On Thu, Apr 21, 2016 at 12:04:21PM +0100, Peter Griffin wrote:

+static int
+st_fdma_elf_sanity_check(struct st_fdma_dev *fdev, const struct firmware *fw)
+{
+	const char *fw_name = fdev->fw_name;
+	struct elf32_hdr *ehdr;
+	char class;
+
+	if (!fw) {
+		dev_err(fdev->dev, "failed to load %s\n", fw_name);
+		return -EINVAL;
+	}
+
+	if (fw->size < sizeof(*ehdr)) {
+		dev_err(fdev->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(fdev->dev, "Unsupported class: %d\n", class);
+		return -EINVAL;
+	}
+
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
+		dev_err(fdev->dev, "Unsupported firmware endianness"
+			"(%d) expected (%d)\n", ehdr->e_ident[EI_DATA],
+			ELFDATA2LSB);
+		return -EINVAL;
+	}
+
+	if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
+		dev_err(fdev->dev, "Image is too small (%u)\n", fw->size);
+		return -EINVAL;
+	}
+
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
+		dev_err(fdev->dev, "Image is corrupted (bad magic)\n");
+		return -EINVAL;
+	}
+
+	if (ehdr->e_phnum != fdev->drvdata->num_mem) {
+		dev_err(fdev->dev, "spurious nb of segments (%d) expected (%d)"
+			"\n", ehdr->e_phnum, fdev->drvdata->num_mem);
+		return -EINVAL;
+	}
+
+	if (ehdr->e_type != ET_EXEC) {
+		dev_err(fdev->dev, "Unsupported ELF header type (%d) expected"
+			" (%d)\n", ehdr->e_type, ET_EXEC);
+		return -EINVAL;
+	}
+
+	if (ehdr->e_machine != EM_SLIM) {
+		dev_err(fdev->dev, "Unsupported ELF header machine (%d) "
+			"expected (%d)\n", ehdr->e_machine, EM_SLIM);
+		return -EINVAL;
+	}
+	if (ehdr->e_phoff > fw->size) {
+		dev_err(fdev->dev, "Firmware size is too small\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+st_fdma_elf_load_segments(struct st_fdma_dev *fdev, const struct firmware *fw)
+{
+	struct device *dev = fdev->dev;
+	struct elf32_hdr *ehdr;
+	struct elf32_phdr *phdr;
+	int i, mem_loaded = 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
+	 * the program header's paddr member to contain device addresses.
+	 * We then go through the physically contiguous memory regions which we
+	 * allocated (and mapped) earlier on the probe,
+	 * and "translate" device address to kernel addresses,
+	 * so we can copy the segments where they are expected.
+	 */
+	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 *dst;
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		dev_dbg(dev, "phdr: type %d da %#x ofst:%#x memsz %#x filesz %#x\n",
+			phdr->p_type, da, offset, memsz, filesz);
+
+		if (filesz > memsz) {
+			dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
+				filesz, memsz);
+			break;
+		}
+
+		if (offset + filesz > fw->size) {
+			dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
+				offset + filesz, fw->size);
+			break;
+		}
+
+		dst = st_fdma_seg_to_mem(fdev, da, memsz);
+		if (!dst) {
+			dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
+			break;
+		}
+
+		if (phdr->p_filesz)
+			memcpy(dst, elf_data + phdr->p_offset, filesz);
+
+		if (memsz > filesz)
+			memset(dst + filesz, 0, memsz - filesz);
+
+		mem_loaded++;
+	}
+
+	return (mem_loaded != fdev->drvdata->num_mem) ? -EIO : 0;
+}

Above two seem to be generic code and should be moved to core, this way
other drivers using ELF firmware binaries can reuse...

this seems quite an odd place to load firmware, can you explain why

-- 
~Vinod