[PATCH 3/4] drm/amdgpu: Read IPMI data for product information

Luben Tuikov luben.tuikov at amd.com
Wed Nov 16 19:48:37 UTC 2022


Read and interpret IPMI data to get the product name, product model, and
product serial number.

Cc: Alex Deucher <Alexander.Deucher at amd.com>
Cc: Kent Russell <kent.russell at amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov at amd.com>
Tested-by: Kent Russell <kent.russell at amd.com>
---
 .../gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c    | 183 ++++++++----------
 1 file changed, 85 insertions(+), 98 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
index 9b2ff386b7c4f8..2c38ac7bc643d5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
@@ -94,39 +94,12 @@ static bool is_fru_eeprom_supported(struct amdgpu_device *adev, u32 *fru_addr)
 	}
 }
 
-static int amdgpu_fru_read_eeprom(struct amdgpu_device *adev, uint32_t addrptr,
-				  unsigned char *buf, size_t buf_size)
-{
-	int ret;
-	u8 size;
-
-	ret = amdgpu_eeprom_read(adev->pm.fru_eeprom_i2c_bus, addrptr, buf, 1);
-	if (ret < 1) {
-		DRM_WARN("FRU: Failed to get size field");
-		return ret;
-	}
-
-	/* The size returned by the i2c requires subtraction of 0xC0 since the
-	 * size apparently always reports as 0xC0+actual size.
-	 */
-	size = buf[0] & 0x3F;
-	size = min_t(size_t, size, buf_size);
-
-	ret = amdgpu_eeprom_read(adev->pm.fru_eeprom_i2c_bus, addrptr + 1,
-				 buf, size);
-	if (ret < 1) {
-		DRM_WARN("FRU: Failed to get data field");
-		return ret;
-	}
-
-	return size;
-}
-
 int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
 {
-	unsigned char buf[AMDGPU_PRODUCT_NAME_LEN];
-	u32 addrptr, fru_addr;
+	unsigned char buf[8], *pia;
+	u32 addr, fru_addr;
 	int size, len;
+	u8 csum;
 
 	if (!is_fru_eeprom_supported(adev, &fru_addr))
 		return 0;
@@ -137,88 +110,102 @@ int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
 		return -ENODEV;
 	}
 
-	/* There's a lot of repetition here. This is due to the FRU having
-	 * variable-length fields. To get the information, we have to find the
-	 * size of each field, and then keep reading along and reading along
-	 * until we get all of the data that we want. We use addrptr to track
-	 * the address as we go
-	 */
-
-	/* The first fields are all of size 1-byte, from 0-7 are offsets that
-	 * contain information that isn't useful to us.
-	 * Bytes 8-a are all 1-byte and refer to the size of the entire struct,
-	 * and the language field, so just start from 0xb, manufacturer size
-	 */
-	addrptr = fru_addr + 0xb;
-	size = amdgpu_fru_read_eeprom(adev, addrptr, buf, sizeof(buf));
-	if (size < 1) {
-		DRM_ERROR("Failed to read FRU Manufacturer, ret:%d", size);
-		return -EINVAL;
+	/* Read the IPMI Common header */
+	len = amdgpu_eeprom_read(adev->pm.fru_eeprom_i2c_bus, fru_addr, buf,
+				 sizeof(buf));
+	if (len != 8) {
+		DRM_ERROR("Couldn't read the IPMI Common Header: %d", len);
+		return len < 0 ? len : -EIO;
 	}
 
-	/* Increment the addrptr by the size of the field, and 1 due to the
-	 * size field being 1 byte. This pattern continues below.
-	 */
-	addrptr += size + 1;
-	size = amdgpu_fru_read_eeprom(adev, addrptr, buf, sizeof(buf));
-	if (size < 1) {
-		DRM_ERROR("Failed to read FRU product name, ret:%d", size);
-		return -EINVAL;
+	if (buf[0] != 1) {
+		DRM_ERROR("Bad IPMI Common Header version: 0x%02x", buf[0]);
+		return -EIO;
 	}
 
-	len = size;
-	if (len >= AMDGPU_PRODUCT_NAME_LEN) {
-		DRM_WARN("FRU Product Name is larger than %d characters. This is likely a mistake",
-				AMDGPU_PRODUCT_NAME_LEN);
-		len = AMDGPU_PRODUCT_NAME_LEN - 1;
-	}
-	memcpy(adev->product_name, buf, len);
-	adev->product_name[len] = '\0';
-
-	addrptr += size + 1;
-	size = amdgpu_fru_read_eeprom(adev, addrptr, buf, sizeof(buf));
-	if (size < 1) {
-		DRM_ERROR("Failed to read FRU product number, ret:%d", size);
-		return -EINVAL;
+	for (csum = 0; len > 0; len--)
+		csum += buf[len - 1];
+	if (csum) {
+		DRM_ERROR("Bad IPMI Common Header checksum: 0x%02x", csum);
+		return -EIO;
 	}
 
