[PATCH V2 1/6] remoteproc: elf_loader: introduce rproc_elf_find_shdr

["Peng Fan (OSS)" <peng.fan@oss.nxp.com>]

From: Peng Fan <peng.fan@nxp.com>

Introduce API rproc_elf_find_shdr to get the shdr pointer. This API
could be used to find the ".resource_table" section, and could also
be used by i.MX driver to find the ".interrupts" section.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/remoteproc/remoteproc_elf_loader.c | 93 +++++++++++++---------
 drivers/remoteproc/remoteproc_internal.h   |  2 +
 2 files changed, 56 insertions(+), 39 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
index 5a412d7b6e0b..c09fd5733aee 100644
--- a/drivers/remoteproc/remoteproc_elf_loader.c
+++ b/drivers/remoteproc/remoteproc_elf_loader.c
@@ -244,22 +244,19 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
 }
 EXPORT_SYMBOL(rproc_elf_load_segments);
 
-static const void *
-find_table(struct device *dev, const struct firmware *fw)
+const void *
+rproc_elf_find_shdr(struct rproc *rproc, const struct firmware *fw, const char *sh_name)
 {
 	const void *shdr, *name_table_shdr;
 	int i;
 	const char *name_table;
-	struct resource_table *table = NULL;
 	const u8 *elf_data = (void *)fw->data;
 	u8 class = fw_elf_get_class(fw);
-	size_t fw_size = fw->size;
 	const void *ehdr = elf_data;
 	u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
 	u32 elf_shdr_get_size = elf_size_of_shdr(class);
 	u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
 
-	/* look for the resource table and handle it */
 	/* First, get the section header according to the elf class */
 	shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
 	/* Compute name table section header entry in shdr array */
@@ -268,49 +265,68 @@ find_table(struct device *dev, const struct firmware *fw)
 	name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
 
 	for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
-		u64 size = elf_shdr_get_sh_size(class, shdr);
-		u64 offset = elf_shdr_get_sh_offset(class, shdr);
 		u32 name = elf_shdr_get_sh_name(class, shdr);
 
-		if (strcmp(name_table + name, ".resource_table"))
+		if (strcmp(name_table + name, sh_name))
 			continue;
 
-		table = (struct resource_table *)(elf_data + offset);
+		return shdr;
+	}
 
-		/* make sure we have the entire table */
-		if (offset + size > fw_size || offset + size < size) {
-			dev_err(dev, "resource table truncated\n");
-			return NULL;
-		}
+	return NULL;
+}
+EXPORT_SYMBOL(rproc_elf_find_shdr);
 
-		/* make sure table has at least the header */
-		if (sizeof(struct resource_table) > size) {
-			dev_err(dev, "header-less resource table\n");
-			return NULL;
-		}
+static const void *
+find_table(struct rproc *rproc, const struct firmware *fw)
+{
+	const u8 *elf_data = (void *)fw->data;
+	u8 class = fw_elf_get_class(fw);
+	size_t fw_size = fw->size;
+	struct resource_table *table = NULL;
+	struct device *dev = &rproc->dev;
+	const void *shdr;
+	u64 size, offset;
 
-		/* we don't support any version beyond the first */
-		if (table->ver != 1) {
-			dev_err(dev, "unsupported fw ver: %d\n", table->ver);
-			return NULL;
-		}
+	shdr = rproc_elf_find_shdr(rproc, fw, ".resource_table");
+	if (!shdr)
+		return NULL;
 
-		/* make sure reserved bytes are zeroes */
-		if (table->reserved[0] || table->reserved[1]) {
-			dev_err(dev, "non zero reserved bytes\n");
-			return NULL;
-		}
+	size = elf_shdr_get_sh_size(class, shdr);
+	offset = elf_shdr_get_sh_offset(class, shdr);
+	table = (struct resource_table *)(elf_data + offset);
 
-		/* make sure the offsets array isn't truncated */
-		if (struct_size(table, offset, table->num) > size) {
-			dev_err(dev, "resource table incomplete\n");
-			return NULL;
-		}
+	/* make sure we have the entire table */
+	if (offset + size > fw_size || offset + size < size) {
+		dev_err(dev, "resource table truncated\n");
+		return NULL;
+	}
 
-		return shdr;
+	/* make sure table has at least the header */
+	if (sizeof(struct resource_table) > size) {
+		dev_err(dev, "header-less resource table\n");
+		return NULL;
 	}
 
-	return NULL;
+	/* we don't support any version beyond the first */
+	if (table->ver != 1) {
+		dev_err(dev, "unsupported fw ver: %d\n", table->ver);
+		return NULL;
+	}
+
+	/* make sure reserved bytes are zeroes */
+	if (table->reserved[0] || table->reserved[1]) {
+		dev_err(dev, "non zero reserved bytes\n");
+		return NULL;
+	}
+
+	/* make sure the offsets array isn't truncated */
+	if (struct_size(table, offset, table->num) > size) {
+		dev_err(dev, "resource table incomplete\n");
+		return NULL;
+	}
+
+	return shdr;
 }
 
 /**
@@ -326,14 +342,13 @@ find_table(struct device *dev, const struct firmware *fw)
 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
 {
 	const void *shdr;
-	struct device *dev = &rproc->dev;
 	struct resource_table *table = NULL;
 	const u8 *elf_data = fw->data;
 	size_t tablesz;
 	u8 class = fw_elf_get_class(fw);
 	u64 sh_offset;
 
-	shdr = find_table(dev, fw);
+	shdr = find_table(rproc, fw);
 	if (!shdr)
 		return -EINVAL;
 
@@ -377,7 +392,7 @@ struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
 	u8 class = fw_elf_get_class(fw);
 	struct device *dev = &rproc->dev;
 
-	shdr = find_table(&rproc->dev, fw);
+	shdr = find_table(rproc, fw);
 	if (!shdr)
 		return NULL;
 
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index d4dbb8d1d80c..2a4f75a401d3 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -117,6 +117,8 @@ int rproc_trigger_recovery(struct rproc *rproc);
 
 int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw);
 u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw);
+const void *rproc_elf_find_shdr(struct rproc *rproc, const struct firmware *fw,
+				const char *sh_name);
 int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw);
 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw);
 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
-- 
2.37.1