// SPDX-License-Identifier: GPL-2.0
/*
 * kexec_file for arm64
 *
 * Copyright (C) 2018 Linaro Limited
 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
 *
 * Most code is derived from arm64 port of kexec-tools
 */

#define pr_fmt(fmt) "kexec_file: " fmt

#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/libfdt.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/vmalloc.h>

const struct kexec_file_ops * const kexec_file_loaders[] = {
        &kexec_image_ops,
        NULL
};

int arch_kimage_file_post_load_cleanup(struct kimage *image)
{
        kvfree(image->arch.dtb);
        image->arch.dtb = NULL;

        vfree(image->elf_headers);
        image->elf_headers = NULL;
        image->elf_headers_sz = 0;

        return kexec_image_post_load_cleanup_default(image);
}

#ifdef CONFIG_CRASH_DUMP
static int prepare_elf_headers(void **addr, unsigned long *sz)
{
        struct crash_mem *cmem;
        unsigned int nr_ranges;
        int ret;
        u64 i;
        phys_addr_t start, end;

        nr_ranges = 2; /* for exclusion of crashkernel region */
        for_each_mem_range(i, &start, &end)
                nr_ranges++;

        cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
        if (!cmem)
                return -ENOMEM;

        cmem->max_nr_ranges = nr_ranges;
        cmem->nr_ranges = 0;
        for_each_mem_range(i, &start, &end) {
                cmem->ranges[cmem->nr_ranges].start = start;
                cmem->ranges[cmem->nr_ranges].end = end - 1;
                cmem->nr_ranges++;
        }

        /* Exclude crashkernel region */
        ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
        if (ret)
                goto out;

        if (crashk_low_res.end) {
                ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
                if (ret)
                        goto out;
        }

        ret = crash_prepare_elf64_headers(cmem, true, addr, sz);

out:
        kfree(cmem);
        return ret;
}
#endif

/*
 * Tries to add the initrd and DTB to the image. If it is not possible to find
 * valid locations, this function will undo changes to the image and return non
 * zero.
 */
int load_other_segments(struct kimage *image,
                        unsigned long kernel_load_addr,
                        unsigned long kernel_size,
                        char *initrd, unsigned long initrd_len,
                        char *cmdline)
{
        struct kexec_buf kbuf = {};
        void *dtb = NULL;
        unsigned long initrd_load_addr = 0, dtb_len,
                      orig_segments = image->nr_segments;
        int ret = 0;

        kbuf.image = image;
        /* not allocate anything below the kernel */
        kbuf.buf_min = kernel_load_addr + kernel_size;

#ifdef CONFIG_CRASH_DUMP
        /* load elf core header */
        void *headers;
        unsigned long headers_sz;
        if (image->type == KEXEC_TYPE_CRASH) {
                ret = prepare_elf_headers(&headers, &headers_sz);
                if (ret) {
                        pr_err("Preparing elf core header failed\n");
                        goto out_err;
                }

                kbuf.buffer = headers;
                kbuf.bufsz = headers_sz;
                kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
                kbuf.memsz = headers_sz;
                kbuf.buf_align = SZ_64K; /* largest supported page size */
                kbuf.buf_max = ULONG_MAX;
                kbuf.top_down = true;

                ret = kexec_add_buffer(&kbuf);
                if (ret) {
                        vfree(headers);
                        goto out_err;
                }
                image->elf_headers = headers;
                image->elf_load_addr = kbuf.mem;
                image->elf_headers_sz = headers_sz;

                kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
                              image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
        }
#endif

        /* load initrd */
        if (initrd) {
                kbuf.buffer = initrd;
                kbuf.bufsz = initrd_len;
                kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
                kbuf.memsz = initrd_len;
                kbuf.buf_align = 0;
                /* within 1GB-aligned window of up to 32GB in size */
                kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
                                                + (unsigned long)SZ_1G * 32;
                kbuf.top_down = false;

                ret = kexec_add_buffer(&kbuf);
                if (ret)
                        goto out_err;
                initrd_load_addr = kbuf.mem;

                kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
                              initrd_load_addr, kbuf.bufsz, kbuf.memsz);
        }

        /* load dtb */
        dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
                                           initrd_len, cmdline, 0);
        if (!dtb) {
                pr_err("Preparing for new dtb failed\n");
                ret = -EINVAL;
                goto out_err;
        }

        /* trim it */
        fdt_pack(dtb);
        dtb_len = fdt_totalsize(dtb);
        kbuf.buffer = dtb;
        kbuf.bufsz = dtb_len;
        kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
        kbuf.memsz = dtb_len;
        /* not across 2MB boundary */
        kbuf.buf_align = SZ_2M;
        kbuf.buf_max = ULONG_MAX;
        kbuf.top_down = true;

        ret = kexec_add_buffer(&kbuf);
        if (ret)
                goto out_err;
        image->arch.dtb = dtb;
        image->arch.dtb_mem = kbuf.mem;

        kexec_dprintk("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
                      kbuf.mem, kbuf.bufsz, kbuf.memsz);

        return 0;

out_err:
        image->nr_segments = orig_segments;
        kvfree(dtb);
        return ret;
}