization has completed,
+ *     SAL has set up the following fields of the reserved page header:
+ *     SAL_signature, SAL_version, partid, and nasids_size. The other
+ *     fields are set up by XPC. (xpc_rsvd_page points to the local
+ *     partition's reserved page.)
  *
- * SAL provides one page per partition of reserved memory.  When SAL
- * initialization is complete, SAL_signature, SAL_version, partid,
- * part_nasids, and mach_nasids are set.
+ *   part_nasids mask
+ *   mach_nasids mask
+ *
+ *     SAL also sets up two bitmaps (or masks), one that reflects the actual
+ *     nasids in this partition (part_nasids), and the other that reflects
+ *     the actual nasids in the entire machine (mach_nasids). We're only
+ *     interested in the even numbered nasids (which contain the processors
+ *     and/or memory), so we only need half as many bits to represent the
+ *     nasids. The part_nasids mask is located starting at the first cacheline
+ *     following the reserved page header. The mach_nasids mask follows right
+ *     after the part_nasids mask. The size in bytes of each mask is reflected
+ *     by the reserved page header field 'nasids_size'. (Local partition's
+ *     mask pointers are xpc_part_nasids and xpc_mach_nasids.)
+ *
+ *   vars
+ *   vars part
+ *
+ *     Immediately following the mach_nasids mask are the XPC variables
+ *     required by other partitions. First are those that are generic to all
+ *     partitions (vars), followed on the next available cacheline by those
+ *     which are partition specific (vars part). These are setup by XPC.
+ *     (Local partition's vars pointers are xpc_vars and xpc_vars_part.)
  *
  * Note: Until vars_pa is set, the partition XPC code has not been initialized.
  */
 struct xpc_rsvd_page {
-       u64 SAL_signature;      /* SAL unique signature */
-       u64 SAL_version;        /* SAL specified version */
-       u8 partid;              /* partition ID from SAL */
+       u64 SAL_signature;      /* SAL: unique signature */
+       u64 SAL_version;        /* SAL: version */
+       u8 partid;              /* SAL: partition ID */
        u8 version;
-       u8 pad[6];              /* pad to u64 align */
+       u8 pad1[6];             /* align to next u64 in cacheline */
        volatile u64 vars_pa;
-       u64 part_nasids[XP_NASID_MASK_WORDS] ____cacheline_aligned;
-       u64 mach_nasids[XP_NASID_MASK_WORDS] ____cacheline_aligned;
+       struct timespec stamp;  /* time when reserved page was setup by XPC */
+       u64 pad2[9];            /* align to last u64 in cacheline */
+       u64 nasids_size;        /* SAL: size of each nasid mask in bytes */
 };
-#define XPC_RP_VERSION _XPC_VERSION(1,0) /* version 1.0 of the reserved page */
 
-#define XPC_RSVD_PAGE_ALIGNED_SIZE \
-                       (L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page)))
+#define XPC_RP_VERSION _XPC_VERSION(1,1) /* version 1.1 of the reserved page */
+
+#define XPC_SUPPORTS_RP_STAMP(_version) \
+                       (_version >= _XPC_VERSION(1,1))
+
+/*
+ * compare stamps - the return value is:
+ *
+ *     < 0,    if stamp1 < stamp2
+ *     = 0,    if stamp1 == stamp2
+ *     > 0,    if stamp1 > stamp2
+ */
+static inline int
+xpc_compare_stamps(struct timespec *stamp1, struct timespec *stamp2)
+{
+       int ret;
+
+
+       if ((ret = stamp1->tv_sec - stamp2->tv_sec) == 0) {
+               ret = stamp1->tv_nsec - stamp2->tv_nsec;
+       }
+       return ret;
+}
 
 
 /*
@@ -121,11 +169,58 @@ struct xpc_vars {
        u64 vars_part_pa;
        u64 amos_page_pa;       /* paddr of page of AMOs from MSPEC driver */
        AMO_t *amos_page;       /* vaddr of page of AMOs from MSPEC driver */
-       AMO_t *act_amos;        /* pointer to the first activation AMO */
 };
-#define XPC_V_VERSION _XPC_VERSION(3,0) /* version 3.0 of the cross vars */
 
-#define XPC_VARS_ALIGNED_SIZE  (L1_CACHE_ALIGN(sizeof(struct xpc_vars)))
+#define XPC_V_VERSION _XPC_VERSION(3,1) /* version 3.1 of the cross vars */
+
+#define XPC_SUPPORTS_DISENGAGE_REQUEST(_version) \
+                       (_version >= _XPC_VERSION(3,1))
+
+
+static inline int
+xpc_hb_allowed(partid_t partid, struct xpc_vars *vars)
+{
+       return ((vars->heartbeating_to_mask & (1UL << partid)) != 0);
+}
+
+static inline void
+xpc_allow_hb(partid_t partid, struct xpc_vars *vars)
+{
+       u64 old_mask, new_mask;
+
+       do {
+               old_mask = vars->heartbeating_to_mask;
+               new_mask = (old_mask | (1UL << partid));
+       } while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
+                                                       old_mask);
+}
+
+static inline void
+xpc_disallow_hb(partid_t partid, struct xpc_vars *vars)
+{
+       u64 old_mask, new_mask;
+
+       do {
+               old_mask = vars->heartbeating_to_mask;
+               new_mask = (old_mask & ~(1UL << partid));
+       } while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
+                                                       old_mask);
+}
+
+
+/*
+ * The AMOs page consists of a number of AMO variables which are divided into
+ * four groups, The first two groups are used to identify an IRQ's sender.
+ * These two groups consist of 64 and 128 AMO variables respectively. The last
+ * two groups, consisting of just one AMO variable each, are used to identify
+ * the remote partitions that are currently engaged (from the viewpoint of
+ * the XPC running on the remote partition).
+ */
+#define XPC_NOTIFY_IRQ_AMOS       0
+#define XPC_ACTIVATE_IRQ_AMOS     (XPC_NOTIFY_IRQ_AMOS + XP_MAX_PARTITIONS)
+#define XPC_ENGAGED_PARTITIONS_AMO (XPC_ACTIVATE_IRQ_AMOS + XP_NASID_MASK_WORDS)
+#define XPC_DISENGAGE_REQUEST_AMO  (XPC_ENGAGED_PARTITIONS_AMO + 1)
+
 
 /*
  * The following structure describes the per partition specific variables.
@@ -165,6 +260,16 @@ struct xpc_vars_part {
 #define XPC_VP_MAGIC2  0x0073726176435058L  /* 'XPCvars\0'L (little endian) */
 
 
+/* the reserved page sizes and offsets */
+
+#define XPC_RP_HEADER_SIZE     L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))
+#define XPC_RP_VARS_SIZE       L1_CACHE_ALIGN(sizeof(struct xpc_vars))
+
+#define XPC_RP_PART_NASIDS(_rp) (u64 *) ((u8 *) _rp + XPC_RP_HEADER_SIZE)
+#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + xp_nasid_mask_words)
+#define XPC_RP_VARS(_rp)       ((struct xpc_vars *) XPC_RP_MACH_NASIDS(_rp) + xp_nasid_mask_words)
+#define XPC_RP_VARS_PART(_rp)  (struct xpc_vars_part *) ((u8 *) XPC_RP_VARS(rp) + XPC_RP_VARS_SIZE)
+
 
 /*
  * Functions registered by add_timer() or called by kernel_thread() only
@@ -349,6 +454,9 @@ struct xpc_channel {
        atomic_t n_on_msg_allocate_wq;   /* #on msg allocation wait queue */
        wait_queue_head_t msg_allocate_wq; /* msg allocation wait queue */
 
+       u8 delayed_IPI_flags;           /* IPI flags received, but delayed */
+                                       /* action until channel disconnected */
+
        /* queue of msg senders who want to be notified when msg received */
 
        atomic_t n_to_notify;           /* #of msg senders to notify */
@@ -358,7 +466,7 @@ struct xpc_channel {
        void *key;                      /* pointer to user's key */
 
        struct semaphore msg_to_pull_sema; /* next msg to pull serialization */
-       struct semaphore teardown_sema;    /* wait for teardown completion */
+       struct semaphore wdisconnect_sema; /* wait for channel disconnect */
 
        struct xpc_openclose_args *local_openclose_args; /* args passed on */
                                        /* opening or closing of channel */
@@ -410,6 +518,8 @@ struct xpc_channel {
 
 #define        XPC_C_DISCONNECTED      0x00002000 /* channel is disconnected */
 #define        XPC_C_DISCONNECTING     0x00004000 /* channel is being disconnected */
+#define        XPC_C_DISCONNECTCALLOUT 0x00008000 /* chan disconnected callout made */
+#define        XPC_C_WDISCONNECT       0x00010000 /* waiting for channel disconnect */
 
 
 
@@ -422,6 +532,8 @@ struct xpc_partition {
 
        /* XPC HB infrastructure */
 
+       u8 remote_rp_version;           /* version# of partition's rsvd pg */
+       struct timespec remote_rp_stamp;/* time when rsvd pg was initialized */
        u64 remote_rp_pa;               /* phys addr of partition's rsvd pg */
        u64 remote_vars_pa;             /* phys addr of partition's vars */
        u64 remote_vars_part_pa;        /* phys addr of partition's vars part */
@@ -432,14 +544,18 @@ struct xpc_partition {
        u32 act_IRQ_rcvd;               /* IRQs since activation */
        spinlock_t act_lock;            /* protect updating of act_state */
        u8 act_state;                   /* from XPC HB viewpoint */
+       u8 remote_vars_version;         /* version# of partition's vars */
        enum xpc_retval reason;         /* reason partition is deactivating */
        int reason_line;                /* line# deactivation initiated from */
        int reactivate_nasid;           /* nasid in partition to reactivate */
 
+       unsigned long disengage_request_timeout; /* timeout in jiffies */
+       struct timer_list disengage_request_timer;
+
 
        /* XPC infrastructure referencing and teardown control */
 
-       volatile u8 setup_state;                        /* infrastructure setup state */
+       volatile u8 setup_state;        /* infrastructure setup state */
        wait_queue_head_t teardown_wq;  /* kthread waiting to teardown infra */
        atomic_t references;            /* #of references to infrastructure */
 
@@ -454,6 +570,7 @@ struct xpc_partition {
 
        u8 nchannels;              /* #of defined channels supported */
        atomic_t nchannels_active; /* #of channels that are not DISCONNECTED */
+       atomic_t nchannels_engaged;/* #of channels engaged with remote part */
        struct xpc_channel *channels;/* array of channel structures */
 
        void *local_GPs_base;     /* base address of kmalloc'd space */
@@ -518,6 +635,7 @@ struct xpc_partition {
 #define XPC_P_TORNDOWN         0x03    /* infrastructure is torndown */
 
 
+
 /*
  * struct xpc_partition IPI_timer #of seconds to wait before checking for
  * dropped IPIs. These occur whenever an IPI amo write doesn't complete until
@@ -526,6 +644,13 @@ struct xpc_partition {
 #define XPC_P_DROPPED_IPI_WAIT (0.25 * HZ)
 
