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authorVishal Verma <vishal.l.verma@intel.com>2016-09-30 17:19:30 -0600
committerDan Williams <dan.j.williams@intel.com>2016-09-30 17:03:45 -0700
commitbd697a80c329072b991475fa6608bb0e665b3d90 (patch)
tree9fbdafc9dce374644ef31c24dc87d85216249cbe /drivers
parent9ffd6350a103cb9e73e3abb4573c900cfead2f9b (diff)
downloadlinux-bd697a80c329072b991475fa6608bb0e665b3d90.tar.bz2
pmem: reduce kmap_atomic sections to the memcpys only
pmem_do_bvec used to kmap_atomic at the begin, and only unmap at the end. Things like nvdimm_clear_poison may want to do nvdimm subsystem bookkeeping operations that may involve taking locks or doing memory allocations, and we can't do that from the atomic context. Reduce the atomic context to just what needs it - the memcpy to/from pmem. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/nvdimm/pmem.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 571a6c7ee2fc..42b3a8217073 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -66,13 +66,32 @@ static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
invalidate_pmem(pmem->virt_addr + offset, len);
}
+static void write_pmem(void *pmem_addr, struct page *page,
+ unsigned int off, unsigned int len)
+{
+ void *mem = kmap_atomic(page);
+
+ memcpy_to_pmem(pmem_addr, mem + off, len);
+ kunmap_atomic(mem);
+}
+
+static int read_pmem(struct page *page, unsigned int off,
+ void *pmem_addr, unsigned int len)
+{
+ int rc;
+ void *mem = kmap_atomic(page);
+
+ rc = memcpy_from_pmem(mem + off, pmem_addr, len);
+ kunmap_atomic(mem);
+ return rc;
+}
+
static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, bool is_write,
sector_t sector)
{
int rc = 0;
bool bad_pmem = false;
- void *mem = kmap_atomic(page);
phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
void *pmem_addr = pmem->virt_addr + pmem_off;
@@ -83,7 +102,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
if (unlikely(bad_pmem))
rc = -EIO;
else {
- rc = memcpy_from_pmem(mem + off, pmem_addr, len);
+ rc = read_pmem(page, off, pmem_addr, len);
flush_dcache_page(page);
}
} else {
@@ -102,14 +121,13 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
* after clear poison.
*/
flush_dcache_page(page);
- memcpy_to_pmem(pmem_addr, mem + off, len);
+ write_pmem(pmem_addr, page, off, len);
if (unlikely(bad_pmem)) {
pmem_clear_poison(pmem, pmem_off, len);
- memcpy_to_pmem(pmem_addr, mem + off, len);
+ write_pmem(pmem_addr, page, off, len);
}
}
- kunmap_atomic(mem);
return rc;
}