diff mbox series

[v4,5/6] drm/i915/dgfx: OPROM OpRegion Setup

Message ID 20220418105408.13444-6-anshuman.gupta@intel.com (mailing list archive)
State New, archived
Headers show
Series DGFX OpRegion | expand

Commit Message

Gupta, Anshuman April 18, 2022, 10:54 a.m. UTC 
On igfx cards ACPI OpRegion retrieve through ASLS.
System BIOS writes ASLS address to pci config space(0xFC) but
on discrete cards OpRegion is part of PCI Option ROM(OPROM) along
with other firmware images, i915 is interested only in
Code Signature System(CSS) and OpRegion + VBT image.

DGFX Cards has it dedicated flash, where OPROM reside.
DGFX card provides SPI controller interface to read the OPROM.
Read OPROM through SPI MMIO because PCI ROM mapping may does not
work on some platforms due to the BIOS not leaving the OPROM mapped.

In order to setup OpRegion and retrieve VBT from OpRegion,
it is required to do OPROM sanity check.

OPROM Sanity checks involves below steps.

Verify OPROM images Signature as Documented in PCI firmware Specs 3.2.
Verify Intel CSS image signature.
Verify the Intel CSS image code type.
Authenticate OPROM RSA Signature. (TODO)
Verify OpRegion image Signature.

After successful sanity check, driver will consume the OPROM
config data to get opreg and vbt accordingly.

v2:
- Add kzalloc NULL check for oprom_opreg pointer.
- Fixed memory leak in intel_spi_get_oprom_opreg().
v3:
- Added kmemdup insead of kzalloc() + memcpy() in
  intel_dgfx_alloc_opregion(), and added necessary
  credit to Manasi.
v4:
- Fix free_{opregion, rvda} abstraction level. [Jani]

PCI Firmware Spec: ID:12886
https://pcisig.com/specifications

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Badal Nilawar <badal.nilawar@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
---
 drivers/gpu/drm/i915/display/intel_opregion.c | 332 +++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_opregion.h |   1 +
 2 files changed, 320 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
index 8e5960ec30de..18770e564044 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.c
+++ b/drivers/gpu/drm/i915/display/intel_opregion.c
@@ -31,6 +31,7 @@ 
 #include <acpi/video.h>
 
 #include "i915_drv.h"
+#include "i915_reg.h"
 #include "intel_acpi.h"
 #include "intel_backlight.h"
 #include "intel_display_types.h"
@@ -145,6 +146,34 @@  struct i915_opregion_func {
 	void (*free_opregion)(struct drm_i915_private *i915, void *opregion);
 };
 
+/* Refer 8_PCI_Firmware_v3.2_01-26-2015_ts_clean_Firmware_Final Page 77 */
+struct expansion_rom_header {
+	u16 signature;		/* Offset[0x0]: Header 0x55 0xAA */
+	u8 resvd[0x16];
+	u16 pcistructoffset;	/* Offset[0x18]: Contains pointer PCI Data Structure */
+	u16 img_base;		/* Offset[0x1A]: Offset to Oprom Image Base start */
+} __packed;
+
+struct pci_data_structure {
+	u32 signature;
+	u8 resvd[12];
+	u16 img_len;
+	u8 resvd1[2];
+	u8 code_type;
+	u8 last_img;
+	u8 resvd2[6];
+} __packed;
+
+/* PCI Firmware Spec specific Macro */
+#define LAST_IMG_INDICATOR		0x80
+#define OPROM_IMAGE_MAGIC		0xAA55       /* Little Endian */
+#define OPROM_IMAGE_PCIR_MAGIC		0x52494350   /* "PCIR" */
+#define OPROM_BYTE_BOUNDARY		512          /* OPROM image sizes are in 512 byte */
+
+#define INTEL_CSS_SIGNATURE		"$CPD"	/* Code Signature System Signature */
+#define NUM_CSS_BYTES			4
+#define INTEL_OPROM_CSS_CODE_TYPE	0xF0
+
 /* Driver readiness indicator */
 #define ASLE_ARDY_READY		(1 << 0)
 #define ASLE_ARDY_NOT_READY	(0 << 0)
@@ -880,6 +909,196 @@  static int intel_load_vbt_firmware(struct drm_i915_private *dev_priv)
 	return ret;
 }
 