 
+/* number of seconds to wait for other partitions to disengage */
+#define XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT        90
+
+/* interval in seconds to print 'waiting disengagement' messages */
+#define XPC_DISENGAGE_PRINTMSG_INTERVAL                10
+
+
 #define XPC_PARTID(_p) ((partid_t) ((_p) - &xpc_partitions[0]))
 
 
@@ -534,24 +659,20 @@ struct xpc_partition {
 extern struct xpc_registration xpc_registrations[];
 
 
-/* >>> found in xpc_main.c only */
+/* found in xpc_main.c */
 extern struct device *xpc_part;
 extern struct device *xpc_chan;
+extern int xpc_disengage_request_timelimit;
 extern irqreturn_t xpc_notify_IRQ_handler(int, void *, struct pt_regs *);
 extern void xpc_dropped_IPI_check(struct xpc_partition *);
+extern void xpc_activate_partition(struct xpc_partition *);
 extern void xpc_activate_kthreads(struct xpc_channel *, int);
 extern void xpc_create_kthreads(struct xpc_channel *, int);
 extern void xpc_disconnect_wait(int);
 
 
-/* found in xpc_main.c and efi-xpc.c */
-extern void xpc_activate_partition(struct xpc_partition *);
-
-
 /* found in xpc_partition.c */
 extern int xpc_exiting;
-extern int xpc_hb_interval;
-extern int xpc_hb_check_interval;
 extern struct xpc_vars *xpc_vars;
 extern struct xpc_rsvd_page *xpc_rsvd_page;
 extern struct xpc_vars_part *xpc_vars_part;
@@ -561,6 +682,7 @@ extern struct xpc_rsvd_page *xpc_rsvd_page_init(void);
 extern void xpc_allow_IPI_ops(void);
 extern void xpc_restrict_IPI_ops(void);
 extern int xpc_identify_act_IRQ_sender(void);
+extern int xpc_partition_disengaged(struct xpc_partition *);
 extern enum xpc_retval xpc_mark_partition_active(struct xpc_partition *);
 extern void xpc_mark_partition_inactive(struct xpc_partition *);
 extern void xpc_discovery(void);
@@ -585,8 +707,8 @@ extern void xpc_connected_callout(struct xpc_channel *);
 extern void xpc_deliver_msg(struct xpc_channel *);
 extern void xpc_disconnect_channel(const int, struct xpc_channel *,
                                        enum xpc_retval, unsigned long *);
-extern void xpc_disconnected_callout(struct xpc_channel *);
-extern void xpc_partition_down(struct xpc_partition *, enum xpc_retval);
+extern void xpc_disconnecting_callout(struct xpc_channel *);
+extern void xpc_partition_going_down(struct xpc_partition *, enum xpc_retval);
 extern void xpc_teardown_infrastructure(struct xpc_partition *);
 
 
@@ -673,6 +795,157 @@ xpc_part_ref(struct xpc_partition *part)
 
 
 
+/*
+ * This next set of inlines are used to keep track of when a partition is
+ * potentially engaged in accessing memory belonging to another partition.
+ */
+
+static inline void
+xpc_mark_partition_engaged(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+       AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
+                               (XPC_ENGAGED_PARTITIONS_AMO * sizeof(AMO_t)));
+
+
+       local_irq_save(irq_flags);
+
+       /* set bit corresponding to our partid in remote partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR,
+                                               (1UL << sn_partition_id));
+       /*
+        * We must always use the nofault function regardless of whether we
+        * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+        * didn't, we'd never know that the other partition is down and would
+        * keep sending IPIs and AMOs to it until the heartbeat times out.
+        */
+       (void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
+                               variable), xp_nofault_PIOR_target));
+
+       local_irq_restore(irq_flags);
+}
+
+static inline void
+xpc_mark_partition_disengaged(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+       AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
+                               (XPC_ENGAGED_PARTITIONS_AMO * sizeof(AMO_t)));
+
+
+       local_irq_save(irq_flags);
+
+       /* clear bit corresponding to our partid in remote partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
+                                               ~(1UL << sn_partition_id));
+       /*
+        * We must always use the nofault function regardless of whether we
+        * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+        * didn't, we'd never know that the other partition is down and would
+        * keep sending IPIs and AMOs to it until the heartbeat times out.
+        */
+       (void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
+                               variable), xp_nofault_PIOR_target));
+
+       local_irq_restore(irq_flags);
+}
+
+static inline void
+xpc_request_partition_disengage(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+       AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
+                               (XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));
+
+
+       local_irq_save(irq_flags);
+
+       /* set bit corresponding to our partid in remote partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR,
+                                               (1UL << sn_partition_id));
+       /*
+        * We must always use the nofault function regardless of whether we
+        * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+        * didn't, we'd never know that the other partition is down and would
+        * keep sending IPIs and AMOs to it until the heartbeat times out.
+        */
+       (void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
+                               variable), xp_nofault_PIOR_target));
+
+       local_irq_restore(irq_flags);
+}
+
+static inline void
+xpc_cancel_partition_disengage_request(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+       AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
+                               (XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));
+
+
+       local_irq_save(irq_flags);
+
+       /* clear bit corresponding to our partid in remote partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
+                                               ~(1UL << sn_partition_id));
+       /*
+        * We must always use the nofault function regardless of whether we
+        * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+        * didn't, we'd never know that the other partition is down and would
+        * keep sending IPIs and AMOs to it until the heartbeat times out.
+        */
+       (void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
+                               variable), xp_nofault_PIOR_target));
+
+       local_irq_restore(irq_flags);
+}
+
+static inline u64
+xpc_partition_engaged(u64 partid_mask)
+{
+       AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
+
+
+       /* return our partition's AMO variable ANDed with partid_mask */
+       return (FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_LOAD) &
+                                                               partid_mask);
+}
+
+static inline u64
+xpc_partition_disengage_requested(u64 partid_mask)
+{
+       AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;
+
+
+       /* return our partition's AMO variable ANDed with partid_mask */
+       return (FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_LOAD) &
+                                                               partid_mask);
+}
+
+static inline void
+xpc_clear_partition_engaged(u64 partid_mask)
+{
+       AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
+
+
+       /* clear bit(s) based on partid_mask in our partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
+                                                               ~partid_mask);
+}
+
+static inline void
+xpc_clear_partition_disengage_request(u64 partid_mask)
+{
+       AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;
+
+
+       /* clear bit(s) based on partid_mask in our partition's AMO */
+       FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
+                                                               ~partid_mask);
+}
+
+
+
 /*
  * The following set of macros and inlines are used for the sending and
  * receiving of IPIs (also known as IRQs). There are two flavors of IPIs,
@@ -722,13 +995,13 @@ xpc_IPI_send(AMO_t *amo, u64 flag, int nasid, int phys_cpuid, int vector)
  * Flag the appropriate AMO variable and send an IPI to the specified node.
  */
 static inline void
-xpc_activate_IRQ_send(u64 amos_page, int from_nasid, int to_nasid,
+xpc_activate_IRQ_send(u64 amos_page_pa, int from_nasid, int to_nasid,
                        int to_phys_cpuid)
 {
        int w_index = XPC_NASID_W_INDEX(from_nasid);
        int b_index = XPC_NASID_B_INDEX(from_nasid);
-       AMO_t *amos = (AMO_t *) __va(amos_page +
-                                       (XP_MAX_PARTITIONS * sizeof(AMO_t)));
+       AMO_t *amos = (AMO_t *) __va(amos_page_pa +
+                               (XPC_ACTIVATE_IRQ_AMOS * sizeof(AMO_t)));
 
 
        (void) xpc_IPI_send(&amos[w_index], (1UL << b_index), to_nasid,
@@ -756,6 +1029,13 @@ xpc_IPI_send_reactivate(struct xpc_partition *part)
                                xpc_vars->act_nasid, xpc_vars->act_phys_cpuid);
 }
 
+static inline void
+xpc_IPI_send_disengage(struct xpc_partition *part)
+{
+       xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
+                       part->remote_act_nasid, part->remote_act_phys_cpuid);
+}
+
 
 /*
  * IPIs associated with SGI_XPC_NOTIFY IRQ.
@@ -836,6 +1116,7 @@ xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
 
 /* given an AMO variable and a channel#, get its associated IPI flags */
 #define XPC_GET_IPI_FLAGS(_amo, _c)    ((u8) (((_amo) >> ((_c) * 8)) & 0xff))
+#define XPC_SET_IPI_FLAGS(_amo, _c, _f)        (_amo) |= ((u64) (_f) << ((_c) * 8))
 
 #define        XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & 0x0f0f0f0f0f0f0f0f)
 #define XPC_ANY_MSG_IPI_FLAGS_SET(_amo)       ((_amo) & 0x1010101010101010)
@@ -903,17 +1184,18 @@ xpc_IPI_send_local_msgrequest(struct xpc_channel *ch)
  * cacheable mapping for the entire region. This will prevent speculative
  * reading of cached copies of our lines from being issued which will cause
  * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
- * (XP_MAX_PARTITIONS) AMO variables for message notification (xpc_main.c)
- * and an additional 16 AMO variables for partition activation (xpc_hb.c).
+ * AMO variables (based on XP_MAX_PARTITIONS) for message notification and an
+ * additional 128 AMO variables (based on XP_NASID_MASK_WORDS) for partition
+ * activation and 2 AMO variables for partition deactivation.
  */
 static inline AMO_t *
-xpc_IPI_init(partid_t partid)
+xpc_IPI_init(int index)
 {
-       AMO_t *part_amo = xpc_vars->amos_page + partid;
+       AMO_t *amo = xpc_vars->amos_page + index;
 
 
-       xpc_IPI_receive(part_amo);
-       return part_amo;
+       (void) xpc_IPI_receive(amo);    /* clear AMO variable */
+       return amo;
 }
 
 
index 94698be..abf4fc2 100644 (file)
@@ -57,6 +57,7 @@ xpc_initialize_channels(struct xpc_partition *part, partid_t partid)
 
                spin_lock_init(&ch->lock);
                sema_init(&ch->msg_to_pull_sema, 1);    /* mutex */
+               sema_init(&ch->wdisconnect_sema, 0);    /* event wait */
 
                atomic_set(&ch->n_on_msg_allocate_wq, 0);
                init_waitqueue_head(&ch->msg_allocate_wq);
@@ -166,6 +167,7 @@ xpc_setup_infrastructure(struct xpc_partition *part)
        xpc_initialize_channels(part, partid);
 
        atomic_set(&part->nchannels_active, 0);
+       atomic_set(&part->nchannels_engaged, 0);
 
 
        /* local_IPI_amo were set to 0 by an earlier memset() */
@@ -555,8 +557,6 @@ xpc_allocate_msgqueues(struct xpc_channel *ch)
                sema_init(&ch->notify_queue[i].sema, 0);
        }
 
-       sema_init(&ch->teardown_sema, 0);       /* event wait */
-
        spin_lock_irqsave(&ch->lock, irq_flags);
        ch->flags |= XPC_C_SETUP;
        spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -625,6 +625,55 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 }
 
