drm/amdgpu: Refine the way to get atom bios

There are several ways to check out a ATOMBIOS. In previous codes, try
a new way to fetch out vbios/rom, until current vbios/rom is started with
0x55aa, then check if this vbios is ATOMBIOS. Now, try a new way to fetch
out vbios until all flags of ATOMBIOS are verified.

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
index f573a95..2602ea1 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
@@ -42,6 +42,51 @@
 #define AMD_IS_VALID_VBIOS(p) ((p)[0] == 0x55 && (p)[1] == 0xAA)
 #define AMD_VBIOS_LENGTH(p) ((p)[2] << 9)
 
+/* Check if current bios is an ATOM BIOS.
+ * Return true if it is ATOM BIOS. Otherwise, return false.
+ */
+static bool check_atom_bios(uint8_t *bios, size_t size)
+{
+       uint16_t tmp, bios_header_start;
+
+       if (!bios || size < 0x49) {
+               DRM_INFO("vbios mem is null or mem size is wrong\n");
+               return false;
+       }
+
+       if (!AMD_IS_VALID_VBIOS(bios)) {
+               DRM_INFO("BIOS signature incorrect %x %x\n", bios[0], bios[1]);
+               return false;
+       }
+
+       tmp = bios[0x18] | (bios[0x19] << 8);
+       if (bios[tmp + 0x14] != 0x0) {
+               DRM_INFO("Not an x86 BIOS ROM\n");
+               return false;
+       }
+
+       bios_header_start = bios[0x48] | (bios[0x49] << 8);
+       if (!bios_header_start) {
+               DRM_INFO("Can't locate bios header\n");
+               return false;
+       }
+
+       tmp = bios_header_start + 4;
+       if (size < tmp) {
+               DRM_INFO("BIOS header is broken\n");
+               return false;
+       }
+
+       if (!memcmp(bios + tmp, "ATOM", 4) ||
+           !memcmp(bios + tmp, "MOTA", 4)) {
+               DRM_DEBUG("ATOMBIOS detected\n");
+               return true;
+       }
+
+       return false;
+}
+
+
 /* If you boot an IGP board with a discrete card as the primary,
  * the IGP rom is not accessible via the rom bar as the IGP rom is
  * part of the system bios.  On boot, the system bios puts a
@@ -65,10 +110,6 @@ static bool igp_read_bios_from_vram(struct amdgpu_device *adev)
                return false;
        }
 
-       if (size == 0 || !AMD_IS_VALID_VBIOS(bios)) {
-               iounmap(bios);
-               return false;
-       }
        adev->bios = kmalloc(size, GFP_KERNEL);
        if (!adev->bios) {
                iounmap(bios);
@@ -77,12 +118,18 @@ static bool igp_read_bios_from_vram(struct amdgpu_device *adev)
        adev->bios_size = size;
        memcpy_fromio(adev->bios, bios, size);
        iounmap(bios);
+
+       if (!check_atom_bios(adev->bios, size)) {
+               kfree(adev->bios);
+               return false;
+       }
+
        return true;
 }
 
 bool amdgpu_read_bios(struct amdgpu_device *adev)
 {
-       uint8_t __iomem *bios, val[2];
+       uint8_t __iomem *bios;
        size_t size;
 
        adev->bios = NULL;
@@ -92,13 +139,6 @@ bool amdgpu_read_bios(struct amdgpu_device *adev)
                return false;
        }
 
-       val[0] = readb(&bios[0]);
-       val[1] = readb(&bios[1]);
-
-       if (size == 0 || !AMD_IS_VALID_VBIOS(val)) {
-               pci_unmap_rom(adev->pdev, bios);
-               return false;
-       }
        adev->bios = kzalloc(size, GFP_KERNEL);
        if (adev->bios == NULL) {
                pci_unmap_rom(adev->pdev, bios);
@@ -107,6 +147,12 @@ bool amdgpu_read_bios(struct amdgpu_device *adev)
        adev->bios_size = size;
        memcpy_fromio(adev->bios, bios, size);
        pci_unmap_rom(adev->pdev, bios);
+
+       if (!check_atom_bios(adev->bios, size)) {
+               kfree(adev->bios);
+               return false;
+       }
+
        return true;
 }
 
@@ -140,7 +186,14 @@ static bool amdgpu_read_bios_from_rom(struct amdgpu_device *adev)
        adev->bios_size = len;
 
        /* read complete BIOS */
-       return amdgpu_asic_read_bios_from_rom(adev, adev->bios, len);
+       amdgpu_asic_read_bios_from_rom(adev, adev->bios, len);
+
+       if (!check_atom_bios(adev->bios, len)) {
+               kfree(adev->bios);
+               return false;
+       }
+
+       return true;
 }
 
 static bool amdgpu_read_platform_bios(struct amdgpu_device *adev)
@@ -155,13 +208,17 @@ static bool amdgpu_read_platform_bios(struct amdgpu_device *adev)
                return false;
        }
 