+/* Refer PCI Firmware Spec Chapter 5 */
+static int
+pci_exp_rom_check_signature(struct drm_i915_private *i915,
+			    struct expansion_rom_header *exprom_hdr,
+			    struct pci_data_structure *exprom_pci_data)
+{
+	if (exprom_hdr->signature != OPROM_IMAGE_MAGIC) {
+		drm_err(&i915->drm, "Invalid PCI ROM header signature.\n");
+		return -EINVAL;
+	}
+
+	if (exprom_pci_data->signature != OPROM_IMAGE_PCIR_MAGIC) {
+		drm_err(&i915->drm, "Invalid PCI ROM data signature.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static u32 intel_spi_oprom_offset(struct drm_i915_private *i915)
+{
+	u32 static_region, offset;
+
+	/* initialize SPI to read the OPROM */
+	static_region = intel_uncore_read(&i915->uncore, SPI_STATIC_REGIONS);
+	static_region &= OPTIONROM_SPI_REGIONID_MASK;
+	intel_uncore_write(&i915->uncore, PRIMARY_SPI_REGIONID, static_region);
+
+	/* read OPROM offset in SPI flash */
+	offset = intel_uncore_read(&i915->uncore, OROM_OFFSET);
+
+	return offset;
+}
+
+static void intel_spi_read_oprom(struct drm_i915_private *i915,
+				 u32 offset, size_t len, void *buf)
+{
+	u32 count, data;
+	u32 *word = buf;
+
+	drm_WARN_ON(&i915->drm, !IS_ALIGNED(len, 4));
+
+	for (count = 0; count < len; count += 4) {
+		intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, offset + count);
+		data = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
+		word[count >> 2] = data;
+	}
+}
+
+static int intel_verify_css(struct drm_i915_private *i915,
+			    struct expansion_rom_header *exprom_hdr,
+			    struct pci_data_structure *exprom_pci_data)
+{
+	if (exprom_pci_data->code_type != INTEL_OPROM_CSS_CODE_TYPE) {
+		drm_dbg_kms(&i915->drm, "Invalid OPROM CSS Code\n");
+		return -EINVAL;
+	}
+	drm_dbg_kms(&i915->drm, "Found CSS image\n");
+	/*
+	 * TODO: Authticate OPROM RSA Signature if required in future
+	 * pubic key and signature are present in CSS image.
+	 */
+
+	return 0;
+}
+
+/**
+ * intel_spi_get_oprom_opreg() get OPROM OpRegion image.
+ * @i915: pointer to i915 device.
+ *
+ * This function parses the DGFX OPROM to retieve the opregion.
+ * OPROM has bundled multiple images but i915 only interested
+ * in CSS and opregion image.
+ *
+ *	+        DGFX OPROM IMAGE LAYOUT             +
+ *	+--------+-------+---------------------------+
+ *	| Offset | Value |   ROM Header Fields       +-----> Image1 (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     |
+ *	|    .       .             .                 |
+ *	+--------------------------------------------+
+ *	|         Signature and Public Key           |
+ *	+--------+-------+---------------------------+
+ *	|    .   |   .   |         .                 |
+ *	|    .   |   .   |         .                 |
+ *	+--------------------------------------------+
+ *	| Offset | Value |   ROM Header Fields       +-----> Image2 (opregion, vbt) (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
+ *	+--------+-----------------------------------+
+ *
+ * Return : Returns the opregion image blob which starts from opregion
+ * signature "IntelGraphicsMem". Error value in case of error
+ */
+static void *
+intel_spi_get_oprom_opreg(struct drm_i915_private *i915)
+{
+	struct expansion_rom_header *exprom_hdr;
+	struct pci_data_structure *exprom_pci_data;
+	u8 img_sig[sizeof(OPREGION_SIGNATURE)];
+	u32 oprom_offset, offset;
+	size_t img_len, opreg_len;
+	void *opreg = ERR_PTR(-ENXIO);
+	int ret;
+
+	oprom_offset = intel_spi_oprom_offset(i915);
+
+	exprom_hdr = kzalloc(sizeof(struct expansion_rom_header), GFP_KERNEL);
+	exprom_pci_data = kzalloc(sizeof(struct pci_data_structure), GFP_KERNEL);
+	if (!exprom_hdr || !exprom_pci_data) {
+		opreg = ERR_PTR(-ENOMEM);
+		goto err_free_hdr;
+	}
+
+	for (offset = oprom_offset; exprom_pci_data->last_img != LAST_IMG_INDICATOR;
+	     offset = offset + img_len) {
+		intel_spi_read_oprom(i915, offset, sizeof(struct expansion_rom_header),
+				     exprom_hdr);
+		intel_spi_read_oprom(i915, offset + exprom_hdr->pcistructoffset,
+				     sizeof(struct pci_data_structure), exprom_pci_data);
+		ret = pci_exp_rom_check_signature(i915, exprom_hdr, exprom_pci_data);
+		if (ret) {
+			opreg = ERR_PTR(ret);
+			goto err_free_hdr;
+		}
+
+		img_len = exprom_pci_data->img_len * OPROM_BYTE_BOUNDARY;
+
+		/* CSS or OpReg signature is present at exprom_hdr->img_base offset */
+		intel_spi_read_oprom(i915, offset + exprom_hdr->img_base,
+				     sizeof(OPREGION_SIGNATURE) - 1, img_sig);
+
+		if (!memcmp(img_sig, INTEL_CSS_SIGNATURE, NUM_CSS_BYTES)) {
+			ret = intel_verify_css(i915, exprom_hdr, exprom_pci_data);
+			if (ret) {
+				opreg = ERR_PTR(ret);
+				goto err_free_hdr;
+			}
+		} else if (!memcmp(img_sig, OPREGION_SIGNATURE, sizeof(OPREGION_SIGNATURE) - 1)) {
+			opreg_len = img_len - exprom_hdr->img_base;
+			opreg_len = ALIGN(opreg_len, 4);
+			opreg = kzalloc(opreg_len, GFP_KERNEL);
+
+			if (!opreg) {
+				opreg = ERR_PTR(-ENOMEM);
+				goto err_free_hdr;
+			}
+
+			intel_spi_read_oprom(i915, offset + exprom_hdr->img_base,
+					     opreg_len, opreg);
+			drm_dbg_kms(&i915->drm, "Found opregion image of size %zu\n", opreg_len);
+			break;
+		}
+	}
+
+err_free_hdr:
+
+	kfree(exprom_pci_data);
+	kfree(exprom_hdr);
+
+	return opreg;
+}
+
 static int intel_opregion_setup(struct drm_i915_private *dev_priv)
 {
 	struct intel_opregion *opregion = &dev_priv->opregion;
@@ -1007,6 +1226,17 @@  static int intel_opregion_setup(struct drm_i915_private *dev_priv)
 	}
 
