diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bfcb1a62a7b48466f3cbe5a08d3e1a632eadc3d2..c87122dd790fcd0621d16b91c5a0ab1747438bcf 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1965,6 +1965,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
or
memmap=0x10000$0x18690000
+ memmap=nn[KMG]!ss[KMG]
+ [KNL,X86] Mark specific memory as protected.
+ Region of memory to be used, from ss to ss+nn.
+ The memory region may be marked as e820 type 12 (0xc)
+ and is NVDIMM or ADR memory.
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b7d31ca5518744983c77bc8339f30756621dfea0..9e3bcd6f4a483d0e1d1aeff5eb729edd5b2115e7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1430,6 +1430,16 @@ config ILLEGAL_POINTER_VALUE
source "mm/Kconfig"
+config X86_PMEM_LEGACY
+ bool "Support non-standard NVDIMMs and ADR protected memory"
+ help
+ Treat memory marked using the non-standard e820 type of 12 as used
+ by the Intel Sandy Bridge-EP reference BIOS as protected memory.
+ The kernel will offer these regions to the 'pmem' driver so
+ they can be used for persistent storage.
+
+ Say Y if unsure.
+
config HIGHPTE
bool "Allocate 3rd-level pagetables from highmem"
depends on HIGHMEM
diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h
index d993e33f523654cf5a985481d62e60810830f66b..960a8a9dc4abafa0326f3822aee80c3c9764af93 100644
--- a/arch/x86/include/uapi/asm/e820.h
+++ b/arch/x86/include/uapi/asm/e820.h
@@ -33,6 +33,16 @@
#define E820_NVS 4
#define E820_UNUSABLE 5
+/*
+ * This is a non-standardized way to represent ADR or NVDIMM regions that
+ * persist over a reboot. The kernel will ignore their special capabilities
+ * unless the CONFIG_X86_PMEM_LEGACY=y option is set.
+ *
+ * ( Note that older platforms also used 6 for the same type of memory,
+ * but newer versions switched to 12 as 6 was assigned differently. Some
+ * time they will learn... )
+ */
+#define E820_PRAM 12
/*
* reserved RAM used by kernel itself
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index cdb1b70ddad0f026cbe42800571d0869211bf6f5..971f18cd9ca0d8d122ead0d627a2a943f91b4286 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -94,6 +94,7 @@ obj-$(CONFIG_KVM_GUEST) += kvm.o kvmclock.o
obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o
obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= paravirt-spinlocks.o
obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o
+obj-$(CONFIG_X86_PMEM_LEGACY) += pmem.o
obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 46201deee923fffd686244546dc7039dbaab8b2b..11cc7d54ec3f0cfeeb4d62db1fc14e3b6082cd79 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -149,6 +149,9 @@ static void __init e820_print_type(u32 type)
case E820_UNUSABLE:
printk(KERN_CONT "unusable");
break;
+ case E820_PRAM:
+ printk(KERN_CONT "persistent (type %u)", type);
+ break;
default:
printk(KERN_CONT "type %u", type);
break;
@@ -343,7 +346,7 @@ int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
* continue building up new bios map based on this
* information
*/
- if (current_type != last_type) {
+ if (current_type != last_type || current_type == E820_PRAM) {
if (last_type != 0) {
new_bios[new_bios_entry].size =
change_point[chgidx]->addr - last_addr;
@@ -688,6 +691,7 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
register_nosave_region(pfn, PFN_UP(ei->addr));
pfn = PFN_DOWN(ei->addr + ei->size);
+
if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
register_nosave_region(PFN_UP(ei->addr), pfn);
@@ -748,7 +752,7 @@ u64 __init early_reserve_e820(u64 size, u64 align)
/*
* Find the highest page frame number we have available
*/
-static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
+static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
{
int i;
unsigned long last_pfn = 0;
@@ -759,7 +763,11 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
unsigned long start_pfn;
unsigned long end_pfn;
- if (ei->type != type)
+ /*
+ * Persistent memory is accounted as ram for purposes of
+ * establishing max_pfn and mem_map.
+ */
+ if (ei->type != E820_RAM && ei->type != E820_PRAM)
continue;
start_pfn = ei->addr >> PAGE_SHIFT;
@@ -784,12 +792,12 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
}
unsigned long __init e820_end_of_ram_pfn(void)
{
- return e820_end_pfn(MAX_ARCH_PFN, E820_RAM);
+ return e820_end_pfn(MAX_ARCH_PFN);
}
unsigned long __init e820_end_of_low_ram_pfn(void)
{
- return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM);
+ return e820_end_pfn(1UL << (32-PAGE_SHIFT));
}
static void early_panic(char *msg)
@@ -866,6 +874,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, &p);
e820_add_region(start_at, mem_size, E820_RESERVED);
+ } else if (*p == '!') {
+ start_at = memparse(p+1, &p);
+ e820_add_region(start_at, mem_size, E820_PRAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
@@ -907,6 +918,7 @@ static inline const char *e820_type_to_string(int e820_type)
case E820_ACPI: return "ACPI Tables";
case E820_NVS: return "ACPI Non-volatile Storage";
case E820_UNUSABLE: return "Unusable memory";
+ case E820_PRAM: return "Persistent RAM";
default: return "reserved";
}
}
@@ -940,7 +952,9 @@ void __init e820_reserve_resources(void)
* pci device BAR resource and insert them later in
* pcibios_resource_survey()
*/
- if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20)) {
+ if (((e820.map[i].type != E820_RESERVED) &&
+ (e820.map[i].type != E820_PRAM)) ||
+ res->start < (1ULL<<20)) {
res->flags |= IORESOURCE_BUSY;
insert_resource(&iomem_resource, res);
}
diff --git a/arch/x86/kernel/pmem.c b/arch/x86/kernel/pmem.c
new file mode 100644
index 0000000000000000000000000000000000000000..3420c874ddc5127a0dad919660958ecb67c8d164
--- /dev/null
+++ b/arch/x86/kernel/pmem.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2015, Christoph Hellwig.
+ */
+#include <linux/memblock.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <asm/e820.h>
+#include <asm/page_types.h>
+#include <asm/setup.h>
+
+static __init void register_pmem_device(struct resource *res)
+{
+ struct platform_device *pdev;
+ int error;
+
+ pdev = platform_device_alloc("pmem", PLATFORM_DEVID_AUTO);
+ if (!pdev)
+ return;
+
+ error = platform_device_add_resources(pdev, res, 1);
+ if (error)
+ goto out_put_pdev;
+
+ error = platform_device_add(pdev);
+ if (error)
+ goto out_put_pdev;
+ return;
+
+out_put_pdev:
+ dev_warn(&pdev->dev, "failed to add 'pmem' (persistent memory) device!\n");
+ platform_device_put(pdev);
+}
+
+static __init int register_pmem_devices(void)
+{
+ int i;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+
+ if (ei->type == E820_PRAM) {
+ struct resource res = {
+ .flags = IORESOURCE_MEM,
+ .start = ei->addr,
+ .end = ei->addr + ei->size - 1,
+ };
+ register_pmem_device(&res);
+ }
+ }
+
+ return 0;
+}
+device_initcall(register_pmem_devices);