 
+/*
+ * Notify those who wanted to be notified upon delivery of their message.
+ */
+static void
+xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put)
+{
+       struct xpc_notify *notify;
+       u8 notify_type;
+       s64 get = ch->w_remote_GP.get - 1;
+
+
+       while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
+
+               notify = &ch->notify_queue[get % ch->local_nentries];
+
+               /*
+                * See if the notify entry indicates it was associated with
+                * a message who's sender wants to be notified. It is possible
+                * that it is, but someone else is doing or has done the
+                * notification.
+                */
+               notify_type = notify->type;
+               if (notify_type == 0 ||
+                               cmpxchg(&notify->type, notify_type, 0) !=
+                                                               notify_type) {
+                       continue;
+               }
+
+               DBUG_ON(notify_type != XPC_N_CALL);
+
+               atomic_dec(&ch->n_to_notify);
+
+               if (notify->func != NULL) {
+                       dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
+                               "msg_number=%ld, partid=%d, channel=%d\n",
+                               (void *) notify, get, ch->partid, ch->number);
+
+                       notify->func(reason, ch->partid, ch->number,
+                                                               notify->key);
+
+                       dev_dbg(xpc_chan, "notify->func() returned, "
+                               "notify=0x%p, msg_number=%ld, partid=%d, "
+                               "channel=%d\n", (void *) notify, get,
+                               ch->partid, ch->number);
+               }
+       }
+}
+
+
 /*
  * Free up message queues and other stuff that were allocated for the specified
  * channel.
@@ -669,9 +718,6 @@ xpc_free_msgqueues(struct xpc_channel *ch)
                ch->remote_msgqueue = NULL;
                kfree(ch->notify_queue);
                ch->notify_queue = NULL;
-
-               /* in case someone is waiting for the teardown to complete */
-               up(&ch->teardown_sema);
        }
 }
 
@@ -683,7 +729,7 @@ static void
 xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 {
        struct xpc_partition *part = &xpc_partitions[ch->partid];
-       u32 ch_flags = ch->flags;
+       u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED);
 
 
        DBUG_ON(!spin_is_locked(&ch->lock));
@@ -701,12 +747,13 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
        }
        DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
 
-       /* it's now safe to free the channel's message queues */
-
-       xpc_free_msgqueues(ch);
-       DBUG_ON(ch->flags & XPC_C_SETUP);
+       if (part->act_state == XPC_P_DEACTIVATING) {
+               /* can't proceed until the other side disengages from us */
+               if (xpc_partition_engaged(1UL << ch->partid)) {
+                       return;
+               }
 
-       if (part->act_state != XPC_P_DEACTIVATING) {
+       } else {
 
                /* as long as the other side is up do the full protocol */
 
@@ -724,16 +771,42 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
                }
        }
 
+       /* wake those waiting for notify completion */
+       if (atomic_read(&ch->n_to_notify) > 0) {
+               /* >>> we do callout while holding ch->lock */
+               xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put);
+       }
+
        /* both sides are disconnected now */
 
-       ch->flags = XPC_C_DISCONNECTED; /* clear all flags, but this one */
+       /* it's now safe to free the channel's message queues */
+       xpc_free_msgqueues(ch);
+
+       /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */
+       ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
 
        atomic_dec(&part->nchannels_active);
 
-       if (ch_flags & XPC_C_WASCONNECTED) {
+       if (channel_was_connected) {
                dev_info(xpc_chan, "channel %d to partition %d disconnected, "
                        "reason=%d\n", ch->number, ch->partid, ch->reason);
        }
+
+       if (ch->flags & XPC_C_WDISCONNECT) {
+               spin_unlock_irqrestore(&ch->lock, *irq_flags);
+               up(&ch->wdisconnect_sema);
+               spin_lock_irqsave(&ch->lock, *irq_flags);
+
+       } else if (ch->delayed_IPI_flags) {
+               if (part->act_state != XPC_P_DEACTIVATING) {
+                       /* time to take action on any delayed IPI flags */
+                       spin_lock(&part->IPI_lock);
+                       XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
+                                                       ch->delayed_IPI_flags);
+                       spin_unlock(&part->IPI_lock);
+               }
+               ch->delayed_IPI_flags = 0;
+       }
 }
 
 
@@ -754,6 +827,19 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
        spin_lock_irqsave(&ch->lock, irq_flags);
 
+again:
+
+       if ((ch->flags & XPC_C_DISCONNECTED) &&
+                                       (ch->flags & XPC_C_WDISCONNECT)) {
+               /*
+                * Delay processing IPI flags until thread waiting disconnect
+                * has had a chance to see that the channel is disconnected.
+                */
+               ch->delayed_IPI_flags |= IPI_flags;
+               spin_unlock_irqrestore(&ch->lock, irq_flags);
+               return;
+       }
+
 
        if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
 
@@ -764,7 +850,7 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                /*
                 * If RCLOSEREQUEST is set, we're probably waiting for
                 * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
-                * with this RCLOSEQREUQEST in the IPI_flags.
+                * with this RCLOSEREQUEST in the IPI_flags.
                 */
 
                if (ch->flags & XPC_C_RCLOSEREQUEST) {
@@ -779,14 +865,22 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
 
                        /* both sides have finished disconnecting */
                        xpc_process_disconnect(ch, &irq_flags);
+                       DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
+                       goto again;
                }
 
                if (ch->flags & XPC_C_DISCONNECTED) {
-                       // >>> explain this section
-
                        if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
-                               DBUG_ON(part->act_state !=
-                                                       XPC_P_DEACTIVATING);
+                               if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
+                                        ch_number) & XPC_IPI_OPENREQUEST)) {
+
+                                       DBUG_ON(ch->delayed_IPI_flags != 0);
+                                       spin_lock(&part->IPI_lock);
+                                       XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+                                                       ch_number,
+                                                       XPC_IPI_CLOSEREQUEST);
+                                       spin_unlock(&part->IPI_lock);
+                               }
                                spin_unlock_irqrestore(&ch->lock, irq_flags);
                                return;
                        }
@@ -816,9 +910,13 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        }
 
                        XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
-               } else {
-                       xpc_process_disconnect(ch, &irq_flags);
+
+                       DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
                }
+
+               xpc_process_disconnect(ch, &irq_flags);
        }
 
 
@@ -834,7 +932,20 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                }
 
                DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
-               DBUG_ON(!(ch->flags & XPC_C_RCLOSEREQUEST));
+
+               if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
+                       if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
+                                               & XPC_IPI_CLOSEREQUEST)) {
+
+                               DBUG_ON(ch->delayed_IPI_flags != 0);
+                               spin_lock(&part->IPI_lock);
+                               XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+                                               ch_number, XPC_IPI_CLOSEREPLY);
+                               spin_unlock(&part->IPI_lock);
+                       }
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
 
                ch->flags |= XPC_C_RCLOSEREPLY;
 
@@ -852,8 +963,14 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        "channel=%d\n", args->msg_size, args->local_nentries,
                        ch->partid, ch->number);
 
-               if ((ch->flags & XPC_C_DISCONNECTING) ||
-                                       part->act_state == XPC_P_DEACTIVATING) {
+               if (part->act_state == XPC_P_DEACTIVATING ||
+                                       (ch->flags & XPC_C_ROPENREQUEST)) {
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
+
+               if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
+                       ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
                        return;
                }
@@ -867,8 +984,11 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                 *      msg_size = size of channel's messages in bytes
                 *      local_nentries = remote partition's local_nentries
                 */
-               DBUG_ON(args->msg_size == 0);
-               DBUG_ON(args->local_nentries == 0);
+               if (args->msg_size == 0 || args->local_nentries == 0) {
+                       /* assume OPENREQUEST was delayed by mistake */
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
 
                ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
                ch->remote_nentries = args->local_nentries;
@@ -906,7 +1026,13 @@ xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
                        return;
                }
-               DBUG_ON(!(ch->flags & XPC_C_OPENREQUEST));
+               if (!(ch->flags & XPC_C_OPENREQUEST)) {
+                       XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError,
+                                                               &irq_flags);
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+                       return;
+               }
+
                DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
                DBUG_ON(ch->flags & XPC_C_CONNECTED);
 
@@ -960,8 +1086,8 @@ xpc_connect_channel(struct xpc_channel *ch)
        struct xpc_registration *registration = &xpc_registrations[ch->number];
 
 
-       if (down_interruptible(&registration->sema) != 0) {
-               return xpcInterrupted;
+       if (down_trylock(&registration->sema) != 0) {
+               return xpcRetry;
        }
 
        if (!XPC_CHANNEL_REGISTERED(ch->number)) {
@@ -1039,55 +1165,6 @@ xpc_connect_channel(struct xpc_channel *ch)
 }
 
 
-/*
- * Notify those who wanted to be notified upon delivery of their message.
- */
-static void
-xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put)
-{
-       struct xpc_notify *notify;
-       u8 notify_type;
-       s64 get = ch->w_remote_GP.get - 1;
-
-
-       while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
-
-               notify = &ch->notify_queue[get % ch->local_nentries];
-
-               /*
-                * See if the notify entry indicates it was associated with
-                * a message who's sender wants to be notified. It is possible
-                * that it is, but someone else is doing or has done the
-                * notification.
-                */
-               notify_type = notify->type;
-               if (notify_type == 0 ||
-                               cmpxchg(&notify->type, notify_type, 0) !=
-                                                               notify_type) {
-                       continue;
-               }
-
-               DBUG_ON(notify_type != XPC_N_CALL);
-
-               atomic_dec(&ch->n_to_notify);
-
-               if (notify->func != NULL) {
-                       dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
-                               "msg_number=%ld, partid=%d, channel=%d\n",
-                               (void *) notify, get, ch->partid, ch->number);
-
-                       notify->func(reason, ch->partid, ch->number,
-                                                               notify->key);
-
-                       dev_dbg(xpc_chan, "notify->func() returned, "
-                               "notify=0x%p, msg_number=%ld, partid=%d, "
-                               "channel=%d\n", (void *) notify, get,
-                               ch->partid, ch->number);
-               }
-       }
-}
-
-
 /*
  * Clear some of the msg flags in the local message queue.
  */
@@ -1240,6 +1317,7 @@ xpc_process_channel_activity(struct xpc_partition *part)
        u64 IPI_amo, IPI_flags;
        struct xpc_channel *ch;
        int ch_number;
+       u32 ch_flags;
 
 
        IPI_amo = xpc_get_IPI_flags(part);
@@ -1266,8 +1344,9 @@ xpc_process_channel_activity(struct xpc_partition *part)
                        xpc_process_openclose_IPI(part, ch_number, IPI_flags);
                }
 
+               ch_flags = ch->flags;   /* need an atomic snapshot of flags */
 
-               if (ch->flags & XPC_C_DISCONNECTING) {
+               if (ch_flags & XPC_C_DISCONNECTING) {
                        spin_lock_irqsave(&ch->lock, irq_flags);
                        xpc_process_disconnect(ch, &irq_flags);
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -1278,9 +1357,9 @@ xpc_process_channel_activity(struct xpc_partition *part)
                        continue;
                }
 
