upl: Add support for reading a upl handoff

Universal Payload provides a standard way of handing off control between
two firmware phases. Add support for reading the handoff information into
a structure.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/upl_read.c b/boot/upl_read.c
new file mode 100644
index 0000000..5063897
--- /dev/null
+++ b/boot/upl_read.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * UPL handoff parsing
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <log.h>
+#include <upl.h>
+#include <dm/ofnode.h>
+#include "upl_common.h"
+
+/**
+ * read_addr() - Read an address
+ *
+ * Reads an address in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @addr: Place to put the address
+ * Return: 0 if OK, -ve on error
+ */
+static int read_addr(const struct upl *upl, ofnode node, const char *prop,
+		     ulong *addrp)
+{
+	int ret;
+
+	if (upl->addr_cells == 1) {
+		u32 val;
+
+		ret = ofnode_read_u32(node, prop, &val);
+		if (!ret)
+			*addrp = val;
+	} else {
+		u64 val;
+
+		ret = ofnode_read_u64(node, prop, &val);
+		if (!ret)
+			*addrp = val;
+	}
+
+	return ret;
+}
+
+/**
+ * read_size() - Read a size
+ *
+ * Reads a size in the correct format, either 32- or 64-bit
+ *
+ * @upl: UPL state
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @addr: Place to put the size
+ * Return: 0 if OK, -ve on error
+ */
+static int read_size(const struct upl *upl, ofnode node, const char *prop,
+		     ulong *sizep)
+{
+	int ret;
+
+	if (upl->size_cells == 1) {
+		u32 val;
+
+		ret = ofnode_read_u32(node, prop, &val);
+		if (!ret)
+			*sizep = val;
+	} else {
+		u64 val;
+
+		ret = ofnode_read_u64(node, prop, &val);
+		if (!ret)
+			*sizep = val;
+	}
+
+	return ret;
+}
+
+/**
+ * ofnode_read_bitmask() - Read a bit mask from a string list
+ *
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @names: Array of names for each bit
+ * @count: Number of array entries
+ * @value: Returns resulting bit-mask value on success
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOSPC if the
+ * string is too long for the (internal) buffer, -EINVAL if no such property
+ */
+static int ofnode_read_bitmask(ofnode node, const char *prop,
+			       const char *const names[], uint count,
+			       uint *valuep)
+{
+	const char **list;
+	const char **strp;
+	uint val;
+	uint bit;
+	int ret;
+
+	ret = ofnode_read_string_list(node, prop, &list);
+	if (ret < 0)
+		return log_msg_ret("rea", ret);
+
+	val = 0;
+	for (strp = list; *strp; strp++) {
+		const char *str = *strp;
+		bool found = false;
+
+		for (bit = 0; bit < count; bit++) {
+			if (!strcmp(str, names[bit])) {
+				found = true;
+				break;
+			}
+		}
+		if (found)
+			val |= BIT(bit);
+		else
+			log_warning("%s/%s: Invalid value '%s'\n",
+				    ofnode_get_name(node), prop, str);
+	}
+	*valuep = val;
+
+	return 0;
+}
+
+/**
+ * ofnode_read_value() - Read a string value as an int using a lookup
+ *
+ * @node: Node to read from
+ * @prop: Property name to read
+ * @names: Array of names for each int value
+ * @count: Number of array entries
+ * @valuep: Returns int value read
+ * Return: 0 if OK, -EINVAL if a bit number is not defined, -ENOENT if the
+ * property does not exist
+ */
+static int ofnode_read_value(ofnode node, const char *prop,
+			     const char *const names[], uint count,
+			     uint *valuep)
+{
+	const char *str;
+	int i;
+
+	str = ofnode_read_string(node, prop);
+	if (!str)
+		return log_msg_ret("rd", -ENOENT);
+
+	for (i = 0; i < count; i++) {
+		if (!strcmp(names[i], str)) {
+			*valuep = i;
+			return 0;
+		}
+	}
+
+	log_debug("Unnamed value '%s'\n", str);
+	return log_msg_ret("val", -EINVAL);
+}
+
+static int read_uint(ofnode node, const char *prop, uint *valp)
