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-rw-r--r--arch/x86/xen/grant-table.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index c6ab2e7ca3a6..65160a8a0ba3 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -54,6 +54,20 @@ static int map_pte_fn(pte_t *pte, struct page *pmd_page,
return 0;
}
+/*
+ * This function is used to map shared frames to store grant status. It is
+ * different from map_pte_fn above, the frames type here is uint64_t.
+ */
+static int map_pte_fn_status(pte_t *pte, struct page *pmd_page,
+ unsigned long addr, void *data)
+{
+ uint64_t **frames = (uint64_t **)data;
+
+ set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
+ (*frames)++;
+ return 0;
+}
+
static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
unsigned long addr, void *data)
{
@@ -83,7 +97,30 @@ int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
return rc;
}
-void arch_gnttab_unmap_shared(void *shared, unsigned long nr_gframes)
+int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
+ unsigned long max_nr_gframes,
+ grant_status_t **__shared)
+{
+ int rc;
+ grant_status_t *shared = *__shared;
+
+ if (shared == NULL) {
+ /* No need to pass in PTE as we are going to do it
+ * in apply_to_page_range anyhow. */
+ struct vm_struct *area =
+ alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
+ BUG_ON(area == NULL);
+ shared = area->addr;
+ *__shared = shared;
+ }
+
+ rc = apply_to_page_range(&init_mm, (unsigned long)shared,
+ PAGE_SIZE * nr_gframes,
+ map_pte_fn_status, &frames);
+ return rc;
+}
+
+void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
apply_to_page_range(&init_mm, (unsigned long)shared,
PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);