1 files changed, 51 insertions, 7 deletions

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index e69c7780c208..44b75ccfbbff 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -65,8 +65,7 @@ static unsigned int nr_grant_frames;
 static int gnttab_free_count;
 static grant_ref_t gnttab_free_head;
 static DEFINE_SPINLOCK(gnttab_list_lock);
-unsigned long xen_hvm_resume_frames;
-EXPORT_SYMBOL_GPL(xen_hvm_resume_frames);
+struct grant_frames xen_auto_xlat_grant_frames;
 
 static union {
         struct grant_entry_v1 *v1;
@@ -838,6 +837,51 @@ unsigned int gnttab_max_grant_frames(void)
 }
 EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
 
+int gnttab_setup_auto_xlat_frames(unsigned long addr)
+{
+        xen_pfn_t *pfn;
+        unsigned int max_nr_gframes = __max_nr_grant_frames();
+        unsigned int i;
+        void *vaddr;
+
+        if (xen_auto_xlat_grant_frames.count)
+                return -EINVAL;
+
+        vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes);
+        if (vaddr == NULL) {
+                pr_warn("Failed to ioremap gnttab share frames (addr=0x%08lx)!\n",
+                        addr);
+                return -ENOMEM;
+        }
+        pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL);
+        if (!pfn) {
+                xen_unmap(vaddr);
+                return -ENOMEM;
+        }
+        for (i = 0; i < max_nr_gframes; i++)
+                pfn[i] = PFN_DOWN(addr) + i;
+
+        xen_auto_xlat_grant_frames.vaddr = vaddr;
+        xen_auto_xlat_grant_frames.pfn = pfn;
+        xen_auto_xlat_grant_frames.count = max_nr_gframes;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames);
+
+void gnttab_free_auto_xlat_frames(void)
+{
+        if (!xen_auto_xlat_grant_frames.count)
+                return;
+        kfree(xen_auto_xlat_grant_frames.pfn);
+        xen_unmap(xen_auto_xlat_grant_frames.vaddr);
+
+        xen_auto_xlat_grant_frames.pfn = NULL;
+        xen_auto_xlat_grant_frames.count = 0;
+        xen_auto_xlat_grant_frames.vaddr = NULL;
+}
+EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
+
 /* Handling of paged out grant targets (GNTST_eagain) */
 #define MAX_DELAY 256
 static inline void
@@ -1068,6 +1112,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
                 struct xen_add_to_physmap xatp;
                 unsigned int i = end_idx;
                 rc = 0;
+                BUG_ON(xen_auto_xlat_grant_frames.count < nr_gframes);
                 /*
                  * Loop backwards, so that the first hypercall has the largest
                  * index, ensuring that the table will grow only once.
@@ -1076,7 +1121,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
                         xatp.domid = DOMID_SELF;
                         xatp.idx = i;
                         xatp.space = XENMAPSPACE_grant_table;
-                        xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
+                        xatp.gpfn = xen_auto_xlat_grant_frames.pfn[i];
                         rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
                         if (rc != 0) {
                                 pr_warn("grant table add_to_physmap failed, err=%d\n",
@@ -1174,11 +1219,10 @@ static int gnttab_setup(void)
                 return -ENOSYS;
 
         if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) {
-                gnttab_shared.addr = xen_remap(xen_hvm_resume_frames,
-                                                PAGE_SIZE * max_nr_gframes);
+                gnttab_shared.addr = xen_auto_xlat_grant_frames.vaddr;
                 if (gnttab_shared.addr == NULL) {
-                        pr_warn("Failed to ioremap gnttab share frames (addr=0x%08lx)!\n",
-                                        xen_hvm_resume_frames);
+                        pr_warn("gnttab share frames (addr=0x%08lx) is not mapped!\n",
+                                (unsigned long)xen_auto_xlat_grant_frames.vaddr);
                         return -ENOMEM;
                 }
         }