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    Subject[PATCH v9 05/11] arm64: kexec_file: load initrd and device-tree
    Date
    load_other_segments() is expected to allocate and place all the necessary
    memory segments other than kernel, including initrd and device-tree
    blob (and elf core header for crash).
    While most of the code was borrowed from kexec-tools' counterpart,
    users may not be allowed to specify dtb explicitly, instead, the dtb
    presented by a boot loader is reused.

    arch_kimage_kernel_post_load_cleanup() is responsible for freeing arm64-
    specific data allocated in load_other_segments().

    Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Cc: Will Deacon <will.deacon@arm.com>
    ---
    arch/arm64/include/asm/kexec.h | 16 +++
    arch/arm64/kernel/machine_kexec_file.c | 160 +++++++++++++++++++++++++
    2 files changed, 176 insertions(+)

    diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
    index e17f0529a882..e4de1223715f 100644
    --- a/arch/arm64/include/asm/kexec.h
    +++ b/arch/arm64/include/asm/kexec.h
    @@ -93,6 +93,22 @@ static inline void crash_prepare_suspend(void) {}
    static inline void crash_post_resume(void) {}
    #endif

    +#ifdef CONFIG_KEXEC_FILE
    +#define ARCH_HAS_KIMAGE_ARCH
    +
    +struct kimage_arch {
    + int kern_segment;
    + phys_addr_t dtb_mem;
    + void *dtb_buf;
    +};
    +
    +struct kimage;
    +
    +extern int load_other_segments(struct kimage *image,
    + char *initrd, unsigned long initrd_len,
    + char *cmdline, unsigned long cmdline_len);
    +#endif
    +
    #endif /* __ASSEMBLY__ */

    #endif
    diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
    index f9ebf54ca247..b3b9b1725d8a 100644
    --- a/arch/arm64/kernel/machine_kexec_file.c
    +++ b/arch/arm64/kernel/machine_kexec_file.c
    @@ -13,7 +13,26 @@
    #include <linux/ioport.h>
    #include <linux/kernel.h>
    #include <linux/kexec.h>
    +#include <linux/libfdt.h>
    #include <linux/memblock.h>
    +#include <linux/of_fdt.h>
    +#include <linux/types.h>
    +#include <asm/byteorder.h>
    +
    +static int __dt_root_addr_cells;
    +static int __dt_root_size_cells;
    +
    +const struct kexec_file_ops * const kexec_file_loaders[] = {
    + NULL
    +};
    +
    +int arch_kimage_file_post_load_cleanup(struct kimage *image)
    +{
    + vfree(image->arch.dtb_buf);
    + image->arch.dtb_buf = NULL;
    +
    + return kexec_image_post_load_cleanup_default(image);
    +}

    int arch_kexec_walk_mem(struct kexec_buf *kbuf,
    int (*func)(struct resource *, void *))
    @@ -55,3 +74,144 @@ int arch_kexec_walk_mem(struct kexec_buf *kbuf,

    return ret;
    }
    +
    +static int setup_dtb(struct kimage *image,
    + unsigned long initrd_load_addr, unsigned long initrd_len,
    + char *cmdline, unsigned long cmdline_len,
    + char **dtb_buf, size_t *dtb_buf_len)
    +{
    + char *buf = NULL;
    + size_t buf_size;
    + int nodeoffset;
    + u64 value;
    + int range_len;
    + int ret;
    +
    + /* duplicate dt blob */
    + buf_size = fdt_totalsize(initial_boot_params);
    + range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
    +
    + if (initrd_load_addr)
    + buf_size += fdt_prop_len("linux,initrd-start", sizeof(u64))
    + + fdt_prop_len("linux,initrd-end", sizeof(u64));
    +
    + if (cmdline)
    + buf_size += fdt_prop_len("bootargs", cmdline_len + 1);
    +
    + buf = vmalloc(buf_size);
    + if (!buf) {
    + ret = -ENOMEM;
    + goto out_err;
    + }
    +
    + ret = fdt_open_into(initial_boot_params, buf, buf_size);
    + if (ret)
    + goto out_err;
    +
    + nodeoffset = fdt_path_offset(buf, "/chosen");
    + if (nodeoffset < 0)
    + goto out_err;
    +
    + /* add bootargs */
    + if (cmdline) {
    + ret = fdt_setprop(buf, nodeoffset, "bootargs",
    + cmdline, cmdline_len + 1);
    + if (ret)
    + goto out_err;
    + }
    +
    + /* add initrd-* */
    + if (initrd_load_addr) {
    + value = cpu_to_fdt64(initrd_load_addr);
    + ret = fdt_setprop(buf, nodeoffset, "linux,initrd-start",
    + &value, sizeof(value));
    + if (ret)
    + goto out_err;
    +
    + value = cpu_to_fdt64(initrd_load_addr + initrd_len);
    + ret = fdt_setprop(buf, nodeoffset, "linux,initrd-end",
    + &value, sizeof(value));
    + if (ret)
    + goto out_err;
    + }
    +
    + /* trim a buffer */
    + fdt_pack(buf);
    + *dtb_buf = buf;
    + *dtb_buf_len = fdt_totalsize(buf);
    +
    + return 0;
    +
    +out_err:
    + vfree(buf);
    + return ret;
    +}
    +
    +int load_other_segments(struct kimage *image,
    + char *initrd, unsigned long initrd_len,
    + char *cmdline, unsigned long cmdline_len)
    +{
    + struct kexec_segment *kern_seg;
    + struct kexec_buf kbuf;
    + unsigned long initrd_load_addr = 0;
    + char *dtb = NULL;
    + unsigned long dtb_len = 0;
    + int ret = 0;
    +
    + kern_seg = &image->segment[image->arch.kern_segment];
    + kbuf.image = image;
    + /* not allocate anything below the kernel */
    + kbuf.buf_min = kern_seg->mem + kern_seg->memsz;
    +
    + /* load initrd */
    + if (initrd) {
    + kbuf.buffer = initrd;
    + kbuf.bufsz = initrd_len;
    + kbuf.memsz = initrd_len;
    + kbuf.buf_align = 0;
    + /* within 1GB-aligned window of up to 32GB in size */
    + kbuf.buf_max = round_down(kern_seg->mem, 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;
    +
    + pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
    + initrd_load_addr, initrd_len, initrd_len);
    + }
    +
    + /* load dtb blob */
    + ret = setup_dtb(image, initrd_load_addr, initrd_len,
    + cmdline, cmdline_len, &dtb, &dtb_len);
    + if (ret) {
    + pr_err("Preparing for new dtb failed\n");
    + goto out_err;
    + }
    +
    + kbuf.buffer = dtb;
    + kbuf.bufsz = dtb_len;
    + 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_mem = kbuf.mem;
    + image->arch.dtb_buf = dtb;
    +
    + pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
    + kbuf.mem, dtb_len, dtb_len);
    +
    + return 0;
    +
    +out_err:
    + vfree(dtb);
    + image->arch.dtb_buf = NULL;
    + return ret;
    +}
    --
    2.17.0
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