-	len = size;
-	/* Product number should only be 16 characters. Any more,
-	 * and something could be wrong. Cap it at 16 to be safe
-	 */
-	if (len >= sizeof(adev->product_number)) {
-		DRM_WARN("FRU Product Number is larger than 16 characters. This is likely a mistake");
-		len = sizeof(adev->product_number) - 1;
-	}
-	memcpy(adev->product_number, buf, len);
-	adev->product_number[len] = '\0';
+	/* Get the offset to the Product Info Area (PIA). */
+	addr = buf[4] * 8;
+	if (!addr)
+		return 0;
 
-	addrptr += size + 1;
-	size = amdgpu_fru_read_eeprom(adev, addrptr, buf, sizeof(buf));
+	/* Get the absolute address to the PIA. */
+	addr += fru_addr;
 
-	if (size < 1) {
-		DRM_ERROR("Failed to read FRU product version, ret:%d", size);
-		return -EINVAL;
+	/* Read the header of the PIA. */
+	len = amdgpu_eeprom_read(adev->pm.fru_eeprom_i2c_bus, addr, buf, 3);
+	if (len != 3) {
+		DRM_ERROR("Couldn't read the Product Info Area header: %d", len);
+		return len < 0 ? len : -EIO;
 	}
 
-	addrptr += size + 1;
-	size = amdgpu_fru_read_eeprom(adev, addrptr, buf, sizeof(buf));
+	if (buf[0] != 1) {
+		DRM_ERROR("Bad IPMI Product Info Area version: 0x%02x", buf[0]);
+		return -EIO;
+	}
 
-	if (size < 1) {
-		DRM_ERROR("Failed to read FRU serial number, ret:%d", size);
-		return -EINVAL;
+	size = buf[1] * 8;
+	pia = kzalloc(size, GFP_KERNEL);
+	if (!pia)
+		return -ENOMEM;
+
+	/* Read the whole PIA. */
+	len = amdgpu_eeprom_read(adev->pm.fru_eeprom_i2c_bus, addr, pia, size);
+	if (len != size) {
+		kfree(pia);
+		DRM_ERROR("Couldn't read the Product Info Area: %d", len);
+		return len < 0 ? len : -EIO;
 	}
 
-	len = size;
-	/* Serial number should only be 16 characters. Any more,
-	 * and something could be wrong. Cap it at 16 to be safe
-	 */
-	if (len >= sizeof(adev->serial)) {
-		DRM_WARN("FRU Serial Number is larger than 16 characters. This is likely a mistake");
-		len = sizeof(adev->serial) - 1;
+	for (csum = 0; size > 0; size--)
+		csum += pia[size - 1];
+	if (csum) {
+		DRM_ERROR("Bad Product Info Area checksum: 0x%02x", csum);
+		return -EIO;
 	}
-	memcpy(adev->serial, buf, len);
-	adev->serial[len] = '\0';
 
+	/* Now extract useful information from the PIA.
+	 *
+	 * Skip the Manufacturer Name at [3] and go directly to
+	 * the Product Name field.
+	 */
+	addr = 3 + 1 + (pia[3] & 0x3F);
+	if (addr + 1 >= len)
+		goto Out;
+	memcpy(adev->product_name, pia + addr + 1,
+	       min_t(size_t,
+		     sizeof(adev->product_name),
+		     pia[addr] & 0x3F));
+	adev->product_name[sizeof(adev->product_name) - 1] = '\0';
+
+	/* Go to the Product Part/Model Number field. */
+	addr += 1 + (pia[addr] & 0x3F);
+	if (addr + 1 >= len)
+		goto Out;
+	memcpy(adev->product_number, pia + addr + 1,
+	       min_t(size_t,
+		     sizeof(adev->product_number),
+		     pia[addr] & 0x3F));
+	adev->product_number[sizeof(adev->product_number) - 1] = '\0';
+
+	/* Go to the Product Version field. */
+	addr += 1 + (pia[addr] & 0x3F);
+
+	/* Go to the Product Serial Number field. */
+	addr += 1 + (pia[addr] & 0x3F);
+	if (addr + 1 >= len)
+		goto Out;
+	memcpy(adev->serial, pia + addr + 1, min_t(size_t,
+						   sizeof(adev->serial),
+						   pia[addr] & 0x3F));
+	adev->serial[sizeof(adev->serial) - 1] = '\0';
+Out:
+	kfree(pia);
 	return 0;
 }
-- 
2.38.1



More information about the amd-gfx mailing list