[PATCH] AGP fix for Xen VMM

When Linux is running on the Xen virtual machine monitor, physical
addresses are virtualised and cannot be directly referenced by the AGP
GART.  This patch fixes the GART driver for Xen by adding a layer of
abstraction between physical addresses and 'GART addresses'.

Architecture-specific functions are also defined for allocating and freeing
the GATT.  Xen requires this to ensure that table really is contiguous from
the point of view of the GART.

These extra interface functions are defined as 'no-ops' for all existing
architectures that use the GART driver.

Signed-off-by: Keir Fraser <keir@xensource.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>

13 files changed, 36 insertions, 35 deletions

diff --git a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
index ad9c11391d8..c1fe013c64f 100644
--- a/drivers/char/agp/agp.h
+++ b/drivers/char/agp/agp.h
@@ -278,6 +278,8 @@ void agp3_generic_cleanup(void);
 #define AGP_GENERIC_SIZES_ENTRIES 11
 extern struct aper_size_info_16 agp3_generic_sizes[];
 
+#define virt_to_gart(x) (phys_to_gart(virt_to_phys(x)))
+#define gart_to_virt(x) (phys_to_virt(gart_to_phys(x)))
 
 extern int agp_off;
 extern int agp_try_unsupported_boot;
diff --git a/drivers/char/agp/ali-agp.c b/drivers/char/agp/ali-agp.c
index 0212febda65..9c9c9c2247c 100644
--- a/drivers/char/agp/ali-agp.c
+++ b/drivers/char/agp/ali-agp.c
@@ -150,7 +150,7 @@ static void *m1541_alloc_page(struct agp_bridge_data *bridge)
         pci_read_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL, &temp);
         pci_write_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL,
                         (((temp & ALI_CACHE_FLUSH_ADDR_MASK) |
-                          virt_to_phys(addr)) | ALI_CACHE_FLUSH_EN ));
+                          virt_to_gart(addr)) | ALI_CACHE_FLUSH_EN ));
         return addr;
 }
 
@@ -174,7 +174,7 @@ static void m1541_destroy_page(void * addr)
         pci_read_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL, &temp);
         pci_write_config_dword(agp_bridge->dev, ALI_CACHE_FLUSH_CTRL,
                         (((temp & ALI_CACHE_FLUSH_ADDR_MASK) |
-                          virt_to_phys(addr)) | ALI_CACHE_FLUSH_EN));
+                          virt_to_gart(addr)) | ALI_CACHE_FLUSH_EN));
         agp_generic_destroy_page(addr);
 }
 
diff --git a/drivers/char/agp/amd-k7-agp.c b/drivers/char/agp/amd-k7-agp.c
index e62a3c2c44a..3a41672e4d6 100644
--- a/drivers/char/agp/amd-k7-agp.c
+++ b/drivers/char/agp/amd-k7-agp.c
@@ -43,7 +43,7 @@ static int amd_create_page_map(struct amd_page_map *page_map)
 
         SetPageReserved(virt_to_page(page_map->real));
         global_cache_flush();
-        page_map->remapped = ioremap_nocache(virt_to_phys(page_map->real),
+        page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real),
                                             PAGE_SIZE);
         if (page_map->remapped == NULL) {
                 ClearPageReserved(virt_to_page(page_map->real));
@@ -154,7 +154,7 @@ static int amd_create_gatt_table(struct agp_bridge_data *bridge)
 
         agp_bridge->gatt_table_real = (u32 *)page_dir.real;
         agp_bridge->gatt_table = (u32 __iomem *)page_dir.remapped;
-        agp_bridge->gatt_bus_addr = virt_to_phys(page_dir.real);
+        agp_bridge->gatt_bus_addr = virt_to_gart(page_dir.real);
 
         /* Get the address for the gart region.
          * This is a bus address even on the alpha, b/c its
@@ -167,7 +167,7 @@ static int amd_create_gatt_table(struct agp_bridge_data *bridge)
 
         /* Calculate the agp offset */
         for (i = 0; i < value->num_entries / 1024; i++, addr += 0x00400000) {
-                writel(virt_to_phys(amd_irongate_private.gatt_pages[i]->real) | 1,
+                writel(virt_to_gart(amd_irongate_private.gatt_pages[i]->real) | 1,
                         page_dir.remapped+GET_PAGE_DIR_OFF(addr));
                 readl(page_dir.remapped+GET_PAGE_DIR_OFF(addr));        /* PCI Posting. */
         }
diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index 399c042f68f..1407945a589 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -219,7 +219,7 @@ static struct aper_size_info_32 amd_8151_sizes[7] =
 
 static int amd_8151_configure(void)
 {
-        unsigned long gatt_bus = virt_to_phys(agp_bridge->gatt_table_real);
+        unsigned long gatt_bus = virt_to_gart(agp_bridge->gatt_table_real);
 
