diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 15 | ||||
| -rw-r--r-- | arch/riscv/kernel/setup.c | 5 | ||||
| -rw-r--r-- | arch/riscv/mm/init.c | 93 |
3 files changed, 99 insertions, 14 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bdc3fa712e92..c8fe9e7194f1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -862,7 +862,7 @@ memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. - [KNL, X86-64, ARM64] Select a region under 4G first, and + [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. See Documentation/admin-guide/kdump/kdump.rst for further details. @@ -875,14 +875,14 @@ Documentation/admin-guide/kdump/kdump.rst for an example. crashkernel=size[KMG],high - [KNL, X86-64, ARM64] range could be above 4G. Allow kernel - to allocate physical memory region from top, so could - be above 4G if system have more than 4G ram installed. - Otherwise memory region will be allocated below 4G, if - available. + [KNL, X86-64, ARM64, RISCV] range could be above 4G. + Allow kernel to allocate physical memory region from top, + so could be above 4G if system have more than 4G ram + installed. Otherwise memory region will be allocated + below 4G, if available. It will be ignored if crashkernel=X is specified. crashkernel=size[KMG],low - [KNL, X86-64, ARM64] range under 4G. When crashkernel=X,high + [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high is passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb @@ -893,6 +893,7 @@ size is platform dependent. --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB) --> arm64: 128MiB + --> riscv: 128MiB This one lets the user specify own low range under 4G for second kernel instead. 0: to disable low allocation. diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 971fe776e2f8..376f5d49ce85 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -178,6 +178,11 @@ static void __init init_resources(void) if (ret < 0) goto error; } + if (crashk_low_res.start != crashk_low_res.end) { + ret = add_resource(&iomem_resource, &crashk_low_res); + if (ret < 0) + goto error; + } #endif #ifdef CONFIG_CRASH_DUMP diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 70fb31960b63..156e09a1ceee 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1297,6 +1297,28 @@ static inline void setup_vm_final(void) } #endif /* CONFIG_MMU */ +/* Reserve 128M low memory by default for swiotlb buffer */ +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) + +static int __init reserve_crashkernel_low(unsigned long long low_size) +{ + unsigned long long low_base; + + low_base = memblock_phys_alloc_range(low_size, PMD_SIZE, 0, dma32_phys_limit); + if (!low_base) { + pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size); + return -ENOMEM; + } + + pr_info("crashkernel low memory reserved: 0x%016llx - 0x%016llx (%lld MB)\n", + low_base, low_base + low_size, low_size >> 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 * @@ -1308,8 +1330,12 @@ static void __init reserve_crashkernel(void) { unsigned long long crash_base = 0; unsigned long long crash_size = 0; + unsigned long long crash_low_size = 0; unsigned long search_start = memblock_start_of_DRAM(); - unsigned long search_end = memblock_end_of_DRAM(); + unsigned long search_end = (unsigned long)dma32_phys_limit; + char *cmdline = boot_command_line; + bool fixed_base = false; + bool high = false; int ret = 0; @@ -1325,14 +1351,36 @@ static void __init reserve_crashkernel(void) return; } - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), &crash_size, &crash_base); - if (ret || !crash_size) + if (ret == -ENOENT) { + /* Fallback to crashkernel=X,[high,low] */ + ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); + if (ret || !crash_size) + return; + + /* + * crashkernel=Y,low is valid only when crashkernel=X,high + * is passed. + */ + ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); + if (ret == -ENOENT) + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + else if (ret) + return; + + search_start = (unsigned long)dma32_phys_limit; + search_end = memblock_end_of_DRAM(); + high = true; + } else if (ret || !crash_size) { + /* Invalid argument value specified */ return; + } crash_size = PAGE_ALIGN(crash_size); if (crash_base) { + fixed_base = true; search_start = crash_base; search_end = crash_base + crash_size; } @@ -1345,12 +1393,37 @@ static void __init reserve_crashkernel(void) * swiotlb can work on the crash kernel. */ crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE, - search_start, - min(search_end, (unsigned long) SZ_4G)); + search_start, search_end); if (crash_base == 0) { - /* Try again without restricting region to 32bit addressible memory */ + /* + * For crashkernel=size[KMG]@offset[KMG], print out failure + * message if can't reserve the specified region. + */ + if (fixed_base) { + pr_warn("crashkernel: allocating failed with given size@offset\n"); + return; + } + + if (high) { + /* + * For crashkernel=size[KMG],high, if the first attempt was + * for high memory, fall back to low memory. + */ + search_start = memblock_start_of_DRAM(); + search_end = (unsigned long)dma32_phys_limit; + } else { + /* + * For crashkernel=size[KMG], if the first attempt was for + * low memory, fall back to high memory, the minimum required + * low memory will be reserved later. + */ + search_start = (unsigned long)dma32_phys_limit; + search_end = memblock_end_of_DRAM(); + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + } + crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE, - search_start, search_end); + search_start, search_end); if (crash_base == 0) { pr_warn("crashkernel: couldn't allocate %lldKB\n", crash_size >> 10); @@ -1358,6 +1431,12 @@ static void __init reserve_crashkernel(void) } } + if ((crash_base >= dma32_phys_limit) && crash_low_size && + reserve_crashkernel_low(crash_low_size)) { + memblock_phys_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); |