[RFC PATCH 4/5] powerpc/kdump: enable kexec_file_load system call to use kexec crash FDT

[Sourabh Jain]

This patch enables the kexec_file_load system to utilize the pre-allocated
space for kexec crash FDT during the system boot.

Signed-off-by: Sourabh Jain <sourabhj...@linux.ibm.com>
---
 arch/powerpc/kexec/elf_64.c       | 22 +++++++++++++++++++---
 arch/powerpc/kexec/file_load_64.c |  4 ++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index eeb258002d1e..3176dea0910d 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -116,13 +116,29 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
        if (ret)
                goto out_free_fdt;
 
-       fdt_pack(fdt);
+#ifdef CONFIG_KEXEC_CRASH_FDT
+       if (kexec_crash_fdt && image->type == KEXEC_TYPE_CRASH) {
+               memcpy(kexec_crash_fdt, fdt, fdt_totalsize(fdt));
+               /* retain the original total size */
+               ((struct fdt_header *)(kexec_crash_fdt))->totalsize = 
cpu_to_fdt32(kexec_crash_fdt_size);
+       } else
+#endif
+       {
+               kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+       }
 
        kbuf.buffer = fdt;
-       kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
+
+#ifdef CONFIG_KEXEC_CRASH_FDT
+       if (kexec_crash_fdt && image->type == KEXEC_TYPE_CRASH) {
+               kbuf.bufsz = kbuf.memsz = fdt_totalsize(kexec_crash_fdt);
+       } else
+#endif
+       {
+               kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
+       }
        kbuf.buf_align = PAGE_SIZE;
        kbuf.top_down = true;
-       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
        ret = kexec_add_buffer(&kbuf);
        if (ret)
                goto out_free_fdt;
diff --git a/arch/powerpc/kexec/file_load_64.c 
b/arch/powerpc/kexec/file_load_64.c
index 02bb2adb1fe2..7a320d9e2098 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -906,6 +906,10 @@ int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
        u64 buf_min, buf_max;
        int ret;
 
+       /* kbuf.mem is already pointing to validate memory hole */
+       if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
+               return 0;
+
        /* Look up the exclude ranges list while locating the memory hole */
        emem = &(kbuf->image->arch.exclude_ranges);
        if (!(*emem) || ((*emem)->nr_ranges == 0)) {
-- 
2.34.1