/* External tools reserve first few grant table entries. */
#define NR_RESERVED_ENTRIES 8
#define GNTTAB_LIST_END 0xffffffff
-#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry))
+#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(struct grant_entry_v1))
static grant_ref_t **gnttab_list;
static unsigned int nr_grant_frames;
unsigned long xen_hvm_resume_frames;
EXPORT_SYMBOL_GPL(xen_hvm_resume_frames);
-static struct grant_entry *shared;
+static union {
+ struct grant_entry_v1 *v1;
+ void *addr;
+} gnttab_shared;
+
+/*This is a structure of function pointers for grant table*/
+struct gnttab_ops {
+ /*
+ * Mapping a list of frames for storing grant entries. First input
+ * parameter is used to storing grant table address when grant table
+ * being setup, second parameter is the number of frames to map grant
+ * table. Returning GNTST_okay means success and negative value means
+ * failure.
+ */
+ int (*map_frames)(unsigned long *, unsigned int);
+ /*
+ * Release a list of frames which are mapped in map_frames for grant
+ * entry status.
+ */
+ void (*unmap_frames)(void);
+ /*
+ * Introducing a valid entry into the grant table, granting the frame
+ * of this grant entry to domain for accessing, or transfering, or
+ * transitively accessing. First input parameter is reference of this
+ * introduced grant entry, second one is domid of granted domain, third
+ * one is the frame to be granted, and the last one is status of the
+ * grant entry to be updated.
+ */
+ void (*update_entry)(grant_ref_t, domid_t, unsigned long, unsigned);
+ /*
+ * Stop granting a grant entry to domain for accessing. First input
+ * parameter is reference of a grant entry whose grant access will be
+ * stopped, second one is not in use now. If the grant entry is
+ * currently mapped for reading or writing, just return failure(==0)
+ * directly and don't tear down the grant access. Otherwise, stop grant
+ * access for this entry and return success(==1).
+ */
+ int (*end_foreign_access_ref)(grant_ref_t, int);
+ /*
+ * Stop granting a grant entry to domain for transfer. If tranfer has
+ * not started, just reclaim the grant entry and return failure(==0).
+ * Otherwise, wait for the transfer to complete and then return the
+ * frame.
+ */
+ unsigned long (*end_foreign_transfer_ref)(grant_ref_t);
+ /*
+ * Query the status of a grant entry. Input parameter is reference of
+ * queried grant entry, return value is the status of queried entry.
+ * Detailed status(writing/reading) can be gotten from the return value
+ * by bit operations.
+ */
+ int (*query_foreign_access)(grant_ref_t);
+};
+
+static struct gnttab_ops *gnttab_interface;
+
+static int grant_table_version;
static struct gnttab_free_callback *gnttab_free_callback_list;
spin_unlock_irqrestore(&gnttab_list_lock, flags);
}
-static void update_grant_entry(grant_ref_t ref, domid_t domid,
- unsigned long frame, unsigned flags)
+/*
+ * Introducing a valid entry into the grant table:
+ * 1. Write ent->domid.
+ * 2. Write ent->frame:
+ * GTF_permit_access: Frame to which access is permitted.
+ * GTF_accept_transfer: Pseudo-phys frame slot being filled by new
+ * frame, or zero if none.
+ * 3. Write memory barrier (WMB).
+ * 4. Write ent->flags, inc. valid type.
+ */
+static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid,
+ unsigned long frame, unsigned flags)
{
- /*
- * Introducing a valid entry into the grant table:
- * 1. Write ent->domid.
- * 2. Write ent->frame:
- * GTF_permit_access: Frame to which access is permitted.
- * GTF_accept_transfer: Pseudo-phys frame slot being filled by new
- * frame, or zero if none.
- * 3. Write memory barrier (WMB).
- * 4. Write ent->flags, inc. valid type.