+{
+	u32 val;
+	int ret;
+
+	ret = ofnode_read_u32(node, prop, &val);
+	if (ret)
+		return ret;
+	*valp = val;
+
+	return 0;
+}
+
+/**
+ * decode_root_props() - Decode root properties from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_root_props(struct upl *upl, ofnode node)
+{
+	int ret;
+
+	ret = read_uint(node, UPLP_ADDRESS_CELLS, &upl->addr_cells);
+	if (!ret)
+		ret = read_uint(node, UPLP_SIZE_CELLS, &upl->size_cells);
+	if (ret)
+		return log_msg_ret("cel", ret);
+
+	return 0;
+}
+
+/**
+ * decode_root_props() - Decode UPL parameters from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_params(struct upl *upl, ofnode options)
+{
+	ofnode node;
+	int ret;
+
+	node = ofnode_find_subnode(options, UPLN_UPL_PARAMS);
+	if (!ofnode_valid(node))
+		return log_msg_ret("par", -EINVAL);
+	log_debug("decoding '%s'\n", ofnode_get_name(node));
+
+	ret = read_addr(upl, node, UPLP_SMBIOS, &upl->smbios);
+	if (ret)
+		return log_msg_ret("smb", ret);
+	ret = read_addr(upl, node, UPLP_ACPI, &upl->acpi);
+	if (ret)
+		return log_msg_ret("acp", ret);
+	ret = ofnode_read_bitmask(node, UPLP_BOOTMODE, bootmode_names,
+				  UPLBM_COUNT, &upl->bootmode);
+	if (ret)
+		return log_msg_ret("boo", ret);
+	ret = read_uint(node, UPLP_ADDR_WIDTH, &upl->addr_width);
+	if (ret)
+		return log_msg_ret("add", ret);
+	ret = read_uint(node, UPLP_ACPI_NVS_SIZE, &upl->acpi_nvs_size);
+	if (ret)
+		return log_msg_ret("nvs", ret);
+
+	return 0;
+}
+
+/**
+ * decode_upl_images() - Decode /options/upl-image nodes
+ *
+ * @node: /options node in which to look for the node
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_images(struct upl *upl, ofnode options)
+{
+	ofnode node, images;
+	int ret;
+
+	images = ofnode_find_subnode(options, UPLN_UPL_IMAGE);
+	if (!ofnode_valid(images))
+		return log_msg_ret("img", -EINVAL);
+	log_debug("decoding '%s'\n", ofnode_get_name(images));
+
+	ret = read_addr(upl, images, UPLP_FIT, &upl->fit);
+	if (!ret)
+		ret = read_uint(images, UPLP_CONF_OFFSET, &upl->conf_offset);
+	if (ret)
+		return log_msg_ret("cnf", ret);
+
+	ofnode_for_each_subnode(node, images) {
+		struct upl_image img;
+
+		ret = read_addr(upl, node, UPLP_LOAD, &img.load);
+		if (!ret)
+			ret = read_size(upl, node, UPLP_SIZE, &img.size);
+		if (!ret)
+			ret = read_uint(node, UPLP_OFFSET, &img.offset);
+		img.description = ofnode_read_string(node, UPLP_DESCRIPTION);
+		if (!img.description)
+			return log_msg_ret("sim", ret);
+		if (!alist_add(&upl->image, img))
+			return log_msg_ret("img", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_addr_size() - Decide a set of addr/size pairs
+ *
+ * Each base/size value from the devicetree is written to the region list
+ *
+ * @upl: UPL state
+ * @buf: Bytes to decode
+ * @size: Number of bytes to decode
+ * @regions: List of regions to process (struct memregion)
+ * Returns: number of regions found, if OK, else -ve on error
+ */
+static int decode_addr_size(const struct upl *upl, const char *buf, int size,
+			    struct alist *regions)
+{
+	const char *ptr, *end = buf + size;
+	int i;
+
+	alist_init_struct(regions, struct memregion);
+	ptr = buf;
+	for (i = 0; ptr < end; i++) {
+		struct memregion reg;
+
+		if (upl->addr_cells == 1)
+			reg.base = fdt32_to_cpu(*(u32 *)ptr);
+		else
+			reg.base = fdt64_to_cpu(*(u64 *)ptr);
+		ptr += upl->addr_cells * sizeof(u32);
+
+		if (upl->size_cells == 1)
+			reg.size = fdt32_to_cpu(*(u32 *)ptr);
+		else
+			reg.size = fdt64_to_cpu(*(u64 *)ptr);
+		ptr += upl->size_cells * sizeof(u32);
+		if (ptr > end)
+			return -ENOSPC;
+
+		if (!alist_add(regions, reg))
+			return log_msg_ret("reg", -ENOMEM);
+	}
+
+	return i;
+}
+
+/**
+ * node_matches_at() - Check if a node name matches "base@..."