         /* Configure AGP regs in each x86-64 host bridge. */
         for_each_nb() {
@@ -591,7 +591,7 @@ static void __devexit agp_amd64_remove(struct pci_dev *pdev)
 {
         struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
 
-        release_mem_region(virt_to_phys(bridge->gatt_table_real),
+        release_mem_region(virt_to_gart(bridge->gatt_table_real),
                            amd64_aperture_sizes[bridge->aperture_size_idx].size);
         agp_remove_bridge(bridge);
         agp_put_bridge(bridge);
diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c
index a65f8827c28..e572ced9100 100644
--- a/drivers/char/agp/ati-agp.c
+++ b/drivers/char/agp/ati-agp.c
@@ -61,7 +61,7 @@ static int ati_create_page_map(ati_page_map *page_map)
 
         SetPageReserved(virt_to_page(page_map->real));
         err = map_page_into_agp(virt_to_page(page_map->real));
-        page_map->remapped = ioremap_nocache(virt_to_phys(page_map->real),
+        page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real),
                                             PAGE_SIZE);
         if (page_map->remapped == NULL || err) {
                 ClearPageReserved(virt_to_page(page_map->real));
@@ -343,7 +343,7 @@ static int ati_create_gatt_table(struct agp_bridge_data *bridge)
 
         agp_bridge->gatt_table_real = (u32 *)page_dir.real;
         agp_bridge->gatt_table = (u32 __iomem *) page_dir.remapped;
-        agp_bridge->gatt_bus_addr = virt_to_bus(page_dir.real);
+        agp_bridge->gatt_bus_addr = virt_to_gart(page_dir.real);
 
         /* Write out the size register */
         current_size = A_SIZE_LVL2(agp_bridge->current_size);
@@ -373,7 +373,7 @@ static int ati_create_gatt_table(struct agp_bridge_data *bridge)
 
         /* Calculate the agp offset */
         for(i = 0; i < value->num_entries / 1024; i++, addr += 0x00400000) {
-                writel(virt_to_bus(ati_generic_private.gatt_pages[i]->real) | 1,
+                writel(virt_to_gart(ati_generic_private.gatt_pages[i]->real) | 1,
                         page_dir.remapped+GET_PAGE_DIR_OFF(addr));
                 readl(page_dir.remapped+GET_PAGE_DIR_OFF(addr));        /* PCI Posting. */
         }
diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index 2f3dfb63bdc..4d4e602fdc7 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -148,7 +148,7 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
                         return -ENOMEM;
                 }
 
-                bridge->scratch_page_real = virt_to_phys(addr);
+                bridge->scratch_page_real = virt_to_gart(addr);
                 bridge->scratch_page =
                     bridge->driver->mask_memory(bridge, bridge->scratch_page_real, 0);
         }
@@ -189,7 +189,7 @@ static int agp_backend_initialize(struct agp_bridge_data *bridge)
 err_out:
         if (bridge->driver->needs_scratch_page)
                 bridge->driver->agp_destroy_page(
-                                phys_to_virt(bridge->scratch_page_real));
+                                gart_to_virt(bridge->scratch_page_real));
         if (got_gatt)
                 bridge->driver->free_gatt_table(bridge);
         if (got_keylist) {
@@ -214,7 +214,7 @@ static void agp_backend_cleanup(struct agp_bridge_data *bridge)
         if (bridge->driver->agp_destroy_page &&
             bridge->driver->needs_scratch_page)
                 bridge->driver->agp_destroy_page(
-                                phys_to_virt(bridge->scratch_page_real));
+                                gart_to_virt(bridge->scratch_page_real));
 }
 
 /* When we remove the global variable agp_bridge from all drivers
diff --git a/drivers/char/agp/efficeon-agp.c b/drivers/char/agp/efficeon-agp.c
index 1383c3165ea..ac19fdcd21c 100644
--- a/drivers/char/agp/efficeon-agp.c
+++ b/drivers/char/agp/efficeon-agp.c
@@ -219,7 +219,7 @@ static int efficeon_create_gatt_table(struct agp_bridge_data *bridge)
 
                 efficeon_private.l1_table[index] = page;
 
