From: zhuling zhuling8@huawei.com
hulk inclusion category: feature bugzilla: 48159 CVE: NA
Enabled e820_pmem in arm64: Use memmap=nn[KMG]!ss[KMG] reserve memory for persistent storage when the kernel restart or update. the data in PMEM will not be lost and can be loaded faster.this is a general features.
if you want use this features, you need do as follows: 1.reserve memory: add memmap to reserve memory in grub.cfg memmap=nn[KMG]!ss[KMG] exp:memmap=100K!0x1a0000000. 2.insmod nd_e820.ko: modprobe nd_e820. 3.check pmem device in /dev exp: /dev/pmem0.
Signed-off-by: zhuling zhuling8@huawei.com --- arch/arm64/Kconfig | 24 ++++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/pmem.c | 35 ++++++++++++++ arch/arm64/kernel/setup.c | 6 +++ arch/arm64/mm/init.c | 98 ++++++++++++++++++++++++++++++++++++++ drivers/nvdimm/Makefile | 1 + include/linux/mm.h | 4 ++ 7 files changed, 169 insertions(+) create mode 100644 arch/arm64/kernel/pmem.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b9c56543c..f1e05d9d2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1141,6 +1141,30 @@ config XEN_DOM0 def_bool y depends on XEN
+config ARM64_PMEM_LEGACY_DEVICE + bool + +config ARM64_PMEM_RESERVE + bool "reserve memory for persistent storage" + default y + help + Use memmap=nn[KMG]!ss[KMG](memmap=100K!0x1a0000000) reserve memory for + persistent storage + + Say y here to enable this feature + +config ARM64_PMEM_LEGACY + tristate "create persistent storage" + depends on ARM64_PMEM_RESERVE + depends on BLK_DEV + select ARM64_PMEM_LEGACY_DEVICE + select LIBNVDIMM + help + Use reserved memory for persistent storage when the kernel restart + or update. the data in PMEM will not be lost and can be loaded faster. + + Say y if unsure. + config XEN bool "Xen guest support on ARM64" depends on ARM64 && OF diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 2621d5c2b..c363639b8 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -63,6 +63,7 @@ obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o obj-$(CONFIG_ARM64_MTE) += mte.o +obj-$(CONFIG_ARM64_PMEM_LEGACY_DEVICE) += pmem.o
obj-y += vdso/ probes/ obj-$(CONFIG_COMPAT_VDSO) += vdso32/ diff --git a/arch/arm64/kernel/pmem.c b/arch/arm64/kernel/pmem.c new file mode 100644 index 000000000..16eaf706f --- /dev/null +++ b/arch/arm64/kernel/pmem.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright(c) 2021 Huawei Technologies Co., Ltd + * + * Derived from x86 and arm64 implement PMEM. + */ +#include <linux/platform_device.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/module.h> + +static int found(struct resource *res, void *data) +{ + return 1; +} + +static int __init register_e820_pmem(void) +{ + struct platform_device *pdev; + int rc; + + rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY, + IORESOURCE_MEM, 0, -1, NULL, found); + if (rc <= 0) + return 0; + + /* + * See drivers/nvdimm/e820.c for the implementation, this is + * simply here to trigger the module to load on demand. + */ + pdev = platform_device_alloc("e820_pmem", -1); + + return platform_device_add(pdev); +} +device_initcall(register_e820_pmem); diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 6aff30de8..7f506036d 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -255,6 +255,12 @@ static void __init request_standard_resources(void) request_resource(res, &crashk_res); #endif } + +#ifdef CONFIG_ARM64_PMEM_RESERVE + if (pmem_res.end && pmem_res.start) + request_resource(&iomem_resource, &pmem_res); +#endif + }