 out:
+	/*
+	 * We might got VBT from OPROM OpRegion but we can't use OPROM OpRegion
+	 * to write ACPI OpRegion MBOX.
+	 */
+	if (!opregion->asls) {
+		drm_dbg(&dev_priv->drm, "ACPI OpRegion MBOX is not supported!\n");
+		opregion->acpi = NULL;
+		opregion->swsci = NULL;
+		opregion->asle = NULL;
+	}
+
 	return 0;
 
 }
@@ -1224,10 +1454,24 @@  intel_opregion_get_asls(struct drm_i915_private *i915)
 	return asls;
 }
 
+static int
+intel_opregion_verify_signature(struct drm_i915_private *i915, const void *base)
+{
+	char buf[sizeof(OPREGION_SIGNATURE)];
+
+	memcpy(buf, base, sizeof(buf));
+
+	if (memcmp(buf, OPREGION_SIGNATURE, 16)) {
+		drm_dbg(&i915->drm, "opregion signature mismatch\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static void *intel_igfx_alloc_opregion(struct drm_i915_private *i915)
 {
 	struct intel_opregion *opregion = &i915->opregion;
-	char buf[sizeof(OPREGION_SIGNATURE)];
 	int err = 0;
 	void *base;
 	u32 asls;
@@ -1243,20 +1487,13 @@  static void *intel_igfx_alloc_opregion(struct drm_i915_private *i915)
 	if (!base)
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(buf, base, sizeof(buf));
-
-	if (memcmp(buf, OPREGION_SIGNATURE, 16)) {
-		drm_dbg(&i915->drm, "opregion signature mismatch\n");
-		err = -EINVAL;
-		goto err_out;
+	err = intel_opregion_verify_signature(i915, base);
+	if (err) {
+		memunmap(base);
+		return ERR_PTR(err);
 	}
 
 	return base;
-
-err_out:
-	memunmap(base);
-
-	return ERR_PTR(err);
 }
 
 static void *intel_igfx_alloc_rvda(struct drm_i915_private *i915)
@@ -1315,9 +1552,70 @@  static const struct i915_opregion_func igfx_opregion_func = {
 	.free_opregion = intel_igfx_free_opregion,
 };
 
