10 files changed, 380 insertions, 6 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5bc92d2f4716..274252f205b7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1972,6 +1972,12 @@ 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/MAINTAINERS b/MAINTAINERS
index dcd43465eae1..db335f98cad0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8130,6 +8130,12 @@ S:	Maintained
 F:      Documentation/blockdev/ramdisk.txt
 F:      drivers/block/brd.c
 
+PERSISTENT MEMORY DRIVER
+M:      Ross Zwisler <ross.zwisler@linux.intel.com>
+L:      linux-nvdimm@lists.01.org
+S:      Supported
+F:      drivers/block/pmem.c
+
 RANDOM NUMBER DRIVER
 M:      "Theodore Ts'o" <tytso@mit.edu>
 S:      Maintained
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 937812b8e0b9..6049d587599e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1421,6 +1421,16 @@ 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 d993e33f5236..960a8a9dc4ab 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 c887cd944f0c..9bcd0b56ca17 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -95,6 +95,7 @@ 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 7d46bb260334..e2ce85db2283 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 000000000000..3420c874ddc5
--- /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);
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 1b8094d4d7af..eb1fed5bd516 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -404,6 +404,17 @@ config BLK_DEV_RAM_DAX
           and will prevent RAM block device backing store memory from being
           allocated from highmem (only a problem for highmem systems).
 
+config BLK_DEV_PMEM
+        tristate "Persistent memory block device support"
+        help
+          Saying Y here will allow you to use a contiguous range of reserved
+          memory as one or more persistent block devices.
+
+          To compile this driver as a module, choose M here: the module will be
+          called 'pmem'.
+
+          If unsure, say N.
+
 config CDROM_PKTCDVD
         tristate "Packet writing on CD/DVD media"
         depends on !UML
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 02b688d1438d..9cc6c18a1c7e 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PS3_VRAM)		+= ps3vram.o
 obj-$(CONFIG_ATARI_FLOPPY)      += ataflop.o
 obj-$(CONFIG_AMIGA_Z2RAM)       += z2ram.o
 obj-$(CONFIG_BLK_DEV_RAM)       += brd.o
+obj-$(CONFIG_BLK_DEV_PMEM)      += pmem.o
 obj-$(CONFIG_BLK_DEV_LOOP)      += loop.o
 obj-$(CONFIG_BLK_CPQ_DA)        += cpqarray.o
 obj-$(CONFIG_BLK_CPQ_CISS_DA)  += cciss.o
diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
new file mode 100644
index 000000000000..eabf4a8d0085
--- /dev/null
+++ b/drivers/block/pmem.c
@@ -0,0 +1,262 @@
+/*
+ * Persistent Memory Driver
+ *
+ * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
+ * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <asm/cacheflush.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+
+#define PMEM_MINORS             16
+
+struct pmem_device {
+        struct request_queue    *pmem_queue;
+        struct gendisk          *pmem_disk;
+
+        /* One contiguous memory region per device */
+        phys_addr_t             phys_addr;
+        void                    *virt_addr;
+        size_t                  size;
+};
+
+static int pmem_major;
+static atomic_t pmem_index;
+
+static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+                        unsigned int len, unsigned int off, int rw,
+                        sector_t sector)
+{
+        void *mem = kmap_atomic(page);
+        size_t pmem_off = sector << 9;
+
+        if (rw == READ) {
+                memcpy(mem + off, pmem->virt_addr + pmem_off, len);
+                flush_dcache_page(page);
+        } else {
+                flush_dcache_page(page);
+                memcpy(pmem->virt_addr + pmem_off, mem + off, len);
+        }
+
+        kunmap_atomic(mem);
+}
+
+static void pmem_make_request(struct request_queue *q, struct bio *bio)
+{
+        struct block_device *bdev = bio->bi_bdev;
+        struct pmem_device *pmem = bdev->bd_disk->private_data;
+        int rw;
+        struct bio_vec bvec;
+        sector_t sector;
+        struct bvec_iter iter;
+        int err = 0;
+
+        if (bio_end_sector(bio) > get_capacity(bdev->bd_disk)) {
+                err = -EIO;
+                goto out;
+        }
+
+        BUG_ON(bio->bi_rw & REQ_DISCARD);
+
+        rw = bio_data_dir(bio);
+        sector = bio->bi_iter.bi_sector;
+        bio_for_each_segment(bvec, bio, iter) {
+                pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
+                             rw, sector);
+                sector += bvec.bv_len >> 9;
+        }
+
+out:
+        bio_endio(bio, err);
+}
+
+static int pmem_rw_page(struct block_device *bdev, sector_t sector,
+                       struct page *page, int rw)
+{
+        struct pmem_device *pmem = bdev->bd_disk->private_data;
+
+        pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+        page_endio(page, rw & WRITE, 0);
+
+        return 0;
+}
+
+static long pmem_direct_access(struct block_device *bdev, sector_t sector,
+                              void **kaddr, unsigned long *pfn, long size)
+{
+        struct pmem_device *pmem = bdev->bd_disk->private_data;
+        size_t offset = sector << 9;
+
+        if (!pmem)
+                return -ENODEV;
+
+        *kaddr = pmem->virt_addr + offset;
+        *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
+
+        return pmem->size - offset;
+}
+
+static const struct block_device_operations pmem_fops = {
+        .owner =                THIS_MODULE,
+        .rw_page =              pmem_rw_page,
+        .direct_access =        pmem_direct_access,
+};
+
+static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
+{
+        struct pmem_device *pmem;
+        struct gendisk *disk;
+        int idx, err;
+
+        err = -ENOMEM;
+        pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
+        if (!pmem)
+                goto out;
+
+        pmem->phys_addr = res->start;
+        pmem->size = resource_size(res);
+
+        err = -EINVAL;
+        if (!request_mem_region(pmem->phys_addr, pmem->size, "pmem")) {
+                dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n", &pmem->phys_addr, pmem->size);
+                goto out_free_dev;
+        }
+
+        /*
+         * Map the memory as non-cachable, as we can't write back the contents
+         * of the CPU caches in case of a crash.
