s390/lowcore: replace lowcore irb array with a per-cpu variable

Remove the 96-byte irb array from the lowcore and create a per-cpu
variable instead. That way we will pick up any change in the definition
of the struct irb automatically.

Acked-By: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index a406f24..2070cad 100644 (file)
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -143,10 +143,7 @@ struct _lowcore {
        __u32   ftrace_func;                    /* 0x02f8 */
        __u32   spinlock_lockval;               /* 0x02fc */
 
-       /* Interrupt response block */
-       __u8    irb[96];                        /* 0x0300 */
-
-       __u8    pad_0x0360[0x0e00-0x0360];      /* 0x0360 */
+       __u8    pad_0x0300[0x0e00-0x0300];      /* 0x0300 */
 
        /*
         * 0xe00 contains the address of the IPL Parameter Information
@@ -292,14 +289,10 @@ struct _lowcore {
        __u32   spinlock_lockval;               /* 0x03a0 */
        __u8    pad_0x03a0[0x0400-0x03a4];      /* 0x03a4 */
 
-       /* Interrupt response block. */
-       __u8    irb[96];                        /* 0x0400 */
-       __u8    pad_0x0460[0x0480-0x0460];      /* 0x0460 */
-
        /* Per cpu primary space access list */
-       __u32   paste[16];                      /* 0x0480 */
+       __u32   paste[16];                      /* 0x0400 */
 
-       __u8    pad_0x04c0[0x0e00-0x04c0];      /* 0x04c0 */
+       __u8    pad_0x04c0[0x0e00-0x0440];      /* 0x0440 */
 
        /*
         * 0xe00 contains the address of the IPL Parameter Information

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 76c4e2f..0c070c4 100644 (file)
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -144,7 +144,6 @@ int main(void)
        DEFINE(__LC_MCCK_CLOCK, offsetof(struct _lowcore, mcck_clock));
        DEFINE(__LC_MACHINE_FLAGS, offsetof(struct _lowcore, machine_flags));
        DEFINE(__LC_FTRACE_FUNC, offsetof(struct _lowcore, ftrace_func));
-       DEFINE(__LC_IRB, offsetof(struct _lowcore, irb));
        DEFINE(__LC_DUMP_REIPL, offsetof(struct _lowcore, ipib));
        BLANK();
        DEFINE(__LC_CPU_TIMER_SAVE_AREA, offsetof(struct _lowcore, cpu_timer_save_area));

diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index fc5fb51..07676c2 100644 (file)
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -252,7 +252,7 @@ static void ccwreq_log_status(struct ccw_device *cdev, enum io_status status)
  */
 void ccw_request_handler(struct ccw_device *cdev)
 {
-       struct irb *irb = (struct irb *)&S390_lowcore.irb;
+       struct irb *irb = &__get_cpu_var(cio_irb);
        struct ccw_request *req = &cdev->private->req;
        enum io_status status;
        int rc = -EOPNOTSUPP;

diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index 1d3661a..3d22d2a 100644 (file)
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -58,7 +58,7 @@ static void chsc_subchannel_irq(struct subchannel *sch)
 {
        struct chsc_private *private = dev_get_drvdata(&sch->dev);
        struct chsc_request *request = private->request;
-       struct irb *irb = (struct irb *)&S390_lowcore.irb;
+       struct irb *irb = &__get_cpu_var(cio_irb);
 
        CHSC_LOG(4, "irb");
        CHSC_LOG_HEX(4, irb, sizeof(*irb));

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 9e058c4..77f9c92 100644 (file)
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -46,6 +46,9 @@ debug_info_t *cio_debug_msg_id;
 debug_info_t *cio_debug_trace_id;
 debug_info_t *cio_debug_crw_id;
 
+DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
+EXPORT_PER_CPU_SYMBOL(cio_irb);
+
 /*
  * Function: cio_debug_init
  * Initializes three debug logs for common I/O:
@@ -560,7 +563,7 @@ static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 
        __this_cpu_write(s390_idle.nohz_delay, 1);
        tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
-       irb = (struct irb *) &S390_lowcore.irb;
+       irb = &__get_cpu_var(cio_irb);
        sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
        if (!sch) {
                /* Clear pending interrupt condition. */
@@ -609,7 +612,7 @@ void cio_tsch(struct subchannel *sch)
        struct irb *irb;
        int irq_context;
 
-       irb = (struct irb *)&S390_lowcore.irb;
+       irb = &__get_cpu_var(cio_irb);
        /* Store interrupt response block to lowcore. */
        if (tsch(sch->schid, irb) != 0)
                /* Not status pending or not operational. */
@@ -746,7 +749,7 @@ __clear_io_subchannel_easy(struct subchannel_id schid)
                struct tpi_info ti;
 
                if (tpi(&ti)) {
-                       tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
+                       tsch(ti.schid, &__get_cpu_var(cio_irb));
                        if (schid_equal(&ti.schid, &schid))
                                return 0;
                }

diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index d42f674..a01376a 100644 (file)
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -102,6 +102,8 @@ struct subchannel {
        struct schib_config config;
 } __attribute__ ((aligned(8)));
 
+DECLARE_PER_CPU(struct irb, cio_irb);
+
 #define to_subchannel(n) container_of(n, struct subchannel, dev)
 
 extern int cio_validate_subchannel (struct subchannel *, struct subchannel_id);

diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index c7638c5..0bc902b 100644 (file)
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -739,7 +739,7 @@ ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
        struct irb *irb;
        int is_cmd;
 
-       irb = (struct irb *)&S390_lowcore.irb;
+       irb = &__get_cpu_var(cio_irb);
        is_cmd = !scsw_is_tm(&irb->scsw);
        /* Check for unsolicited interrupt. */
        if (!scsw_is_solicited(&irb->scsw)) {
@@ -805,7 +805,7 @@ ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 {
        struct irb *irb;
 
-       irb = (struct irb *)&S390_lowcore.irb;
+       irb = &__get_cpu_var(cio_irb);
        /* Check for unsolicited interrupt. */
        if (scsw_stctl(&irb->scsw) ==
            (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {

diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c
index 3a2ee4a..c4f7bf3 100644 (file)
--- a/drivers/s390/cio/eadm_sch.c
+++ b/drivers/s390/cio/eadm_sch.c
@@ -134,7 +134,7 @@ static void eadm_subchannel_irq(struct subchannel *sch)
 {
        struct eadm_private *private = get_eadm_private(sch);
        struct eadm_scsw *scsw = &sch->schib.scsw.eadm;
-       struct irb *irb = (struct irb *)&S390_lowcore.irb;
+       struct irb *irb = &__get_cpu_var(cio_irb);
        int error = 0;
 
        EADM_LOG(6, "irq");