-                value = __pa(page) | pati | present | index;
+                value = virt_to_gart(page) | pati | present | index;
 
                 pci_write_config_dword(agp_bridge->dev,
                         EFFICEON_ATTPAGE, value);
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index c321a924e38..d62505b5d25 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -153,7 +153,7 @@ void agp_free_memory(struct agp_memory *curr)
         }
         if (curr->page_count != 0) {
                 for (i = 0; i < curr->page_count; i++) {
-                        curr->bridge->driver->agp_destroy_page(phys_to_virt(curr->memory[i]));
+                        curr->bridge->driver->agp_destroy_page(gart_to_virt(curr->memory[i]));
                 }
         }
         agp_free_key(curr->key);
@@ -209,7 +209,7 @@ struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge,
                         agp_free_memory(new);
                         return NULL;
                 }
-                new->memory[i] = virt_to_phys(addr);
+                new->memory[i] = virt_to_gart(addr);
                 new->page_count++;
         }
        new->bridge = bridge;
@@ -806,8 +806,7 @@ int agp_generic_create_gatt_table(struct agp_bridge_data *bridge)
                                 break;
                         }
 
-                        table = (char *) __get_free_pages(GFP_KERNEL,
-                                                          page_order);
+                        table = alloc_gatt_pages(page_order);
 
                         if (table == NULL) {
                                 i++;
@@ -838,7 +837,7 @@ int agp_generic_create_gatt_table(struct agp_bridge_data *bridge)
                 size = ((struct aper_size_info_fixed *) temp)->size;
                 page_order = ((struct aper_size_info_fixed *) temp)->page_order;
                 num_entries = ((struct aper_size_info_fixed *) temp)->num_entries;
-                table = (char *) __get_free_pages(GFP_KERNEL, page_order);
+                table = alloc_gatt_pages(page_order);
         }
 
         if (table == NULL)
@@ -853,7 +852,7 @@ int agp_generic_create_gatt_table(struct agp_bridge_data *bridge)
         agp_gatt_table = (void *)table;
 
         bridge->driver->cache_flush();
-        bridge->gatt_table = ioremap_nocache(virt_to_phys(table),
+        bridge->gatt_table = ioremap_nocache(virt_to_gart(table),
                                         (PAGE_SIZE * (1 << page_order)));
         bridge->driver->cache_flush();
 
@@ -861,11 +860,11 @@ int agp_generic_create_gatt_table(struct agp_bridge_data *bridge)
                 for (page = virt_to_page(table); page <= virt_to_page(table_end); page++)
                         ClearPageReserved(page);
 
-                free_pages((unsigned long) table, page_order);
+                free_gatt_pages(table, page_order);
 
                 return -ENOMEM;
         }
-        bridge->gatt_bus_addr = virt_to_phys(bridge->gatt_table_real);
+        bridge->gatt_bus_addr = virt_to_gart(bridge->gatt_table_real);
 
         /* AK: bogus, should encode addresses > 4GB */
         for (i = 0; i < num_entries; i++) {
@@ -919,7 +918,7 @@ int agp_generic_free_gatt_table(struct agp_bridge_data *bridge)
         for (page = virt_to_page(table); page <= virt_to_page(table_end); page++)
                 ClearPageReserved(page);
 
-        free_pages((unsigned long) bridge->gatt_table_real, page_order);
+        free_gatt_pages(bridge->gatt_table_real, page_order);
 
         agp_gatt_table = NULL;
         bridge->gatt_table = NULL;
diff --git a/drivers/char/agp/hp-agp.c b/drivers/char/agp/hp-agp.c
index 6052bfa04c7..99762b6c19a 100644
--- a/drivers/char/agp/hp-agp.c
+++ b/drivers/char/agp/hp-agp.c
@@ -110,7 +110,7 @@ static int __init hp_zx1_ioc_shared(void)
         hp->gart_size = HP_ZX1_GART_SIZE;
         hp->gatt_entries = hp->gart_size / hp->io_page_size;
 
-        hp->io_pdir = phys_to_virt(readq(hp->ioc_regs+HP_ZX1_PDIR_BASE));
+        hp->io_pdir = gart_to_virt(readq(hp->ioc_regs+HP_ZX1_PDIR_BASE));
         hp->gatt = &hp->io_pdir[HP_ZX1_IOVA_TO_PDIR(hp->gart_base)];
 
         if (hp->gatt[0] != HP_ZX1_SBA_IOMMU_COOKIE) {
@@ -248,7 +248,7 @@ hp_zx1_configure (void)
         agp_bridge->mode = readl(hp->lba_regs+hp->lba_cap_offset+PCI_AGP_STATUS);
 
         if (hp->io_pdir_owner) {
-                writel(virt_to_phys(hp->io_pdir), hp->ioc_regs+HP_ZX1_PDIR_BASE);
+                writel(virt_to_gart(hp->io_pdir), hp->ioc_regs+HP_ZX1_PDIR_BASE);
                 readl(hp->ioc_regs+HP_ZX1_PDIR_BASE);
                 writel(hp->io_tlb_ps, hp->ioc_regs+HP_ZX1_TCNFG);
                 readl(hp->ioc_regs+HP_ZX1_TCNFG);
diff --git a/drivers/char/agp/i460-agp.c b/drivers/char/agp/i460-agp.c
index adbea896c0d..94943298c03 100644
--- a/drivers/char/agp/i460-agp.c
+++ b/drivers/char/agp/i460-agp.c
@@ -372,7 +372,7 @@ static int i460_alloc_large_page (struct lp_desc *lp)
         }
         memset(lp->alloced_map, 0, map_size);
 
