From: Baoquan He <bhe@redhat.com>
To: Chen Zhou <chenzhou10@huawei.com>
Cc: tglx@linutronix.de, mingo@redhat.com, catalin.marinas@arm.com,
will@kernel.org, dyoung@redhat.com, robh+dt@kernel.org,
John.p.donnelly@oracle.com, arnd@arndb.de,
devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
horms@verge.net.au, guohanjun@huawei.com, pkushwaha@marvell.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v8 1/5] x86: kdump: move reserve_crashkernel_low() into crash_core.c
Date: Tue, 26 May 2020 08:56:15 +0800 [thread overview]
Message-ID: <20200526005615.GD20045@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20200521093805.64398-2-chenzhou10@huawei.com>
On 05/21/20 at 05:38pm, Chen Zhou wrote:
> In preparation for supporting reserve_crashkernel_low in arm64 as
> x86_64 does, move reserve_crashkernel_low() into kernel/crash_core.c.
> BTW, move x86 CRASH_ALIGN to 2M.
The reason is?
>
> Note, in arm64, we reserve low memory if and only if crashkernel=X,low
> is specified. Different with x86_64, don't set low memory automatically.
>
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
> Tested-by: John Donnelly <John.p.donnelly@oracle.com>
> Tested-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
> ---
> arch/x86/kernel/setup.c | 66 ++++-------------------------
> include/linux/crash_core.h | 3 ++
> include/linux/kexec.h | 2 -
> kernel/crash_core.c | 85 ++++++++++++++++++++++++++++++++++++++
> kernel/kexec_core.c | 17 --------
> 5 files changed, 96 insertions(+), 77 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 4b3fa6cd3106..de75fec73d47 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -395,8 +395,8 @@ static void __init memblock_x86_reserve_range_setup_data(void)
>
> #ifdef CONFIG_KEXEC_CORE
>
> -/* 16M alignment for crash kernel regions */
> -#define CRASH_ALIGN SZ_16M
> +/* 2M alignment for crash kernel regions */
> +#define CRASH_ALIGN SZ_2M
>
> /*
> * Keep the crash kernel below this limit.
> @@ -419,59 +419,6 @@ static void __init memblock_x86_reserve_range_setup_data(void)
> # 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 total_low_mem;
> - int ret;
> -
> - total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
> -
> - /* crashkernel=Y,low */
> - ret = parse_crashkernel_low(boot_command_line, total_low_mem, &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_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
> - if (!low_base) {
> - pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
> - (unsigned long)(low_size >> 20));
> - return -ENOMEM;
> - }
> -
> - ret = memblock_reserve(low_base, low_size);
> - if (ret) {
> - pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
> - return ret;
> - }
> -
> - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
> - (unsigned long)(low_size >> 20),
> - (unsigned long)(low_base >> 20),
> - (unsigned long)(total_low_mem >> 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;
> @@ -535,9 +482,12 @@ static void __init reserve_crashkernel(void)
> return;
> }
>
> - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
> - memblock_free(crash_base, crash_size);
> - return;
> + if (crash_base >= (1ULL << 32)) {
> + if (reserve_crashkernel_low()) {
> + memblock_free(crash_base, crash_size);
> + return;
> + }
> + insert_resource(&iomem_resource, &crashk_low_res);
> }
>
> pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 525510a9f965..4df8c0bff03e 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -63,6 +63,8 @@ phys_addr_t paddr_vmcoreinfo_note(void);
> 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;
>
> Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
> void *data, size_t data_len);
> @@ -74,5 +76,6 @@ 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 1776eb2e43a4..5d5d9635b18d 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -330,8 +330,6 @@ 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 9f1557b98468..a7580d291c37 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -7,6 +7,8 @@
> #include <linux/crash_core.h>
> #include <linux/utsname.h>
> #include <linux/vmalloc.h>
> +#include <linux/memblock.h>
> +#include <linux/swiotlb.h>
>
> #include <asm/page.h>
> #include <asm/sections.h>
> @@ -19,6 +21,22 @@ 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
> *
> @@ -292,6 +310,73 @@ int __init parse_crashkernel_low(char *cmdline,
> "crashkernel=", suffix_tbl[SUFFIX_LOW]);
> }
>
> +#if defined(CONFIG_X86_64) || defined(CONFIG_ARM64)
> +#define CRASH_ALIGN SZ_2M
> +#endif
> +
> +int __init reserve_crashkernel_low(void)
> +{
> +#if defined(CONFIG_X86_64) || defined(CONFIG_ARM64)
> + unsigned long long base, low_base = 0, low_size = 0;
> + unsigned long total_low_mem;
> + int ret;
> +
> + total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
> +
> + /* crashkernel=Y,low */
> + ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size,
> + &base);
> + if (ret) {
> +#ifdef CONFIG_X86_64
> + /*
> + * two parts from lib/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
> + /*
> + * in arm64, reserve low memory if and only if crashkernel=X,low
> + * specified.
