arch, x86: pmem api for ensuring durability of persistent memory updates

[mirror_ubuntu-artful-kernel.git] / drivers / nvdimm / pmem.c

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 42b766f33e59678f5ce2a5618e7fb07ffaebe127..ade9eb917a4d945b4ff9bd69ebbed1b3fedfd742 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
+#include <linux/pmem.h>
 #include <linux/nd.h>
 #include "nd.h"
 
@@ -32,7 +33,7 @@ struct pmem_device {
 
        /* One contiguous memory region per device */
        phys_addr_t             phys_addr;
-       void                    *virt_addr;
+       void __pmem             *virt_addr;
        size_t                  size;
 };
 
@@ -44,13 +45,14 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
 {
        void *mem = kmap_atomic(page);
        size_t pmem_off = sector << 9;
+       void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
 
        if (rw == READ) {
-               memcpy(mem + off, pmem->virt_addr + pmem_off, len);
+               memcpy_from_pmem(mem + off, pmem_addr, len);
                flush_dcache_page(page);
        } else {
                flush_dcache_page(page);
-               memcpy(pmem->virt_addr + pmem_off, mem + off, len);
+               memcpy_to_pmem(pmem_addr, mem + off, len);
        }
 
        kunmap_atomic(mem);
@@ -71,6 +73,10 @@ static void pmem_make_request(struct request_queue *q, struct bio *bio)
                                bio_data_dir(bio), iter.bi_sector);
        if (do_acct)
                nd_iostat_end(bio, start);
+
+       if (bio_data_dir(bio))
+               wmb_pmem();
+
        bio_endio(bio, 0);
 }
 
@@ -94,7 +100,8 @@ static long pmem_direct_access(struct block_device *bdev, sector_t sector,
        if (!pmem)
                return -ENODEV;
 
-       *kaddr = pmem->virt_addr + offset;
+       /* FIXME convert DAX to comprehend that this mapping has a lifetime */
+       *kaddr = (void __force *) pmem->virt_addr + offset;
        *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
 
        return pmem->size - offset;
@@ -118,6 +125,8 @@ static struct pmem_device *pmem_alloc(struct device *dev,
 
        pmem->phys_addr = res->start;
        pmem->size = resource_size(res);
+       if (!arch_has_pmem_api())
+               dev_warn(dev, "unable to guarantee persistence of writes\n");
 
        if (!request_mem_region(pmem->phys_addr, pmem->size, dev_name(dev))) {
                dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
@@ -126,11 +135,7 @@ static struct pmem_device *pmem_alloc(struct device *dev,
                return ERR_PTR(-EBUSY);
        }
 
-       /*
-        * Map the memory as non-cachable, as we can't write back the contents
-        * of the CPU caches in case of a crash.
-        */
-       pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
+       pmem->virt_addr = memremap_pmem(pmem->phys_addr, pmem->size);
        if (!pmem->virt_addr) {
                release_mem_region(pmem->phys_addr, pmem->size);
                kfree(pmem);
@@ -195,16 +200,18 @@ static int pmem_rw_bytes(struct nd_namespace_common *ndns,
        }
 
        if (rw == READ)
-               memcpy(buf, pmem->virt_addr + offset, size);
-       else
-               memcpy(pmem->virt_addr + offset, buf, size);
+               memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
+       else {
+               memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
+               wmb_pmem();
+       }
 
        return 0;
 }
 
 static void pmem_free(struct pmem_device *pmem)
 {
-       iounmap(pmem->virt_addr);
+       memunmap_pmem(pmem->virt_addr);
        release_mem_region(pmem->phys_addr, pmem->size);
        kfree(pmem);
 }