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charset="us-ascii"; Format="flowed" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On 10/9/20 12:50 PM, ira.weiny@intel.com wrote: > From: Ira Weiny > > 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 > --- > drivers/nvdimm/pmem.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index fab29b514372..e4dc1ae990fc 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(false); > rc = read_pmem(page, page_off, pmem_addr, len); > + dev_access_disable(false); Hi Ira! The APIs should be tweaked to use a symbol (GLOBAL, PER_THREAD), instead of true/false. Try reading the above and you'll see that it sounds like it's doing the opposite of what it is ("enable_this(false)" sounds like a clumsy API design to *disable*, right?). And there is no hint about the scope. And it *could* be so much more readable like this: dev_access_enable(DEV_ACCESS_THIS_THREAD); thanks, -- John Hubbard NVIDIA ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/