Re: [PATCH v8 3/5] crash: Use crash_exclude_core_ranges() on powerpc

[Sourabh Jain <sourabhjain@linux.ibm.com>]

Changes look good to me.
I tested this on LPAR and QEMU, and dump capture works fine with these 
changes.
I even tried reserving kdump memory using crashkernel=xxM,cma.

Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>


On 02/03/26 09:23, Jinjie Ruan wrote:
> The crash memory exclude of crashk_res and crashk_cma memory on powerpc
> are almost identical to the generic crash_exclude_core_ranges().
>
> By introducing the architecture-specific arch_crash_exclude_mem_range()
> function with a default implementation of crash_exclude_mem_range(),
> and using crash_exclude_mem_range_guarded as powerpc's separate
> implementation, the generic crash_exclude_core_ranges() helper function
> can be reused.
>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>   arch/powerpc/include/asm/kexec_ranges.h |  3 ---
>   arch/powerpc/kexec/crash.c              |  2 +-
>   arch/powerpc/kexec/ranges.c             | 16 ++++------------
>   include/linux/crash_core.h              |  4 ++++
>   kernel/crash_core.c                     | 19 +++++++++++++------
>   5 files changed, 22 insertions(+), 22 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
> index ad95e3792d10..8489e844b447 100644
> --- a/arch/powerpc/include/asm/kexec_ranges.h
> +++ b/arch/powerpc/include/asm/kexec_ranges.h
> @@ -7,9 +7,6 @@
>   void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
>   struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
>   int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
> -int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
> -				    unsigned long long mstart,
> -				    unsigned long long mend);
>   int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
>   int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
>   int get_crash_memory_ranges(struct crash_mem **mem_ranges);
> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
> index 898742a5205c..e59e909c369d 100644
> --- a/arch/powerpc/kexec/crash.c
> +++ b/arch/powerpc/kexec/crash.c
> @@ -451,7 +451,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
>   		base_addr = PFN_PHYS(mn->start_pfn);
>   		size = mn->nr_pages * PAGE_SIZE;
>   		end = base_addr + size - 1;
> -		ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
> +		ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
>   		if (ret) {
>   			pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
>   			goto out;
> diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
> index 6c58bcc3e130..e5fea23b191b 100644
> --- a/arch/powerpc/kexec/ranges.c
> +++ b/arch/powerpc/kexec/ranges.c
> @@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
>   #endif /* CONFIG_KEXEC_FILE */
>   
>   #ifdef CONFIG_CRASH_DUMP
> -int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
> -					   unsigned long long mstart,
> -					   unsigned long long mend)
> +int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
> +				 unsigned long long mstart,
> +				 unsigned long long mend)
>   {
>   	struct crash_mem *tmem = *mem_ranges;
>   
> @@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
>   			sort_memory_ranges(*mem_ranges, true);
>   	}
>   
> -	/* Exclude crashkernel region */
> -	ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
> +	ret = crash_exclude_core_ranges(mem_ranges);
>   	if (ret)
>   		goto out;
>   
> -	for (i = 0; i < crashk_cma_cnt; ++i) {
> -		ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
> -					      crashk_cma_ranges[i].end);
> -		if (ret)
> -			goto out;
> -	}
> -
>   	/*
>   	 * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
>   	 *        regions are exported to save their context at the time of
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 033b20204aca..dbec826dc53b 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -68,6 +68,7 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_ma
>   				       void **addr, unsigned long *sz);
>   extern int crash_prepare_headers(int need_kernel_map, void **addr,
>   				 unsigned long *sz, unsigned long *nr_mem_ranges);
> +extern int crash_exclude_core_ranges(struct crash_mem **cmem);
>   
>   struct kimage;
>   struct kexec_segment;
> @@ -88,6 +89,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
>   extern unsigned int arch_get_system_nr_ranges(void);
>   extern int arch_crash_populate_cmem(struct crash_mem *cmem);
>   extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
> +extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
> +					unsigned long long mstart,
> +					unsigned long long mend);
>   
>   #else /* !CONFIG_CRASH_DUMP*/
>   struct pt_regs;
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 96a96e511f5a..300d44ad5471 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -287,24 +287,31 @@ unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
>   int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
>   int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
>   
> -static int crash_exclude_core_ranges(struct crash_mem *cmem)
> +int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
> +					unsigned long long mstart,
> +					unsigned long long mend)
> +{
> +	return crash_exclude_mem_range(*mem, mstart, mend);
> +}
> +
> +int crash_exclude_core_ranges(struct crash_mem **cmem)
>   {
>   	int ret, i;
>   
>   	/* Exclude crashkernel region */
> -	ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> +	ret = arch_crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
>   	if (ret)
>   		return ret;
>   
>   	if (crashk_low_res.end) {
> -		ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> +		ret = arch_crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
>   		if (ret)
>   			return ret;
>   	}
>   
>   	for (i = 0; i < crashk_cma_cnt; ++i) {
> -		ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> -					      crashk_cma_ranges[i].end);
> +		ret = arch_crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> +						   crashk_cma_ranges[i].end);
>   		if (ret)
>   			return ret;
>   	}
> @@ -331,7 +338,7 @@ int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
>   	if (ret)
>   		goto out;
>   
> -	ret = crash_exclude_core_ranges(cmem);
> +	ret = crash_exclude_core_ranges(&cmem);
>   	if (ret)
>   		goto out;
>