[SCSI] mpt fusion: Fixing 1078 data corruption issue for 36GB memory region

The reason for this change is there is a data corruption when four different
physical memory regions in the 36GB to 37GB region are
accessed. This is only affecting 1078.

The solution is we need to use different addressing when filling in
the scatter gather table for the effected memory regions.  So instead
of snooping on all four different memory holes, we treat any physical
addresses in the 36GB address with the same algorithm.

The fix is explained below
1) Ensure that the message frames are NOT located in the trouble
region. There is no remapping available for message frames, they must
be allocated outside the problem region.
2) Ensure that Sense buffers are NOT in the trouble region. There is
no remapping available.
3) Walk through the SGE entries and if any are inside the trouble region
   then they need to be remapped as discussed below.
	1) Set the Local Address bit in the SGE Flags field.
  	MPI_SGE_FLAGS_LOCAL_ADDRESS
  	2) Ensure we are using 64-bit SGEs
  	3) Set MSb (Bit 63) of the 64-bit address, this will indicate buffer
	location is Host Memory.

Signed-off-by: Kashyap Desai <kadesai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/message/fusion/mptfc.c b/drivers/message/fusion/mptfc.c
index c3c24fdf9fb..da16b47a3f3 100644
--- a/drivers/message/fusion/mptfc.c
+++ b/drivers/message/fusion/mptfc.c
@@ -1251,17 +1251,15 @@ mptfc_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	 * A slightly different algorithm is required for
 	 * 64bit SGEs.
 	 */
-	scale = ioc->req_sz/(sizeof(dma_addr_t) + sizeof(u32));
-	if (sizeof(dma_addr_t) == sizeof(u64)) {
+	scale = ioc->req_sz/ioc->SGE_size;
+	if (ioc->sg_addr_size == sizeof(u64)) {
 		numSGE = (scale - 1) *
 		  (ioc->facts.MaxChainDepth-1) + scale +
-		  (ioc->req_sz - 60) / (sizeof(dma_addr_t) +
-		  sizeof(u32));
+		  (ioc->req_sz - 60) / ioc->SGE_size;
 	} else {
 		numSGE = 1 + (scale - 1) *
 		  (ioc->facts.MaxChainDepth-1) + scale +
-		  (ioc->req_sz - 64) / (sizeof(dma_addr_t) +
-		  sizeof(u32));
+		  (ioc->req_sz - 64) / ioc->SGE_size;
 	}
 
 	if (numSGE < sh->sg_tablesize) {