[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 ad9c113..c1fe013 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 0212feb..9c9c9c2 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 e62a3c2..3a41672 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 399c042..1407945 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 a65f882..e572ced 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 2f3dfb6..4d4e602 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 1383c31..ac19fdc 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 c321a92..d62505b 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 6052bfa..99762b6 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 adbea89..9494329 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 6a5047e..51266d6 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 10c2330..a9fb12c 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 a673971..c825531 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;