[PATCH 3/3] soc: qcom: mdt_loader: Read hash from firmware blob

[Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>]

Since the split elf blobs will always contain the hash segment, we rely on
the blob file to get the hash rather than assume that it will be present in
the mdt file. This change uses the hash index to read the appropriate elf
blob to get the hash segment.

Signed-off-by: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
---
 drivers/remoteproc/qcom_q6v5_mss.c  |  4 ++--
 drivers/soc/qcom/mdt_loader.c       | 38 +++++++++++++++++++++++++++----------
 include/linux/soc/qcom/mdt_loader.h |  3 ++-
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index 66106ba..74c0229 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c
@@ -4,7 +4,7 @@
  *
  * Copyright (C) 2016 Linaro Ltd.
  * Copyright (C) 2014 Sony Mobile Communications AB
- * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2012-2013, 2020 The Linux Foundation. All rights reserved.
  */
 
 #include <linux/clk.h>
@@ -828,7 +828,7 @@ static int q6v5_mpss_init_image(struct q6v5 *qproc, const struct firmware *fw)
 	void *ptr;
 	int ret;
 
-	metadata = qcom_mdt_read_metadata(fw, &size);
+	metadata = qcom_mdt_read_metadata(qproc->dev, fw, qproc->hexagon_mdt_image, &size);
 	if (IS_ERR(metadata))
 		return PTR_ERR(metadata);
 
diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
index c9bbd8c..6876c0b 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -103,15 +103,18 @@ EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
  *
  * Return: pointer to data, or ERR_PTR()
  */
-void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
+void *qcom_mdt_read_metadata(struct device *dev, const struct firmware *fw, const char *firmware,
+			     size_t *data_len)
 {
 	const struct elf32_phdr *phdrs;
 	const struct elf32_hdr *ehdr;
-	size_t hash_offset;
+	const struct firmware *seg_fw;
 	size_t hash_index;
 	size_t hash_size;
 	size_t ehdr_size;
+	char *fw_name;
 	void *data;
+	int ret;
 
 	ehdr = (struct elf32_hdr *)fw->data;
 	phdrs = (struct elf32_phdr *)(ehdr + 1);
@@ -137,14 +140,29 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
 	if (!data)
 		return ERR_PTR(-ENOMEM);
 
-	/* Is the header and hash already packed */
-	if (qcom_mdt_bins_are_split(fw))
-		hash_offset = phdrs[0].p_filesz;
-	else
-		hash_offset = phdrs[hash_index].p_offset;
-
+	/* copy elf header */
 	memcpy(data, fw->data, ehdr_size);
-	memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
+
+	if (qcom_mdt_bins_are_split(fw)) {
+		fw_name = kstrdup(firmware, GFP_KERNEL);
+		if (!fw_name) {
+			kfree(data);
+			return ERR_PTR(-ENOMEM);
+		}
+		snprintf(fw_name + strlen(fw_name) - 3, 4, "b%02d", hash_index);
+
+		ret = request_firmware_into_buf(&seg_fw, fw_name, dev, data + ehdr_size, hash_size);
+		kfree(fw_name);
+
+		if (ret) {
+			kfree(data);
+			return ERR_PTR(ret);
+		}
+
+		release_firmware(seg_fw);
+	} else {
+		memcpy(data + ehdr_size, fw->data + phdrs[hash_index].p_offset, hash_size);
+	}
 
 	*data_len = ehdr_size + hash_size;
 
@@ -191,7 +209,7 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
 		return -ENOMEM;
 
 	if (pas_init) {
-		metadata = qcom_mdt_read_metadata(fw, &metadata_len);
+		metadata = qcom_mdt_read_metadata(dev, fw, firmware, &metadata_len);
 		if (IS_ERR(metadata)) {
 			ret = PTR_ERR(metadata);
 			goto out;
diff --git a/include/linux/soc/qcom/mdt_loader.h b/include/linux/soc/qcom/mdt_loader.h
index e600bae..04ba5e8 100644
--- a/include/linux/soc/qcom/mdt_loader.h
+++ b/include/linux/soc/qcom/mdt_loader.h
@@ -21,6 +21,7 @@ int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
 			  const char *fw_name, int pas_id, void *mem_region,
 			  phys_addr_t mem_phys, size_t mem_size,
 			  phys_addr_t *reloc_base);
-void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len);
+void *qcom_mdt_read_metadata(struct device *dev, const struct firmware *fw, const char *firmware,
+			     size_t *data_len);
 
 #endif
-- 
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