-               if (!(ch->flags & XPC_C_CONNECTED)) {
-                       if (!(ch->flags & XPC_C_OPENREQUEST)) {
-                               DBUG_ON(ch->flags & XPC_C_SETUP);
+               if (!(ch_flags & XPC_C_CONNECTED)) {
+                       if (!(ch_flags & XPC_C_OPENREQUEST)) {
+                               DBUG_ON(ch_flags & XPC_C_SETUP);
                                (void) xpc_connect_channel(ch);
                        } else {
                                spin_lock_irqsave(&ch->lock, irq_flags);
@@ -1305,8 +1384,8 @@ xpc_process_channel_activity(struct xpc_partition *part)
 
 
 /*
- * XPC's heartbeat code calls this function to inform XPC that a partition has
- * gone down.  XPC responds by tearing down the XPartition Communication
+ * XPC's heartbeat code calls this function to inform XPC that a partition is
+ * going down.  XPC responds by tearing down the XPartition Communication
  * infrastructure used for the just downed partition.
  *
  * XPC's heartbeat code will never call this function and xpc_partition_up()
@@ -1314,7 +1393,7 @@ xpc_process_channel_activity(struct xpc_partition *part)
  * at the same time.
  */
 void
-xpc_partition_down(struct xpc_partition *part, enum xpc_retval reason)
+xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason)
 {
        unsigned long irq_flags;
        int ch_number;
@@ -1330,12 +1409,11 @@ xpc_partition_down(struct xpc_partition *part, enum xpc_retval reason)
        }
 
 
-       /* disconnect all channels associated with the downed partition */
+       /* disconnect channels associated with the partition going down */
 
        for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
                ch = &part->channels[ch_number];
 
-
                xpc_msgqueue_ref(ch);
                spin_lock_irqsave(&ch->lock, irq_flags);
 
@@ -1370,6 +1448,7 @@ xpc_teardown_infrastructure(struct xpc_partition *part)
         * this partition.
         */
 
+       DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
        DBUG_ON(atomic_read(&part->nchannels_active) != 0);
        DBUG_ON(part->setup_state != XPC_P_SETUP);
        part->setup_state = XPC_P_WTEARDOWN;
@@ -1428,19 +1507,11 @@ xpc_initiate_connect(int ch_number)
                if (xpc_part_ref(part)) {
                        ch = &part->channels[ch_number];
 
-                       if (!(ch->flags & XPC_C_DISCONNECTING)) {
-                               DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
-                               DBUG_ON(ch->flags & XPC_C_CONNECTED);
-                               DBUG_ON(ch->flags & XPC_C_SETUP);
-
-                               /*
-                                * Initiate the establishment of a connection
-                                * on the newly registered channel to the
-                                * remote partition.
-                                */
-                               xpc_wakeup_channel_mgr(part);
-                       }
-
+                       /*
+                        * Initiate the establishment of a connection on the
+                        * newly registered channel to the remote partition.
+                        */
+                       xpc_wakeup_channel_mgr(part);
                        xpc_part_deref(part);
                }
        }
@@ -1450,9 +1521,6 @@ xpc_initiate_connect(int ch_number)
 void
 xpc_connected_callout(struct xpc_channel *ch)
 {
-       unsigned long irq_flags;
-
-
        /* let the registerer know that a connection has been established */
 
        if (ch->func != NULL) {
@@ -1465,10 +1533,6 @@ xpc_connected_callout(struct xpc_channel *ch)
                dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
                        "partid=%d, channel=%d\n", ch->partid, ch->number);
        }
-
-       spin_lock_irqsave(&ch->lock, irq_flags);
-       ch->flags |= XPC_C_CONNECTCALLOUT;
-       spin_unlock_irqrestore(&ch->lock, irq_flags);
 }
 
 
@@ -1506,8 +1570,12 @@ xpc_initiate_disconnect(int ch_number)
 
                        spin_lock_irqsave(&ch->lock, irq_flags);
 
-                       XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering,
+                       if (!(ch->flags & XPC_C_DISCONNECTED)) {
+                               ch->flags |= XPC_C_WDISCONNECT;
+
+                               XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering,
                                                                &irq_flags);
+                       }
 
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
 
@@ -1523,8 +1591,9 @@ xpc_initiate_disconnect(int ch_number)
 /*
  * To disconnect a channel, and reflect it back to all who may be waiting.
  *
- * >>> An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
- * >>> xpc_free_msgqueues().
+ * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
+ * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by
+ * xpc_disconnect_wait().
  *
  * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN.
  */
@@ -1532,7 +1601,7 @@ void
 xpc_disconnect_channel(const int line, struct xpc_channel *ch,
                        enum xpc_retval reason, unsigned long *irq_flags)
 {
-       u32 flags;
+       u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED);
 
 
        DBUG_ON(!spin_is_locked(&ch->lock));
@@ -1547,61 +1616,53 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 
        XPC_SET_REASON(ch, reason, line);
 
-       flags = ch->flags;
+       ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING);
        /* some of these may not have been set */
        ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY |
                        XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
                        XPC_C_CONNECTING | XPC_C_CONNECTED);
 
-       ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING);
        xpc_IPI_send_closerequest(ch, irq_flags);
 
-       if (flags & XPC_C_CONNECTED) {
+       if (channel_was_connected) {
                ch->flags |= XPC_C_WASCONNECTED;
        }
 
+       spin_unlock_irqrestore(&ch->lock, *irq_flags);
+
+       /* wake all idle kthreads so they can exit */
        if (atomic_read(&ch->kthreads_idle) > 0) {
-               /* wake all idle kthreads so they can exit */
                wake_up_all(&ch->idle_wq);
        }
 
-       spin_unlock_irqrestore(&ch->lock, *irq_flags);
-
-
        /* wake those waiting to allocate an entry from the local msg queue */
-
        if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
                wake_up(&ch->msg_allocate_wq);
        }
 
-       /* wake those waiting for notify completion */
-
-       if (atomic_read(&ch->n_to_notify) > 0) {
-               xpc_notify_senders(ch, reason, ch->w_local_GP.put);
-       }
-
        spin_lock_irqsave(&ch->lock, *irq_flags);
 }
 
 
 void
-xpc_disconnected_callout(struct xpc_channel *ch)
+xpc_disconnecting_callout(struct xpc_channel *ch)
 {
        /*
-        * Let the channel's registerer know that the channel is now
+        * Let the channel's registerer know that the channel is being
         * disconnected. We don't want to do this if the registerer was never
-        * informed of a connection being made, unless the disconnect was for
-        * abnormal reasons.
+        * informed of a connection being made.
         */
 
        if (ch->func != NULL) {
-               dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, "
-                       "channel=%d\n", ch->reason, ch->partid, ch->number);
+               dev_dbg(xpc_chan, "ch->func() called, reason=xpcDisconnecting,"
+                       " partid=%d, channel=%d\n", ch->partid, ch->number);
 
-               ch->func(ch->reason, ch->partid, ch->number, NULL, ch->key);
+               ch->func(xpcDisconnecting, ch->partid, ch->number, NULL,
+                                                               ch->key);
 
-               dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, "
-                       "channel=%d\n", ch->reason, ch->partid, ch->number);
+               dev_dbg(xpc_chan, "ch->func() returned, reason="
+                       "xpcDisconnecting, partid=%d, channel=%d\n",
+                       ch->partid, ch->number);
        }
 }
 
@@ -1848,7 +1909,7 @@ xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
                        xpc_notify_func func, void *key)
 {
        enum xpc_retval ret = xpcSuccess;
-       struct xpc_notify *notify = NULL;   // >>> to keep the compiler happy!!
+       struct xpc_notify *notify = notify;
        s64 put, msg_number = msg->number;
 
 
index ed7c215..cece3c7 100644 (file)
@@ -54,6 +54,7 @@
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/reboot.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/uaccess.h>
@@ -82,11 +83,17 @@ struct device *xpc_chan = &xpc_chan_dbg_subname;
 
 /* systune related variables for /proc/sys directories */
 
-static int xpc_hb_min = 1;
-static int xpc_hb_max = 10;
+static int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
+static int xpc_hb_min_interval = 1;
+static int xpc_hb_max_interval = 10;
 
-static int xpc_hb_check_min = 10;
-static int xpc_hb_check_max = 120;
+static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
+static int xpc_hb_check_min_interval = 10;
+static int xpc_hb_check_max_interval = 120;
+
+int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
+static int xpc_disengage_request_min_timelimit = 0;
+static int xpc_disengage_request_max_timelimit = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
        {
@@ -99,7 +106,8 @@ static ctl_table xpc_sys_xpc_hb_dir[] = {
                &proc_dointvec_minmax,
                &sysctl_intvec,
                NULL,
-               &xpc_hb_min, &xpc_hb_max
+               &xpc_hb_min_interval,
+               &xpc_hb_max_interval
        },
        {
                2,
@@ -111,7 +119,8 @@ static ctl_table xpc_sys_xpc_hb_dir[] = {
                &proc_dointvec_minmax,
                &sysctl_intvec,
                NULL,
-               &xpc_hb_check_min, &xpc_hb_check_max
+               &xpc_hb_check_min_interval,
+               &xpc_hb_check_max_interval
        },
        {0}
 };
@@ -124,6 +133,19 @@ static ctl_table xpc_sys_xpc_dir[] = {
                0555,
                xpc_sys_xpc_hb_dir
        },
+       {
+               2,
+               "disengage_request_timelimit",
+               &xpc_disengage_request_timelimit,
+               sizeof(int),
+               0644,
+               NULL,
+               &proc_dointvec_minmax,
+               &sysctl_intvec,
+               NULL,
+               &xpc_disengage_request_min_timelimit,
+               &xpc_disengage_request_max_timelimit
+       },
        {0}
 };
 static ctl_table xpc_sys_dir[] = {
@@ -148,10 +170,10 @@ static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);
 
 static unsigned long xpc_hb_check_timeout;
 
-/* xpc_hb_checker thread exited notification */
+/* notification that the xpc_hb_checker thread has exited */
 static DECLARE_MUTEX_LOCKED(xpc_hb_checker_exited);
 
-/* xpc_discovery thread exited notification */
+/* notification that the xpc_discovery thread has exited */
 static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
 
 
@@ -161,6 +183,30 @@ static struct timer_list xpc_hb_timer;
 static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
 
 
+static int xpc_system_reboot(struct notifier_block *, unsigned long, void *);
+static struct notifier_block xpc_reboot_notifier = {
+       .notifier_call = xpc_system_reboot,
+};
+
+
+/*
+ * Timer function to enforce the timelimit on the partition disengage request.
+ */
+static void
+xpc_timeout_partition_disengage_request(unsigned long data)
+{
+       struct xpc_partition *part = (struct xpc_partition *) data;
+
+
+       DBUG_ON(jiffies < part->disengage_request_timeout);
+
+       (void) xpc_partition_disengaged(part);
+
+       DBUG_ON(part->disengage_request_timeout != 0);
+       DBUG_ON(xpc_partition_engaged(1UL << XPC_PARTID(part)) != 0);
+}
+
+
 /*
  * Notify the heartbeat check thread that an IRQ has been received.
  */
@@ -214,12 +260,6 @@ xpc_hb_checker(void *ignore)
 
        while (!(volatile int) xpc_exiting) {
 
-               /* wait for IRQ or timeout */
-               (void) wait_event_interruptible(xpc_act_IRQ_wq,
-                           (last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
-                                       jiffies >= xpc_hb_check_timeout ||
-                                               (volatile int) xpc_exiting));
-
                dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
                        "been received\n",
                        (int) (xpc_hb_check_timeout - jiffies),
@@ -240,6 +280,7 @@ xpc_hb_checker(void *ignore)
                }
 
