| Message ID | 20201031074437.168008-5-chenzhou10@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
On Sat, Oct 31, 2020 at 03:44:33PM +0800, Chen Zhou wrote: > Make the functions reserve_crashkernel[_low]() as generic. > Arm64 will use these to reimplement crashkernel=X. > > Signed-off-by: Chen Zhou <chenzhou10@huawei.com> > Tested-by: John Donnelly <John.p.donnelly@oracle.com> > --- > arch/x86/include/asm/kexec.h | 25 ++++++ > arch/x86/kernel/setup.c | 151 +------------------------------- > include/linux/crash_core.h | 4 + > include/linux/kexec.h | 2 - > kernel/crash_core.c | 164 +++++++++++++++++++++++++++++++++++ > kernel/kexec_core.c | 17 ---- > 6 files changed, 195 insertions(+), 168 deletions(-) > > diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > index 8cf9d3fd31c7..34afa7b645f9 100644 > --- a/arch/x86/include/asm/kexec.h > +++ b/arch/x86/include/asm/kexec.h > @@ -21,6 +21,27 @@ > /* 2M 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 > + > #ifndef __ASSEMBLY__ > > #include <linux/string.h> > @@ -200,6 +221,10 @@ typedef void crash_vmclear_fn(void); > extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; > extern void kdump_nmi_shootdown_cpus(void); > > +#ifdef CONFIG_KEXEC_CORE > +extern void __init reserve_crashkernel(void); > +#endif > + > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_X86_KEXEC_H */ > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 1289f079ad5f..00b3840d30f9 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -25,8 +25,6 @@ > > #include <uapi/linux/mount.h> > > -#include <xen/xen.h> > - > #include <asm/apic.h> > #include <asm/numa.h> > #include <asm/bios_ebda.h> > @@ -38,6 +36,7 @@ > #include <asm/io_apic.h> > #include <asm/kasan.h> > #include <asm/kaslr.h> > +#include <asm/kexec.h> > #include <asm/mce.h> > #include <asm/mtrr.h> > #include <asm/realmode.h> > @@ -389,153 +388,7 @@ static void __init memblock_x86_reserve_range_setup_data(void) > } > } > > -/* > - * --------- Crashkernel reservation ------------------------------ > - */ > - > -#ifdef CONFIG_KEXEC_CORE > - > -/* > - * 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) > -{ > -#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, CRASH_ALIGN, 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; > - bool high = false; > - int ret; > - > - total_mem = memblock_phys_mem_size(); > - > - /* crashkernel=XM */ > - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); > - 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; > - } > - > - if (xen_pv_domain()) { > - pr_info("Ignoring crashkernel for a Xen PV domain\n"); > - return; > - } This is relevant only to x86, maybe we could move this check to setup_arch before calling reserve_crashkernel() to keep it in x86? > - > - /* 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 CRASH_ADDR_LOW_MAX, > - * 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, CRASH_ALIGN, crash_base, > - crash_base + crash_size); > - if (start != crash_base) { > - pr_info("crashkernel reservation failed - memory is in use.\n"); > - return; > - } > - } > - > - if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { > - memblock_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); > -} > -#else > +#ifndef CONFIG_KEXEC_CORE > static void __init reserve_crashkernel(void) > { > } > diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h > index 206bde8308b2..5021d7c70aee 100644 > --- a/include/linux/crash_core.h > +++ b/include/linux/crash_core.h > @@ -69,6 +69,9 @@ extern unsigned char *vmcoreinfo_data; > extern size_t vmcoreinfo_size; > extern u32 *vmcoreinfo_note; > > +extern struct resource crashk_res; > +extern struct resource crashk_low_res; > + > /* raw contents of kernel .notes section */ > extern const void __start_notes __weak; > extern const void __stop_notes __weak; > @@ -83,5 +86,6 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, > unsigned long long *crash_size, unsigned long long *crash_base); > int parse_crashkernel_low(char *cmdline, unsigned long long system_ram, > unsigned long long *crash_size, unsigned long long *crash_base); > +int __init reserve_crashkernel_low(void); > > #endif /* LINUX_CRASH_CORE_H */ > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > index 9e93bef52968..f301f2f5cfc4 100644 > --- a/include/linux/kexec.h > +++ b/include/linux/kexec.h > @@ -337,8 +337,6 @@ extern int kexec_load_disabled; > > /* Location of a reserved region to hold the crash kernel. > */ > -extern struct resource crashk_res; > -extern struct resource crashk_low_res; > extern note_buf_t __percpu *crash_notes; > > /* flag to track if kexec reboot is in progress */ > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 