| Message ID | 20190403030546.23718-2-chenzhou10@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
Hi, On Wed, Apr 03, 2019 at 11:05:44AM +0800, Chen Zhou wrote: > When crashkernel is reserved above 4G in memory, kernel should > reserve some amount of low memory for swiotlb and some DMA buffers. > > Kernel would try to allocate at least 256M below 4G automatically > as x86_64 if crashkernel is above 4G. Meanwhile, support > crashkernel=X,[high,low] in arm64. > > Signed-off-by: Chen Zhou <chenzhou10@huawei.com> > --- > arch/arm64/kernel/setup.c | 3 ++ > arch/arm64/mm/init.c | 71 +++++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 71 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index 413d566..82cd9a0 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -243,6 +243,9 @@ static void __init request_standard_resources(void) > request_resource(res, &kernel_data); > #ifdef CONFIG_KEXEC_CORE > /* Userspace will find "Crash kernel" region in /proc/iomem. */ > + 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 6bc1350..ceb2a25 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -64,6 +64,57 @@ EXPORT_SYMBOL(memstart_addr); > phys_addr_t arm64_dma_phys_limit __ro_after_init; > > #ifdef CONFIG_KEXEC_CORE > +static int __init reserve_crashkernel_low(void) > +{ > + 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 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 { > + /* passed with crashkernel=0,low ? */ > + if (!low_size) > + return 0; > + } > + > + low_base = memblock_find_in_range(0, 1ULL << 32, low_size, SZ_2M); > + 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 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; > + > + return 0; > +} > + > /* > * reserve_crashkernel() - reserves memory for crash kernel > * > @@ -74,19 +125,28 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init; > static void __init reserve_crashkernel(void) > { > unsigned long long crash_base, crash_size; > + bool high = false; > int ret; > > ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > &crash_size, &crash_base); > /* no crashkernel= or invalid value specified */ > - if (ret || !crash_size) > - return; > + if (ret || !crash_size) { > + /* crashkernel=X,high */ > + ret = parse_crashkernel_high(boot_command_line, memblock_phys_mem_size(), > + &crash_size, &crash_base); > + if (ret || !crash_size) > + return; > + high = true; > + } > > crash_size = PAGE_ALIGN(crash_size); > > if (crash_base == 0) { > /* Current arm64 boot protocol requires 2MB alignment */ > - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, > + crash_base = memblock_find_in_range(0, > + high ? memblock_end_of_DRAM() > + : ARCH_LOW_ADDRESS_LIMIT, > crash_size, SZ_2M); > if (crash_base == 0) { > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > @@ -112,6 +172,11 @@ static void __init reserve_crashkernel(void) > } > memblock_reserve(crash_base, crash_size); > > + if (crash_base >= SZ_4G && reserve_crashkernel_low()) { > + memblock_free(crash_base, crash_size); > + return; > + } > + This very reminds what x86 does. Any chance some of the code can be reused rather than duplicated? > pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", > crash_base, crash_base + crash_size, crash_size >> 20); > > -- > 2.7.4 >
Hi Mike, On 2019/4/4 22:46, Mike Rapoport wrote: > Hi, > > On Wed, Apr 03, 2019 at 11:05:44AM +0800, Chen Zhou wrote: >> When crashkernel is reserved above 4G in memory, kernel should >> reserve some amount of low memory for swiotlb and some DMA buffers. >> >> Kernel would try to allocate at least 256M below 4G automatically >> as x86_64 if crashkernel is above 4G. Meanwhile, support >> crashkernel=X,[high,low] in arm64. >> >> Signed-off-by: Chen Zhou <chenzhou10@huawei.com> >> --- >> arch/arm64/kernel/setup.c | 3 ++ >> arch/arm64/mm/init.c | 71 +++++++++++++++++++++++++++++++++++++++++++++-- >> 2 files changed, 71 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c >> index 413d566..82cd9a0 100644 >> --- a/arch/arm64/kernel/setup.c >> +++ b/arch/arm64/kernel/setup.c >> @@ -243,6 +243,9 @@ static void __init request_standard_resources(void) >> request_resource(res, &kernel_data); >> #ifdef CONFIG_KEXEC_CORE >> /* Userspace will find "Crash kernel" region in /proc/iomem. */ >> + 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 6bc1350..ceb2a25 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -64,6 +64,57 @@ EXPORT_SYMBOL(memstart_addr); >> phys_addr_t arm64_dma_phys_limit __ro_after_init; >> >> #ifdef CONFIG_KEXEC_CORE >> +static int __init reserve_crashkernel_low(void) >> +{ >> + 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 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 { >> + /* passed with crashkernel=0,low ? */ >> + if (!low_size) >> + return 0; >> + } >> + >> + low_base = memblock_find_in_range(0, 1ULL << 32, low_size, SZ_2M); >> + 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 