@@ -13,5 +13,6 @@ obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
obj-$(CONFIG_OF_RESOLVE) += resolver.o
obj-$(CONFIG_OF_OVERLAY) += overlay.o
obj-$(CONFIG_OF_NUMA) += of_numa.o
+obj-$(CONFIG_KEXEC_FILE) += kexec.o
obj-$(CONFIG_OF_UNITTEST) += unittest-data/
new file mode 100644
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ *
+ * Based on arch/arm64/kernel/machine_kexec_file.c:
+ * Copyright (C) 2018 Linaro Limited
+ *
+ * And arch/powerpc/kexec/file_load.c:
+ * Copyright (C) 2016 IBM Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/random.h>
+#include <linux/types.h>
+
+/* relevant device tree properties */
+#define FDT_PROP_KEXEC_ELFHDR "linux,elfcorehdr"
+#define FDT_PROP_MEM_RANGE "linux,usable-memory-range"
+#define FDT_PROP_INITRD_START "linux,initrd-start"
+#define FDT_PROP_INITRD_END "linux,initrd-end"
+#define FDT_PROP_BOOTARGS "bootargs"
+#define FDT_PROP_KASLR_SEED "kaslr-seed"
+#define FDT_PROP_RNG_SEED "rng-seed"
+#define RNG_SEED_SIZE 128
+
+/**
+ * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt: Flattened device tree for the current kernel.
+ * @start: Starting address of the reserved memory.
+ * @size: Size of the reserved memory.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+ int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+ for (i = 0; i < num_rsvs; i++) {
+ u64 rsv_start, rsv_size;
+
+ ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+ if (ret) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+
+ if (rsv_start == start && rsv_size == size) {
+ ret = fdt_del_mem_rsv(fdt, i);
+ if (ret) {
+ pr_err("Error deleting device tree reservation.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+/*
+ * of_kexec_setup_new_fdt - modify /chosen and memory reservation for the next kernel
+ *
+ * @image: kexec image being loaded.
+ * @fdt: Flattened device tree for the next kernel.
+ * @initrd_load_addr: Address where the next initrd will be loaded.
+ * @initrd_len: Size of the next initrd, or 0 if there will be none.
+ * @cmdline: Command line for the next kernel, or NULL if there will
+ * be none.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt,
+ unsigned long initrd_load_addr, unsigned long initrd_len,
+ const char *cmdline)
+{
+ int ret, chosen_node;
+ const void *prop;
+
+ /* Remove memory reservation for the current device tree. */
+ ret = fdt_find_and_del_mem_rsv(fdt, __pa(initial_boot_params),
+ fdt_totalsize(initial_boot_params));
+ if (ret == -EINVAL)
+ return ret;
+
+ chosen_node = fdt_path_offset(fdt, "/chosen");
+ if (chosen_node == -FDT_ERR_NOTFOUND)
+ chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+ "chosen");
+ if (chosen_node < 0) {
+ ret = chosen_node;
+ goto out;
+ }
+
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KEXEC_ELFHDR);
+ if (ret && ret != -FDT_ERR_NOTFOUND)
+ goto out;
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_MEM_RANGE);
+ if (ret && ret != -FDT_ERR_NOTFOUND)
+ goto out;
+
+ /* Did we boot using an initrd? */
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+ if (prop) {
+ u64 tmp_start, tmp_end, tmp_size;
+
+ tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+ if (!prop)
+ return -EINVAL;
+
+ tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ /*
+ * kexec reserves exact initrd size, while firmware may
+ * reserve a multiple of PAGE_SIZE, so check for both.
+ */
+ tmp_size = tmp_end - tmp_start;
+ ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size);
+ if (ret == -ENOENT)
+ ret = fdt_find_and_del_mem_rsv(fdt, tmp_start,
+ round_up(tmp_size, PAGE_SIZE));
+ if (ret == -EINVAL)
+ return ret;
+ }
+
+ /* add initrd-* */
+ if (initrd_load_addr) {
+ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_START,
+ initrd_load_addr);
+ if (ret)
+ goto out;
+
+ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_END,
+ initrd_load_addr + initrd_len);
+ if (ret)
+ goto out;
+
+ ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+ if (ret)
+ goto out;
+
+ } else {
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_START);
+ if (ret && (ret != -FDT_ERR_NOTFOUND))
+ goto out;
+
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_END);
+ if (ret && (ret != -FDT_ERR_NOTFOUND))
+ goto out;
+ }
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ /* add linux,elfcorehdr */
+ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+ FDT_PROP_KEXEC_ELFHDR,
+ image->arch.elf_headers_mem,
+ image->arch.elf_headers_sz);
+ if (ret)
+ goto out;
+
+ /*
+ * Avoid elfcorehdr from being stomped on in kdump kernel by
+ * setting up memory reserve map.
+ */
+ ret = fdt_add_mem_rsv(fdt, image->arch.elf_headers_mem,
+ image->arch.elf_headers_sz);
+ if (ret)
+ goto out;
+
+ /* add linux,usable-memory-range */
+ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+ FDT_PROP_MEM_RANGE,
+ crashk_res.start,
+ crashk_res.end - crashk_res.start + 1);
+ if (ret)
+ goto out;
+ }
+
+ /* add bootargs */
+ if (cmdline) {
+ ret = fdt_setprop_string(fdt, chosen_node, FDT_PROP_BOOTARGS, cmdline);
+ if (ret)
+ goto out;
+ } else {
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_BOOTARGS);
+ if (ret && (ret != -FDT_ERR_NOTFOUND))
+ goto out;
+ }
+
+ /* add kaslr-seed */
+ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KASLR_SEED);
+ if (ret == -FDT_ERR_NOTFOUND)
+ ret = 0;
+ else if (ret)
+ goto out;
+
+ if (rng_is_initialized()) {
+ u64 seed = get_random_u64();
+
+ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_KASLR_SEED, seed);
+ if (ret)
+ goto out;
+ } else {
+ pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+ FDT_PROP_KASLR_SEED);
+ }
+
+ /* add rng-seed */
+ if (rng_is_initialized()) {
+ void *rng_seed;
+
+ ret = fdt_setprop_placeholder(fdt, chosen_node, FDT_PROP_RNG_SEED,
+ RNG_SEED_SIZE, &rng_seed);
+ if (ret)
+ goto out;
+ get_random_bytes(rng_seed, RNG_SEED_SIZE);
+ } else {
+ pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+ FDT_PROP_RNG_SEED);
+ }
+
+ ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+
+out:
+ if (ret)
+ return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
+
+ return 0;
+}
@@ -558,6 +558,11 @@ int of_map_id(struct device_node *np, u32 id,
const char *map_name, const char *map_mask_name,
struct device_node **target, u32 *id_out);
+struct kimage;
+int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt,
+ unsigned long initrd_load_addr, unsigned long initrd_len,
+ const char *cmdline);
+
#else /* CONFIG_OF */
static inline void of_core_init(void)