remoteproc: elf_loader: Add elf resource table load support

Add rproc_elf_load_rsc_table(), which searches for a resource table in
an elf64/elf32 image, and if found, copies it to device memory.
Add also the elf32 and elf64 variants of this API.
Add a test for this.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

1 files changed, 269 insertions, 0 deletions

diff --git a/drivers/remoteproc/rproc-elf-loader.c b/drivers/remoteproc/rproc-elf-loader.c
index e8026cdfbb..538481241f 100644
--- a/drivers/remoteproc/rproc-elf-loader.c
+++ b/drivers/remoteproc/rproc-elf-loader.c
@@ -8,6 +8,39 @@
 #include <elf.h>
 #include <remoteproc.h>
 
+/**
+ * struct resource_table - firmware resource table header
+ * @ver: version number
+ * @num: number of resource entries
+ * @reserved: reserved (must be zero)
+ * @offset: array of offsets pointing at the various resource entries
+ *
+ * A resource table is essentially a list of system resources required
+ * by the remote processor. It may also include configuration entries.
+ * If needed, the remote processor firmware should contain this table
+ * as a dedicated ".resource_table" ELF section.
+ *
+ * Some resources entries are mere announcements, where the host is informed
+ * of specific remoteproc configuration. Other entries require the host to
+ * do something (e.g. allocate a system resource). Sometimes a negotiation
+ * is expected, where the firmware requests a resource, and once allocated,
+ * the host should provide back its details (e.g. address of an allocated
+ * memory region).
+ *
+ * The header of the resource table, as expressed by this structure,
+ * contains a version number (should we need to change this format in the
+ * future), the number of available resource entries, and their offsets
+ * in the table.
+ *
+ * Immediately following this header are the resource entries themselves.
+ */
+struct resource_table {
+	u32 ver;
+	u32 num;
+	u32 reserved[2];
+	u32 offset[0];
+} __packed;
+
 /* Basic function to verify ELF32 image format */
 int rproc_elf32_sanity_check(ulong addr, ulong size)
 {
@@ -276,3 +309,239 @@ ulong rproc_elf_get_boot_addr(struct udevice *dev, ulong addr)
 	else
 		return rproc_elf32_get_boot_addr(addr);
 }
+
+/*
+ * Search for the resource table in an ELF32 image.
+ * Returns the address of the resource table section if found, NULL if there is
+ * no resource table section, or error pointer.
+ */
+static Elf32_Shdr *rproc_elf32_find_rsc_table(struct udevice *dev,
+					      ulong fw_addr, ulong fw_size)
+{
+	int ret;
+	unsigned int i;
+	const char *name_table;
+	struct resource_table *table;
+	const u8 *elf_data = (void *)fw_addr;
+	Elf32_Ehdr *ehdr = (Elf32_Ehdr *)fw_addr;
+	Elf32_Shdr *shdr;
+
+	ret = rproc_elf32_sanity_check(fw_addr, fw_size);
+	if (ret) {
+		pr_debug("Invalid ELF32 Image %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	/* look for the resource table and handle it */
+	shdr = (Elf32_Shdr *)(elf_data + ehdr->e_shoff);
+	name_table = (const char *)(elf_data +
+				    shdr[ehdr->e_shstrndx].sh_offset);
+
+	for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
+		u32 size = shdr->sh_size;
+		u32 offset = shdr->sh_offset;
+
+		if (strcmp(name_table + shdr->sh_name, ".resource_table"))
+			continue;
+
+		table = (struct resource_table *)(elf_data + offset);
+
+		/* make sure we have the entire table */
+		if (offset + size > fw_size) {
+			pr_debug("resource table truncated\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		/* make sure table has at least the header */
+		if (sizeof(*table) > size) {
+			pr_debug("header-less resource table\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		/* we don't support any version beyond the first */
+		if (table->ver != 1) {
+			pr_debug("unsupported fw ver: %d\n", table->ver);
+			return ERR_PTR(-EPROTONOSUPPORT);
+		}
+
+		/* make sure reserved bytes are zeroes */
+		if (table->reserved[0] || table->reserved[1]) {
+			pr_debug("non zero reserved bytes\n");
+			return ERR_PTR(-EBADF);
+		}
+
+		/* make sure the offsets array isn't truncated */
+		if (table->num * sizeof(table->offset[0]) +
+				 sizeof(*table) > size) {
+			pr_debug("resource table incomplete\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		return shdr;
+	}
+
+	return NULL;
+}
+
+/* Load the resource table from an ELF32 image */
+int rproc_elf32_load_rsc_table(struct udevice *dev, ulong fw_addr,
