| Message ID | 20200521093805.64398-3-chenzhou10@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
On 05/21/20 at 05:38pm, Chen Zhou wrote: > Crashkernel=X tries to reserve memory for the crash dump kernel under > 4G. If crashkernel=X,low is specified simultaneously, reserve spcified > size low memory for crash kdump kernel devices firstly and then reserve > memory above 4G. Wondering why crashkernel=,high is not introduced to arm64 to be consistent with x86_64, to make the behaviour be the same on all architecutres. > > 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/arm64/kernel/setup.c | 8 +++++++- > arch/arm64/mm/init.c | 31 +++++++++++++++++++++++++++++-- > 2 files changed, 36 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index 3fd2c11c09fc..a8487e4d3e5a 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -238,7 +238,13 @@ static void __init request_standard_resources(void) > kernel_data.end <= res->end) > request_resource(res, &kernel_data); > #ifdef CONFIG_KEXEC_CORE > - /* Userspace will find "Crash kernel" region in /proc/iomem. */ > + /* > + * Userspace will find "Crash kernel" region in /proc/iomem. > + * Note: the low region is renamed as Crash kernel (low). > + */ > + if (crashk_low_res.end && crashk_low_res.start >= res->start && > + crashk_low_res.end <= res->end) > + request_resource(res, &crashk_low_res); > if (crashk_res.end && crashk_res.start >= res->start && > crashk_res.end <= res->end) > request_resource(res, &crashk_res); > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index e42727e3568e..71498acf0cd8 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -81,6 +81,7 @@ static void __init reserve_crashkernel(void) > { > unsigned long long crash_base, crash_size; > int ret; > + phys_addr_t crash_max = arm64_dma32_phys_limit; > > ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > &crash_size, &crash_base); > @@ -88,12 +89,38 @@ static void __init reserve_crashkernel(void) > if (ret || !crash_size) > return; > > + ret = reserve_crashkernel_low(); > + if (!ret && crashk_low_res.end) { > + /* > + * If crashkernel=X,low specified, there may be two regions, > + * we need to make some changes as follows: > + * > + * 1. rename the low region as "Crash kernel (low)" > + * In order to distinct from the high region and make no effect > + * to the use of existing kexec-tools, rename the low region as > + * "Crash kernel (low)". > + * > + * 2. change the upper bound for crash memory > + * Set MEMBLOCK_ALLOC_ACCESSIBLE upper bound for crash memory. > + * > + * 3. mark the low region as "nomap" > + * The low region is intended to be used for crash dump kernel > + * devices, just mark the low region as "nomap" simply. > + */ > + const char *rename = "Crash kernel (low)"; > + > + crashk_low_res.name = rename; > + crash_max = MEMBLOCK_ALLOC_ACCESSIBLE; > + memblock_mark_nomap(crashk_low_res.start, > + resource_size(&crashk_low_res)); > + } > + > crash_size = PAGE_ALIGN(crash_size); > > if (crash_base == 0) { > /* Current arm64 boot protocol requires 2MB alignment */ > - crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, > - crash_size, SZ_2M); > + crash_base = memblock_find_in_range(0, crash_max, crash_size, > + SZ_2M); > if (crash_base == 0) { > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > crash_size); > -- > 2.20.1 > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec >
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 3fd2c11c09fc..a8487e4d3e5a 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -238,7 +238,13 @@ static void __init request_standard_resources(void) kernel_data.end <= res->end) request_resource(res, &kernel_data); #ifdef CONFIG_KEXEC_CORE - /* Userspace will find "Crash kernel" region in /proc/iomem. */ + /* + * Userspace will find "Crash kernel" region in /proc/iomem. + * Note: the low region is renamed as Crash kernel (low). + */ + if (crashk_low_res.end && crashk_low_res.start >= res->start && + crashk_low_res.end <= res->end) + request_resource(res, &crashk_low_res); if (crashk_res.end && crashk_res.start >= res->start && crashk_res.end <= res->end) request_resource(res, &crashk_res); diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e42727e3568e..71498acf0cd8 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -81,6 +81,7 @@ static void __init reserve_crashkernel(void) { unsigned long long crash_base, crash_size; int ret; + phys_addr_t crash_max = arm64_dma32_phys_limit; ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base); @@ -88,12 +89,38 @@ static void __init reserve_crashkernel(void) if (ret || !crash_size) return; + ret = reserve_crashkernel_low(); + if (!ret && crashk_low_res.end) { + /* + * If crashkernel=X,low specified, there may be two regions, + * we need to make some changes as follows: + * + * 1. rename the low region as "Crash kernel (low)" + * In order to distinct from the high region and make no effect + * to the use of existing kexec-tools, rename the low region as + * "Crash kernel (low)". + * + * 2. change the upper bound for crash memory + * Set MEMBLOCK_ALLOC_ACCESSIBLE upper bound for crash memory. + * + * 3. mark the low region as "nomap" + * The low region is intended to be used for crash dump kernel + * devices, just mark the low region as "nomap" simply. + */ + const char *rename = "Crash kernel (low)"; + + crashk_low_res.name = rename; + crash_max = MEMBLOCK_ALLOC_ACCESSIBLE; + memblock_mark_nomap(crashk_low_res.start, + resource_size(&crashk_low_res)); + } + crash_size = PAGE_ALIGN(crash_size); if (crash_base == 0) { /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, - crash_size, SZ_2M); + crash_base = memblock_find_in_range(0, crash_max, crash_size, + SZ_2M); if (crash_base == 0) { pr_warn("cannot allocate crashkernel (size:0x%llx)\n", crash_size);