+         */
+        err = -ENOMEM;
+        pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
+        if (!pmem->virt_addr)
+                goto out_release_region;
+
+        pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL);
+        if (!pmem->pmem_queue)
+                goto out_unmap;
+
+        blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
+        blk_queue_max_hw_sectors(pmem->pmem_queue, 1024);
+        blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
+
+        disk = alloc_disk(PMEM_MINORS);
+        if (!disk)
+                goto out_free_queue;
+
+        idx = atomic_inc_return(&pmem_index) - 1;
+
+        disk->major             = pmem_major;
+        disk->first_minor       = PMEM_MINORS * idx;
+        disk->fops              = &pmem_fops;
+        disk->private_data      = pmem;
+        disk->queue             = pmem->pmem_queue;
+        disk->flags             = GENHD_FL_EXT_DEVT;
+        sprintf(disk->disk_name, "pmem%d", idx);
+        disk->driverfs_dev = dev;
+        set_capacity(disk, pmem->size >> 9);
+        pmem->pmem_disk = disk;
+
+        add_disk(disk);
+
+        return pmem;
+
+out_free_queue:
+        blk_cleanup_queue(pmem->pmem_queue);
+out_unmap:
+        iounmap(pmem->virt_addr);
+out_release_region:
+        release_mem_region(pmem->phys_addr, pmem->size);
+out_free_dev:
+        kfree(pmem);
+out:
+        return ERR_PTR(err);
+}
+
+static void pmem_free(struct pmem_device *pmem)
+{
+        del_gendisk(pmem->pmem_disk);
+        put_disk(pmem->pmem_disk);
+        blk_cleanup_queue(pmem->pmem_queue);
+        iounmap(pmem->virt_addr);
+        release_mem_region(pmem->phys_addr, pmem->size);
+        kfree(pmem);
+}
+
+static int pmem_probe(struct platform_device *pdev)
+{
+        struct pmem_device *pmem;
+        struct resource *res;
+
+        if (WARN_ON(pdev->num_resources > 1))
+                return -ENXIO;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENXIO;
+
+        pmem = pmem_alloc(&pdev->dev, res);
+        if (IS_ERR(pmem))
+                return PTR_ERR(pmem);
+
+        platform_set_drvdata(pdev, pmem);
+
+        return 0;
+}
+
+static int pmem_remove(struct platform_device *pdev)
+{
+        struct pmem_device *pmem = platform_get_drvdata(pdev);
+
+        pmem_free(pmem);
+        return 0;
+}
+
+static struct platform_driver pmem_driver = {
+        .probe          = pmem_probe,
+        .remove         = pmem_remove,
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "pmem",
+        },
+};
+
+static int __init pmem_init(void)
+{
+        int error;
+
+        pmem_major = register_blkdev(0, "pmem");
+        if (pmem_major < 0)
+                return pmem_major;
+
+        error = platform_driver_register(&pmem_driver);
+        if (error)
+                unregister_blkdev(pmem_major, "pmem");
+        return error;
+}
+module_init(pmem_init);
+
+static void pmem_exit(void)
+{
+        platform_driver_unregister(&pmem_driver);
+        unregister_blkdev(pmem_major, "pmem");
+}
+module_exit(pmem_exit);
+
+MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
+MODULE_LICENSE("GPL v2");