 
+               /* check for outstanding IRQs */
                new_IRQ_count = atomic_read(&xpc_act_IRQ_rcvd);
                if (last_IRQ_count < new_IRQ_count || force_IRQ != 0) {
                        force_IRQ = 0;
@@ -257,12 +298,18 @@ xpc_hb_checker(void *ignore)
                        xpc_hb_check_timeout = jiffies +
                                           (xpc_hb_check_interval * HZ);
                }
+
+               /* wait for IRQ or timeout */
+               (void) wait_event_interruptible(xpc_act_IRQ_wq,
+                           (last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
+                                       jiffies >= xpc_hb_check_timeout ||
+                                               (volatile int) xpc_exiting));
        }
 
        dev_dbg(xpc_part, "heartbeat checker is exiting\n");
 
 
-       /* mark this thread as inactive */
+       /* mark this thread as having exited */
        up(&xpc_hb_checker_exited);
        return 0;
 }
@@ -282,7 +329,7 @@ xpc_initiate_discovery(void *ignore)
 
        dev_dbg(xpc_part, "discovery thread is exiting\n");
 
-       /* mark this thread as inactive */
+       /* mark this thread as having exited */
        up(&xpc_discovery_exited);
        return 0;
 }
@@ -309,7 +356,7 @@ xpc_make_first_contact(struct xpc_partition *part)
                        "partition %d\n", XPC_PARTID(part));
 
                /* wait a 1/4 of a second or so */
-               msleep_interruptible(250);
+               (void) msleep_interruptible(250);
 
                if (part->act_state == XPC_P_DEACTIVATING) {
                        return part->reason;
@@ -336,7 +383,8 @@ static void
 xpc_channel_mgr(struct xpc_partition *part)
 {
        while (part->act_state != XPC_P_DEACTIVATING ||
-                               atomic_read(&part->nchannels_active) > 0) {
+                       atomic_read(&part->nchannels_active) > 0 ||
+                                       !xpc_partition_disengaged(part)) {
 
                xpc_process_channel_activity(part);
 
@@ -360,7 +408,8 @@ xpc_channel_mgr(struct xpc_partition *part)
                                (volatile u64) part->local_IPI_amo != 0 ||
                                ((volatile u8) part->act_state ==
                                                        XPC_P_DEACTIVATING &&
-                               atomic_read(&part->nchannels_active) == 0)));
+                               atomic_read(&part->nchannels_active) == 0 &&
+                               xpc_partition_disengaged(part))));
                atomic_set(&part->channel_mgr_requests, 1);
 
                // >>> Does it need to wakeup periodically as well? In case we
@@ -482,7 +531,7 @@ xpc_activating(void *__partid)
                return 0;
        }
 
-       XPC_ALLOW_HB(partid, xpc_vars);
+       xpc_allow_hb(partid, xpc_vars);
        xpc_IPI_send_activated(part);
 
 
@@ -492,6 +541,7 @@ xpc_activating(void *__partid)
         */
        (void) xpc_partition_up(part);
 
+       xpc_disallow_hb(partid, xpc_vars);
        xpc_mark_partition_inactive(part);
 
        if (part->reason == xpcReactivating) {
@@ -670,6 +720,7 @@ xpc_daemonize_kthread(void *args)
        struct xpc_partition *part = &xpc_partitions[partid];
        struct xpc_channel *ch;
        int n_needed;
+       unsigned long irq_flags;
 
 
        daemonize("xpc%02dc%d", partid, ch_number);
@@ -680,11 +731,14 @@ xpc_daemonize_kthread(void *args)
        ch = &part->channels[ch_number];
 
        if (!(ch->flags & XPC_C_DISCONNECTING)) {
-               DBUG_ON(!(ch->flags & XPC_C_CONNECTED));
 
                /* let registerer know that connection has been established */
 
-               if (atomic_read(&ch->kthreads_assigned) == 1) {
+               spin_lock_irqsave(&ch->lock, irq_flags);
+               if (!(ch->flags & XPC_C_CONNECTCALLOUT)) {
+                       ch->flags |= XPC_C_CONNECTCALLOUT;
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+
                        xpc_connected_callout(ch);
 
                        /*
@@ -699,16 +753,28 @@ xpc_daemonize_kthread(void *args)
                                        !(ch->flags & XPC_C_DISCONNECTING)) {
                                xpc_activate_kthreads(ch, n_needed);
                        }
+               } else {
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
                }
 
                xpc_kthread_waitmsgs(part, ch);
        }
 
-       if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
-                       ((ch->flags & XPC_C_CONNECTCALLOUT) ||
-                               (ch->reason != xpcUnregistering &&
-                                       ch->reason != xpcOtherUnregistering))) {
-               xpc_disconnected_callout(ch);
+       if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
+               spin_lock_irqsave(&ch->lock, irq_flags);
+               if ((ch->flags & XPC_C_CONNECTCALLOUT) &&
+                               !(ch->flags & XPC_C_DISCONNECTCALLOUT)) {
+                       ch->flags |= XPC_C_DISCONNECTCALLOUT;
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+                       xpc_disconnecting_callout(ch);
+               } else {
+                       spin_unlock_irqrestore(&ch->lock, irq_flags);
+               }
+               if (atomic_dec_return(&part->nchannels_engaged) == 0) {
+                       xpc_mark_partition_disengaged(part);
+                       xpc_IPI_send_disengage(part);
+               }
        }
 
 
@@ -740,12 +806,33 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
        unsigned long irq_flags;
        pid_t pid;
        u64 args = XPC_PACK_ARGS(ch->partid, ch->number);
+       struct xpc_partition *part = &xpc_partitions[ch->partid];
 
 
        while (needed-- > 0) {
+
+               /*
+                * The following is done on behalf of the newly created
+                * kthread. That kthread is responsible for doing the
+                * counterpart to the following before it exits.
+                */
+               (void) xpc_part_ref(part);
+               xpc_msgqueue_ref(ch);
+               if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+                   atomic_inc_return(&part->nchannels_engaged) == 1) {
+                       xpc_mark_partition_engaged(part);
+               }
+
                pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
                if (pid < 0) {
                        /* the fork failed */
+                       if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+                           atomic_dec_return(&part->nchannels_engaged) == 0) {
+                               xpc_mark_partition_disengaged(part);
+                               xpc_IPI_send_disengage(part);
+                       }
+                       xpc_msgqueue_deref(ch);
+                       xpc_part_deref(part);
 
                        if (atomic_read(&ch->kthreads_assigned) <
                                                ch->kthreads_idle_limit) {
@@ -765,14 +852,6 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
                        break;
                }
 
-               /*
-                * The following is done on behalf of the newly created
-                * kthread. That kthread is responsible for doing the
-                * counterpart to the following before it exits.
-                */
-               (void) xpc_part_ref(&xpc_partitions[ch->partid]);
-               xpc_msgqueue_ref(ch);
-               atomic_inc(&ch->kthreads_assigned);
                ch->kthreads_created++; // >>> temporary debug only!!!
        }
 }
@@ -781,87 +860,142 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
 void
 xpc_disconnect_wait(int ch_number)
 {
+       unsigned long irq_flags;
        partid_t partid;
        struct xpc_partition *part;
        struct xpc_channel *ch;
+       int wakeup_channel_mgr;
 
 
        /* now wait for all callouts to the caller's function to cease */
        for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
                part = &xpc_partitions[partid];
 
-               if (xpc_part_ref(part)) {
-                       ch = &part->channels[ch_number];
+               if (!xpc_part_ref(part)) {
+                       continue;
+               }
 
-// >>> how do we keep from falling into the window between our check and going
-// >>> down and coming back up where sema is re-inited?
-                       if (ch->flags & XPC_C_SETUP) {
-                               (void) down(&ch->teardown_sema);
-                       }
+               ch = &part->channels[ch_number];
 
+               if (!(ch->flags & XPC_C_WDISCONNECT)) {
                        xpc_part_deref(part);
+                       continue;
+               }
+
+               (void) down(&ch->wdisconnect_sema);
+
+               spin_lock_irqsave(&ch->lock, irq_flags);
+               DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
+               wakeup_channel_mgr = 0;
+
+               if (ch->delayed_IPI_flags) {
+                       if (part->act_state != XPC_P_DEACTIVATING) {
+                               spin_lock(&part->IPI_lock);
+                               XPC_SET_IPI_FLAGS(part->local_IPI_amo,
+                                       ch->number, ch->delayed_IPI_flags);
+                               spin_unlock(&part->IPI_lock);
+                               wakeup_channel_mgr = 1;
+                       }
+                       ch->delayed_IPI_flags = 0;
                }
+
+               ch->flags &= ~XPC_C_WDISCONNECT;
+               spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+               if (wakeup_channel_mgr) {
+                       xpc_wakeup_channel_mgr(part);
+               }
+
+               xpc_part_deref(part);
        }
 }
 
 
 static void
-xpc_do_exit(void)
+xpc_do_exit(enum xpc_retval reason)
 {
        partid_t partid;
        int active_part_count;
        struct xpc_partition *part;
+       unsigned long printmsg_time;
 
 
-       /* now it's time to eliminate our heartbeat */
-       del_timer_sync(&xpc_hb_timer);
-       xpc_vars->heartbeating_to_mask = 0;
-
-       /* indicate to others that our reserved page is uninitialized */
-       xpc_rsvd_page->vars_pa = 0;
-
-       /*
-        * Ignore all incoming interrupts. Without interupts the heartbeat
-        * checker won't activate any new partitions that may come up.
-        */
-       free_irq(SGI_XPC_ACTIVATE, NULL);
+       /* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
+       DBUG_ON(xpc_exiting == 1);
 
        /*
-        * Cause the heartbeat checker and the discovery threads to exit.
-        * We don't want them attempting to activate new partitions as we
-        * try to deactivate the existing ones.
+        * Let the heartbeat checker thread and the discovery thread
+        * (if one is running) know that they should exit. Also wake up
+        * the heartbeat checker thread in case it's sleeping.
         */
        xpc_exiting = 1;
        wake_up_interruptible(&xpc_act_IRQ_wq);
 
-       /* wait for the heartbeat checker thread to mark itself inactive */
-       down(&xpc_hb_checker_exited);
+       /* ignore all incoming interrupts */
+       free_irq(SGI_XPC_ACTIVATE, NULL);
 
-       /* wait for the discovery thread to mark itself inactive */
+       /* wait for the discovery thread to exit */
        down(&xpc_discovery_exited);
 
+       /* wait for the heartbeat checker thread to exit */
+       down(&xpc_hb_checker_exited);
 
-       msleep_interruptible(300);
+
+       /* sleep for a 1/3 of a second or so */
+       (void) msleep_interruptible(300);
 
