drm/i915/dmc: extract function to parse package_header

Like parse_csr_fw_css() this parses the package_header from firmware and
saves the relevant fields in the csr struct. In this function we also
lookup the fw_info we are interested in.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190607091230.1489-6-lucas.demarchi@intel.com

diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
index 3cf2f2b..a0188f8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_csr.c
+++ b/drivers/gpu/drm/i915/intel_csr.c
@@ -332,6 +332,64 @@ static u32 find_dmc_fw_offset(const struct intel_fw_info *fw_info,
        return dmc_offset;
 }
 
+static u32
+parse_csr_fw_package(struct intel_csr *csr,
+                    const struct intel_package_header *package_header,
+                    const struct stepping_info *si,
+                    size_t rem_size)
+{
+       u32 package_size = sizeof(struct intel_package_header);
+       u32 num_entries, max_entries, dmc_offset;
+       const struct intel_fw_info *fw_info;
+
+       if (rem_size < package_size)
+               goto error_truncated;
+
+       if (package_header->header_ver == 1) {
+               max_entries = PACKAGE_MAX_FW_INFO_ENTRIES;
+       } else if (package_header->header_ver == 2) {
+               max_entries = PACKAGE_V2_MAX_FW_INFO_ENTRIES;
+       } else {
+               DRM_ERROR("DMC firmware has unknown header version %u\n",
+                         package_header->header_ver);
+               return 0;
+       }
+
+       /*
+        * We should always have space for max_entries,
+        * even if not all are used
+        */
+       package_size += max_entries * sizeof(struct intel_fw_info);
+       if (rem_size < package_size)
+               goto error_truncated;
+
+       if (package_header->header_len * 4 != package_size) {
+               DRM_ERROR("DMC firmware has wrong package header length "
+                         "(%u bytes)\n", package_size);
+               return 0;
+       }
+
+       num_entries = package_header->num_entries;
+       if (WARN_ON(package_header->num_entries > max_entries))
+               num_entries = max_entries;
+
+       fw_info = (const struct intel_fw_info *)
+               ((u8 *)package_header + sizeof(*package_header));
+       dmc_offset = find_dmc_fw_offset(fw_info, num_entries, si);
+       if (dmc_offset == CSR_DEFAULT_FW_OFFSET) {
+               DRM_ERROR("DMC firmware not supported for %c stepping\n",
+                         si->stepping);
+               return 0;
+       }
+
+       /* dmc_offset is in dwords */
+       return package_size + dmc_offset * 4;
+
+error_truncated:
+       DRM_ERROR("Truncated DMC firmware, refusing.\n");
+       return 0;
+}
+
 /* Return number of bytes parsed or 0 on error */
 static u32 parse_csr_fw_css(struct intel_csr *csr,
                            struct intel_css_header *css_header,
@@ -374,7 +432,7 @@ 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, num_entries, max_entries, readcount = 0, nbytes;
+       u32 readcount = 0, nbytes;
        u32 i, r;
        u32 *dmc_payload;
        size_t fsize;
@@ -389,59 +447,16 @@ static u32 *parse_csr_fw(struct drm_i915_private *dev_priv,
                return NULL;
 
        readcount += r;
-       fsize = readcount +
-               sizeof(struct intel_package_header) +
-               sizeof(struct intel_dmc_header);
-       if (fsize > fw->size)
-               goto error_truncated;
-
-       /* Extract Package Header information*/
-       package_header = (struct intel_package_header *)
-               &fw->data[readcount];
-
-       readcount += sizeof(struct intel_package_header);
-
-       if (package_header->header_ver == 1) {
-               max_entries = PACKAGE_MAX_FW_INFO_ENTRIES;
-       } else if (package_header->header_ver == 2) {
-               max_entries = PACKAGE_V2_MAX_FW_INFO_ENTRIES;
-       } else {
-               DRM_ERROR("DMC firmware has unknown header version %u\n",
-                         package_header->header_ver);
-               return NULL;
-       }
-
-       if (package_header->header_len * 4 !=
-           sizeof(struct intel_package_header) +
-           max_entries * sizeof(struct intel_fw_info)) {
-               DRM_ERROR("DMC firmware has wrong package header length "
-                         "(%u bytes)\n", package_header->header_len * 4);
-               return NULL;
-       }
-
-       num_entries = package_header->num_entries;
-       if (WARN_ON(package_header->num_entries > max_entries))
-               num_entries = max_entries;
-
-       fsize += max_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);
+       /* Extract Package Header information */
+       package_header = (struct intel_package_header *)&fw->data[readcount];
+       r = parse_csr_fw_package(csr, package_header, si, fw->size - readcount);
+       if (!r)
                return NULL;
-       }
 
-       /* we always have space for max_entries, even if not all are used */
-       readcount += max_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;
-       fsize += dmc_offset;
+       readcount += r;
+       fsize = readcount +
+               sizeof(struct intel_dmc_header);
        if (fsize > fw->size)
                goto error_truncated;