106e4500fd53..d39892bdb9ae 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -7,7 +7,12 @@ > #include <linux/crash_core.h> > #include <linux/utsname.h> > #include <linux/vmalloc.h> > +#include <linux/memblock.h> > +#include <linux/swiotlb.h> > > +#include <xen/xen.h> > + > +#include <asm/kexec.h> > #include <asm/page.h> > #include <asm/sections.h> > > @@ -21,6 +26,22 @@ u32 *vmcoreinfo_note; > /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ > static unsigned char *vmcoreinfo_data_safecopy; > > +/* Location of the reserved area for the crash kernel */ > +struct resource crashk_res = { > + .name = "Crash kernel", > + .start = 0, > + .end = 0, > + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, > + .desc = IORES_DESC_CRASH_KERNEL > +}; > +struct resource crashk_low_res = { > + .name = "Crash kernel", > + .start = 0, > + .end = 0, > + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, > + .desc = IORES_DESC_CRASH_KERNEL > +}; > + > /* > * parsing the "crashkernel" commandline > * > @@ -294,6 +315,149 @@ int __init parse_crashkernel_low(char *cmdline, > "crashkernel=", suffix_tbl[SUFFIX_LOW]); > } > > +/* > + * --------- Crashkernel reservation ------------------------------ > + */ > + > +int __init reserve_crashkernel_low(void) static? > +{ > +#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, CRASH_ALIGN, > + 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; > +} > + > +#ifdef CONFIG_X86 > +#ifdef CONFIG_KEXEC_CORE > +/* > + * 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. > + */ > +void __init reserve_crashkernel(void) > +{ > + unsigned long long crash_size, crash_base, total_mem; > + bool high = false; > + int ret; > + > + total_mem = memblock_phys_mem_size(); > + > + /* crashkernel=XM */ > + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); > + 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; > + } > + > + 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 CRASH_ADDR_LOW_MAX, > + * 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 { > + /* User specifies base address explicitly. */ > + unsigned long long start; > + > + if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) { > + pr_warn("cannot reserve crashkernel: base address is not %ldMB aligned\n", > + (unsigned long)CRASH_ALIGN >> 20); > + return; > + } > + > + start = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, > + crash_base + crash_size); > + if (start != crash_base) { > + pr_info("crashkernel reservation failed - memory is in use.\n"); > + return; > + } > + } > + > + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { > + memblock_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); > +} > +#endif /* CONFIG_KEXEC_CORE */ > +#endif > + > Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, > void *data, size_t data_len) > { > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c > index 8798a8183974..2ca887514145 100644 > --- a/kernel/kexec_core.c > +++ b/kernel/kexec_core.c > @@ -53,23 +53,6 @@ note_buf_t __percpu *crash_notes; > /* Flag to indicate we are going to kexec a new kernel */ > bool kexec_in_progress = false; > > - > -/* Location of the reserved area for the crash kernel */ > -struct resource crashk_res = { > - .name = "Crash kernel", > - .start = 0, > - .end = 0, > - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, > - .desc = IORES_DESC_CRASH_KERNEL > -}; > -struct resource crashk_low_res = { > - .name = "Crash kernel", > - .start = 0, > - .end = 0, > - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, > - .desc = IORES_DESC_CRASH_KERNEL > -}; > - > int kexec_should_crash(struct task_struct *p) > { > /* > -- > 2.20.1 >
On 2020/11/12 16:11, Mike Rapoport wrote: > On Sat, Oct 31, 2020 at 03:44:33PM +0800, Chen Zhou wrote: >> Make the functions reserve_crashkernel[_low]() as generic. >> Arm64 will use these to reimplement crashkernel=X. >> >> Signed-off-by: Chen Zhou <chenzhou10@huawei.com> >> Tested-by: John Donnelly <John.p.donnelly@oracle.com> >> --- >> arch/x86/include/asm/kexec.h | 25 ++++++ >> arch/x86/kernel/setup.c | 151 +------------------------------- >> include/linux/crash_core.h | 4 + >> include/linux/kexec.h | 2 - >> kernel/crash_core.c | 164 +++++++++++++++++++++++++++++++++++ >> kernel/kexec_core.c | 17 ---- >> 6 files changed, 195 insertions(+), 168 deletions(-) >> >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h >> index 8cf9d3fd31c7..34afa7b645f9 100644 >> --- a/arch/x86/include/asm/kexec.h >> +++ b/arch/x86/include/asm/kexec.h >> @@ -21,6 +21,27 @@ >> /* 2M 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 >> + >> #ifndef __ASSEMBLY__ >> >> #include <linux/string.h> >> @@ -200,6 +221,10 @@ typedef void