On 2023/8/29 20:16, Baoquan He wrote:
> With the help of newly changed function parse_crashkernel() and
> generic reserve_crashkernel_generic(), crashkernel reservation can be
> simplified by steps:
>
> 1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
> CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
> DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;
>
> 2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
> reserve_crashkernel_generic();
>
> 3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
> arch/arm64/Kconfig.
>
> The old reserve_crashkernel_low() and reserve_crashkernel() can be
> removed.
Reviewed-by: Zhen Lei <thunder.leiz...@huawei.com>
>
> Signed-off-by: Baoquan He <b...@redhat.com>
> ---
> arch/arm64/Kconfig | 3 +
> arch/arm64/include/asm/crash_core.h | 10 ++
> arch/arm64/mm/init.c | 140 ++--------------------------
> 3 files changed, 21 insertions(+), 132 deletions(-)
> create mode 100644 arch/arm64/include/asm/crash_core.h
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 29db061db9bb..07fb8c71339d 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1481,6 +1481,9 @@ config KEXEC_FILE
> for kernel and initramfs as opposed to list of segments as
> accepted by previous system call.
>
> +config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
> + def_bool CRASH_CORE
> +
> config KEXEC_SIG
> bool "Verify kernel signature during kexec_file_load() syscall"
> depends on KEXEC_FILE
> diff --git a/arch/arm64/include/asm/crash_core.h
> b/arch/arm64/include/asm/crash_core.h
> new file mode 100644
> index 000000000000..9f5c8d339f44
> --- /dev/null
> +++ b/arch/arm64/include/asm/crash_core.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef _ARM64_CRASH_CORE_H
> +#define _ARM64_CRASH_CORE_H
> +
> +/* Current arm64 boot protocol requires 2MB alignment */
> +#define CRASH_ALIGN SZ_2M
> +
> +#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
> +#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1)
> +#endif
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 4ad637508b75..48ab23531bb6 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -64,15 +64,6 @@ EXPORT_SYMBOL(memstart_addr);
> */
> phys_addr_t __ro_after_init arm64_dma_phys_limit;
>
> -/* Current arm64 boot protocol requires 2MB alignment */
> -#define CRASH_ALIGN SZ_2M
> -
> -#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
> -#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1)
> -#define CRASH_HIGH_SEARCH_BASE SZ_4G
> -
> -#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
> -
> /*
> * To make optimal use of block mappings when laying out the linear
> * mapping, round down the base of physical memory to a size that can
> @@ -100,140 +91,25 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit;
> #define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT)
> #endif
>
> -static int __init reserve_crashkernel_low(unsigned long long low_size)
> -{
> - unsigned long long low_base;
> -
> - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0,
> CRASH_ADDR_LOW_MAX);
> - if (!low_base) {
> - pr_err("cannot allocate crashkernel low memory
> (size:0x%llx).\n", low_size);
> - return -ENOMEM;
> - }
> -
> - pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld
> MB)\n",
> - low_base, low_base + low_size, low_size >> 20);
> -
> - crashk_low_res.start = low_base;
> - crashk_low_res.end = low_base + low_size - 1;
> - insert_resource(&iomem_resource, &crashk_low_res);
> -
> - return 0;
> -}
> -
> -/*
> - * reserve_crashkernel() - reserves memory for crash kernel
> - *
> - * This function reserves memory area given in "crashkernel=" kernel command
> - * line parameter. The memory reserved is used by dump capture kernel when
> - * primary kernel is crashing.
> - */
> -static void __init reserve_crashkernel(void)
> +static void __init arch_reserve_crashkernel(void)
> {
> - unsigned long long crash_low_size = 0, search_base = 0;
> - unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
> + unsigned long long low_size = 0;
> unsigned long long crash_base, crash_size;
> char *cmdline = boot_command_line;
> - bool fixed_base = false;
> bool high = false;
> int ret;
>
> if (!IS_ENABLED(CONFIG_KEXEC_CORE))
> return;
>
> - /* crashkernel=X[@offset] */
> ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
> - &crash_size, &crash_base, NULL, NULL);
> - if (ret == -ENOENT) {
> - ret = parse_crashkernel_high(cmdline, 0, &crash_size,
> &crash_base);
> - if (ret || !crash_size)
> - return;
> -
> - /*
> - * crashkernel=Y,low can be specified or not, but invalid value
> - * is not allowed.
> - */
> - ret = parse_crashkernel_low(cmdline, 0, &crash_low_size,
> &crash_base);
> - if (ret == -ENOENT)
> - crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
> - else if (ret)
> - return;
> -
> - search_base = CRASH_HIGH_SEARCH_BASE;
> - crash_max = CRASH_ADDR_HIGH_MAX;
> - high = true;
> - } else if (ret || !crash_size) {
> - /* The specified value is invalid */
> + &crash_size, &crash_base,
> + &low_size, &high);
> + if (ret)
> return;
> - }
> -
> - crash_size = PAGE_ALIGN(crash_size);
> -
> - /* User specifies base address explicitly. */
> - if (crash_base) {
> - fixed_base = true;
> - search_base = crash_base;
> - crash_max = crash_base + crash_size;
> - }
> -
> -retry:
> - crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
> - search_base, crash_max);
> - if (!crash_base) {
> - /*
> - * For crashkernel=size[KMG]@offset[KMG], print out failure
> - * message if can't reserve the specified region.
> - */
> - if (fixed_base) {
> - pr_warn("crashkernel reservation failed - memory is in
> use.\n");
> - return;
> - }
> -
> - /*
> - * For crashkernel=size[KMG], if the first attempt was for
> - * low memory, fall back to high memory, the minimum required
> - * low memory will be reserved later.
> - */
> - if (!high && crash_max == CRASH_ADDR_LOW_MAX) {
> - crash_max = CRASH_ADDR_HIGH_MAX;
> - search_base = CRASH_ADDR_LOW_MAX;
> - crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
> - goto retry;
> - }
> -
> - /*
> - * For crashkernel=size[KMG],high, if the first attempt was
> - * for high memory, fall back to low memory.
> - */
> - if (high && crash_max == CRASH_ADDR_HIGH_MAX) {
> - crash_max = CRASH_ADDR_LOW_MAX;
> - search_base = 0;
> - goto retry;
> - }
> - pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
> - crash_size);
> - return;
> - }
> -
> - if ((crash_base >= CRASH_ADDR_LOW_MAX) && crash_low_size &&
> - reserve_crashkernel_low(crash_low_size)) {
> - memblock_phys_free(crash_base, crash_size);
> - return;
> - }
> -
> - pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
> - crash_base, crash_base + crash_size, crash_size >> 20);
> -
> - /*
> - * The crashkernel memory will be removed from the kernel linear
> - * map. Inform kmemleak so that it won't try to access it.
> - */
> - kmemleak_ignore_phys(crash_base);
> - if (crashk_low_res.end)
> - kmemleak_ignore_phys(crashk_low_res.start);
>
> - crashk_res.start = crash_base;
> - crashk_res.end = crash_base + crash_size - 1;
> - insert_resource(&iomem_resource, &crashk_res);
> + reserve_crashkernel_generic(cmdline, crash_size, crash_base,
> + low_size, high);
> }
>
> /*
> @@ -481,7 +357,7 @@ void __init bootmem_init(void)
> * request_standard_resources() depends on crashkernel's memory being
> * reserved, so do it here.
> */
> - reserve_crashkernel();
> + arch_reserve_crashkernel();
>
> memblock_dump_all();
> }
>
--
Regards,
Zhen Lei
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