-        lp->paddr = virt_to_phys(lpage);
+        lp->paddr = virt_to_gart(lpage);
         lp->refcount = 0;
         atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
         return 0;
@@ -383,7 +383,7 @@ static void i460_free_large_page (struct lp_desc *lp)
         kfree(lp->alloced_map);
         lp->alloced_map = NULL;
 
-        free_pages((unsigned long) phys_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
+        free_pages((unsigned long) gart_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
         atomic_sub(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
 }
 
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 6a5047e0d33..51266d6b4d7 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -286,7 +286,7 @@ static struct agp_memory *alloc_agpphysmem_i8xx(size_t pg_count, int type)
         if (new == NULL)
                 return NULL;
 
-        new->memory[0] = virt_to_phys(addr);
+        new->memory[0] = virt_to_gart(addr);
         if (pg_count == 4) {
                 /* kludge to get 4 physical pages for ARGB cursor */
                 new->memory[1] = new->memory[0] + PAGE_SIZE;
@@ -329,10 +329,10 @@ static void intel_i810_free_by_type(struct agp_memory *curr)
         agp_free_key(curr->key);
         if(curr->type == AGP_PHYS_MEMORY) {
                 if (curr->page_count == 4)
-                        i8xx_destroy_pages(phys_to_virt(curr->memory[0]));
+                        i8xx_destroy_pages(gart_to_virt(curr->memory[0]));
                 else
                         agp_bridge->driver->agp_destroy_page(
-                                 phys_to_virt(curr->memory[0]));
+                                 gart_to_virt(curr->memory[0]));
                 vfree(curr->memory);
         }
         kfree(curr);
diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
index 10c23302dd8..a9fb12c20eb 100644
--- a/drivers/char/agp/sworks-agp.c
+++ b/drivers/char/agp/sworks-agp.c
@@ -51,7 +51,7 @@ static int serverworks_create_page_map(struct serverworks_page_map *page_map)
         }
         SetPageReserved(virt_to_page(page_map->real));
         global_cache_flush();
-        page_map->remapped = ioremap_nocache(virt_to_phys(page_map->real), 
+        page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real),
                                             PAGE_SIZE);
         if (page_map->remapped == NULL) {
                 ClearPageReserved(virt_to_page(page_map->real));
@@ -162,7 +162,7 @@ static int serverworks_create_gatt_table(struct agp_bridge_data *bridge)
         /* Create a fake scratch directory */
         for(i = 0; i < 1024; i++) {
                 writel(agp_bridge->scratch_page, serverworks_private.scratch_dir.remapped+i);
-                writel(virt_to_phys(serverworks_private.scratch_dir.real) | 1, page_dir.remapped+i);
+                writel(virt_to_gart(serverworks_private.scratch_dir.real) | 1, page_dir.remapped+i);
         }
 
         retval = serverworks_create_gatt_pages(value->num_entries / 1024);
@@ -174,7 +174,7 @@ static int serverworks_create_gatt_table(struct agp_bridge_data *bridge)
 
         agp_bridge->gatt_table_real = (u32 *)page_dir.real;
         agp_bridge->gatt_table = (u32 __iomem *)page_dir.remapped;
-        agp_bridge->gatt_bus_addr = virt_to_phys(page_dir.real);
+        agp_bridge->gatt_bus_addr = virt_to_gart(page_dir.real);
 
         /* Get the address for the gart region.
          * This is a bus address even on the alpha, b/c its
@@ -187,7 +187,7 @@ static int serverworks_create_gatt_table(struct agp_bridge_data *bridge)
         /* Calculate the agp offset */  
 
         for(i = 0; i < value->num_entries / 1024; i++)
-                writel(virt_to_phys(serverworks_private.gatt_pages[i]->real)|1, page_dir.remapped+i);
+                writel(virt_to_gart(serverworks_private.gatt_pages[i]->real)|1, page_dir.remapped+i);
 
         return 0;
 }
diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c
index a673971f2a9..c8255312b8c 100644
--- a/drivers/char/agp/uninorth-agp.c
+++ b/drivers/char/agp/uninorth-agp.c
@@ -407,7 +407,7 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 
         bridge->gatt_table_real = (u32 *) table;
         bridge->gatt_table = (u32 *)table;
-        bridge->gatt_bus_addr = virt_to_phys(table);
+        bridge->gatt_bus_addr = virt_to_gart(table);
 
         for (i = 0; i < num_entries; i++)
                 bridge->gatt_table[i] = 0;