6 files changed, 75 insertions, 13 deletions

diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
index ac6789aad059..709c4b4d2f1d 100644
--- a/arch/arm/include/asm/xen/page.h
+++ b/arch/arm/include/asm/xen/page.h
@@ -118,5 +118,6 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 }
 
 #define xen_remap(cookie, size) ioremap_cached((cookie), (size))
+#define xen_unmap(cookie) iounmap((cookie))
 
 #endif /* _ASM_ARM_XEN_PAGE_H */
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 85501238b425..2162172c0ddc 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -208,6 +208,7 @@ static int __init xen_guest_init(void)
         const char *version = NULL;
         const char *xen_prefix = "xen,xen-";
         struct resource res;
+        unsigned long grant_frames;
 
         node = of_find_compatible_node(NULL, NULL, "xen,xen");
         if (!node) {
@@ -224,10 +225,10 @@ static int __init xen_guest_init(void)
         }
         if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
                 return 0;
-        xen_hvm_resume_frames = res.start;
+        grant_frames = res.start;
         xen_events_irq = irq_of_parse_and_map(node, 0);
         pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n",
-                        version, xen_events_irq, (xen_hvm_resume_frames >> PAGE_SHIFT));
+                        version, xen_events_irq, (grant_frames >> PAGE_SHIFT));
         xen_domain_type = XEN_HVM_DOMAIN;
 
         xen_setup_features();
@@ -265,6 +266,10 @@ static int __init xen_guest_init(void)
         if (xen_vcpu_info == NULL)
                 return -ENOMEM;
 
+        if (gnttab_setup_auto_xlat_frames(grant_frames)) {
+                free_percpu(xen_vcpu_info);
+                return -ENOMEM;
+        }
         gnttab_init();
         if (!xen_initial_domain())
                 xenbus_probe(NULL);
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 4a092ccdd147..3e276eb23d1b 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -227,5 +227,6 @@ void make_lowmem_page_readonly(void *vaddr);
 void make_lowmem_page_readwrite(void *vaddr);
 
 #define xen_remap(cookie, size) ioremap((cookie), (size));
+#define xen_unmap(cookie) iounmap((cookie))
 
 #endif /* _ASM_X86_XEN_PAGE_H */
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;
                 }
         }
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index 2f3528e93cb9..f1947ac218d9 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -108,6 +108,7 @@ static int platform_pci_init(struct pci_dev *pdev,
         long ioaddr;
         long mmio_addr, mmio_len;
         unsigned int max_nr_gframes;
+        unsigned long grant_frames;
 
         if (!xen_domain())
                 return -ENODEV;
@@ -154,13 +155,16 @@ static int platform_pci_init(struct pci_dev *pdev,
         }
 
         max_nr_gframes = gnttab_max_grant_frames();
-        xen_hvm_resume_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
+        grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
+        if (gnttab_setup_auto_xlat_frames(grant_frames))
+                goto out;
         ret = gnttab_init();
         if (ret)
-                goto out;
+                goto grant_out;
         xenbus_probe(NULL);
         return 0;
-
+grant_out:
+        gnttab_free_auto_xlat_frames();
 out:
         pci_release_region(pdev, 0);
 mem_out:
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 694dcaf266e6..5acb1e4ac0d3 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -178,8 +178,15 @@ int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
                            grant_status_t **__shared);
 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
 
-extern unsigned long xen_hvm_resume_frames;
+struct grant_frames {
+        xen_pfn_t *pfn;
+        unsigned int count;
+        void *vaddr;
+};
+extern struct grant_frames xen_auto_xlat_grant_frames;
 unsigned int gnttab_max_grant_frames(void);
+int gnttab_setup_auto_xlat_frames(unsigned long addr);
+void gnttab_free_auto_xlat_frames(void);
 
 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))