 
        /* wait for all partitions to become inactive */
 
+       printmsg_time = jiffies;
+
        do {
                active_part_count = 0;
 
                for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
                        part = &xpc_partitions[partid];
-                       if (part->act_state != XPC_P_INACTIVE) {
-                               active_part_count++;
 
-                               XPC_DEACTIVATE_PARTITION(part, xpcUnloading);
+                       if (xpc_partition_disengaged(part) &&
+                                       part->act_state == XPC_P_INACTIVE) {
+                               continue;
                        }
+
+                       active_part_count++;
+
+                       XPC_DEACTIVATE_PARTITION(part, reason);
                }
 
-               if (active_part_count)
-                       msleep_interruptible(300);
-       } while (active_part_count > 0);
+               if (active_part_count == 0) {
+                       break;
+               }
 
+               if (jiffies >= printmsg_time) {
+                       dev_info(xpc_part, "waiting for partitions to "
+                               "deactivate/disengage, active count=%d, remote "
+                               "engaged=0x%lx\n", active_part_count,
+                               xpc_partition_engaged(1UL << partid));
+
+                       printmsg_time = jiffies +
+                                       (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
+               }
+
+               /* sleep for a 1/3 of a second or so */
+               (void) msleep_interruptible(300);
+
+       } while (1);
+
+       DBUG_ON(xpc_partition_engaged(-1UL));
+
+
+       /* indicate to others that our reserved page is uninitialized */
+       xpc_rsvd_page->vars_pa = 0;
+
+       /* now it's time to eliminate our heartbeat */
+       del_timer_sync(&xpc_hb_timer);
+       DBUG_ON(xpc_vars->heartbeating_to_mask != 0);
+
+       /* take ourselves off of the reboot_notifier_list */
+       (void) unregister_reboot_notifier(&xpc_reboot_notifier);
 
        /* close down protections for IPI operations */
        xpc_restrict_IPI_ops();
@@ -876,6 +1010,34 @@ xpc_do_exit(void)
 }
 
 
+/*
+ * This function is called when the system is being rebooted.
+ */
+static int
+xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
+{
+       enum xpc_retval reason;
+
+
+       switch (event) {
+       case SYS_RESTART:
+               reason = xpcSystemReboot;
+               break;
+       case SYS_HALT:
+               reason = xpcSystemHalt;
+               break;
+       case SYS_POWER_OFF:
+               reason = xpcSystemPoweroff;
+               break;
+       default:
+               reason = xpcSystemGoingDown;
+       }
+
+       xpc_do_exit(reason);
+       return NOTIFY_DONE;
+}
+
+
 int __init
 xpc_init(void)
 {
@@ -891,11 +1053,11 @@ xpc_init(void)
 
        /*
         * xpc_remote_copy_buffer is used as a temporary buffer for bte_copy'ng
-        * both a partition's reserved page and its XPC variables. Its size was
-        * based on the size of a reserved page. So we need to ensure that the
-        * XPC variables will fit as well.
+        * various portions of a partition's reserved page. Its size is based
+        * on the size of the reserved page header and part_nasids mask. So we
+        * need to ensure that the other items will fit as well.
         */
-       if (XPC_VARS_ALIGNED_SIZE > XPC_RSVD_PAGE_ALIGNED_SIZE) {
+       if (XPC_RP_VARS_SIZE > XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES) {
                dev_err(xpc_part, "xpc_remote_copy_buffer is not big enough\n");
                return -EPERM;
        }
@@ -924,6 +1086,12 @@ xpc_init(void)
                spin_lock_init(&part->act_lock);
                part->act_state = XPC_P_INACTIVE;
                XPC_SET_REASON(part, 0, 0);
+
+               init_timer(&part->disengage_request_timer);
+               part->disengage_request_timer.function =
+                               xpc_timeout_partition_disengage_request;
+               part->disengage_request_timer.data = (unsigned long) part;
+
                part->setup_state = XPC_P_UNSET;
                init_waitqueue_head(&part->teardown_wq);
                atomic_set(&part->references, 0);
@@ -980,6 +1148,13 @@ xpc_init(void)
        }
 
 
+       /* add ourselves to the reboot_notifier_list */
+       ret = register_reboot_notifier(&xpc_reboot_notifier);
+       if (ret != 0) {
+               dev_warn(xpc_part, "can't register reboot notifier\n");
+       }
+
+
        /*
         * Set the beating to other partitions into motion.  This is
         * the last requirement for other partitions' discovery to
@@ -1001,6 +1176,9 @@ xpc_init(void)
                /* indicate to others that our reserved page is uninitialized */
                xpc_rsvd_page->vars_pa = 0;
 
+               /* take ourselves off of the reboot_notifier_list */
+               (void) unregister_reboot_notifier(&xpc_reboot_notifier);
+
                del_timer_sync(&xpc_hb_timer);
                free_irq(SGI_XPC_ACTIVATE, NULL);
                xpc_restrict_IPI_ops();
@@ -1024,7 +1202,7 @@ xpc_init(void)
                /* mark this new thread as a non-starter */
                up(&xpc_discovery_exited);
 
-               xpc_do_exit();
+               xpc_do_exit(xpcUnloading);
                return -EBUSY;
        }
 
@@ -1043,7 +1221,7 @@ module_init(xpc_init);
 void __exit
 xpc_exit(void)
 {
-       xpc_do_exit();
+       xpc_do_exit(xpcUnloading);
 }
 module_exit(xpc_exit);
 
@@ -1060,3 +1238,7 @@ module_param(xpc_hb_check_interval, int, 0);
 MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
                "heartbeat checks.");
 
+module_param(xpc_disengage_request_timelimit, int, 0);
+MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
+               "for disengage request to complete.");
+
index 72ef330..581e113 100644 (file)
@@ -47,13 +47,16 @@ static u64 xpc_sh2_IPI_access3;
 u64 xpc_prot_vec[MAX_NUMNODES];
 
 
-/* this partition's reserved page */
+/* this partition's reserved page pointers */
 struct xpc_rsvd_page *xpc_rsvd_page;
-
-/* this partition's XPC variables (within the reserved page) */
+static u64 *xpc_part_nasids;
+static u64 *xpc_mach_nasids;
 struct xpc_vars *xpc_vars;
 struct xpc_vars_part *xpc_vars_part;
 
+static int xp_nasid_mask_bytes;        /* actual size in bytes of nasid mask */
+static int xp_nasid_mask_words;        /* actual size in words of nasid mask */
+
 
 /*
  * For performance reasons, each entry of xpc_partitions[] is cacheline
@@ -65,20 +68,16 @@ struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
 
 
 /*
- * Generic buffer used to store a local copy of the remote partitions
- * reserved page or XPC variables.
+ * Generic buffer used to store a local copy of portions of a remote
+ * partition's reserved page (either its header and part_nasids mask,
+ * or its vars).
  *
  * xpc_discovery runs only once and is a seperate thread that is
  * very likely going to be processing in parallel with receiving
  * interrupts.
  */
-char ____cacheline_aligned
-               xpc_remote_copy_buffer[XPC_RSVD_PAGE_ALIGNED_SIZE];
-
-
-/* systune related variables */
-int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
-int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
+char ____cacheline_aligned xpc_remote_copy_buffer[XPC_RP_HEADER_SIZE +
+                                                       XP_NASID_MASK_BYTES];
 
 
 /*
@@ -86,13 +85,16 @@ int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
  * for that nasid. This function returns 0 on any error.
  */
 static u64
-xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
+xpc_get_rsvd_page_pa(int nasid)
 {
        bte_result_t bte_res;
        s64 status;
        u64 cookie = 0;
        u64 rp_pa = nasid;      /* seed with nasid */
        u64 len = 0;
+       u64 buf = buf;
+       u64 buf_len = 0;
+       void *buf_base = NULL;
 
 
        while (1) {
@@ -108,13 +110,22 @@ xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
                        break;
                }
 
-               if (len > buf_size) {
-                       dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
-                       status = SALRET_ERROR;
-                       break;
+               if (L1_CACHE_ALIGN(len) > buf_len) {
+                       if (buf_base != NULL) {
+                               kfree(buf_base);
+                       }
+                       buf_len = L1_CACHE_ALIGN(len);
+                       buf = (u64) xpc_kmalloc_cacheline_aligned(buf_len,
+                                                       GFP_KERNEL, &buf_base);
+                       if (buf_base == NULL) {
+                               dev_err(xpc_part, "unable to kmalloc "
+                                       "len=0x%016lx\n", buf_len);
+                               status = SALRET_ERROR;
+                               break;
+                       }
                }
 
-               bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
+               bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_len,
                                        (BTE_NOTIFY | BTE_WACQUIRE), NULL);
                if (bte_res != BTE_SUCCESS) {
                        dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
@@ -123,6 +134,10 @@ xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
                }
        }
 
+       if (buf_base != NULL) {
+               kfree(buf_base);
+       }
+
        if (status != SALRET_OK) {
                rp_pa = 0;
        }
@@ -141,15 +156,15 @@ xpc_rsvd_page_init(void)
 {
        struct xpc_rsvd_page *rp;
        AMO_t *amos_page;
-       u64 rp_pa, next_cl, nasid_array = 0;
+       u64 rp_pa, nasid_array = 0;
        int i, ret;
 
 
        /* get the local reserved page's address */
 
-       rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
-                                       (u64) xpc_remote_copy_buffer,
-                                               XPC_RSVD_PAGE_ALIGNED_SIZE);
+       preempt_disable();
+       rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
+       preempt_enable();
        if (rp_pa == 0) {
                dev_err(xpc_part, "SAL failed to locate the reserved page\n");
                return NULL;
@@ -164,12 +179,19 @@ xpc_rsvd_page_init(void)
 
        rp->version = XPC_RP_VERSION;
 
-       /*
-        * Place the XPC variables on the cache line following the
-        * reserved page structure.
-        */
-       next_cl = (u64) rp + XPC_RSVD_PAGE_ALIGNED_SIZE;
-       xpc_vars = (struct xpc_vars *) next_cl;
+       /* establish the actual sizes of the nasid masks */
+       if (rp->SAL_version == 1) {
+               /* SAL_version 1 didn't set the nasids_size field */
+               rp->nasids_size = 128;
+       }
+       xp_nasid_mask_bytes = rp->nasids_size;
+       xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
+
+       /* setup the pointers to the various items in the reserved page */
+       xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
+       xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
+       xpc_vars = XPC_RP_VARS(rp);
+       xpc_vars_part = XPC_RP_VARS_PART(rp);
 
        /*
         * Before clearing xpc_vars, see if a page of AMOs had been previously
@@ -221,33 +243,32 @@ xpc_rsvd_page_init(void)
                amos_page = (AMO_t *) TO_AMO((u64) amos_page);
        }
 
+       /* clear xpc_vars */
        memset(xpc_vars, 0, sizeof(struct xpc_vars));
 
