9 files changed, 44 insertions, 4 deletions

diff --git a/drivers/char/agp/ali-agp.c b/drivers/char/agp/ali-agp.c
index d2ce68f27e4b..fd793519ea2b 100644
--- a/drivers/char/agp/ali-agp.c
+++ b/drivers/char/agp/ali-agp.c
@@ -204,6 +204,7 @@ static const struct agp_bridge_driver ali_generic_bridge = {
         .aperture_sizes         = ali_generic_sizes,
         .size_type              = U32_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = ali_configure,
         .fetch_size             = ali_fetch_size,
         .cleanup                = ali_cleanup,
diff --git a/drivers/char/agp/amd-k7-agp.c b/drivers/char/agp/amd-k7-agp.c
index a7637d72cef6..b6b1568314c8 100644
--- a/drivers/char/agp/amd-k7-agp.c
+++ b/drivers/char/agp/amd-k7-agp.c
@@ -142,6 +142,7 @@ static int amd_create_gatt_table(struct agp_bridge_data *bridge)
 {
         struct aper_size_info_lvl2 *value;
         struct amd_page_map page_dir;
+        unsigned long __iomem *cur_gatt;
         unsigned long addr;
         int retval;
         u32 temp;
@@ -178,6 +179,13 @@ static int amd_create_gatt_table(struct agp_bridge_data *bridge)
                 readl(page_dir.remapped+GET_PAGE_DIR_OFF(addr));        /* PCI Posting. */
         }
 
+        for (i = 0; i < value->num_entries; i++) {
+                addr = (i * PAGE_SIZE) + agp_bridge->gart_bus_addr;
+                cur_gatt = GET_GATT(addr);
+                writel(agp_bridge->scratch_page, cur_gatt+GET_GATT_OFF(addr));
+                readl(cur_gatt+GET_GATT_OFF(addr));     /* PCI Posting. */
+        }
+
         return 0;
 }
 
@@ -375,6 +383,7 @@ static const struct agp_bridge_driver amd_irongate_driver = {
         .aperture_sizes         = amd_irongate_sizes,
         .size_type              = LVL2_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = amd_irongate_configure,
         .fetch_size             = amd_irongate_fetch_size,
         .cleanup                = amd_irongate_cleanup,
diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index fd50ead59c79..73703b115cd2 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -210,6 +210,7 @@ static const struct agp_bridge_driver amd_8151_driver = {
         .aperture_sizes         = amd_8151_sizes,
         .size_type              = U32_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = amd_8151_configure,
         .fetch_size             = amd64_fetch_size,
         .cleanup                = amd64_cleanup,
diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c
index 3b2ecbe86ebe..dc30e2243494 100644
--- a/drivers/char/agp/ati-agp.c
+++ b/drivers/char/agp/ati-agp.c
@@ -341,6 +341,7 @@ static int ati_create_gatt_table(struct agp_bridge_data *bridge)
 {
         struct aper_size_info_lvl2 *value;
         struct ati_page_map page_dir;
+        unsigned long __iomem *cur_gatt;
         unsigned long addr;
         int retval;
         u32 temp;
@@ -395,6 +396,12 @@ static int ati_create_gatt_table(struct agp_bridge_data *bridge)
                 readl(page_dir.remapped+GET_PAGE_DIR_OFF(addr));        /* PCI Posting. */
         }
 
+        for (i = 0; i < value->num_entries; i++) {
+                addr = (i * PAGE_SIZE) + agp_bridge->gart_bus_addr;
+                cur_gatt = GET_GATT(addr);
+                writel(agp_bridge->scratch_page, cur_gatt+GET_GATT_OFF(addr));
+        }
+
         return 0;
 }
 