> + */
> + return -EINVAL;
> +#endif
> + } else {
> + /* passed with crashkernel=0,low ? */
> + if (!low_size)
> + return 0;
> + }
> +
> + low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
> + if (!low_base) {
> + pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
> + (unsigned long)(low_size >> 20));
> + return -ENOMEM;
> + }
> +
> + ret = memblock_reserve(low_base, low_size);
> + if (ret) {
> + pr_err("%s: Error reserving crashkernel low memblock.\n",
> + __func__);
> + return ret;
> + }
> +
> + pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
> + (unsigned long)(low_size >> 20),
> + (unsigned long)(low_base >> 20),
> + (unsigned long)(total_low_mem >> 20));
> +
> + crashk_low_res.start = low_base;
> + crashk_low_res.end = low_base + low_size - 1;
> +#endif
> + return 0;
> +}
> +
> 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 c19c0dad1ebe..db66bbabfff3 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
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>
next prev parent reply other threads:[~2020-05-26 0:56 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 9:38 [PATCH v8 0/5] support reserving crashkernel above 4G on arm64 kdump Chen Zhou
2020-05-21 9:38 ` [PATCH v8 1/5] x86: kdump: move reserve_crashkernel_low() into crash_core.c Chen Zhou
2020-05-26 0:56 ` Baoquan He [this message]
2020-05-21 9:38 ` [PATCH v8 2/5] arm64: kdump: reserve crashkenel above 4G for crash dump kernel Chen Zhou
2020-05-26 0:59 ` Baoquan He
2020-05-21 9:38 ` [PATCH v8 3/5] arm64: kdump: add memory for devices by DT property, low-memory-range Chen Zhou
2020-05-21 9:38 ` [PATCH v8 4/5] kdump: update Documentation about crashkernel on arm64 Chen Zhou
2020-05-21 9:38 ` [PATCH v8 5/5] dt-bindings: chosen: Document linux,low-memory-range for arm64 kdump Chen Zhou
2020-05-21 13:29 ` Rob Herring
2020-05-22 3:24 ` chenzhou
2020-05-26 21:18 ` Rob Herring
2020-05-29 16:11 ` James Morse
2020-06-20 3:54 ` chenzhou
2020-05-26 1:42 ` [PATCH v8 0/5] support reserving crashkernel above 4G on " Baoquan He
2020-05-26 2:28 ` chenzhou
2020-05-28 22:20 ` John Donnelly
2020-05-29 8:05 ` Will Deacon
2020-06-01 12:02 ` Prabhakar Kushwaha
2020-06-01 19:30 ` John Donnelly
2020-06-01 21:02 ` Bhupesh Sharma
2020-06-01 21:59 ` John Donnelly
2020-06-02 5:38 ` Prabhakar Kushwaha
2020-06-02 14:41 ` John Donnelly
2020-06-03 11:47 ` Prabhakar Kushwaha
2020-06-03 13:20 ` chenzhou
2020-06-03 15:30 ` John Donnelly
2020-06-03 19:47 ` Bhupesh Sharma
2020-06-04 7:14 ` Will Deacon
2020-06-04 17:01 ` Nicolas Saenz Julienne
2020-06-05 2:26 ` John Donnelly
2020-06-05 8:21 ` Nicolas Saenz Julienne
2020-06-19 2:32 ` John Donnelly
2020-06-19 8:21 ` chenzhou
2020-06-20 0:01 ` John Donnelly
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