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; >> + >> + return 0; >> +} >> + >> /* >> * reserve_crashkernel() - reserves memory for crash kernel >> * >> @@ -74,19 +125,28 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init; >> static void __init reserve_crashkernel(void) >> { >> unsigned long long crash_base, crash_size; >> + bool high = false; >> int ret; >> >> ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), >> &crash_size, &crash_base); >> /* no crashkernel= or invalid value specified */ >> - if (ret || !crash_size) >> - return; >> + if (ret || !crash_size) { >> + /* crashkernel=X,high */ >> + ret = parse_crashkernel_high(boot_command_line, memblock_phys_mem_size(), >> + &crash_size, &crash_base); >> + if (ret || !crash_size) >> + return; >> + high = true; >> + } >> >> crash_size = PAGE_ALIGN(crash_size); >> >> if (crash_base == 0) { >> /* Current arm64 boot protocol requires 2MB alignment */ >> - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, >> + crash_base = memblock_find_in_range(0, >> + high ? memblock_end_of_DRAM() >> + : ARCH_LOW_ADDRESS_LIMIT, >> crash_size, SZ_2M); >> if (crash_base == 0) { >> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", >> @@ -112,6 +172,11 @@ static void __init reserve_crashkernel(void) >> } >> memblock_reserve(crash_base, crash_size); >> >> + if (crash_base >= SZ_4G && reserve_crashkernel_low()) { >> + memblock_free(crash_base, crash_size); >> + return; >> + } >> + > > This very reminds what x86 does. Any chance some of the code can be reused > rather than duplicated? As i said in the comment, i transport reserve_crashkernel_low() from x86_64. There are minor differences. In arm64, we don't need to do insert_resource(), we do request_resource() in request_standard_resources() later. How about doing like this: move common reserve_crashkernel_low() code into kernel/kexec_core.c. and do in x86 like this: --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -573,9 +573,12 @@ 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; + } else + insert_resource(&iomem_resource, &crashk_low_res); } > >> pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", >> crash_base, crash_base + crash_size, crash_size >> 20); >> >> -- >> 2.7.4 >> >
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 413d566..82cd9a0 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -243,6 +243,9 @@ static void __init request_standard_resources(void) request_resource(res, &kernel_data); #ifdef CONFIG_KEXEC_CORE /* Userspace will find "Crash kernel" region in /proc/iomem. */ + 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 6bc1350..ceb2a25 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -64,6 +64,57 @@ EXPORT_SYMBOL(memstart_addr); phys_addr_t arm64_dma_phys_limit __ro_after_init; #ifdef CONFIG_KEXEC_CORE +static int __init reserve_crashkernel_low(void) +{ + 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 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 { + /* passed with crashkernel=0,low ? */ + if (!low_size) + return 0; + } + + low_base = memblock_find_in_range(0, 1ULL << 32, low_size, SZ_2M); + 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 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; + + return 0; +} + /* * reserve_crashkernel() - reserves memory for crash kernel * @@ -74,19 +125,28 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init; static void __init reserve_crashkernel(void) { unsigned long long crash_base, crash_size; + bool high = false; int ret; ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base); /* no crashkernel= or invalid value specified */ - if (ret || !crash_size) - return; + if (ret || !crash_size) { + /* crashkernel=X,high */ + ret = parse_crashkernel_high(boot_command_line, memblock_phys_mem_size(), + &crash_size, &crash_base); + if (ret || !crash_size) + return; + high = true; + } crash_size = PAGE_ALIGN(crash_size); if (crash_base == 0) { /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, + crash_base = memblock_find_in_range(0, + high ? memblock_end_of_DRAM() + : ARCH_LOW_ADDRESS_LIMIT, crash_size, SZ_2M); if (crash_base == 0) { pr_warn("cannot allocate crashkernel (size:0x%llx)\n", @@ -112,6 +172,11 @@ static void __init reserve_crashkernel(void) } memblock_reserve(crash_base, crash_size); + if (crash_base >= SZ_4G && reserve_crashkernel_low()) { + memblock_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);
When crashkernel is reserved above 4G in memory, kernel should reserve some amount of low memory for swiotlb and some DMA buffers. Kernel would try to allocate at least 256M below 4G automatically as x86_64 if crashkernel is above 4G. Meanwhile, support crashkernel=X,[high,low] in arm64. Signed-off-by: Chen Zhou <chenzhou10@huawei.com> --- arch/arm64/kernel/setup.c | 3 ++ arch/arm64/mm/init.c | 71 +++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 71 insertions(+), 3 deletions(-)