[PATCH v2] mpt3sas: Use 63-bit DMA addressing on SAS35 HBA

[Suganath Prabu <suganath-prabu.subramani@xxxxxxxxxxxx>]

Although SAS3 & SAS3.5 IT HBA controllers support
64-bit DMA addressing, as per hardware design,
if DMA able range contains all 64-bits set (0xFFFFFFFF-FFFFFFFF) then
it results in a firmware fault.

e.g. SGE's start address is 0xFFFFFFFF-FFFF000 and
data length is 0x1000 bytes. when HBA tries to DMA the data
at 0xFFFFFFFF-FFFFFFFF location then HBA will
fault the firmware.

Fix:
Driver will set 63-bit DMA mask to ensure the above address
will not be used.

Cc: <stable@xxxxxxxxxxxxxxx> # 5.1.20+
Signed-off-by: Suganath Prabu <suganath-prabu.subramani@xxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
V1 Change: Added tag for stable tree
V2 Change: Updated patch description.
 
 drivers/scsi/mpt3sas/mpt3sas_base.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 6846628..050c0f0 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -2703,6 +2703,8 @@ _base_config_dma_addressing(struct MPT3SAS_ADAPTER *ioc, struct pci_dev *pdev)
 {
 	u64 required_mask, coherent_mask;
 	struct sysinfo s;
+	/* Set 63 bit DMA mask for all SAS3 and SAS35 controllers */
+	int dma_mask = (ioc->hba_mpi_version_belonged > MPI2_VERSION) ? 63 : 64;
 
 	if (ioc->is_mcpu_endpoint)
 		goto try_32bit;
@@ -2712,17 +2714,17 @@ _base_config_dma_addressing(struct MPT3SAS_ADAPTER *ioc, struct pci_dev *pdev)
 		goto try_32bit;
 
 	if (ioc->dma_mask)
-		coherent_mask = DMA_BIT_MASK(64);
+		coherent_mask = DMA_BIT_MASK(dma_mask);
 	else
 		coherent_mask = DMA_BIT_MASK(32);
 
-	if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)) ||
+	if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(dma_mask)) ||
 	    dma_set_coherent_mask(&pdev->dev, coherent_mask))
 		goto try_32bit;
 
 	ioc->base_add_sg_single = &_base_add_sg_single_64;
 	ioc->sge_size = sizeof(Mpi2SGESimple64_t);
-	ioc->dma_mask = 64;
+	ioc->dma_mask = dma_mask;
 	goto out;
 
  try_32bit:
@@ -2744,7 +2746,7 @@ static int
 _base_change_consistent_dma_mask(struct MPT3SAS_ADAPTER *ioc,
 				      struct pci_dev *pdev)
 {
-	if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64))) {
+	if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(ioc->dma_mask))) {
 		if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)))
 			return -ENODEV;
 	}
@@ -4989,7 +4991,7 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		total_sz += sz;
 	} while (ioc->rdpq_array_enable && (++i < ioc->reply_queue_count));
 
-	if (ioc->dma_mask == 64) {
+	if (ioc->dma_mask > 32) {
 		if (_base_change_consistent_dma_mask(ioc, ioc->pdev) != 0) {
 			ioc_warn(ioc, "no suitable consistent DMA mask for %s\n",
 				 pci_name(ioc->pdev));
-- 
1.8.3.1