- */
- shared[ref].frame = frame;
- shared[ref].domid = domid;
+ gnttab_shared.v1[ref].domid = domid;
+ gnttab_shared.v1[ref].frame = frame;
wmb();
- shared[ref].flags = flags;
+ gnttab_shared.v1[ref].flags = flags;
}
/*
void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
unsigned long frame, int readonly)
{
- update_grant_entry(ref, domid, frame,
+ gnttab_interface->update_entry(ref, domid, frame,
GTF_permit_access | (readonly ? GTF_readonly : 0));
}
EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref);
}
EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
-int gnttab_query_foreign_access(grant_ref_t ref)
+static int gnttab_query_foreign_access_v1(grant_ref_t ref)
{
- u16 nflags;
-
- nflags = shared[ref].flags;
+ return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing);
+}
- return nflags & (GTF_reading|GTF_writing);
+int gnttab_query_foreign_access(grant_ref_t ref)
+{
+ return gnttab_interface->query_foreign_access(ref);
}
EXPORT_SYMBOL_GPL(gnttab_query_foreign_access);
-int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
+static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly)
{
u16 flags, nflags;
+ u16 *pflags;
- nflags = shared[ref].flags;
+ pflags = &gnttab_shared.v1[ref].flags;
+ nflags = *pflags;
do {
flags = nflags;
if (flags & (GTF_reading|GTF_writing)) {
printk(KERN_ALERT "WARNING: g.e. still in use!\n");
return 0;
}
- } while ((nflags = sync_cmpxchg(&shared[ref].flags, flags, 0)) != flags);
+ } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags);
return 1;
}
+
+int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
+{
+ return gnttab_interface->end_foreign_access_ref(ref, readonly);
+}
EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref);
void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
unsigned long pfn)
{
- update_grant_entry(ref, domid, pfn, GTF_accept_transfer);
+ gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer);
}
EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref);
-unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref)
+static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref)
{
unsigned long frame;
u16 flags;
+ u16 *pflags;
+
+ pflags = &gnttab_shared.v1[ref].flags;
/*
* If a transfer is not even yet started, try to reclaim the grant
* reference and return failure (== 0).
*/
- while (!((flags = shared[ref].flags) & GTF_transfer_committed)) {
- if (sync_cmpxchg(&shared[ref].flags, flags, 0) == flags)
+ while (!((flags = *pflags) & GTF_transfer_committed)) {
+ if (sync_cmpxchg(pflags, flags, 0) == flags)
return 0;
cpu_relax();
}
/* If a transfer is in progress then wait until it is completed. */
while (!(flags & GTF_transfer_completed)) {
- flags = shared[ref].flags;
+ flags = *pflags;
cpu_relax();
}
rmb(); /* Read the frame number /after/ reading completion status. */
- frame = shared[ref].frame;
+ frame = gnttab_shared.v1[ref].frame;
BUG_ON(frame == 0);
return frame;
}
+
+unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref)
+{
+ return gnttab_interface->end_foreign_transfer_ref(ref);
+}
EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref);
unsigned long gnttab_end_foreign_transfer(grant_ref_t ref)
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
+static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes)
+{
+ int rc;
+
+ rc = arch_gnttab_map_shared(frames, nr_gframes,
+ gnttab_max_grant_frames(),
+ &gnttab_shared.addr);
+ BUG_ON(rc);
+
+ return 0;
+}
+
+static void gnttab_unmap_frames_v1(void)
+{
+ arch_gnttab_unmap_shared(gnttab_shared.addr, nr_grant_frames);
+}
+
static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
{
struct gnttab_setup_table setup;
BUG_ON(rc || setup.status);
- rc = arch_gnttab_map_shared(frames, nr_gframes, gnttab_max_grant_frames(),
- &shared);
- BUG_ON(rc);
+ rc = gnttab_interface->map_frames(frames, nr_gframes);
kfree(frames);
- return 0;
+ return rc;
+}
+
+static struct gnttab_ops gnttab_v1_ops = {
+ .map_frames = gnttab_map_frames_v1,
+ .unmap_frames = gnttab_unmap_frames_v1,
+ .update_entry = gnttab_update_entry_v1,
+ .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1,
+ .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1,
+ .query_foreign_access = gnttab_query_foreign_access_v1,
+};
+
+static void gnttab_request_version(void)
+{
+ grant_table_version = 1;
+ gnttab_interface = &gnttab_v1_ops;
+ printk(KERN_INFO "Grant tables using version %d layout.\n",
+ grant_table_version);
}
int gnttab_resume(void)
{
unsigned int max_nr_gframes;
+ gnttab_request_version();
max_nr_gframes = gnttab_max_grant_frames();
if (max_nr_gframes < nr_grant_frames)
return -ENOSYS;
if (xen_pv_domain())
return gnttab_map(0, nr_grant_frames - 1);
- if (!shared) {
- shared = ioremap(xen_hvm_resume_frames, PAGE_SIZE * max_nr_gframes);
- if (shared == NULL) {
+ if (gnttab_shared.addr == NULL) {
+ gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
+ PAGE_SIZE * max_nr_gframes);
+ if (gnttab_shared.addr == NULL) {
printk(KERN_WARNING
"Failed to ioremap gnttab share frames!");
return -ENOMEM;
int gnttab_suspend(void)
{
- arch_gnttab_unmap_shared(shared, nr_grant_frames);
+ gnttab_interface->unmap_frames();
return 0;
}
projects / cascardo / linux.git / blobdiff