From a9e1a3d84e4a0ea560ed4d84c28d06dbfdffed22 Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Thu, 14 Sep 2023 11:31:35 +0800 Subject: crash_core: change the prototype of function parse_crashkernel() Add two parameters 'low_size' and 'high' to function parse_crashkernel(), later crashkernel=,high|low parsing will be added. Make adjustments in all call sites of parse_crashkernel() in arch. Link: https://lkml.kernel.org/r/20230914033142.676708-3-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton --- arch/x86/kernel/setup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel/setup.c') diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index b098b1fa2470..655c04812905 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -553,7 +553,8 @@ static void __init reserve_crashkernel(void) total_mem = memblock_phys_mem_size(); /* crashkernel=XM */ - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); + ret = parse_crashkernel(boot_command_line, total_mem, + &crash_size, &crash_base, NULL, NULL); if (ret != 0 || crash_size <= 0) { /* crashkernel=X,high */ ret = parse_crashkernel_high(boot_command_line, total_mem, -- cgit v1.2.3 From 9c08a2a139fe83f217625ee0352ce531b9a666ea Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Thu, 14 Sep 2023 11:31:39 +0800 Subject: x86: kdump: use generic interface to simplify crashkernel reservation code 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 , and define CRASH_ALIGN, CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and DEFAULT_CRASH_KERNEL_LOW_SIZE in ; 2) Add arch_reserve_crashkernel() to call parse_crashkernel() and reserve_crashkernel_generic(), and do the ARCH specific work if needed. 3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in arch/x86/Kconfig. When adding DEFAULT_CRASH_KERNEL_LOW_SIZE, add crash_low_size_default() to calculate crashkernel low memory because x86_64 has special requirement. The old reserve_crashkernel_low() and reserve_crashkernel() can be removed. [bhe@redhat.com: move crash_low_size_default() code into ] Link: https://lkml.kernel.org/r/ZQpeAjOmuMJBFw1/@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20230914033142.676708-7-bhe@redhat.com Signed-off-by: Baoquan He Cc: Catalin Marinas Cc: Chen Jiahao Cc: Zhen Lei Signed-off-by: Andrew Morton --- arch/x86/Kconfig | 3 + arch/x86/include/asm/crash_core.h | 42 +++++++++++ arch/x86/kernel/setup.c | 148 +++----------------------------------- 3 files changed, 56 insertions(+), 137 deletions(-) create mode 100644 arch/x86/include/asm/crash_core.h (limited to 'arch/x86/kernel/setup.c') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 66bfabae8814..36b2f12f31c3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2062,6 +2062,9 @@ config ARCH_SUPPORTS_CRASH_DUMP config ARCH_SUPPORTS_CRASH_HOTPLUG def_bool y +config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION + def_bool CRASH_CORE + config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) default "0x1000000" diff --git a/arch/x86/include/asm/crash_core.h b/arch/x86/include/asm/crash_core.h new file mode 100644 index 000000000000..76af98f4e801 --- /dev/null +++ b/arch/x86/include/asm/crash_core.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X86_CRASH_CORE_H +#define _X86_CRASH_CORE_H + +/* 16M alignment for crash kernel regions */ +#define CRASH_ALIGN SZ_16M + +/* + * Keep the crash kernel below this limit. + * + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range + * due to mapping restrictions. + * + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is + * the upper limit of system RAM in 4-level paging mode. Since the kdump + * jump could be from 5-level paging to 4-level paging, the jump will fail if + * the kernel is put above 64 TB, and during the 1st kernel bootup there's + * no good way to detect the paging mode of the target kernel which will be + * loaded for dumping. + */ +extern unsigned long swiotlb_size_or_default(void); + +#ifdef CONFIG_X86_32 +# define CRASH_ADDR_LOW_MAX SZ_512M +# define CRASH_ADDR_HIGH_MAX SZ_512M +#else +# define CRASH_ADDR_LOW_MAX SZ_4G +# define CRASH_ADDR_HIGH_MAX SZ_64T +#endif + +# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default() + +static inline unsigned long crash_low_size_default(void) +{ +#ifdef CONFIG_X86_64 + return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); +#else + return 0; +#endif +} + +#endif /* _X86_CRASH_CORE_H */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 655c04812905..25a3f9a100f6 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -466,155 +466,29 @@ static void __init memblock_x86_reserve_range_setup_data(void) } } -/* - * --------- Crashkernel reservation ------------------------------ - */ - -/* 16M alignment