remoteproc: Move Elf related functions to separate file

Prepare for introduction of custom firmware loaders by
moving all ELF related handling into a separate file.

The functions: rproc_find_rsc_table(), rproc_fw_sanity_check(),
rproc_find_rsc_table() and rproc_get_boot_addr() are moved
to the new file remoteproc_elf_loader.c. The function
rproc_da_to_va() is made non-static and is declared in
remoteproc_internal.h

No functional changes are introduced in this patch.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
[ohad: rebase, fix kerneldoc, put prototypes in remoteproc_internal.h]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

1 files changed, 287 insertions, 0 deletions

diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
new file mode 100644
index 000000000000..2c6fe6ad2d95
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_elf_loader.c
@@ -0,0 +1,287 @@
+/*
+ * Remote Processor Framework Elf loader
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Brian Swetland <swetland@google.com>
+ * Mark Grosen <mgrosen@ti.com>
+ * Fernando Guzman Lugo <fernando.lugo@ti.com>
+ * Suman Anna <s-anna@ti.com>
+ * Robert Tivy <rtivy@ti.com>
+ * Armando Uribe De Leon <x0095078@ti.com>
+ * Sjur Brændeland <sjur.brandeland@stericsson.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt)    "%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/firmware.h>
+#include <linux/remoteproc.h>
+#include <linux/elf.h>
+
+#include "remoteproc_internal.h"
+
+/**
+ * rproc_fw_sanity_check() - Sanity Check ELF firmware image
+ * @rproc: the remote processor handle
+ * @fw: the ELF firmware image
+ *
+ * Make sure this fw image is sane.
+ */
+int
+rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw)
+{
+	const char *name = rproc->firmware;
+	struct device *dev = &rproc->dev;
+	struct elf32_hdr *ehdr;
+	char class;
+
+	if (!fw) {
+		dev_err(dev, "failed to load %s\n", name);
+		return -EINVAL;
+	}
+
+	if (fw->size < sizeof(struct elf32_hdr)) {
+		dev_err(dev, "Image is too small\n");
+		return -EINVAL;
+	}
+
+	ehdr = (struct elf32_hdr *)fw->data;
+
+	/* We only support ELF32 at this point */
+	class = ehdr->e_ident[EI_CLASS];
+	if (class != ELFCLASS32) {
+		dev_err(dev, "Unsupported class: %d\n", class);
+		return -EINVAL;
+	}
+
+	/* We assume the firmware has the same endianess as the host */
+# ifdef __LITTLE_ENDIAN
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
+# else /* BIG ENDIAN */
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
+# endif
+		dev_err(dev, "Unsupported firmware endianess\n");
+		return -EINVAL;
+	}
+
+	if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
+		dev_err(dev, "Image is too small\n");
+		return -EINVAL;
+	}
+
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
+		dev_err(dev, "Image is corrupted (bad magic)\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_phnum == 0) {
+		dev_err(dev, "No loadable segments\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_phoff > fw->size) {
+		dev_err(dev, "Firmware size is too small\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * rproc_get_boot_addr() - Get rproc's boot address.
+ * @rproc: the remote processor handle
+ * @fw: the ELF firmware image
+ *
+ * This function returns the entry point address of the ELF
+ * image.
+ *
+ * Note that the boot address is not a configurable property of all remote
+ * processors. Some will always boot at a specific hard-coded address.
+ */
+u32 rproc_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
+{
+	struct elf32_hdr *ehdr  = (struct elf32_hdr *)fw->data;
+
+	return ehdr->e_entry;
+}
+
+/**
+ * rproc_load_segments() - load firmware segments to memory
+ * @rproc: remote processor which will be booted using these fw segments
+ * @fw: the ELF firmware image
+ *
+ * This function loads the firmware segments to memory, where the remote
+ * processor expects them.
+ *
+ * Some remote processors will expect their code and data to be placed
+ * in specific device addresses, and can't have them dynamically assigned.
+ *
+ * We currently support only those kind of remote processors, and expect
