diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 154648a2c0277910fc0bc247249485110a75880f..97c9229b9299ce0fb0c2bb2b3139af306a2cb376 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -1360,9 +1360,50 @@ static void r100_vram_get_type(struct radeon_device *rdev)
 	}
 }
 
-void r100_vram_info(struct radeon_device *rdev)
+static u32 r100_get_accessible_vram(struct radeon_device *rdev)
 {
-	r100_vram_get_type(rdev);
+	u32 aper_size;
+	u8 byte;
+
+	aper_size = RREG32(RADEON_CONFIG_APER_SIZE);
+
+	/* Set HDP_APER_CNTL only on cards that are known not to be broken,
+	 * that is has the 2nd generation multifunction PCI interface
+	 */
+	if (rdev->family == CHIP_RV280 ||
+	    rdev->family >= CHIP_RV350) {
+		WREG32_P(RADEON_HOST_PATH_CNTL, RADEON_HDP_APER_CNTL,
+		       ~RADEON_HDP_APER_CNTL);
+		DRM_INFO("Generation 2 PCI interface, using max accessible memory\n");
+		return aper_size * 2;
+	}
+
+	/* Older cards have all sorts of funny issues to deal with. First
+	 * check if it's a multifunction card by reading the PCI config
+	 * header type... Limit those to one aperture size
+	 */
+	pci_read_config_byte(rdev->pdev, 0xe, &byte);
+	if (byte & 0x80) {
+		DRM_INFO("Generation 1 PCI interface in multifunction mode\n");
+		DRM_INFO("Limiting VRAM to one aperture\n");
+		return aper_size;
+	}
+
+	/* Single function older card. We read HDP_APER_CNTL to see how the BIOS
+	 * have set it up. We don't write this as it's broken on some ASICs but
+	 * we expect the BIOS to have done the right thing (might be too optimistic...)
+	 */
+	if (RREG32(RADEON_HOST_PATH_CNTL) & RADEON_HDP_APER_CNTL)
+		return aper_size * 2;
+	return aper_size;
+}
+
+void r100_vram_init_sizes(struct radeon_device *rdev)
+{
+	u64 config_aper_size;
+	u32 accessible;
+
+	config_aper_size = RREG32(RADEON_CONFIG_APER_SIZE);
 
 	if (rdev->flags & RADEON_IS_IGP) {
 		uint32_t tom;
@@ -1383,10 +1424,30 @@ void r100_vram_info(struct radeon_device *rdev)
 		}
 		/* let driver place VRAM */
 		rdev->mc.vram_location = 0xFFFFFFFFUL;
+		 /* Fix for RN50, M6, M7 with 8/16/32(??) MBs of VRAM - 
+		  * Novell bug 204882 + along with lots of ubuntu ones */
+		if (config_aper_size > rdev->mc.vram_size)
+			rdev->mc.vram_size = config_aper_size;
 	}
 
+	/* work out accessible VRAM */
+	accessible = r100_get_accessible_vram(rdev);
+
 	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
 	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
+
+	if (accessible > rdev->mc.aper_size)
+		accessible = rdev->mc.aper_size;
+
+	if (rdev->mc.vram_size > rdev->mc.aper_size)
+		rdev->mc.vram_size = rdev->mc.aper_size;
+}
+
+void r100_vram_info(struct radeon_device *rdev)
+{
+	r100_vram_get_type(rdev);
+
+	r100_vram_init_sizes(rdev);
 }
 
 
diff --git a/drivers/gpu/drm/radeon/r300.c b/drivers/gpu/drm/radeon/r300.c
index 6435d659cbd13d1f86117d44f02e90f36874b996..0e0e094da50308b2c31f2501ff3a1e7dd9e0a28e 100644
--- a/drivers/gpu/drm/radeon/r300.c
+++ b/drivers/gpu/drm/radeon/r300.c
@@ -585,10 +585,8 @@ void r300_vram_info(struct radeon_device *rdev)
 	} else {
 		rdev->mc.vram_width = 64;
 	}
-	rdev->mc.vram_size = RREG32(RADEON_CONFIG_MEMSIZE);
 