for crash kernel regions */ -#define CRASH_ALIGN SZ_16M - -/* - * Keep the crash kernel below this limit. - * - * Earlier 32-bits kernels would limit the kernel to the low 512 MB range - * due to mapping restrictions. - * - * 64-bit kdump kernels need to be restricted to be under 64 TB, which is - * the upper limit of system RAM in 4-level paging mode. Since the kdump - * jump could be from 5-level paging to 4-level paging, the jump will fail if - * the kernel is put above 64 TB, and during the 1st kernel bootup there's - * no good way to detect the paging mode of the target kernel which will be - * loaded for dumping. - */ -#ifdef CONFIG_X86_32 -# define CRASH_ADDR_LOW_MAX SZ_512M -# define CRASH_ADDR_HIGH_MAX SZ_512M -#else -# define CRASH_ADDR_LOW_MAX SZ_4G -# define CRASH_ADDR_HIGH_MAX SZ_64T -#endif - -static int __init reserve_crashkernel_low(void) +static void __init arch_reserve_crashkernel(void) { -#ifdef CONFIG_X86_64 - unsigned long long base, low_base = 0, low_size = 0; - unsigned long low_mem_limit; - int ret; - - low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); - - /* crashkernel=Y,low */ - ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); - if (ret) { - /* - * two parts from kernel/dma/swiotlb.c: - * -swiotlb size: user-specified with swiotlb= or default. - * - * -swiotlb overflow buffer: now hardcoded to 32k. We round it - * to 8M for other buffers that may need to stay low too. Also - * make sure we allocate enough extra low memory so that we - * don't run out of DMA buffers for 32-bit devices. - */ - low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); - } else { - /* passed with crashkernel=0,low ? */ - if (!low_size) - return 0; - } - - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX); - if (!low_base) { - pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", - (unsigned long)(low_size >> 20)); - return -ENOMEM; - } - - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", - (unsigned long)(low_size >> 20), - (unsigned long)(low_base >> 20), - (unsigned long)(low_mem_limit >> 20)); - - crashk_low_res.start = low_base; - crashk_low_res.end = low_base + low_size - 1; - insert_resource(&iomem_resource, &crashk_low_res); -#endif - return 0; -} - -static void __init reserve_crashkernel(void) -{ - unsigned long long crash_size, crash_base, total_mem; + unsigned long long crash_base, crash_size, low_size = 0; + char *cmdline = boot_command_line; bool high = false; int ret; if (!IS_ENABLED(CONFIG_KEXEC_CORE)) return; - total_mem = memblock_phys_mem_size(); - - /* crashkernel=XM */ - ret = parse_crashkernel(boot_command_line, total_mem, - &crash_size, &crash_base, NULL, NULL); - if (ret != 0 || crash_size <= 0) { - /* crashkernel=X,high */ - ret = parse_crashkernel_high(boot_command_line, total_mem, - &crash_size, &crash_base); - if (ret != 0 || crash_size <= 0) - return; - high = true; - } + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), + &crash_size, &crash_base, + &low_size, &high); + if (ret) + return; if (xen_pv_domain()) { pr_info("Ignoring crashkernel for a Xen PV domain\n"); return; } - /* 0 means: find the address automatically */ - if (!crash_base) { - /* - * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, - * crashkernel=x,high reserves memory over 4G, also allocates - * 256M extra low memory for DMA buffers and swiotlb. - * But the extra memory is not required for all machines. - * So try low memory first and fall back to high memory - * unless "crashkernel=size[KMG],high" is specified. - */ - if (!high) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_LOW_MAX); - if (!crash_base) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_HIGH_MAX); - if (!crash_base) { - pr_info("crashkernel reservation failed - No suitable area found.\n"); - return; - } - } else { - unsigned long long start; - - start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base, - crash_base + crash_size); - if (start != crash_base) { - pr_info("crashkernel reservation failed - memory is in use.\n"); - return; - } - } - - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) { - memblock_phys_free(crash_base, crash_size); - return; - } - - pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", - (unsigned long)(crash_size >> 20), - (unsigned long)(crash_base >> 20), - (unsigned long)(total_mem >> 20)); - - 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); } static struct resource standard_io_resources[] = { @@ -1228,7 +1102,7 @@ void __init setup_arch(char **cmdline_p) * Reserve memory for crash kernel after SRAT is parsed so that it * won't consume hotpluggable memory. */ - reserve_crashkernel(); + arch_reserve_crashkernel(); memblock_find_dma_reserve(); -- cgit v1.2.3