+static void *intel_dgfx_setup_asls(struct drm_i915_private *i915)
+{
+	struct intel_opregion *opregion = &i915->opregion;
+	struct opregion_asle *asls_asle;
+	const struct opregion_asle *spi_asle;
+	void *base;
+	int ret;
+
+	if (!opregion->dgfx_oprom_opreg)
+		return ERR_PTR(-EINVAL);
+
+	spi_asle = opregion->dgfx_oprom_opreg + OPREGION_ASLE_OFFSET;
+
+	/*
+	 * DGFX MBD configs supports ASL storage.
+	 * Populate the RVDA and RVDS field from OPROM opregion.
+	 */
+	base = memremap(opregion->asls, OPREGION_SIZE, MEMREMAP_WB);
+	if (!base)
+		return ERR_PTR(-ENOMEM);
+
+	ret = intel_opregion_verify_signature(i915, base);
+	if (ret) {
+		memunmap(base);
+		return ERR_PTR(ret);
+	}
+
+	asls_asle = base + OPREGION_ASLE_OFFSET;
+	asls_asle->rvda = spi_asle->rvda;
+	asls_asle->rvds = spi_asle->rvds;
+
+	return base;
+}
+
 static void *intel_dgfx_alloc_opregion(struct drm_i915_private *i915)
 {
-	return ERR_PTR(-EOPNOTSUPP);
+	struct intel_opregion *opregion = &i915->opregion;
+	void *oprom_opreg;
+	void *asls_opreg;
+
+	BUILD_BUG_ON(sizeof(struct expansion_rom_header) != 28);
+	BUILD_BUG_ON(sizeof(struct pci_data_structure) != 28);
+
+	oprom_opreg = intel_spi_get_oprom_opreg(i915);
+
+	if (IS_ERR(oprom_opreg)) {
+		drm_err(&i915->drm, "Unable to get opregion image from dgfx oprom Err: %ld\n",
+			PTR_ERR(oprom_opreg));
+		return oprom_opreg;
+	}
+
+	/* Cache the OPROM opregion + vbt image to retrieve vbt later */
+	opregion->dgfx_oprom_opreg = oprom_opreg;
+
+	opregion->asls = intel_opregion_get_asls(i915);
+	if (opregion->asls) {
+		asls_opreg = intel_dgfx_setup_asls(i915);
+		if (!IS_ERR(asls_opreg))
+			return asls_opreg;
+	}
+
+	oprom_opreg = kmemdup(opregion->dgfx_oprom_opreg, OPREGION_SIZE, GFP_KERNEL);
+
+	return oprom_opreg ?: ERR_PTR(-ENOMEM);
 }
 
 static void *intel_dgfx_alloc_rvda(struct drm_i915_private *i915)
@@ -1331,6 +1629,14 @@  static void intel_dgfx_free_rvda(struct drm_i915_private *i915, void *rvda)
 
 static void intel_dgfx_free_opregion(struct drm_i915_private *i915, void *opreg)
 {
+	if (IS_ERR(opreg))
+		return;
+
+	if (opreg)
+		memunmap(opreg);
+	else
+		kfree(opreg);
+
 }
 
 static const struct i915_opregion_func dgfx_opregion_func = {
diff --git a/drivers/gpu/drm/i915/display/intel_opregion.h b/drivers/gpu/drm/i915/display/intel_opregion.h
index 7500c396b74d..65a9aa4fdb59 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.h
+++ b/drivers/gpu/drm/i915/display/intel_opregion.h
@@ -52,6 +52,7 @@  struct intel_opregion {
 	void *rvda;
 	void *vbt_firmware;
 	const void *vbt;
+	const void *dgfx_oprom_opreg;
 	u32 vbt_size;
 	u32 *lid_state;
 	struct work_struct asle_work;