static int __init reserve_memblock_reserved_regions(void) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 794f992cb..e4dc19145 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -63,6 +63,18 @@ EXPORT_SYMBOL(memstart_addr); phys_addr_t arm64_dma_phys_limit __ro_after_init; phys_addr_t arm64_dma32_phys_limit __ro_after_init;
+static unsigned long long pmem_size, pmem_start; + +#ifdef CONFIG_ARM64_PMEM_RESERVE +struct resource pmem_res = { + .name = "Persistent Memory (legacy)", + .start = 0, + .end = 0, + .flags = IORESOURCE_MEM, + .desc = IORES_DESC_PERSISTENT_MEMORY_LEGACY +}; +#endif + #ifndef CONFIG_KEXEC_CORE static void __init reserve_crashkernel(void) { @@ -236,6 +248,88 @@ static void __init fdt_enforce_memory_region(void) memblock_add(usable_rgns[1].base, usable_rgns[1].size); }
+static int __init is_mem_valid(unsigned long long mem_size, unsigned long long mem_start) +{ + if (!memblock_is_region_memory(mem_start, mem_size)) { + pr_warn("cannot reserve mem: region is not memory!\n"); + return -EINVAL; + } + + if (memblock_is_region_reserved(mem_start, mem_size)) { + pr_warn("cannot reserve mem: region overlaps reserved memory!\n"); + return -EINVAL; + } + + if (!IS_ALIGNED(mem_start, SZ_2M)) { + pr_warn("cannot reserve mem: base address is not 2MB aligned!\n"); + return -EINVAL; + } + + return 0; +} + +static int __init parse_memmap_one(char *p) +{ + char *oldp; + phys_addr_t start_at, mem_size; + int ret; + + if (!p) + return -EINVAL; + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + return -EINVAL; + + if (!mem_size) + return -EINVAL; + + mem_size = PAGE_ALIGN(mem_size); + + if (*p == '!') { + start_at = memparse(p+1, &p); + + if (is_mem_valid(mem_size, start_at) != 0) + return -EINVAL; + + pr_info("pmem reserved: 0x%016llx - 0x%016llx (%lld MB)\n", + start_at, start_at + mem_size, mem_size >> 20); + pmem_start = start_at; + pmem_size = mem_size; + } else + pr_info("Unrecognized memmap option, please check the parameter.\n"); + + return *p == '\0' ? 0 : -EINVAL; +} + +static int __init parse_memmap_opt(char *str) +{ + while (str) { + char *k = strchr(str, ','); + + if (k) + *k++ = 0; + + parse_memmap_one(str); + str = k; + } + + return 0; +} +early_param("memmap", parse_memmap_opt); + +#ifdef CONFIG_ARM64_PMEM_RESERVE +static void __init reserve_pmem(void) +{ + memblock_remove(pmem_start, pmem_size); + pr_info("pmem reserved: 0x%016llx - 0x%016llx (%lld MB)\n", + pmem_start, pmem_start + pmem_size, pmem_size >> 20); + pmem_res.start = pmem_start; + pmem_res.end = pmem_start + pmem_size - 1; +} +#endif + void __init arm64_memblock_init(void) { const s64 linear_region_size = BIT(vabits_actual - 1); @@ -359,6 +453,10 @@ void __init arm64_memblock_init(void)
reserve_elfcorehdr();
+#ifdef CONFIG_ARM64_PMEM_RESERVE + reserve_pmem(); +#endif + high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
dma_contiguous_reserve(arm64_dma32_phys_limit); diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index 29203f3d3..b97760e9f 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o obj-$(CONFIG_ND_BTT) += nd_btt.o obj-$(CONFIG_ND_BLK) += nd_blk.o obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o +obj-$(CONFIG_ARM64_PMEM_LEGACY) += nd_e820.o obj-$(CONFIG_OF_PMEM) += of_pmem.o obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
diff --git a/include/linux/mm.h b/include/linux/mm.h index cd5c31372..a5e50495e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -45,6 +45,10 @@ extern int sysctl_page_lock_unfairness;
void init_mm_internals(void);
+#ifdef CONFIG_ARM64_PMEM_RESERVE +extern struct resource pmem_res; +#endif + #ifndef CONFIG_NEED_MULTIPLE_NODES /* Don't use mapnrs, do it properly */ extern unsigned long max_mapnr;