[RFC PATCH 14/15] nvdimm/pmem: Stray write protection for pmem->virt_addr
From: <hidden>
Date: 2020-07-14 07:04:50
Also in:
linux-fsdevel, linux-kselftest, linux-mm, lkml, nvdimm
Subsystem:
libnvdimm pmem: persistent memory driver, libnvdimm: non-volatile memory device subsystem, the rest · Maintainers:
Dan Williams, Vishal Verma, Dave Jiang, Alison Schofield, Linus Torvalds
From: Ira Weiny <redacted> The pmem driver uses a cached virtual address to access its memory directly. Because the nvdimm driver is well aware of the special protections it has mapped memory with, we call dev_access_[en|dis]able() around the direct pmem->virt_addr (pmem_addr) usage instead of the unnecessary overhead of trying to get a page to kmap. Signed-off-by: Ira Weiny <redacted> --- drivers/nvdimm/pmem.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index d25e66fd942d..46c11a09b813 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c@@ -148,7 +148,9 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) return BLK_STS_IOERR; + dev_access_enable(); rc = read_pmem(page, page_off, pmem_addr, len); + dev_access_disable(); flush_dcache_page(page); return rc; }
@@ -180,11 +182,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, * after clear poison. */ flush_dcache_page(page); + dev_access_enable(); write_pmem(pmem_addr, page, page_off, len); if (unlikely(bad_pmem)) { rc = pmem_clear_poison(pmem, pmem_off, len); write_pmem(pmem_addr, page, page_off, len); } + dev_access_disable(); return rc; }
--
2.25.1