-       /*
-        * Place the XPC per partition specific variables on the cache line
-        * following the XPC variables structure.
-        */
-       next_cl += XPC_VARS_ALIGNED_SIZE;
-       memset((u64 *) next_cl, 0, sizeof(struct xpc_vars_part) *
-                                                       XP_MAX_PARTITIONS);
-       xpc_vars_part = (struct xpc_vars_part *) next_cl;
-       xpc_vars->vars_part_pa = __pa(next_cl);
-
        xpc_vars->version = XPC_V_VERSION;
        xpc_vars->act_nasid = cpuid_to_nasid(0);
        xpc_vars->act_phys_cpuid = cpu_physical_id(0);
+       xpc_vars->vars_part_pa = __pa(xpc_vars_part);
+       xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
        xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
 
 
-       /*
-        * Initialize the activation related AMO variables.
-        */
-       xpc_vars->act_amos = xpc_IPI_init(XP_MAX_PARTITIONS);
-       for (i = 1; i < XP_NASID_MASK_WORDS; i++) {
-               xpc_IPI_init(i + XP_MAX_PARTITIONS);
+       /* clear xpc_vars_part */
+       memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
+                                                       XP_MAX_PARTITIONS);
+
+       /* initialize the activate IRQ related AMO variables */
+       for (i = 0; i < xp_nasid_mask_words; i++) {
+               (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
        }
-       /* export AMO page's physical address to other partitions */
-       xpc_vars->amos_page_pa = ia64_tpa((u64) xpc_vars->amos_page);
+
+       /* initialize the engaged remote partitions related AMO variables */
+       (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
+       (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
+
+       /* timestamp of when reserved page was setup by XPC */
+       rp->stamp = CURRENT_TIME;
 
        /*
         * This signifies to the remote partition that our reserved
@@ -387,6 +408,11 @@ xpc_check_remote_hb(void)
        remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 
        for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+
+               if (xpc_exiting) {
+                       break;
+               }
+
                if (partid == sn_partition_id) {
                        continue;
                }
@@ -401,7 +427,7 @@ xpc_check_remote_hb(void)
                /* pull the remote_hb cache line */
                bres = xp_bte_copy(part->remote_vars_pa,
                                        ia64_tpa((u64) remote_vars),
-                                       XPC_VARS_ALIGNED_SIZE,
+                                       XPC_RP_VARS_SIZE,
                                        (BTE_NOTIFY | BTE_WACQUIRE), NULL);
                if (bres != BTE_SUCCESS) {
                        XPC_DEACTIVATE_PARTITION(part,
@@ -417,7 +443,7 @@ xpc_check_remote_hb(void)
 
                if (((remote_vars->heartbeat == part->last_heartbeat) &&
                        (remote_vars->kdb_status == 0)) ||
-                            !XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
+                            !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 
                        XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
                        continue;
@@ -429,31 +455,31 @@ xpc_check_remote_hb(void)
 
 
 /*
- * Get a copy of the remote partition's rsvd page.
+ * Get a copy of a portion of the remote partition's rsvd page.
  *
  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
- * assumed to be of size XPC_RSVD_PAGE_ALIGNED_SIZE.
+ * is large enough to contain a copy of their reserved page header and
+ * part_nasids mask.
  */
 static enum xpc_retval
 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
-               struct xpc_rsvd_page *remote_rp, u64 *remote_rsvd_page_pa)
+               struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 {
        int bres, i;
 
 
        /* get the reserved page's physical address */
 
-       *remote_rsvd_page_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
-                                               XPC_RSVD_PAGE_ALIGNED_SIZE);
-       if (*remote_rsvd_page_pa == 0) {
+       *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
+       if (*remote_rp_pa == 0) {
                return xpcNoRsvdPageAddr;
        }
 
 
-       /* pull over the reserved page structure */
+       /* pull over the reserved page header and part_nasids mask */
 
-       bres = xp_bte_copy(*remote_rsvd_page_pa, ia64_tpa((u64) remote_rp),
-                               XPC_RSVD_PAGE_ALIGNED_SIZE,
+       bres = xp_bte_copy(*remote_rp_pa, ia64_tpa((u64) remote_rp),
+                               XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
                                (BTE_NOTIFY | BTE_WACQUIRE), NULL);
        if (bres != BTE_SUCCESS) {
                return xpc_map_bte_errors(bres);
@@ -461,8 +487,11 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 
 
        if (discovered_nasids != NULL) {
-               for (i = 0; i < XP_NASID_MASK_WORDS; i++) {
-                       discovered_nasids[i] |= remote_rp->part_nasids[i];
+               u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
+
+
+               for (i = 0; i < xp_nasid_mask_words; i++) {
+                       discovered_nasids[i] |= remote_part_nasids[i];
                }
        }
 
@@ -489,10 +518,10 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 
 
 /*
- * Get a copy of the remote partition's XPC variables.
+ * Get a copy of the remote partition's XPC variables from the reserved page.
  *
  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
- * assumed to be of size XPC_VARS_ALIGNED_SIZE.
+ * assumed to be of size XPC_RP_VARS_SIZE.
  */
 static enum xpc_retval
 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
@@ -508,7 +537,7 @@ xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
        /* pull over the cross partition variables */
 
        bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
-                               XPC_VARS_ALIGNED_SIZE,
+                               XPC_RP_VARS_SIZE,
                                (BTE_NOTIFY | BTE_WACQUIRE), NULL);
        if (bres != BTE_SUCCESS) {
                return xpc_map_bte_errors(bres);
@@ -524,7 +553,56 @@ xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 
 
 /*
- * Prior code has determine the nasid which generated an IPI.  Inspect
+ * Update the remote partition's info.
+ */
+static void
+xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
+               struct timespec *remote_rp_stamp, u64 remote_rp_pa,
+               u64 remote_vars_pa, struct xpc_vars *remote_vars)
+{
+       part->remote_rp_version = remote_rp_version;
+       dev_dbg(xpc_part, "  remote_rp_version = 0x%016lx\n",
+               part->remote_rp_version);
+
+       part->remote_rp_stamp = *remote_rp_stamp;
+       dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
+               part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
+
+       part->remote_rp_pa = remote_rp_pa;
+       dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
+
+       part->remote_vars_pa = remote_vars_pa;
+       dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
+               part->remote_vars_pa);
+
+       part->last_heartbeat = remote_vars->heartbeat;
+       dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
+               part->last_heartbeat);
+
+       part->remote_vars_part_pa = remote_vars->vars_part_pa;
+       dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
+               part->remote_vars_part_pa);
+
+       part->remote_act_nasid = remote_vars->act_nasid;
+       dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
+               part->remote_act_nasid);
+
+       part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
+       dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
+               part->remote_act_phys_cpuid);
+
+       part->remote_amos_page_pa = remote_vars->amos_page_pa;
+       dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
+               part->remote_amos_page_pa);
+
+       part->remote_vars_version = remote_vars->version;
+       dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
+               part->remote_vars_version);
+}
+
+
+/*
+ * Prior code has determined the nasid which generated an IPI.  Inspect
  * that nasid to determine if its partition needs to be activated or
  * deactivated.
  *
@@ -542,8 +620,12 @@ xpc_identify_act_IRQ_req(int nasid)
 {
        struct xpc_rsvd_page *remote_rp;
        struct xpc_vars *remote_vars;
-       u64 remote_rsvd_page_pa;
+       u64 remote_rp_pa;
        u64 remote_vars_pa;
+       int remote_rp_version;
+       int reactivate = 0;
+       int stamp_diff;
+       struct timespec remote_rp_stamp = { 0, 0 };
        partid_t partid;
        struct xpc_partition *part;
        enum xpc_retval ret;
@@ -553,7 +635,7 @@ xpc_identify_act_IRQ_req(int nasid)
 
        remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
 
-       ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rsvd_page_pa);
+       ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
        if (ret != xpcSuccess) {
                dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
                        "which sent interrupt, reason=%d\n", nasid, ret);
@@ -561,6 +643,10 @@ xpc_identify_act_IRQ_req(int nasid)
        }
 
        remote_vars_pa = remote_rp->vars_pa;
+       remote_rp_version = remote_rp->version;
+       if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+               remote_rp_stamp = remote_rp->stamp;
+       }
        partid = remote_rp->partid;
        part = &xpc_partitions[partid];
 
@@ -586,44 +672,117 @@ xpc_identify_act_IRQ_req(int nasid)
                "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
                remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 
+       if (xpc_partition_disengaged(part) &&
+                                       part->act_state == XPC_P_INACTIVE) {
 
-       if (part->act_state == XPC_P_INACTIVE) {
+               xpc_update_partition_info(part, remote_rp_version,
+                                       &remote_rp_stamp, remote_rp_pa,
+                                       remote_vars_pa, remote_vars);
 
-               part->remote_rp_pa = remote_rsvd_page_pa;
-               dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n",
-                       part->remote_rp_pa);
+               if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+                       if (xpc_partition_disengage_requested(1UL << partid)) {
+                               /*
+                                * Other side is waiting on us to disengage,
+                                * even though we already have.
+                                */
+                               return;
+                       }
+               } else {
+                       /* other side doesn't support disengage requests */
+                       xpc_clear_partition_disengage_request(1UL << partid);
+               }
 
-               part->remote_vars_pa = remote_vars_pa;
-               dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
-                       part->remote_vars_pa);
+               xpc_activate_partition(part);
+               return;
+       }
 
-               part->last_heartbeat = remote_vars->heartbeat;
-               dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
-                       part->last_heartbeat);
+       DBUG_ON(part->remote_rp_version == 0);
+       DBUG_ON(part->remote_vars_version == 0);
+
+       if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
+               DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
+                                                       remote_vars_version));
+
+               if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+                       DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
+                                                               version));
+                       /* see if the other side rebooted */
+                       if (part->remote_amos_page_pa ==
+                               remote_vars->amos_page_pa &&
+                                       xpc_hb_allowed(sn_partition_id,
+                                                               remote_vars)) {
+                               /* doesn't look that way, so ignore the IPI */
+                               return;
+                       }
+               }
 
-               part->remote_vars_part_pa = remote_vars->vars_part_pa;
-               dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
-                       part->remote_vars_part_pa);
+               /*
+                * Other side rebooted and previous XPC didn't support the
+                * disengage request, so we don't need to do anything special.
+                */
 
-               part->remote_act_nasid = remote_vars->act_nasid;
-               dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
-                       part->remote_act_nasid);
+               xpc_update_partition_info(part, remote_rp_version,
+                                               &remote_rp_stamp, remote_rp_pa,
+                                               remote_vars_pa, remote_vars);
+               part->reactivate_nasid = nasid;
+               XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
+               return;
+       }
 
-               part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
-               dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
-                       part->remote_act_phys_cpuid);
+       DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
 
-               part->remote_amos_page_pa = remote_vars->amos_page_pa;
-               dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
-                       part->remote_amos_page_pa);
+       if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
+               DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 
-               xpc_activate_partition(part);
+               /*
+                * Other side rebooted and previous XPC did support the
+                * disengage request, but the new one doesn't.
+                */
+
+               xpc_clear_partition_engaged(1UL << partid);
+               xpc_clear_partition_disengage_request(1UL << partid);
 
