--- v18
+++ v15
@@ -1,59 +1,304 @@
-The architecture specific field, elf_headers_mem in struct kimage_arch,
-that holds the address of the buffer in memory for ELF core header for
-arm64 has a different name than the one used for powerpc. This makes
-it hard to have a common code for setting up the device tree for
-kexec system call.
-
-Rename elf_headers_mem to elf_load_addr to align with powerpc name so
-common code can use it.
-
-Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
-Suggested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
+From: Rob Herring <robh@kernel.org>
+
+Both arm64 and powerpc do essentially the same FDT /chosen setup for
+kexec. The differences are either omissions that arm64 should have
+or additional properties that will be ignored. The setup code can be
+combined and shared by both powerpc and arm64.
+
+The differences relative to the arm64 version:
+ - If /chosen doesn't exist, it will be created (should never happen).
+ - Any old dtb and initrd reserved memory will be released.
+ - The new initrd and elfcorehdr are marked reserved.
+ - "linux,booted-from-kexec" is set.
+
+The differences relative to the powerpc version:
+ - "kaslr-seed" and "rng-seed" may be set.
+ - "linux,elfcorehdr" is set.
+ - Any existing "linux,usable-memory-range" is removed.
+
+Combine the code for setting up the /chosen node in the FDT and updating
+the memory reservation for kexec, for powerpc and arm64, in
+of_kexec_setup_new_fdt() and move it to "drivers/of/kexec.c".
+
+Signed-off-by: Rob Herring <robh@kernel.org>
+Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
+Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
- arch/arm64/include/asm/kexec.h | 2 +-
- arch/arm64/kernel/machine_kexec_file.c | 6 +++---
- 2 files changed, 4 insertions(+), 4 deletions(-)
-
-diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
-index d24b527e8c00..e6a99dfdffb8 100644
---- a/arch/arm64/include/asm/kexec.h
-+++ b/arch/arm64/include/asm/kexec.h
-@@ -98,7 +98,7 @@ struct kimage_arch {
- unsigned long dtb_mem;
- /* Core ELF header buffer */
- void *elf_headers;
-- unsigned long elf_headers_mem;
-+ unsigned long elf_load_addr;
- unsigned long elf_headers_sz;
- };
+ drivers/of/Makefile | 1 +
+ drivers/of/kexec.c | 236 ++++++++++++++++++++++++++++++++++++++++++++
+ include/linux/of.h | 5 +
+ 3 files changed, 242 insertions(+)
+ create mode 100644 drivers/of/kexec.c
+
+diff --git a/drivers/of/Makefile b/drivers/of/Makefile
+index 6e1e5212f058..8ce11955afde 100644
+--- a/drivers/of/Makefile
++++ b/drivers/of/Makefile
+@@ -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-$(CONFIG_KEXEC_FILE) += kexec.o
-diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
-index 03210f644790..d98bacec9426 100644
---- a/arch/arm64/kernel/machine_kexec_file.c
-+++ b/arch/arm64/kernel/machine_kexec_file.c
-@@ -73,7 +73,7 @@ static int setup_dtb(struct kimage *image,
- /* add linux,elfcorehdr */
- ret = fdt_appendprop_addrrange(dtb, 0, off,
- FDT_PROP_KEXEC_ELFHDR,
-- image->arch.elf_headers_mem,
-+ image->arch.elf_load_addr,
- image->arch.elf_headers_sz);
- if (ret)
- return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
-@@ -283,11 +283,11 @@ int load_other_segments(struct kimage *image,
- goto out_err;
- }
- image->arch.elf_headers = headers;
-- image->arch.elf_headers_mem = kbuf.mem;
-+ image->arch.elf_load_addr = kbuf.mem;
- image->arch.elf_headers_sz = headers_sz;
+ obj-$(CONFIG_OF_UNITTEST) += unittest-data/
+diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
+new file mode 100644
+index 000000000000..4afd3cc1c04a
+--- /dev/null
++++ b/drivers/of/kexec.c
+@@ -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;
++}
+diff --git a/include/linux/of.h b/include/linux/of.h
+index 5d51891cbf1a..3375f5295875 100644
+--- a/include/linux/of.h
++++ b/include/linux/of.h
+@@ -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);
- pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-- image->arch.elf_headers_mem, kbuf.bufsz, kbuf.memsz);
-+ image->arch.elf_load_addr, kbuf.bufsz, kbuf.memsz);
- }
++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 */
- /* load initrd */
+ static inline void of_core_init(void)
--
2.30.0