-	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
-	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
+	r100_vram_init_sizes(rdev);
 }
 
 
diff --git a/drivers/gpu/drm/radeon/r520.c b/drivers/gpu/drm/radeon/r520.c
index 570a244bd88b6815725129def0a3d8280281a8ed..b6bd3758db6b871d90c0c84c7e057522869c209d 100644
--- a/drivers/gpu/drm/radeon/r520.c
+++ b/drivers/gpu/drm/radeon/r520.c
@@ -227,8 +227,6 @@ static void r520_vram_get_type(struct radeon_device *rdev)
 void r520_vram_info(struct radeon_device *rdev)
 {
 	r520_vram_get_type(rdev);
-	rdev->mc.vram_size = RREG32(RADEON_CONFIG_MEMSIZE);
 
-	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
-	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
+	r100_vram_init_sizes(rdev);
 }
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 3060ce14071e2c35e9da4bbf72a80f6f187a0e46..248e3341a984621f193fead3111473270afdfab8 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -541,6 +541,8 @@ union radeon_asic_config {
 	struct r300_asic	r300;
 };
 
+/* r100 */
+void r100_vram_init_sizes(struct radeon_device *rdev);
 
 /*
  * IOCTL.
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 27a5ac969953333714ee345387c7aa666c8ece04..cdef6eb01baf096adadea61915c6dfa60888d881 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -561,12 +561,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	}
 	/* Get vram informations */
 	radeon_vram_info(rdev);
-	/* Device is severly broken if aper size > vram size.
-	 * for RN50/M6/M7 - Novell bug 204882 ?
-	 */
-	if (rdev->mc.vram_size < rdev->mc.aper_size) {
-		rdev->mc.vram_size = rdev->mc.aper_size;
-	}
+
 	/* Add an MTRR for the VRAM */
 	rdev->mc.vram_mtrr = mtrr_add(rdev->mc.aper_base, rdev->mc.aper_size,
 				      MTRR_TYPE_WRCOMB, 1);
diff --git a/drivers/gpu/drm/radeon/rs400.c b/drivers/gpu/drm/radeon/rs400.c
index a18d053065c0877b732824e9f1a82b04bbd4d0c5..daf24e85cba30d571fbdc899d7fe77374fb60879 100644
--- a/drivers/gpu/drm/radeon/rs400.c
+++ b/drivers/gpu/drm/radeon/rs400.c
@@ -292,24 +292,12 @@ void rs400_gpu_init(struct radeon_device *rdev)
  */
 void rs400_vram_info(struct radeon_device *rdev)
 {
-	uint32_t tom;
-
 	rs400_gart_adjust_size(rdev);
 	/* DDR for all card after R300 & IGP */
 	rdev->mc.vram_is_ddr = true;
 	rdev->mc.vram_width = 128;
 
-	/* read NB_TOM to get the amount of ram stolen for the GPU */
-	tom = RREG32(RADEON_NB_TOM);
-	rdev->mc.vram_size = (((tom >> 16) - (tom & 0xffff) + 1) << 16);
-	WREG32(RADEON_CONFIG_MEMSIZE, rdev->mc.vram_size);
-
-	/* RS480 IGPs don't seem to translate to main RAM, they
-	 * just reserve and scan out of it. So setting VRAM location
-	 * to say 0, will actually trash the OS. */
-	rdev->mc.vram_location = (tom & 0xffff) << 16;
-	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
-	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
+	r100_vram_init_sizes(rdev);
 }
 
 
diff --git a/drivers/gpu/drm/radeon/rv515.c b/drivers/gpu/drm/radeon/rv515.c
index d1384d3991add87d3b7596c98534c1bb232e3370..677929ed8ed3648188cfff96e1132432f896818f 100644
--- a/drivers/gpu/drm/radeon/rv515.c
+++ b/drivers/gpu/drm/radeon/rv515.c
@@ -395,10 +395,8 @@ static void rv515_vram_get_type(struct radeon_device *rdev)
 void rv515_vram_info(struct radeon_device *rdev)
 {
 	rv515_vram_get_type(rdev);
-	rdev->mc.vram_size = RREG32(RADEON_CONFIG_MEMSIZE);
-
-	rdev->mc.aper_base = drm_get_resource_start(rdev->ddev, 0);
-	rdev->mc.aper_size = drm_get_resource_len(rdev->ddev, 0);
+	
+	r100_vram_init_sizes(rdev);
 }