-       if (size == 0 || !AMD_IS_VALID_VBIOS(bios)) {
+       adev->bios = kzalloc(size, GFP_KERNEL);
+       if (adev->bios == NULL)
                return false;
-       }
-       adev->bios = kmemdup(bios, size, GFP_KERNEL);
-       if (adev->bios == NULL) {
+
+       memcpy_fromio(adev->bios, bios, size);
+
+       if (!check_atom_bios(adev->bios, size)) {
+               kfree(adev->bios);
                return false;
        }
+
        adev->bios_size = size;
 
        return true;
@@ -273,7 +330,7 @@ static bool amdgpu_atrm_get_bios(struct amdgpu_device *adev)
                        break;
        }
 
-       if (i == 0 || !AMD_IS_VALID_VBIOS(adev->bios)) {
+       if (!check_atom_bios(adev->bios, size)) {
                kfree(adev->bios);
                return false;
        }
@@ -298,7 +355,6 @@ static bool amdgpu_read_disabled_bios(struct amdgpu_device *adev)
 #ifdef CONFIG_ACPI
 static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
 {
-       bool ret = false;
        struct acpi_table_header *hdr;
        acpi_size tbl_size;
        UEFI_ACPI_VFCT *vfct;
@@ -310,13 +366,13 @@ static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
        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;
+               return false;
        }
 
        vbios = (GOP_VBIOS_CONTENT *)((char *)hdr + vfct->VBIOSImageOffset);
@@ -331,20 +387,25 @@ static bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
            vhdr->VendorID != adev->pdev->vendor ||
            vhdr->DeviceID != adev->pdev->device) {
                DRM_INFO("ACPI VFCT table is not for this card\n");
-               goto out_unmap;
+               return false;
        }
 
        if (vfct->VBIOSImageOffset + sizeof(VFCT_IMAGE_HEADER) + vhdr->ImageLength > tbl_size) {
                DRM_ERROR("ACPI VFCT image truncated\n");
-               goto out_unmap;
+               return false;
        }
 
-       adev->bios = kmemdup(&vbios->VbiosContent, vhdr->ImageLength, GFP_KERNEL);
+       adev->bios = kmemdup(&vbios->VbiosContent,
+                               vhdr->ImageLength,
+                               GFP_KERNEL);
+
+       if (!check_atom_bios(adev->bios, vhdr->ImageLength)) {
+               kfree(adev->bios);
+               return false;
+       }
        adev->bios_size = vhdr->ImageLength;
-       ret = !!adev->bios;
 
-out_unmap:
-       return ret;
+       return true;
 }
 #else
 static inline bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
@@ -355,57 +416,27 @@ static inline bool amdgpu_acpi_vfct_bios(struct amdgpu_device *adev)
 
 bool amdgpu_get_bios(struct amdgpu_device *adev)
 {
-       bool r;
-       uint16_t tmp, bios_header_start;
+       if (amdgpu_atrm_get_bios(adev))
+               return true;
 
-       r = amdgpu_atrm_get_bios(adev);
-       if (!r)
-               r = amdgpu_acpi_vfct_bios(adev);
-       if (!r)
-               r = igp_read_bios_from_vram(adev);
-       if (!r)
-               r = amdgpu_read_bios(adev);
-       if (!r) {
-               r = amdgpu_read_bios_from_rom(adev);
-       }
-       if (!r) {
-               r = amdgpu_read_disabled_bios(adev);
-       }
-       if (!r) {
-               r = amdgpu_read_platform_bios(adev);
-       }
-       if (!r || adev->bios == NULL) {
-               DRM_ERROR("Unable to locate a BIOS ROM\n");
-               adev->bios = NULL;
-               return false;
-       }
-       if (!AMD_IS_VALID_VBIOS(adev->bios)) {
-               printk("BIOS signature incorrect %x %x\n", adev->bios[0], adev->bios[1]);
-               goto free_bios;
-       }
+       if (amdgpu_acpi_vfct_bios(adev))
+               return true;
 
-       tmp = RBIOS16(0x18);
-       if (RBIOS8(tmp + 0x14) != 0x0) {
-               DRM_INFO("Not an x86 BIOS ROM, not using.\n");
-               goto free_bios;
-       }
+       if (igp_read_bios_from_vram(adev))
+               return true;
 
-       bios_header_start = RBIOS16(0x48);
-       if (!bios_header_start) {
-               goto free_bios;
-       }
+       if (amdgpu_read_bios(adev))
+               return true;
 
-       /* Must be an ATOMBIOS */
-       tmp = bios_header_start + 4;
-       if (memcmp(adev->bios + tmp, "ATOM", 4) &&
-           memcmp(adev->bios + tmp, "MOTA", 4)) {
-               goto free_bios;
-       }
+       if (amdgpu_read_bios_from_rom(adev))
+               return true;
 
-       DRM_DEBUG("ATOMBIOS detected\n");
-       return true;
-free_bios:
-       kfree(adev->bios);
-       adev->bios = NULL;
+       if (amdgpu_read_disabled_bios(adev))
+               return true;
+
+       if (amdgpu_read_platform_bios(adev))
+               return true;
+
+       DRM_ERROR("Unable to locate a BIOS ROM\n");
        return false;
 }