+			       ulong fw_size, ulong *rsc_addr, ulong *rsc_size)
+{
+	const struct dm_rproc_ops *ops;
+	Elf32_Shdr *shdr;
+	void *src, *dst;
+
+	shdr = rproc_elf32_find_rsc_table(dev, fw_addr, fw_size);
+	if (!shdr)
+		return -ENODATA;
+	if (IS_ERR(shdr))
+		return PTR_ERR(shdr);
+
+	ops = rproc_get_ops(dev);
+	*rsc_addr = (ulong)shdr->sh_addr;
+	*rsc_size = (ulong)shdr->sh_size;
+
+	src = (void *)fw_addr + shdr->sh_offset;
+	if (ops->device_to_virt)
+		dst = (void *)ops->device_to_virt(dev, *rsc_addr, *rsc_size);
+	else
+		dst = (void *)rsc_addr;
+
+	dev_dbg(dev, "Loading resource table to 0x%8lx (%ld bytes)\n",
+		(ulong)dst, *rsc_size);
+
+	memcpy(dst, src, *rsc_size);
+	flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
+		    roundup((unsigned long)dst + *rsc_size,
+			    ARCH_DMA_MINALIGN) -
+		    rounddown((unsigned long)dst, ARCH_DMA_MINALIGN));
+
+	return 0;
+}
+
+/*
+ * Search for the resource table in an ELF64 image.
+ * Returns the address of the resource table section if found, NULL if there is
+ * no resource table section, or error pointer.
+ */
+static Elf64_Shdr *rproc_elf64_find_rsc_table(struct udevice *dev,
+					      ulong fw_addr, ulong fw_size)
+{
+	int ret;
+	unsigned int i;
+	const char *name_table;
+	struct resource_table *table;
+	const u8 *elf_data = (void *)fw_addr;
+	Elf64_Ehdr *ehdr = (Elf64_Ehdr *)fw_addr;
+	Elf64_Shdr *shdr;
+
+	ret = rproc_elf64_sanity_check(fw_addr, fw_size);
+	if (ret) {
+		pr_debug("Invalid ELF64 Image %d\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	/* look for the resource table and handle it */
+	shdr = (Elf64_Shdr *)(elf_data + ehdr->e_shoff);
+	name_table = (const char *)(elf_data +
+				    shdr[ehdr->e_shstrndx].sh_offset);
+
+	for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
+		u64 size = shdr->sh_size;
+		u64 offset = shdr->sh_offset;
+
+		if (strcmp(name_table + shdr->sh_name, ".resource_table"))
+			continue;
+
+		table = (struct resource_table *)(elf_data + offset);
+
+		/* make sure we have the entire table */
+		if (offset + size > fw_size) {
+			pr_debug("resource table truncated\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		/* make sure table has at least the header */
+		if (sizeof(*table) > size) {
+			pr_debug("header-less resource table\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		/* we don't support any version beyond the first */
+		if (table->ver != 1) {
+			pr_debug("unsupported fw ver: %d\n", table->ver);
+			return ERR_PTR(-EPROTONOSUPPORT);
+		}
+
+		/* make sure reserved bytes are zeroes */
+		if (table->reserved[0] || table->reserved[1]) {
+			pr_debug("non zero reserved bytes\n");
+			return ERR_PTR(-EBADF);
+		}
+
+		/* make sure the offsets array isn't truncated */
+		if (table->num * sizeof(table->offset[0]) +
+				 sizeof(*table) > size) {
+			pr_debug("resource table incomplete\n");
+			return ERR_PTR(-ENOSPC);
+		}
+
+		return shdr;
+	}
+
+	return NULL;
+}
+
+/* Load the resource table from an ELF64 image */
+int rproc_elf64_load_rsc_table(struct udevice *dev, ulong fw_addr,
+			       ulong fw_size, ulong *rsc_addr, ulong *rsc_size)
+{
+	const struct dm_rproc_ops *ops;
+	Elf64_Shdr *shdr;
+	void *src, *dst;
+
+	shdr = rproc_elf64_find_rsc_table(dev, fw_addr, fw_size);
+	if (!shdr)
+		return -ENODATA;
+	if (IS_ERR(shdr))
+		return PTR_ERR(shdr);
+
+	ops = rproc_get_ops(dev);
+	*rsc_addr = (ulong)shdr->sh_addr;
+	*rsc_size = (ulong)shdr->sh_size;
+
+	src = (void *)fw_addr + shdr->sh_offset;
+	if (ops->device_to_virt)
+		dst = (void *)ops->device_to_virt(dev, *rsc_addr, *rsc_size);
+	else
+		dst = (void *)rsc_addr;
+
+	dev_dbg(dev, "Loading resource table to 0x%8lx (%ld bytes)\n",
+		(ulong)dst, *rsc_size);
+
+	memcpy(dst, src, *rsc_size);
+	flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
+		    roundup((unsigned long)dst + *rsc_size,
+			    ARCH_DMA_MINALIGN) -
+		    rounddown((unsigned long)dst, ARCH_DMA_MINALIGN));
+
+	return 0;
+}
+
+/* Load the resource table from an ELF32 or ELF64 image */
+int rproc_elf_load_rsc_table(struct udevice *dev, ulong fw_addr,
+			     ulong fw_size, ulong *rsc_addr, ulong *rsc_size)
+
+{
+	Elf32_Ehdr *ehdr = (Elf32_Ehdr *)fw_addr;
+
+	if (!fw_addr)
+		return -EFAULT;
+
+	if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
+		return rproc_elf64_load_rsc_table(dev, fw_addr, fw_size,
+						  rsc_addr, rsc_size);
+	else
+		return rproc_elf32_load_rsc_table(dev, fw_addr, fw_size,
+						  rsc_addr, rsc_size);
+}