Re: [PATCH] powerpc/kexec_file: Restore FDT size estimation for kdump kernel
From: Lakshmi Ramasubramanian <hidden>
Date: 2021-02-19 16:01:03
Also in:
kexec, lkml
On 2/19/21 6:25 AM, Thiago Jung Bauermann wrote: One small nit in the function header (please see below), but otherwise the change looks good. Reviewed-by: Lakshmi Ramasubramanian <redacted>
quoted hunk ↗ jump to hunk
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump kernel") fixed how elf64_load() estimates the FDT size needed by the crashdump kernel. At the same time, commit 130b2d59cec0 ("powerpc: Use common of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That change made the code overestimate it a bit by counting twice the space required for the kernel command line and /chosen properties. Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra space needed by the kdump kernel, and change the function name so that it better reflects what the function is now doing. Signed-off-by: Thiago Jung Bauermann <redacted> --- arch/powerpc/include/asm/kexec.h | 2 +- arch/powerpc/kexec/elf_64.c | 2 +- arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------ 3 files changed, 10 insertions(+), 20 deletions(-) Applies on top of next-20210219.diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index baab158e215c..5a11cc8d2350 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h@@ -128,7 +128,7 @@ int load_crashdump_segments_ppc64(struct kimage *image, int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, unsigned long fdt_load_addr); -unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image); +unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image); int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, unsigned long initrd_load_addr, unsigned long initrd_len, const char *cmdline);diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 0492ca6003f3..5a569bb51349 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c@@ -104,7 +104,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr, initrd_len, cmdline, - kexec_fdt_totalsize_ppc64(image)); + kexec_extra_fdt_size_ppc64(image)); if (!fdt) { pr_err("Error setting up the new device tree.\n"); ret = -EINVAL;diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index 3609de30a170..8541ba731908 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c@@ -927,37 +927,27 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, } /** - * kexec_fdt_totalsize_ppc64 - Return the estimated size needed to setup FDT - * for kexec/kdump kernel. - * @image: kexec image being loaded. + * kexec_extra_fdt_size_ppc63 - Return the estimated size needed to setup FDT
Perhaps change to "Return the estimated additional size needed to setup FDT for kexec/kdump kernel"? -lakshmi
+ * for kexec/kdump kernel.
+ * @image: kexec image being loaded.
*
- * Returns the estimated size needed for kexec/kdump kernel FDT.
+ * Returns the estimated extra size needed for kexec/kdump kernel FDT.
*/
-unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image)
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image)
{
- unsigned int fdt_size;
u64 usm_entries;
- /*
- * The below estimate more than accounts for a typical kexec case where
- * the additional space is to accommodate things like kexec cmdline,
- * chosen node with properties for initrd start & end addresses and
- * a property to indicate kexec boot..
- */
- fdt_size = fdt_totalsize(initial_boot_params) + (2 * COMMAND_LINE_SIZE);
if (image->type != KEXEC_TYPE_CRASH)
- return fdt_size;
+ return 0;
/*
- * For kdump kernel, also account for linux,usable-memory and
+ * For kdump kernel, account for linux,usable-memory and
* linux,drconf-usable-memory properties. Get an approximate on the
* number of usable memory entries and use for FDT size estimation.
*/
usm_entries = ((memblock_end_of_DRAM() / drmem_lmb_size()) +
(2 * (resource_size(&crashk_res) / drmem_lmb_size())));
- fdt_size += (unsigned int)(usm_entries * sizeof(u64));
-
- return fdt_size;
+ return (unsigned int)(usm_entries * sizeof(u64));
}
/**