@@ -415,6 +422,7 @@ static const struct agp_bridge_driver ati_generic_bridge = {
         .aperture_sizes         = ati_generic_sizes,
         .size_type              = LVL2_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = ati_configure,
         .fetch_size             = ati_fetch_size,
         .cleanup                = ati_cleanup,
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 034644eeedf2..d836a71bf06d 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -464,6 +464,7 @@ static const struct agp_bridge_driver intel_generic_driver = {
         .aperture_sizes         = intel_generic_sizes,
         .size_type              = U16_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_configure,
         .fetch_size             = intel_fetch_size,
         .cleanup                = intel_cleanup,
@@ -490,6 +491,7 @@ static const struct agp_bridge_driver intel_815_driver = {
         .aperture_sizes         = intel_815_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 2,
+        .needs_scratch_page     = true,
         .configure              = intel_815_configure,
         .fetch_size             = intel_815_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -516,6 +518,7 @@ static const struct agp_bridge_driver intel_820_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_820_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_820_cleanup,
@@ -542,6 +545,7 @@ static const struct agp_bridge_driver intel_830mp_driver = {
         .aperture_sizes         = intel_830mp_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 4,
+        .needs_scratch_page     = true,
         .configure              = intel_830mp_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -568,6 +572,7 @@ static const struct agp_bridge_driver intel_840_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_840_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -594,6 +599,7 @@ static const struct agp_bridge_driver intel_845_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_845_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -620,6 +626,7 @@ static const struct agp_bridge_driver intel_850_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_850_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -646,6 +653,7 @@ static const struct agp_bridge_driver intel_860_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_860_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
@@ -672,6 +680,7 @@ static const struct agp_bridge_driver intel_7505_driver = {
         .aperture_sizes         = intel_8xx_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = intel_7505_configure,
         .fetch_size             = intel_8xx_fetch_size,
         .cleanup                = intel_8xx_cleanup,
diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c
index 10f24e349a26..b9734a978186 100644
--- a/drivers/char/agp/nvidia-agp.c
+++ b/drivers/char/agp/nvidia-agp.c
@@ -310,6 +310,7 @@ static const struct agp_bridge_driver nvidia_driver = {
         .aperture_sizes         = nvidia_generic_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 5,
+        .needs_scratch_page     = true,
         .configure              = nvidia_configure,
         .fetch_size             = nvidia_fetch_size,
         .cleanup                = nvidia_cleanup,
diff --git a/drivers/char/agp/sis-agp.c b/drivers/char/agp/sis-agp.c
index 6c3837a0184d..b53d5f4e9cb2 100644
--- a/drivers/char/agp/sis-agp.c
+++ b/drivers/char/agp/sis-agp.c
@@ -125,6 +125,7 @@ static struct agp_bridge_driver sis_driver = {
         .aperture_sizes         = sis_generic_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 7,
+        .needs_scratch_page     = true,
         .configure              = sis_configure,
         .fetch_size             = sis_fetch_size,
         .cleanup                = sis_cleanup,
diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c
index 6f48931ac1ce..95db71360d24 100644
--- a/drivers/char/agp/uninorth-agp.c
+++ b/drivers/char/agp/uninorth-agp.c
@@ -28,6 +28,7 @@
  */
 static int uninorth_rev;
 static int is_u3;
+static u32 scratch_value;
 
 #define DEFAULT_APERTURE_SIZE 256
 #define DEFAULT_APERTURE_STRING "256"
@@ -172,7 +173,7 @@ static int uninorth_insert_memory(struct agp_memory *mem, off_t pg_start, int ty
 
         gp = (u32 *) &agp_bridge->gatt_table[pg_start];
         for (i = 0; i < mem->page_count; ++i) {
-                if (gp[i]) {
+                if (gp[i] != scratch_value) {
                         dev_info(&agp_bridge->dev->dev,
                                  "uninorth_insert_memory: entry 0x%x occupied (%x)\n",
                                  i, gp[i]);
@@ -214,8 +215,9 @@ int uninorth_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
                 return 0;
 
         gp = (u32 *) &agp_bridge->gatt_table[pg_start];
-        for (i = 0; i < mem->page_count; ++i)
-                gp[i] = 0;
+        for (i = 0; i < mem->page_count; ++i) {
+                gp[i] = scratch_value;
+        }
         mb();
         uninorth_tlbflush(mem);
 
@@ -421,8 +423,13 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 
         bridge->gatt_bus_addr = virt_to_phys(table);
 
+        if (is_u3)
+                scratch_value = (page_to_phys(agp_bridge->scratch_page_page) >> PAGE_SHIFT) | 0x80000000UL;
+        else
+                scratch_value = cpu_to_le32((page_to_phys(agp_bridge->scratch_page_page) & 0xFFFFF000UL) |
+                                0x1UL);
         for (i = 0; i < num_entries; i++)
-                bridge->gatt_table[i] = 0;
+                bridge->gatt_table[i] = scratch_value;
 
         return 0;
 
@@ -519,6 +526,7 @@ const struct agp_bridge_driver uninorth_agp_driver = {
         .agp_destroy_pages      = agp_generic_destroy_pages,
         .agp_type_to_mask_type  = agp_generic_type_to_mask_type,
         .cant_use_aperture      = true,
+        .needs_scratch_page     = true,
 };
 
 const struct agp_bridge_driver u3_agp_driver = {
diff --git a/drivers/char/agp/via-agp.c b/drivers/char/agp/via-agp.c
index d3bd243867fc..df67e80019d2 100644
--- a/drivers/char/agp/via-agp.c
+++ b/drivers/char/agp/via-agp.c
@@ -175,6 +175,7 @@ static const struct agp_bridge_driver via_agp3_driver = {
         .aperture_sizes         = agp3_generic_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 10,
+        .needs_scratch_page     = true,
         .configure              = via_configure_agp3,
         .fetch_size             = via_fetch_size_agp3,
         .cleanup                = via_cleanup_agp3,
@@ -201,6 +202,7 @@ static const struct agp_bridge_driver via_driver = {
         .aperture_sizes         = via_generic_sizes,
         .size_type              = U8_APER_SIZE,
         .num_aperture_sizes     = 9,
+        .needs_scratch_page     = true,
         .configure              = via_configure,
         .fetch_size             = via_fetch_size,
         .cleanup                = via_cleanup,