crash_vmclear_fn(void); >> extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; >> extern void kdump_nmi_shootdown_cpus(void); >> >> +#ifdef CONFIG_KEXEC_CORE >> +extern void __init reserve_crashkernel(void); >> +#endif >> + >> #endif /* __ASSEMBLY__ */ >> >> #endif /* _ASM_X86_KEXEC_H */ >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> index 1289f079ad5f..00b3840d30f9 100644 >> --- a/arch/x86/kernel/setup.c >> +++ b/arch/x86/kernel/setup.c >> @@ -25,8 +25,6 @@ >> >> #include <uapi/linux/mount.h> >> >> -#include <xen/xen.h> >> - >> #include <asm/apic.h> >> #include <asm/numa.h> >> #include <asm/bios_ebda.h> >> @@ -38,6 +36,7 @@ >> #include <asm/io_apic.h> >> #include <asm/kasan.h> >> #include <asm/kaslr.h> >> +#include <asm/kexec.h> >> #include <asm/mce.h> >> #include <asm/mtrr.h> >> #include <asm/realmode.h> >> @@ -389,153 +388,7 @@ static void __init memblock_x86_reserve_range_setup_data(void) >> } >> } >> >> -/* >> - * --------- Crashkernel reservation ------------------------------ >> - */ >> - >> -#ifdef CONFIG_KEXEC_CORE >> - >> -/* >> - * 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) >> -{ >> -#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, CRASH_ALIGN, 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; >> - bool high = false; >> - int ret; >> - >> - total_mem = memblock_phys_mem_size(); >> - >> - /* crashkernel=XM */ >> - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); >> - 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; >> - } >> - >> - if (xen_pv_domain()) { >> - pr_info("Ignoring crashkernel for a Xen PV domain\n"); >> - return; >> - } > This is relevant only to x86, maybe we could move this check to > setup_arch before calling reserve_crashkernel() to keep it in x86? Yes, we could move this check to setup_arch. > >> - >> - /* 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 CRASH_ADDR_LOW_MAX, >> - * 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, CRASH_ALIGN, crash_base, >> - crash_base + crash_size); >> - if (start != crash_base) { >> - pr_info("crashkernel reservation failed - memory is in use.\n"); >> - return; >> - } >> - } >> - >> - if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> - memblock_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); >> -} >> -#else >> +#ifndef CONFIG_KEXEC_CORE >> static void __init reserve_crashkernel(void) >> { >> } >> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h >> index 206bde8308b2..5021d7c70aee 100644 >> --- a/include/linux/crash_core.h >> +++ b/include/linux/crash_core.h >> @@ -69,6 +69,9 @@ extern unsigned char *vmcoreinfo_data; >> extern size_t vmcoreinfo_size; >> extern u32 *vmcoreinfo_note; >> >> +extern struct resource crashk_res; >> +extern struct resource crashk_low_res; >> + >> /* raw contents of kernel .notes section */ >> extern const void __start_notes __weak; >> extern const void __stop_notes __weak; >> @@ -83,5 +86,6 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, >> unsigned long long *crash_size, unsigned long long *crash_base); >> int parse_crashkernel_low(char *cmdline, unsigned long long system_ram, >> unsigned long long *crash_size, unsigned long long *crash_base); >> +int __init reserve_crashkernel_low(void); >> >> #endif /* LINUX_CRASH_CORE_H */ >> diff --git a/include/linux/kexec.h b/include/linux/kexec.h >> index 9e93bef52968..f301f2f5cfc4 100644 >> --- a/include/linux/kexec.h >> +++ b/include/linux/kexec.h >> @@ -337,8 +337,6 @@ extern int kexec_load_disabled; >> >> /* Location of a reserved region to hold the crash kernel. >> */ >> -extern struct resource crashk_res; >> -extern struct resource crashk_low_res; >> extern note_buf_t __percpu *crash_notes; >> >> /* flag to track if kexec reboot is in progress */ >> diff --git a/kernel/crash_core.c b/kernel/crash_core.c >> index 106e4500fd53..d39892bdb9ae 100644 >> --- a/kernel/crash_core.c >> +++ b/kernel/crash_core.c >> @@ -7,7 +7,12 @@ >> #include <linux/crash_core.h> >> #include <linux/utsname.h> >> #include <linux/vmalloc.h> >> +#include <linux/memblock.h> >> +#include <linux/swiotlb.h> >> >> +#include <xen/xen.h> >> + >> +#include <asm/kexec.h> >> #include <asm/page.h> >> #include <asm/sections.h> >> >> @@ -21,6 +26,22 @@ u32 *vmcoreinfo_note; >> /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ >> static unsigned char *vmcoreinfo_data_safecopy; >> >> +/* Location of the reserved area for the crash kernel */ >> +struct resource crashk_res = { >> + .name = "Crash kernel", >> + .start = 0, >> + .end = 0, >> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> + .desc = IORES_DESC_CRASH_KERNEL >> +}; >> +struct resource crashk_low_res = { >> + .name = "Crash kernel", >> + .start = 0, >> + .end = 