spl: Allow to load a FIT containing U-Boot from FS

This provides a way to load a FIT containing U-Boot and a selection of device
tree files from a File system. Making sure that all the reads and writes
are aligned to their respective needs.

Tested-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[trini: Make this still apply with Michal's alignment change for 'fit']
Signed-off-by: Tom Rini <trini@konsulko.com>

common/spl/spl_fit.c

@@ -87,6 +87,42 @@ static int spl_fit_select_fdt(const void *fdt, int images, int *fdt_offsetp)
 	return -ENOENT;
 }
 
+static int get_aligned_image_offset(struct spl_load_info *info, int offset)
+{
+	/*
+	 * If it is a FS read, get the first address before offset which is
+	 * aligned to ARCH_DMA_MINALIGN. If it is raw read return the
+	 * block number to which offset belongs.
+	 */
+	if (info->filename)
+		return offset & ~(ARCH_DMA_MINALIGN - 1);
+
+	return offset / info->bl_len;
+}
+
+static int get_aligned_image_overhead(struct spl_load_info *info, int offset)
+{
+	/*
+	 * If it is a FS read, get the difference between the offset and
+	 * the first address before offset which is aligned to
+	 * ARCH_DMA_MINALIGN. If it is raw read return the offset within the
+	 * block.
+	 */
+	if (info->filename)
+		return offset & (ARCH_DMA_MINALIGN - 1);
+
+	return offset % info->bl_len;
+}
+
+static int get_aligned_image_size(struct spl_load_info *info, int data_size,
+				  int offset)
+{
+	if (info->filename)
+		return data_size + get_aligned_image_overhead(info, offset);
+
+	return (data_size + info->bl_len - 1) / info->bl_len;
+}
+
 int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 {
 	int sectors;
@@ -96,7 +132,7 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 	void *load_ptr;
 	int fdt_offset, fdt_len;
 	int data_offset, data_size;
-	int base_offset;
+	int base_offset, align_len = ARCH_DMA_MINALIGN - 1;
 	int src_sector;
 	void *dst;
 
@@ -124,7 +160,7 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 	 */
 	fit = (void *)(CONFIG_SYS_TEXT_BASE - size - info->bl_len);
 	fit = (void *)ALIGN((ulong)fit, 8);
-	sectors = (size + info->bl_len - 1) / info->bl_len;
+	sectors = get_aligned_image_size(info, size, 0);
 	count = info->read(info, sector, sectors, fit);
 	debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu\n",
 	      sector, sectors, fit, count);
@@ -157,19 +193,23 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 	 * byte will be at 'load'. This may mean we need to load it starting
 	 * before then, since we can only read whole blocks.
 	 */
-	sectors = (data_size + info->bl_len - 1) / info->bl_len;
 	data_offset += base_offset;
+	sectors = get_aligned_image_size(info, data_size, data_offset);
 	load_ptr = (void *)load;
 	debug("U-Boot size %x, data %p\n", data_size, load_ptr);
-	dst = load_ptr - (data_offset % info->bl_len);
+	dst = load_ptr;
 
 	/* Read the image */
-	src_sector = sector + data_offset / info->bl_len;
-	debug("image: data_offset=%x, dst=%p, src_sector=%x, sectors=%x\n",
-	      data_offset, dst, src_sector, sectors);
+	src_sector = sector + get_aligned_image_offset(info, data_offset);
+	debug("Aligned image read: dst=%p, src_sector=%x, sectors=%x\n",
+	      dst, src_sector, sectors);
 	count = info->read(info, src_sector, sectors, dst);
 	if (count != sectors)
 		return -EIO;
+	debug("image: dst=%p, data_offset=%x, size=%x\n", dst, data_offset,
+	      data_size);
+	memcpy(dst, dst + get_aligned_image_overhead(info, data_offset),
+	       data_size);
 
 	/* Figure out which device tree the board wants to use */
 	fdt_len = spl_fit_select_fdt(fit, images, &fdt_offset);
@@ -179,14 +219,15 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 	/*
 	 * Read the device tree and place it after the image. There may be
 	 * some extra data before it since we can only read entire blocks.
+	 * And also align the destination address to ARCH_DMA_MINALIGN.
 	 */
-	dst = load_ptr + data_size;
+	dst = (void *)((load + data_size + align_len) & ~align_len);
 	fdt_offset += base_offset;
-	sectors = (fdt_len + info->bl_len - 1) / info->bl_len;
-	count = info->read(info, sector + fdt_offset / info->bl_len, sectors,
-			   dst);
-	debug("fit read %x sectors to %x, dst %p, data_offset %x\n",
-	      sectors, spl_image.load_addr, dst, fdt_offset);
+	sectors = get_aligned_image_size(info, fdt_len, fdt_offset);
+	src_sector = sector + get_aligned_image_offset(info, fdt_offset);
+	count = info->read(info, src_sector, sectors, dst);
+	debug("Aligned fdt read: dst %p, src_sector = %x, sectors %x\n",
+	      dst, src_sector, sectors);
 	if (count != sectors)
 		return -EIO;
 
@@ -195,7 +236,10 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 	 * After this we will have the U-Boot image and its device tree ready
 	 * for us to start.
 	 */
-	memcpy(dst, dst + fdt_offset % info->bl_len, fdt_len);
+	debug("fdt: dst=%p, data_offset=%x, size=%x\n", dst, fdt_offset,
+	      fdt_len);
+	memcpy(load_ptr + data_size,
+	       dst + get_aligned_image_overhead(info, fdt_offset), fdt_len);
 
 	return 0;
 }

common/spl/spl_mmc.c

@@ -77,6 +77,7 @@ static int mmc_load_image_raw_sector(struct mmc *mmc, unsigned long sector)
 		debug("Found FIT\n");
 		load.dev = mmc;
 		load.priv = NULL;
+		load.filename = NULL;
 		load.bl_len = mmc->read_bl_len;
 		load.read = h_spl_load_read;
 		ret = spl_load_simple_fit(&load, sector, header);

include/spl.h

@@ -35,16 +35,28 @@ struct spl_image_info {
  * @dev: Pointer to the device, e.g. struct mmc *
  * @priv: Private data for the device
  * @bl_len: Block length for reading in bytes
+ * @filename: Name of the fit image file.
  * @read: Function to call to read from the device
  */
 struct spl_load_info {
 	void *dev;
 	void *priv;
 	int bl_len;
+	const char *filename;
 	ulong (*read)(struct spl_load_info *load, ulong sector, ulong count,
 		      void *buf);
 };
 
+/**
+ * spl_load_simple_fit() - Loads a fit image from a device.
+ * @info:	Structure containing the information required to load data.
+ * @sector:	Sector number where FIT image is located in the device
+ * @fdt:	Pointer to the copied FIT header.
+ *
+ * Reads the FIT image @sector in the device. Loads u-boot image to
+ * specified load address and copies the dtb to end of u-boot image.
+ * Returns 0 on success.
+ */
 int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fdt);
 
 #define SPL_COPY_PAYLOAD_ONLY	1