Commit 56b206bc authored by Lucas De Marchi's avatar Lucas De Marchi
Browse files

drm/i915/dmc: extract fw_info and table walk from intel_package_header 



Move fw_info out of struct intel_package_header to allow it to grow more
easily in future. To make a cleaner move, let's also extract a function to
search the header for the dmc_offset.

While reviewing this code I wondered why we continued the search even
after finding a suitable firmware. Add a comment to explain we will
continue to try to find a more specific firmware version, even if this
is not required by the spec.

Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: default avatarAnusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190607091230.1489-3-lucas.demarchi@intel.com
parent 8a6f9d5c

drivers/gpu/drm/i915/intel_csr.c

+55 −17
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ MODULE_FIRMWARE(SKL_CSR_PATH); 
MODULE_FIRMWARE(BXT_CSR_PATH);



#define CSR_DEFAULT_FW_OFFSET		0xFFFFFFFF

#define PACKAGE_MAX_FW_INFO_ENTRIES	20



struct intel_css_header {

	/* 0x09 for DMC */
@@ -139,8 +140,6 @@ struct intel_package_header { 


	/* Number of valid entries in the FWInfo array below */

	u32 num_entries;



	struct intel_fw_info fw_info[20];

} __packed;



struct intel_dmc_header {
@@ -292,6 +291,46 @@ void intel_csr_load_program(struct drm_i915_private *dev_priv) 
	gen9_set_dc_state_debugmask(dev_priv);

}



/*

 * Search fw_info table for dmc_offset to find firmware binary: num_entries is

 * already sanitized.

 */

static u32 find_dmc_fw_offset(const struct intel_fw_info *fw_info,

			      unsigned int num_entries,

			      const struct stepping_info *si)

{

	u32 dmc_offset = CSR_DEFAULT_FW_OFFSET;

	unsigned int i;



	for (i = 0; i < num_entries; i++) {

		if (fw_info[i].substepping == '*' &&

		    si->stepping == fw_info[i].stepping) {

			dmc_offset = fw_info[i].offset;

			break;

		}



		if (si->stepping == fw_info[i].stepping &&

		    si->substepping == fw_info[i].substepping) {

			dmc_offset = fw_info[i].offset;

			break;

		}



		if (fw_info[i].stepping == '*' &&

		    fw_info[i].substepping == '*') {

			/*

			 * In theory we should stop the search as generic

			 * entries should always come after the more specific

			 * ones, but let's continue to make sure to work even

			 * with "broken" firmwares. If we don't find a more

			 * specific one, then we use this entry

			 */

			dmc_offset = fw_info[i].offset;

		}

	}



	return dmc_offset;

}



static u32 *parse_csr_fw(struct drm_i915_private *dev_priv,

			 const struct firmware *fw)

{
@@ -300,7 +339,7 @@ static u32 *parse_csr_fw(struct drm_i915_private *dev_priv, 
	struct intel_dmc_header *dmc_header;

	struct intel_csr *csr = &dev_priv->csr;

	const struct stepping_info *si = intel_get_stepping_info(dev_priv);

	u32 dmc_offset = CSR_DEFAULT_FW_OFFSET, readcount = 0, nbytes;

	u32 dmc_offset, num_entries, readcount = 0, nbytes;

	u32 i;

	u32 *dmc_payload;

	size_t fsize;
@@ -349,27 +388,26 @@ static u32 *parse_csr_fw(struct drm_i915_private *dev_priv, 
			  (package_header->header_len * 4));

		return NULL;

	}



	readcount += sizeof(struct intel_package_header);

	num_entries = package_header->num_entries;

	if (WARN_ON(package_header->num_entries > PACKAGE_MAX_FW_INFO_ENTRIES))

		num_entries = PACKAGE_MAX_FW_INFO_ENTRIES;



	/* Search for dmc_offset to find firware binary. */

	for (i = 0; i < package_header->num_entries; i++) {

		if (package_header->fw_info[i].substepping == '*' &&

		    si->stepping == package_header->fw_info[i].stepping) {

			dmc_offset = package_header->fw_info[i].offset;

			break;

		} else if (si->stepping == package_header->fw_info[i].stepping &&

			   si->substepping == package_header->fw_info[i].substepping) {

			dmc_offset = package_header->fw_info[i].offset;

			break;

		} else if (package_header->fw_info[i].stepping == '*' &&

			   package_header->fw_info[i].substepping == '*')

			dmc_offset = package_header->fw_info[i].offset;

	}

	fsize += PACKAGE_MAX_FW_INFO_ENTRIES * sizeof(struct intel_fw_info);

	if (fsize > fw->size)

		goto error_truncated;



	dmc_offset = find_dmc_fw_offset((struct intel_fw_info *)

					&fw->data[readcount], num_entries, si);

	if (dmc_offset == CSR_DEFAULT_FW_OFFSET) {

		DRM_ERROR("DMC firmware not supported for %c stepping\n",

			  si->stepping);

		return NULL;

	}

	/* we always have space for PACKAGE_MAX_FW_INFO_ENTRIES */

	readcount += PACKAGE_MAX_FW_INFO_ENTRIES * sizeof(struct intel_fw_info);



	/* Convert dmc_offset into number of bytes. By default it is in dwords*/

	dmc_offset *= 4;

	readcount += dmc_offset;

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