+ *
+ * Return: true if the node name matches the base string followed by an @ sign;
+ * false otherwise
+ */
+static bool node_matches_at(ofnode node, const char *base)
+{
+	const char *name = ofnode_get_name(node);
+	int len = strlen(base);
+
+	return !strncmp(base, name, len) && name[len] == '@';
+}
+
+/**
+ * decode_upl_memory_node() - Decode a /memory node from the tree
+ *
+ * @upl: UPL state
+ * @node: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memory_node(struct upl *upl, ofnode node)
+{
+	struct upl_mem mem;
+	const char *buf;
+	int size, len;
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing '%s' property\n",
+			    ofnode_get_name(node), UPLP_REG);
+		return log_msg_ret("reg", -EINVAL);
+	}
+	len = decode_addr_size(upl, buf, size, &mem.region);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+	mem.hotpluggable = ofnode_read_bool(node, UPLP_HOTPLUGGABLE);
+	if (!alist_add(&upl->mem, mem))
+		return log_msg_ret("mem", -ENOMEM);
+
+	return 0;
+}
+
+/**
+ * decode_upl_memmap() - Decode memory-map nodes from the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node containing the /memory-map nodes
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memmap(struct upl *upl, ofnode root)
+{
+	ofnode node;
+
+	ofnode_for_each_subnode(node, root) {
+		struct upl_memmap memmap;
+		int size, len, ret;
+		const char *buf;
+
+		memmap.name = ofnode_get_name(node);
+		memmap.usage = 0;
+
+		buf = ofnode_read_prop(node, UPLP_REG, &size);
+		if (!buf) {
+			log_warning("Node '%s': Missing '%s' property\n",
+				    ofnode_get_name(node), UPLP_REG);
+			continue;
+		}
+
+		len = decode_addr_size(upl, buf, size, &memmap.region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+		ret = ofnode_read_bitmask(node, UPLP_USAGE, usage_names,
+					  UPLUS_COUNT, &memmap.usage);
+		if (ret && ret != -EINVAL)	/* optional property */
+			return log_msg_ret("bit", ret);
+
+		if (!alist_add(&upl->memmap, memmap))
+			return log_msg_ret("mmp", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_upl_memres() - Decode reserved-memory nodes from the tree
+ *
+ * @upl: UPL state
+ * @root: Parent node containing the reserved-memory nodes
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_memres(struct upl *upl, ofnode root)
+{
+	ofnode node;
+
+	ofnode_for_each_subnode(node, root) {
+		struct upl_memres memres;
+		const char *buf;
+		int size, len;
+
+		log_debug("decoding '%s'\n", ofnode_get_name(node));
+		memres.name = ofnode_get_name(node);
+
+		buf = ofnode_read_prop(node, UPLP_REG, &size);
+		if (!buf) {
+			log_warning("Node '%s': Missing 'reg' property\n",
+				    ofnode_get_name(node));
+			continue;
+		}
+
+		len = decode_addr_size(upl, buf, size, &memres.region);
+		if (len < 0)
+			return log_msg_ret("buf", len);
+		memres.no_map = ofnode_read_bool(node, UPLP_NO_MAP);
+
+		if (!alist_add(&upl->memres, memres))
+			return log_msg_ret("mre", -ENOMEM);
+	}
+
+	return 0;
+}
+
+/**
+ * decode_upl_serial() - Decode the serial node
+ *
+ * @upl: UPL state
+ * @root: Parent node contain node
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_serial(struct upl *upl, ofnode node)
+{
+	struct upl_serial *ser = &upl->serial;
+	const char *buf;
+	int len, size;
+	int ret;
+
+	ser->compatible = ofnode_read_string(node, UPLP_COMPATIBLE);
+	if (!ser->compatible) {
+		log_warning("Node '%s': Missing compatible string\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("com", -EINVAL);
+	}
+	ret = read_uint(node, UPLP_CLOCK_FREQUENCY, &ser->clock_frequency);