+ * the program header's paddr member to contain those addresses. We then go
+ * through the physically contiguous "carveout" memory regions which we
+ * allocated (and mapped) earlier on behalf of the remote processor,
+ * and "translate" device address to kernel addresses, so we can copy the
+ * segments where they are expected.
+ *
+ * Currently we only support remote processors that required carveout
+ * allocations and got them mapped onto their iommus. Some processors
+ * might be different: they might not have iommus, and would prefer to
+ * directly allocate memory for every segment/resource. This is not yet
+ * supported, though.
+ */
+int
+rproc_load_segments(struct rproc *rproc, const struct firmware *fw)
+{
+	struct device *dev = &rproc->dev;
+	struct elf32_hdr *ehdr;
+	struct elf32_phdr *phdr;
+	int i, ret = 0;
+	const u8 *elf_data = fw->data;
+
+	ehdr = (struct elf32_hdr *)elf_data;
+	phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
+
+	/* go through the available ELF segments */
+	for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+		u32 da = phdr->p_paddr;
+		u32 memsz = phdr->p_memsz;
+		u32 filesz = phdr->p_filesz;
+		u32 offset = phdr->p_offset;
+		void *ptr;
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
+					phdr->p_type, da, memsz, filesz);
+
+		if (filesz > memsz) {
+			dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
+							filesz, memsz);
+			ret = -EINVAL;
+			break;
+		}
+
+		if (offset + filesz > fw->size) {
+			dev_err(dev, "truncated fw: need 0x%x avail 0x%x\n",
+					offset + filesz, fw->size);
+			ret = -EINVAL;
+			break;
+		}
+
+		/* grab the kernel address for this device address */
+		ptr = rproc_da_to_va(rproc, da, memsz);
+		if (!ptr) {
+			dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
+			ret = -EINVAL;
+			break;
+		}
+
+		/* put the segment where the remote processor expects it */
+		if (phdr->p_filesz)
+			memcpy(ptr, elf_data + phdr->p_offset, filesz);
+
+		/*
+		 * Zero out remaining memory for this segment.
+		 *
+		 * This isn't strictly required since dma_alloc_coherent already
+		 * did this for us. albeit harmless, we may consider removing
+		 * this.
+		 */
+		if (memsz > filesz)
+			memset(ptr + filesz, 0, memsz - filesz);
+	}
+
+	return ret;
+}
+
+/**
+ * rproc_find_rsc_table() - find the resource table
+ * @rproc: the rproc handle
+ * @fw: the ELF firmware image
+ * @tablesz: place holder for providing back the table size
+ *
+ * This function finds the resource table inside the remote processor's
+ * firmware. It is used both upon the registration of @rproc (in order
+ * to look for and register the supported virito devices), and when the
+ * @rproc is booted.
+ *
+ * Returns the pointer to the resource table if it is found, and write its
+ * size into @tablesz. If a valid table isn't found, NULL is returned
+ * (and @tablesz isn't set).
+ */
+struct resource_table *
+rproc_find_rsc_table(struct rproc *rproc, const struct firmware *fw,
+							int *tablesz)
+{
+	struct elf32_hdr *ehdr;
+	struct elf32_shdr *shdr;
+	const char *name_table;
+	struct device *dev = &rproc->dev;
+	struct resource_table *table = NULL;
+	int i;
+	const u8 *elf_data = fw->data;
+
+	ehdr = (struct elf32_hdr *)elf_data;
+	shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
+	name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;
+
+	/* look for the resource table and handle it */
+	for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
+		int size = shdr->sh_size;
+		int 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) {
+			dev_err(dev, "resource table truncated\n");
+			return NULL;
+		}
+
+		/* make sure table has at least the header */
+		if (sizeof(struct resource_table) > size) {
+			dev_err(dev, "header-less resource table\n");
+			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 (table->num * sizeof(table->offset[0]) +
+				sizeof(struct resource_table) > size) {
+			dev_err(dev, "resource table incomplete\n");
+			return NULL;
+		}
+
+		*tablesz = shdr->sh_size;
+		break;
+	}
+
+	return table;
+}