IB/srp: Fix FMR mapping for 32-bit kernels and addresses above 4G

struct srp_device.fmr_page_mask was unsigned long, which means that
the top part of addresses above 4G was being chopped off on 32-bit
architectures.  Of course nothing good happens when data from SRP
targets is DMAed to the wrong place.

Fix this by changing fmr_page_mask to u64, to match the addresses
actually used by IB devices.

Thanks to Brian Cain <Brian.Cain@ge.com> and David McMillen
<davem@systemfabricworks.com> for help diagnosing the bug and testing
the fix.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index e9b6a6f07dd7..cdecbf5911c8 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1898,7 +1898,7 @@ static void srp_add_one(struct ib_device *device)
          */
         srp_dev->fmr_page_shift = max(9, ffs(dev_attr->page_size_cap) - 1);
         srp_dev->fmr_page_size  = 1 << srp_dev->fmr_page_shift;
-        srp_dev->fmr_page_mask  = ~((unsigned long) srp_dev->fmr_page_size - 1);
+        srp_dev->fmr_page_mask  = ~((u64) srp_dev->fmr_page_size - 1);
 
         INIT_LIST_HEAD(&srp_dev->dev_list);
 
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index 868a540ef7cd..c21772317b86 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -87,7 +87,7 @@ struct srp_device {
         struct ib_fmr_pool     *fmr_pool;
         int                     fmr_page_shift;
         int                     fmr_page_size;
-        unsigned long           fmr_page_mask;
+        u64                     fmr_page_mask;
 };
 
 struct srp_host {