+	if (!ret)
+		ret = read_uint(node, UPLP_CURRENT_SPEED, &ser->current_speed);
+	if (ret)
+		return log_msg_ret("spe", ret);
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing 'reg' property\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("reg", -EINVAL);
+	}
+
+	len = decode_addr_size(upl, buf, sizeof(buf), &ser->reg);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+
+	/* set defaults */
+	ser->reg_io_shift = UPLD_REG_IO_SHIFT;
+	ser->reg_offset = UPLD_REG_OFFSET;
+	ser->reg_io_width = UPLD_REG_IO_WIDTH;
+	read_uint(node, UPLP_REG_IO_SHIFT, &ser->reg_io_shift);
+	read_uint(node, UPLP_REG_OFFSET, &ser->reg_offset);
+	read_uint(node, UPLP_REG_IO_WIDTH, &ser->reg_io_width);
+	read_addr(upl, node, UPLP_VIRTUAL_REG, &ser->virtual_reg);
+	ret = ofnode_read_value(node, UPLP_ACCESS_TYPE, access_types,
+				ARRAY_SIZE(access_types), &ser->access_type);
+	if (ret && ret != -ENOENT)
+		return log_msg_ret("ser", ret);
+
+	return 0;
+}
+
+/**
+ * decode_upl_graphics() - Decode graphics node
+ *
+ * @upl: UPL state
+ * @root: Node to decode
+ * Return 0 if OK, -ve on error
+ */
+static int decode_upl_graphics(struct upl *upl, ofnode node)
+{
+	struct upl_graphics *gra = &upl->graphics;
+	const char *buf, *compat;
+	int len, size;
+	int ret;
+
+	compat = ofnode_read_string(node, UPLP_COMPATIBLE);
+	if (!compat) {
+		log_warning("Node '%s': Missing compatible string\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("com", -EINVAL);
+	}
+	if (strcmp(UPLC_GRAPHICS, compat)) {
+		log_warning("Node '%s': Ignoring compatible '%s'\n",
+			    ofnode_get_name(node), compat);
+		return 0;
+	}
+
+	buf = ofnode_read_prop(node, UPLP_REG, &size);
+	if (!buf) {
+		log_warning("Node '%s': Missing 'reg' property\n",
+			    ofnode_get_name(node));
+		return log_msg_ret("reg", -EINVAL);
+	}
+
+	len = decode_addr_size(upl, buf, sizeof(buf), &gra->reg);
+	if (len < 0)
+		return log_msg_ret("buf", len);
+
+	ret = read_uint(node, UPLP_WIDTH, &gra->width);
+	if (!ret)
+		ret = read_uint(node, UPLP_HEIGHT, &gra->height);
+	if (!ret)
+		ret = read_uint(node, UPLP_STRIDE, &gra->stride);
+	if (!ret) {
+		ret = ofnode_read_value(node, UPLP_GRAPHICS_FORMAT,
+					graphics_formats,
+					ARRAY_SIZE(graphics_formats),
+					&gra->format);
+	}
+	if (ret)
+		return log_msg_ret("pro", ret);
+
+	return 0;
+}
+
+int upl_read_handoff(struct upl *upl, oftree tree)
+{
+	ofnode root, node;
+	int ret;
+
+	if (!oftree_valid(tree))
+		return log_msg_ret("tre", -EINVAL);
+
+	root = oftree_root(tree);
+
+	upl_init(upl);
+	ret = decode_root_props(upl, root);
+	if (ret)
+		return log_msg_ret("roo", ret);
+
+	ofnode_for_each_subnode(node, root) {
+		const char *name = ofnode_get_name(node);
+
+		log_debug("decoding '%s'\n", name);
+		if (!strcmp(UPLN_OPTIONS, name)) {
+			ret = decode_upl_params(upl, node);
+			if (ret)
+				return log_msg_ret("opt", ret);
+
+			ret = decode_upl_images(upl, node);
+		} else if (node_matches_at(node, UPLN_MEMORY)) {
+			ret = decode_upl_memory_node(upl, node);
+		} else if (!strcmp(UPLN_MEMORY_MAP, name)) {
+			ret = decode_upl_memmap(upl, node);
+		} else if (!strcmp(UPLN_MEMORY_RESERVED, name)) {
+			ret = decode_upl_memres(upl, node);
+		} else if (node_matches_at(node, UPLN_SERIAL)) {
+			ret = decode_upl_serial(upl, node);
+		} else if (node_matches_at(node, UPLN_GRAPHICS)) {
+			ret = decode_upl_graphics(upl, node);
+		} else {
+			log_debug("Unknown node '%s'\n", name);
+			ret = 0;
+		}
+		if (ret)
+			return log_msg_ret("err", ret);
+	}
+
+	return 0;
+}