-       } else if (part->remote_amos_page_pa != remote_vars->amos_page_pa ||
-                       !XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
+               xpc_update_partition_info(part, remote_rp_version,
+                                               &remote_rp_stamp, remote_rp_pa,
+                                               remote_vars_pa, remote_vars);
+               reactivate = 1;
+
+       } else {
+               DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 
+               stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
+                                                       &remote_rp_stamp);
+               if (stamp_diff != 0) {
+                       DBUG_ON(stamp_diff >= 0);
+
+                       /*
+                        * Other side rebooted and the previous XPC did support
+                        * the disengage request, as does the new one.
+                        */
+
+                       DBUG_ON(xpc_partition_engaged(1UL << partid));
+                       DBUG_ON(xpc_partition_disengage_requested(1UL <<
+                                                               partid));
+
+                       xpc_update_partition_info(part, remote_rp_version,
+                                               &remote_rp_stamp, remote_rp_pa,
+                                               remote_vars_pa, remote_vars);
+                       reactivate = 1;
+               }
+       }
+
+       if (!xpc_partition_disengaged(part)) {
+               /* still waiting on other side to disengage from us */
+               return;
+       }
+
+       if (reactivate) {
                part->reactivate_nasid = nasid;
                XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
+
+       } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
+                       xpc_partition_disengage_requested(1UL << partid)) {
+               XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
        }
 }
 
@@ -643,14 +802,17 @@ xpc_identify_act_IRQ_sender(void)
        u64 nasid;                      /* remote nasid */
        int n_IRQs_detected = 0;
        AMO_t *act_amos;
-       struct xpc_rsvd_page *rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
 
 
-       act_amos = xpc_vars->act_amos;
+       act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 
 
        /* scan through act AMO variable looking for non-zero entries */
-       for (word = 0; word < XP_NASID_MASK_WORDS; word++) {
+       for (word = 0; word < xp_nasid_mask_words; word++) {
+
+               if (xpc_exiting) {
+                       break;
+               }
 
                nasid_mask = xpc_IPI_receive(&act_amos[word]);
                if (nasid_mask == 0) {
@@ -668,7 +830,7 @@ xpc_identify_act_IRQ_sender(void)
                 * remote nasid in our reserved pages machine mask.
                 * This is used in the event of module reload.
                 */
-               rp->mach_nasids[word] |= nasid_mask;
+               xpc_mach_nasids[word] |= nasid_mask;
 
 
                /* locate the nasid(s) which sent interrupts */
@@ -687,6 +849,55 @@ xpc_identify_act_IRQ_sender(void)
 }
 
 
+/*
+ * See if the other side has responded to a partition disengage request
+ * from us.
+ */
+int
+xpc_partition_disengaged(struct xpc_partition *part)
+{
+       partid_t partid = XPC_PARTID(part);
+       int disengaged;
+
+
+       disengaged = (xpc_partition_engaged(1UL << partid) == 0);
+       if (part->disengage_request_timeout) {
+               if (!disengaged) {
+                       if (jiffies < part->disengage_request_timeout) {
+                               /* timelimit hasn't been reached yet */
+                               return 0;
+                       }
+
+                       /*
+                        * Other side hasn't responded to our disengage
+                        * request in a timely fashion, so assume it's dead.
+                        */
+
+                       xpc_clear_partition_engaged(1UL << partid);
+                       disengaged = 1;
+               }
+               part->disengage_request_timeout = 0;
+
+               /* cancel the timer function, provided it's not us */
+               if (!in_interrupt()) {
+                       del_singleshot_timer_sync(&part->
+                                                     disengage_request_timer);
+               }
+
+               DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
+                                       part->act_state != XPC_P_INACTIVE);
+               if (part->act_state != XPC_P_INACTIVE) {
+                       xpc_wakeup_channel_mgr(part);
+               }
+
+               if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+                       xpc_cancel_partition_disengage_request(part);
+               }
+       }
+       return disengaged;
+}
+
+
 /*
  * Mark specified partition as active.
  */
@@ -721,7 +932,6 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
                                enum xpc_retval reason)
 {
        unsigned long irq_flags;
-       partid_t partid = XPC_PARTID(part);
 
 
        spin_lock_irqsave(&part->act_lock, irq_flags);
@@ -749,17 +959,27 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
 
        spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-       XPC_DISALLOW_HB(partid, xpc_vars);
+       if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
+               xpc_request_partition_disengage(part);
+               xpc_IPI_send_disengage(part);
 
-       dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n", partid,
-               reason);
+               /* set a timelimit on the disengage request */
+               part->disengage_request_timeout = jiffies +
+                                       (xpc_disengage_request_timelimit * HZ);
+               part->disengage_request_timer.expires =
+                                       part->disengage_request_timeout;
+               add_timer(&part->disengage_request_timer);
+       }
+
+       dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
+               XPC_PARTID(part), reason);
 
-       xpc_partition_down(part, reason);
+       xpc_partition_going_down(part, reason);
 }
 
 
 /*
- * Mark specified partition as active.
+ * Mark specified partition as inactive.
  */
 void
 xpc_mark_partition_inactive(struct xpc_partition *part)
@@ -792,9 +1012,10 @@ xpc_discovery(void)
        void *remote_rp_base;
        struct xpc_rsvd_page *remote_rp;
        struct xpc_vars *remote_vars;
-       u64 remote_rsvd_page_pa;
+       u64 remote_rp_pa;
        u64 remote_vars_pa;
        int region;
+       int region_size;
        int max_regions;
        int nasid;
        struct xpc_rsvd_page *rp;
@@ -804,7 +1025,8 @@ xpc_discovery(void)
        enum xpc_retval ret;
 
 
-       remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RSVD_PAGE_ALIGNED_SIZE,
+       remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
+                                               xp_nasid_mask_bytes,
                                                GFP_KERNEL, &remote_rp_base);
        if (remote_rp == NULL) {
                return;
@@ -812,13 +1034,13 @@ xpc_discovery(void)
        remote_vars = (struct xpc_vars *) remote_rp;
 
 
-       discovered_nasids = kmalloc(sizeof(u64) * XP_NASID_MASK_WORDS,
+       discovered_nasids = kmalloc(sizeof(u64) * xp_nasid_mask_words,
                                                        GFP_KERNEL);
        if (discovered_nasids == NULL) {
                kfree(remote_rp_base);
                return;
        }
-       memset(discovered_nasids, 0, sizeof(u64) * XP_NASID_MASK_WORDS);
+       memset(discovered_nasids, 0, sizeof(u64) * xp_nasid_mask_words);
 
        rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
 
@@ -827,11 +1049,19 @@ xpc_discovery(void)
         * nodes that can comprise an access protection grouping. The access
         * protection is in regards to memory, IOI and IPI.
         */
-//>>> move the next two #defines into either include/asm-ia64/sn/arch.h or
-//>>> include/asm-ia64/sn/addrs.h
-#define SH1_MAX_REGIONS                64
-#define SH2_MAX_REGIONS                256
-       max_regions = is_shub2() ? SH2_MAX_REGIONS : SH1_MAX_REGIONS;
+       max_regions = 64;
+       region_size = sn_region_size;
+
+       switch (region_size) {
+       case 128:
+               max_regions *= 2;
+       case 64:
+               max_regions *= 2;
+       case 32:
+               max_regions *= 2;
+               region_size = 16;
+               DBUG_ON(!is_shub2());
+       }
 
        for (region = 0; region < max_regions; region++) {
 
@@ -841,8 +1071,8 @@ xpc_discovery(void)
 
                dev_dbg(xpc_part, "searching region %d\n", region);
 
-               for (nasid = (region * sn_region_size * 2);
-                    nasid < ((region + 1) * sn_region_size * 2);
+               for (nasid = (region * region_size * 2);
+                    nasid < ((region + 1) * region_size * 2);
                     nasid += 2) {
 
                        if ((volatile int) xpc_exiting) {
@@ -852,14 +1082,14 @@ xpc_discovery(void)
                        dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 
 
-                       if (XPC_NASID_IN_ARRAY(nasid, rp->part_nasids)) {
+                       if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
                                dev_dbg(xpc_part, "PROM indicates Nasid %d is "
                                        "part of the local partition; skipping "
                                        "region\n", nasid);
                                break;
                        }
 
-                       if (!(XPC_NASID_IN_ARRAY(nasid, rp->mach_nasids))) {
+                       if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
                                dev_dbg(xpc_part, "PROM indicates Nasid %d was "
                                        "not on Numa-Link network at reset\n",
                                        nasid);
@@ -877,7 +1107,7 @@ xpc_discovery(void)
                        /* pull over the reserved page structure */
 
                        ret = xpc_get_remote_rp(nasid, discovered_nasids,
-                                             remote_rp, &remote_rsvd_page_pa);
+                                             remote_rp, &remote_rp_pa);
                        if (ret != xpcSuccess) {
                                dev_dbg(xpc_part, "unable to get reserved page "
                                        "from nasid %d, reason=%d\n", nasid,
@@ -948,6 +1178,13 @@ xpc_discovery(void)
                                remote_vars->act_nasid,
                                remote_vars->act_phys_cpuid);
 
+                       if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
+                                                               version)) {
+                               part->remote_amos_page_pa =
+                                               remote_vars->amos_page_pa;
+                               xpc_mark_partition_disengaged(part);
+                               xpc_cancel_partition_disengage_request(part);
+                       }
                        xpc_IPI_send_activate(remote_vars);
                }
        }
@@ -974,12 +1211,12 @@ xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
                return xpcPartitionDown;
        }
 
-       part_nasid_pa = part->remote_rp_pa +
-               (u64) &((struct xpc_rsvd_page *) 0)->part_nasids;
+       memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
+
+       part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
 
        bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
-                               L1_CACHE_ALIGN(XP_NASID_MASK_BYTES),
-                               (BTE_NOTIFY | BTE_WACQUIRE), NULL);
+                       xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 
        return xpc_map_bte_errors(bte_res);
 }
index 75a2f39..49faf8f 100644 (file)
@@ -217,7 +217,17 @@ enum xpc_retval {
        xpcInvalidPartid,       /* 42: invalid partition ID */
        xpcLocalPartid,         /* 43: local partition ID */
 
-       xpcUnknownReason        /* 44: unknown reason -- must be last in list */
+       xpcOtherGoingDown,      /* 44: other side going down, reason unknown */
+       xpcSystemGoingDown,     /* 45: system is going down, reason unknown */
+       xpcSystemHalt,          /* 46: system is being halted */
+       xpcSystemReboot,        /* 47: system is being rebooted */
+       xpcSystemPoweroff,      /* 48: system is being powered off */
+
+       xpcDisconnecting,       /* 49: channel disconnecting (closing) */
+
+       xpcOpenCloseError,      /* 50: channel open/close protocol error */
+
+       xpcUnknownReason        /* 51: unknown reason -- must be last in list */
 };
 
 
@@ -342,7 +352,7 @@ typedef void (*xpc_notify_func)(enum xpc_retval reason, partid_t partid,
  *
  * The 'func' field points to the function to call when aynchronous
  * notification is required for such events as: a connection established/lost,
- * or an incomming message received, or an error condition encountered. A
+ * or an incoming message received, or an error condition encountered. A
  * non-NULL 'func' field indicates that there is an active registration for
  * the channel.
  */