0, >> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> + .desc = IORES_DESC_CRASH_KERNEL >> +}; >> + >> /* >> * parsing the "crashkernel" commandline >> * >> @@ -294,6 +315,149 @@ int __init parse_crashkernel_low(char *cmdline, >> "crashkernel=", suffix_tbl[SUFFIX_LOW]); >> } >> >> +/* >> + * --------- Crashkernel reservation ------------------------------ >> + */ >> + >> +int __init reserve_crashkernel_low(void) > static? Ok, i will update in next version. > >> +{ >> +#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, CRASH_ALIGN, >> + 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; >> +} >> + >> +#ifdef CONFIG_X86 >> +#ifdef CONFIG_KEXEC_CORE >> +/* >> + * 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. >> + */ >> +void __init reserve_crashkernel(void) >> +{ >> + unsigned long long crash_size, crash_base, total_mem; >> + bool high = false; >> + int ret; >> + >> + total_mem = memblock_phys_mem_size(); >> + >> + /* crashkernel=XM */ >> + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); >> + 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; >> + } >> + >> + 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 CRASH_ADDR_LOW_MAX, >> + * 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 { >> + /* User specifies base address explicitly. */ >> + unsigned long long start; >> + >> + if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) { >> + pr_warn("cannot reserve crashkernel: base address is not %ldMB aligned\n", >> + (unsigned long)CRASH_ALIGN >> 20); >> + return; >> + } >> + >> + start = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, >> + crash_base + crash_size); >> + if (start != crash_base) { >> + pr_info("crashkernel reservation failed - memory is in use.\n"); >> + return; >> + } >> + } >> + >> + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> + memblock_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); >> +} >> +#endif /* CONFIG_KEXEC_CORE */ >> +#endif >> + >> Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, >> void *data, size_t data_len) >> { >> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c >> index 8798a8183974..2ca887514145 100644 >> --- a/kernel/kexec_core.c >> +++ b/kernel/kexec_core.c >> @@ -53,23 +53,6 @@ note_buf_t __percpu *crash_notes; >> /* Flag to indicate we are going to kexec a new kernel */ >> bool kexec_in_progress = false; >> >> - >> -/* Location of the reserved area for the crash kernel */ >> -struct resource crashk_res = { >> - .name = "Crash kernel", >> - .start = 0, >> - .end = 0, >> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> - .desc = IORES_DESC_CRASH_KERNEL >> -}; >> -struct resource crashk_low_res = { >> - .name = "Crash kernel", >> - .start = 0, >> - .end = 0, >> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> - .desc = IORES_DESC_CRASH_KERNEL >> -}; >> - >> int kexec_should_crash(struct task_struct *p) >> { >> /* >> -- >> 2.20.1 >>
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 8cf9d3fd31c7..34afa7b645f9 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -21,6 +21,27 @@ /* 2M 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 + #ifndef __ASSEMBLY__ #include <linux/string.h> @@ -200,6 +221,10 @@ typedef void crash_vmclear_fn(void); extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; extern void kdump_nmi_shootdown_cpus(void); +#ifdef CONFIG_KEXEC_CORE +extern void __init reserve_crashkernel(void); +#endif + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 1289f079ad5f..00b3840d30f9 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -25,8 +25,6 @@ #include <uapi/linux/mount.h> -#include <xen/xen.h> - #include <asm/apic.h> #include <asm/numa.h> #include <asm/bios_ebda.h> @@ -38,6 +36,7 @@ #include <asm/io_apic.h> #include <asm/kasan.h> #include <asm/kaslr.h> +#include <asm/kexec.h> #include <asm/mce.h> #include <asm/mtrr.h> #include <asm/realmode.h> @@ -389,153 +388,7 @@ static void __init memblock_x86_reserve_range_setup_data(void) } } -/* - * --------- Crashkernel reservation ------------------------------ - */ - -#ifdef CONFIG_KEXEC_CORE - -/* - * 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) -{ -#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, CRASH_ALIGN, 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; - bool high = false; - int ret; - - total_mem = memblock_phys_mem_size(); - - /* crashkernel=XM */ - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); - 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; - } - - 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 CRASH_ADDR_LOW_MAX, - * 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, CRASH_ALIGN, crash_base, - crash_base + crash_size); - if (start != crash_base) { - pr_info("crashkernel reservation failed - memory is in use.