drm/radeon: handle vfct with multiple vbios images

[ Upstream commit a882f5de ]

The vfct table can contain multiple vbios images if the
platform contains multiple GPUs. Noticed by netkas on
phoronix forums.  This patch fixes those platforms.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

drivers/gpu/drm/radeon/radeon_bios.c

@@ -597,51 +597,57 @@ static bool radeon_read_disabled_bios(struct radeon_device *rdev)
 #ifdef CONFIG_ACPI
 static bool radeon_acpi_vfct_bios(struct radeon_device *rdev)
 {
-	bool ret = false;
 	struct acpi_table_header *hdr;
 	acpi_size tbl_size;
 	UEFI_ACPI_VFCT *vfct;
-	GOP_VBIOS_CONTENT *vbios;
-	VFCT_IMAGE_HEADER *vhdr;
+	unsigned offset;
 
 	if (!ACPI_SUCCESS(acpi_get_table_with_size("VFCT", 1, &hdr, &tbl_size)))
 		return false;
 	if (tbl_size < sizeof(UEFI_ACPI_VFCT)) {
 		DRM_ERROR("ACPI VFCT table present but broken (too short #1)\n");
-		goto out_unmap;
+		return false;
 	}
 
 	vfct = (UEFI_ACPI_VFCT *)hdr;
-	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) > tbl_size) {
-		DRM_ERROR("ACPI VFCT table present but broken (too short #2)\n");
-		goto out_unmap;
-	}
+	offset = vfct->VBIOSImageOffset;
 
-	vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + vfct->VBIOSImageOffset);
-	vhdr = &vbios->VbiosHeader;
-	DRM_INFO("ACPI VFCT contains a BIOS for %02x:%02x.%d %04x:%04x, size %d\n",
-			vhdr->PCIBus, vhdr->PCIDevice, vhdr->PCIFunction,
-			vhdr->VendorID, vhdr->DeviceID, vhdr->ImageLength);
+	while (offset < tbl_size) {
+		GOP_VBIOS_CONTENT *vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + offset);
+		VFCT_IMAGE_HEADER *vhdr = &vbios->VbiosHeader;
 
-	if (vhdr->PCIBus != rdev->pdev->bus->number ||
-	    vhdr->PCIDevice != PCI_SLOT(rdev->pdev->devfn) ||
-	    vhdr->PCIFunction != PCI_FUNC(rdev->pdev->devfn) ||
-	    vhdr->VendorID != rdev->pdev->vendor ||
-	    vhdr->DeviceID != rdev->pdev->device) {
-		DRM_INFO("ACPI VFCT table is not for this card\n");
-		goto out_unmap;
+		offset += sizeof(VFCT_IMAGE_HEADER);
+		if (offset > tbl_size) {
+			DRM_ERROR("ACPI VFCT image header truncated\n");
+			return false;
 		}
 
-	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) + vhdr->ImageLength > tbl_size) {
+		offset += vhdr->ImageLength;
+		if (offset > tbl_size) {
 			DRM_ERROR("ACPI VFCT image truncated\n");
-		goto out_unmap;
+			return false;
 		}
 
-	rdev->bios = kmemdup(&vbios->VbiosContent, vhdr->ImageLength, GFP_KERNEL);
-	ret = !!rdev->bios;
+		if (vhdr->ImageLength &&
+		    vhdr->PCIBus == rdev->pdev->bus->number &&
+		    vhdr->PCIDevice == PCI_SLOT(rdev->pdev->devfn) &&
+		    vhdr->PCIFunction == PCI_FUNC(rdev->pdev->devfn) &&
+		    vhdr->VendorID == rdev->pdev->vendor &&
+		    vhdr->DeviceID == rdev->pdev->device) {
+			rdev->bios = kmemdup(&vbios->VbiosContent,
+					     vhdr->ImageLength,
+					     GFP_KERNEL);
 
-out_unmap:
-	return ret;
+			if (!rdev->bios) {
+				kfree(rdev->bios);
+				return false;
+			}
+			return true;
+		}
+	}
+
+	DRM_ERROR("ACPI VFCT table present but broken (too short #2)\n");
+	return false;
 }
 #else
 static inline bool radeon_acpi_vfct_bios(struct radeon_device *rdev)