On Thu, May 28, 2015 at 3:35 PM, Ross Zwisler
Even though we use ioremap_nocache() to map our persistent memory in
pmem driver, the memory we are mapping behaves like normal memory and
not I/O memory in that it can be accessed using regular memcpy()
operations and doesn't need to go through memcpy_toio() and
memcpy_fromio(). Force casting the pointers received from
ioremap_nocache() and given to iounmap() gives us the correct behavior
and makes sparse happy.
Signed-off-by: Ross Zwisler <ross.zwisler(a)linux.intel.com>
Cc: Dan Williams <dan.j.williams(a)intel.com>
drivers/block/nd/pmem.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/block/nd/pmem.c b/drivers/block/nd/pmem.c
index 5e8c9c629f22..a8712e41e7f5 100644
@@ -163,7 +163,8 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct
* of the CPU caches in case of a crash.
err = -ENOMEM;
- pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
+ pmem->virt_addr = (__force void *)ioremap_nocache(pmem->phys_addr,
I think I'd rather see casting when ->virt_addr is used (the
__io_virt() helper can be used to make this a tad cleaner), or provide
ioremap apis that don't attach __iomem to their return value. Because
in this and other cases ioremap() is being on non "i/o" memory.