\n"); - return; - } - } - - if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { - memblock_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); -} -#else +#ifndef CONFIG_KEXEC_CORE static void __init reserve_crashkernel(void) { } diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index 206bde8308b2..5021d7c70aee 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h @@ -69,6 +69,9 @@ extern unsigned char *vmcoreinfo_data; extern size_t vmcoreinfo_size; extern u32 *vmcoreinfo_note; +extern struct resource crashk_res; +extern struct resource crashk_low_res; + /* raw contents of kernel .notes section */ extern const void __start_notes __weak; extern const void __stop_notes __weak; @@ -83,5 +86,6 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); int parse_crashkernel_low(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); +int __init reserve_crashkernel_low(void); #endif /* LINUX_CRASH_CORE_H */ diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 9e93bef52968..f301f2f5cfc4 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -337,8 +337,6 @@ extern int kexec_load_disabled; /* Location of a reserved region to hold the crash kernel. */ -extern struct resource crashk_res; -extern struct resource crashk_low_res; extern note_buf_t __percpu *crash_notes; /* flag to track if kexec reboot is in progress */ diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 106e4500fd53..d39892bdb9ae 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -7,7 +7,12 @@ #include <linux/crash_core.h> #include <linux/utsname.h> #include <linux/vmalloc.h> +#include <linux/memblock.h> +#include <linux/swiotlb.h> +#include <xen/xen.h> + +#include <asm/kexec.h> #include <asm/page.h> #include <asm/sections.h> @@ -21,6 +26,22 @@ u32 *vmcoreinfo_note; /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ static unsigned char *vmcoreinfo_data_safecopy; +/* Location of the reserved area for the crash kernel */ +struct resource crashk_res = { + .name = "Crash kernel", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, + .desc = IORES_DESC_CRASH_KERNEL +}; +struct resource crashk_low_res = { + .name = "Crash kernel", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, + .desc = IORES_DESC_CRASH_KERNEL +}; + /* * parsing the "crashkernel" commandline * @@ -294,6 +315,149 @@ int __init parse_crashkernel_low(char *cmdline, "crashkernel=", suffix_tbl[SUFFIX_LOW]); } +/* + * --------- Crashkernel reservation ------------------------------ + */ + +int __init reserve_crashkernel_low(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, CRASH_ALIGN, + 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; +} + +#ifdef CONFIG_X86 +#ifdef CONFIG_KEXEC_CORE +/* + * 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. + */ +void __init reserve_crashkernel(void) +{ + unsigned long long crash_size, crash_base, total_mem; + bool high = false; + int ret; + + total_mem = memblock_phys_mem_size(); + + /* crashkernel=XM */ + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); + 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; + } + + 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 CRASH_ADDR_LOW_MAX, + * 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 { + /* User specifies base address explicitly. */ + unsigned long long start; + + if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) { + pr_warn("cannot reserve crashkernel: base address is not %ldMB aligned\n", + (unsigned long)CRASH_ALIGN >> 20); + return; + } + + start = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, + crash_base + crash_size); + if (start != crash_base) { + pr_info("crashkernel reservation failed - memory is in use.\n"); + return; + } + } + + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { + memblock_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); +} +#endif /* CONFIG_KEXEC_CORE */ +#endif + Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len) { diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 8798a8183974..2ca887514145 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -53,23 +53,6 @@ note_buf_t __percpu *crash_notes; /* Flag to indicate we are going to kexec a new kernel */ bool kexec_in_progress = false; - -/* Location of the reserved area for the crash kernel */ -struct resource crashk_res = { - .name = "Crash kernel", - .start = 0, - .end = 0, - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, - .desc = IORES_DESC_CRASH_KERNEL -}; -struct resource crashk_low_res = { - .name = "Crash kernel", - .start = 0, - .end = 0, - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, - .desc = IORES_DESC_CRASH_KERNEL -}; - int kexec_should_crash(struct task_struct *p) { /*