[Intel-gfx] [RFC PATCH 120/162] drm/i915/oprom: Basic sanitization
Matthew Auld
matthew.auld at intel.com
Fri Nov 27 12:06:36 UTC 2020
From: Anshuman Gupta <anshuman.gupta at intel.com>
Sanitize OPROM header, CPD signature and OPROM PCI version.
OPROM_HEADER, EXPANSION_ROM_HEADER and OPROM_MEU_BLOB structures
and PCI struct offsets are provided by GSC counterparts.
These are yet to be Documented in B.Spec.
After successful sanitization, extract VBT from opregion
image.
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Uma Shankar <uma.shankar at intel.com>
Cc: Uma Shankar <uma.shankar at intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
drivers/gpu/drm/i915/display/intel_bios.c | 49 +++--
drivers/gpu/drm/i915/display/intel_opregion.c | 169 ++++++++++++++++++
drivers/gpu/drm/i915/display/intel_opregion.h | 31 +++-
3 files changed, 221 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 91044fc52acb..358576bc0be2 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -2088,37 +2088,36 @@ bool intel_bios_is_valid_vbt(const void *buf, size_t size)
static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *dev_priv)
{
- u32 count, data, found, store = 0;
- u32 static_region, oprom_offset;
- u32 oprom_size = 0x200000;
- u16 vbt_size;
- u32 *vbt;
-
- static_region = I915_READ(SPI_STATIC_REGIONS);
- static_region &= OPTIONROM_SPI_REGIONID_MASK;
- I915_WRITE(PRIMARY_SPI_REGIONID, static_region);
+ u32 count, found;
+ u32 *vbt, *oprom_opreg = NULL;
+ u16 vbt_size, opreg_size;
+ u8 *parse_ptr;
- oprom_offset = I915_READ(OROM_OFFSET);
- oprom_offset &= OROM_OFFSET_MASK;
+ if (intel_oprom_verify_signature(&oprom_opreg, &opreg_size, dev_priv)) {
+ drm_err(&dev_priv->drm, "oprom signature verification failed\n");
+ goto err_not_found;
+ }
- for (count = 0; count < oprom_size; count += 4) {
- I915_WRITE(PRIMARY_SPI_ADDRESS, oprom_offset + count);
- data = I915_READ(PRIMARY_SPI_TRIGGER);
+ if (!oprom_opreg) {
+ drm_err(&dev_priv->drm, "opregion not found\n");
+ goto err_not_found;
+ }
- if (data == *((const u32 *)"$VBT")) {
- found = oprom_offset + count;
+ for (count = 0; count < opreg_size; count += 4) {
+ if (oprom_opreg[count / 4] == *((const u32 *)"$VBT")) {
+ found = count;
break;
}
}
- if (count >= oprom_size)
+ if (count >= opreg_size) {
+ drm_err(&dev_priv->drm, "VBT not found in opregion\n");
goto err_not_found;
+ }
/* Get VBT size and allocate space for the VBT */
- I915_WRITE(PRIMARY_SPI_ADDRESS, found +
- offsetof(struct vbt_header, vbt_size));
- vbt_size = I915_READ(PRIMARY_SPI_TRIGGER);
- vbt_size &= 0xffff;
+ parse_ptr = (u8 *)oprom_opreg + found;
+ vbt_size = ((struct vbt_header *)parse_ptr)->vbt_size;
vbt = kzalloc(vbt_size, GFP_KERNEL);
if (!vbt) {
@@ -2127,16 +2126,12 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *dev_priv)
goto err_not_found;
}
- for (count = 0; count < vbt_size; count += 4) {
- I915_WRITE(PRIMARY_SPI_ADDRESS, found + count);
- data = I915_READ(PRIMARY_SPI_TRIGGER);
- *(vbt + store++) = data;
- }
-
+ memcpy(vbt, parse_ptr, vbt_size);
if (!intel_bios_is_valid_vbt(vbt, vbt_size))
goto err_free_vbt;
DRM_DEBUG_KMS("Found valid VBT in SPI flash\n");
+ kfree(oprom_opreg);
return (struct vbt_header *)vbt;
diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
index 4f77cf849171..81e5946393dd 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.c
+++ b/drivers/gpu/drm/i915/display/intel_opregion.c
@@ -983,6 +983,175 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv)
return err;
}
+static int oprom_image_parse_helper(u8 *parse_ptr, u8 *last_img, u8 *code_type,
+ struct drm_i915_private *i915)
+{
+ u8 size_512_bytes;
+
+ if (((union oprom_header *)parse_ptr)->signature != OPROM_IMAGE_MAGIC) {
+ drm_err(&i915->drm, "Wrong OPROM header signature.\n");
+ return -EINVAL;
+ }
+
+ size_512_bytes = parse_ptr[((struct expansion_rom_header *)parse_ptr)->pcistructoffset + PCI_IMAGE_LENGTH_OFFSET];
+ *code_type = parse_ptr[((struct expansion_rom_header *)parse_ptr)->pcistructoffset + PCI_CODE_TYPE_OFFSET];
+ *last_img = parse_ptr[((struct expansion_rom_header *)parse_ptr)->pcistructoffset + PCI_LAST_IMAGE_INDICATOR_OFFSET];
+
+ return size_512_bytes;
+}
+
+static void spi_read_oprom_helper(size_t len, u32 offset, u32 *buf,
+ struct drm_i915_private *dev_priv)
+{
+ u32 count, data;
+
+ for (count = 0; count < len; count += 4) {
+ I915_WRITE(PRIMARY_SPI_ADDRESS, offset + count);
+ data = I915_READ(PRIMARY_SPI_TRIGGER);
+ buf[count / 4] = data;
+ }
+}
+
+/**
+ * + DASH+G OPROM IMAGE LAYOUT +
+ * +--------+-------+---------------------------+
+ * | Offset | Value | ROM Header Fields +-----> Image 1 (CSS)
+ * +--------------------------------------------+
+ * | 0h | 55h | ROM Signature Byte1 |
+ * | 1h | AAh | ROM Signature Byte2 |
+ * | 2h | xx | Reserved |
+ * | 18+19h| xx | Ptr to PCI DataStructure |
+ * +----------------+---------------------------+
+ * | PCI Data Structure |
+ * +--------------------------------------------+
+ * | . . . |
+ * | . . . |
+ * | 10 + xx + Image Length |
+ * | 14 + xx + Code Type |
+ * | 15 + xx + Last Image Indicator |
+ * | . . . |
+ * +--------------------------------------------+
+ * | MEU BLOB |
+ * +--------------------------------------------+
+ * | CPD Header |
+ * | CPD Entry |
+ * | Reserved |
+ * | SignedDataPart1 |
+ * | PublicKey |
+ * | RSA Signature |
+ * | SignedDataPart2 |
+ * | IFWI Metadata |
+ * +--------+-------+---------------------------+
+ * | . | . | . |
+ * | . | . | . |
+ * +--------------------------------------------+
+ * | Offset | Value | ROM Header Fields +-----> Image 2 (Config Data) (Offset: 0x800)
+ * +--------------------------------------------+
+ * | 0h | 55h | ROM Signature Byte1 |
+ * | 1h | AAh | ROM Signature Byte2 |
+ * | 2h | xx | Reserved |
+ * | 18+19h| xx | Ptr to PCI DataStructure |
+ * +----------------+---------------------------+
+ * | PCI Data Structure |
+ * +--------------------------------------------+
+ * | . . . |
+ * | . . . |
+ * | 10 + xx + Image Length |
+ * | 14 + xx + Code Type |
+ * | 15 + xx + Last Image Indicator |
+ * | . . . |
+ * | 1A + 3C + Ptr to Opregion Signature |
+ * | . . . |
+ * | . . . |
+ * | 83Ch + IntelGraphicsMem | <---+ Opregion Signature
+ * +--------+-----------------------------------+
+ *
+ * intel_oprom_verify_signature() verify OPROM signature.
+ * @opreg: pointer to opregion buffer output.
+ * @opreg_size: pointer to opregion size output.
+ * @dev_priv: i915 device.
