From a882f5de402ded769af74fbf276132f9c175049c Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Wed, 25 Jan 2017 15:33:44 -0500
Subject: [PATCH] drm/radeon: handle vfct with multiple vbios images

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
---
 drivers/gpu/drm/radeon/radeon_bios.c | 70 +++++++++++++++-------------
 1 file changed, 38 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index c829cfb02fc4..00cfb5d2875f 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -596,52 +596,58 @@ 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("VFCT", 1, &hdr)))
 		return false;
 	tbl_size = hdr->length;
 	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;
+
+	while (offset < tbl_size) {
+		GOP_VBIOS_CONTENT *vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + offset);
+		VFCT_IMAGE_HEADER *vhdr = &vbios->VbiosHeader;
+
+		offset += sizeof(VFCT_IMAGE_HEADER);
+		if (offset > tbl_size) {
+			DRM_ERROR("ACPI VFCT image header truncated\n");
+			return false;
+		}
+
+		offset += vhdr->ImageLength;
+		if (offset > tbl_size) {
+			DRM_ERROR("ACPI VFCT image truncated\n");
+			return false;
+		}
+
+		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);
+
+			if (!rdev->bios) {
+				kfree(rdev->bios);
+				return false;
+			}
+			return true;
+		}
 	}
 
-	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);
-
-	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;
-	}
-
-	if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) + vhdr->ImageLength > tbl_size) {
-		DRM_ERROR("ACPI VFCT image truncated\n");
-		goto out_unmap;
-	}
-
-	rdev->bios = kmemdup(&vbios->VbiosContent, vhdr->ImageLength, GFP_KERNEL);
-	ret = !!rdev->bios;
-
-out_unmap:
-	return ret;
+	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)