+ */
+int
+intel_oprom_verify_signature(u32 **opreg, u16 *opreg_size,
+ struct drm_i915_private *dev_priv)
+{
+ u8 img_sig[sizeof(OPREGION_SIGNATURE)];
+ u8 code_type, last_img;
+ u32 static_region, offset;
+ u32 *oprom_img, *oprom_img_hdr;
+ u16 opreg_base, img_len;
+ u8 *parse_ptr;
+ int img_size;
+ int ret = -EINVAL;
+
+ /* initialize SPI to read the OPROM */
+ static_region = I915_READ(SPI_STATIC_REGIONS);
+ static_region &= OPTIONROM_SPI_REGIONID_MASK;
+ I915_WRITE(PRIMARY_SPI_REGIONID, static_region);
+ /* read OPROM offset in SPI flash */
+ offset = I915_READ(OROM_OFFSET);
+ offset &= OROM_OFFSET_MASK;
+
+ oprom_img_hdr = kzalloc(OPROM_INITIAL_READ_SIZE, GFP_KERNEL);
+ if (!oprom_img_hdr)
+ return -ENOMEM;
+
+ do {
+ spi_read_oprom_helper(OPROM_INITIAL_READ_SIZE, offset,
+ oprom_img_hdr, dev_priv);
+ img_size = oprom_image_parse_helper((u8 *)oprom_img_hdr, &last_img,
+ &code_type, dev_priv);
+ if (img_size <= 0) {
+ ret = -EINVAL;
+ goto err_free_hdr;
+ }
+
+ img_len = img_size * OPROM_BYTE_BOUNDARY;
+ oprom_img = kzalloc(img_len, GFP_KERNEL);
+ if (!oprom_img) {
+ ret = -ENOMEM;
+ goto err_free_hdr;
+ }
+
+ spi_read_oprom_helper(img_len, offset, oprom_img, dev_priv);
+ parse_ptr = (u8 *)oprom_img;
+ offset = offset + img_len;
+
+ /* opregion base offset */
+ opreg_base = ((struct expansion_rom_header *)parse_ptr)->opregion_base;
+ /* CPD or opreg signature is present at opregion_base offset */
+ memcpy(img_sig, parse_ptr + opreg_base, sizeof(OPREGION_SIGNATURE));
+
+ if (!memcmp(img_sig, OPREGION_SIGNATURE, sizeof(OPREGION_SIGNATURE) - 1)) {
+ *opreg = oprom_img;
+ *opreg_size = img_len;
+ drm_dbg_kms(&dev_priv->drm, "Found opregion image\n");
+ ret = 0;
+ break;
+ } else if (!memcmp(img_sig, CPD_SIGNATURE, NUM_CPD_BYTES)) {
+ if (code_type != OPROM_CSS_CODE_TYPE) {
+ drm_err(&dev_priv->drm, "Invalid OPROM\n");
+ ret = -EINVAL;
+ goto err_free_img;
+ }
+ drm_dbg_kms(&dev_priv->drm, "Found CSS image\n");
+ /* proceed here onwards for signature authentication */
+ kfree(oprom_img);
+ continue;
+ }
+
+ } while (last_img != LAST_IMG_INDICATOR);
+
+ return ret;
+
+err_free_img:
+ kfree(oprom_img);
+err_free_hdr:
+ kfree(oprom_img_hdr);
+
+ return ret;
+}
+
static int intel_use_opregion_panel_type_callback(const struct dmi_system_id *id)
{
DRM_INFO("Using panel type from OpRegion on %s\n", id->ident);
diff --git a/drivers/gpu/drm/i915/display/intel_opregion.h b/drivers/gpu/drm/i915/display/intel_opregion.h
index 4aa68ffbd30e..4e2eeadf101e 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.h
+++ b/drivers/gpu/drm/i915/display/intel_opregion.h
@@ -54,6 +54,34 @@ struct intel_opregion {
#define OPREGION_SIZE (8 * 1024)
+#define CPD_SIGNATURE "$CPD" /* CPD Signature */
+#define NUM_CPD_BYTES 4
+#define PCI_IMAGE_LENGTH_OFFSET 0x10
+#define PCI_CODE_TYPE_OFFSET 0x14
+#define PCI_LAST_IMAGE_INDICATOR_OFFSET 0x15
+#define LAST_IMG_INDICATOR 0x80
+#define OPROM_IMAGE_MAGIC 0xAA55 /* Little Endian */
+#define OPROM_CSS_CODE_TYPE 0xF0
+#define OPROM_BYTE_BOUNDARY 512 /* OPROM image sizes are indicated in 512 byte boundaries */
+#define OPROM_INITIAL_READ_SIZE 60 /* Read 60 bytes to compute the Img Len from PCI structure */
+
+union oprom_header {
+ u32 data;
+ struct {
+ u16 signature; /* Offset[0x0]: Header 0x55 0xAA */
+ u8 sizein512bytes;
+ u8 reserved;
+ };
+};
+
+struct expansion_rom_header {
+ union oprom_header header; /* Offset[0x0]: Oprom Header */
+ u16 vbiospostoffset; /* Offset[0x4]: pointer to VBIOS entry point */
+ u8 resvd[0x12];
+ u16 pcistructoffset; /* Offset[0x18]: Contains pointer PCI Data Structure */
+ u16 opregion_base; /* Offset[0x1A]: Offset to Opregion Base start */
+};
+
#ifdef CONFIG_ACPI
int intel_opregion_setup(struct drm_i915_private *dev_priv);
@@ -118,5 +146,6 @@ static inline int intel_opregion_get_panel_type(struct drm_i915_private *dev)
}
#endif /* CONFIG_ACPI */
-
+int intel_oprom_verify_signature(u32 **opreg, u16 *opreg_size,
+ struct drm_i915_private *i915);
#endif
--
2.26.2
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