[PATCH V2 1/3] scsi: mptxsas: try 64 bit DMA when 32 bit DMA fails

Sinan Kaya
2015-11-09T01:57:44Z

Current code gives up when 32 bit DMA is not supported.
This problem has been observed on systems without any
memory below 4 gig.

This patch tests 64 bit support before bailing out to find
a working combination.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/scsi/mpt2sas/mpt2sas_base.c | 21 ++++++++++++++++++++-
drivers/scsi/mpt3sas/mpt3sas_base.c | 22 +++++++++++++++++++++-
2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index c167911..c61c82a 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1217,8 +1217,27 @@ _base_config_dma_addressing(struct MPT2SAS_ADAPTER *ioc, struct pci_dev *pdev)
ioc->base_add_sg_single = &_base_add_sg_single_32;
ioc->sge_size = sizeof(Mpi2SGESimple32_t);
ioc->dma_mask = 32;
- } else
+ } else {
+ /* Try 64 bit, 32 bit failed */
+ consistent_dma_mask = DMA_BIT_MASK(64);
+
+ if (sizeof(dma_addr_t) > 4) {
+ const uint64_t required_mask =
+ dma_get_required_mask(&pdev->dev);
+ if ((required_mask > DMA_BIT_MASK(32)) &&
+ !pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) &&
+ !pci_set_consistent_dma_mask(pdev,
+ consistent_dma_mask)) {
+ ioc->base_add_sg_single =
+ &_base_add_sg_single_64;
+ ioc->sge_size = sizeof(Mpi2SGESimple64_t);
+ ioc->dma_mask = 64;
+ goto out;
+ }
+ }
+
return -ENODEV;
+ }

out:
si_meminfo(&s);
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index d4f1dcd..6dc391c 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -1535,9 +1535,29 @@ _base_config_dma_addressing(struct MPT3SAS_ADAPTER *ioc, struct pci_dev *pdev)
ioc->base_add_sg_single = &_base_add_sg_single_32;
ioc->sge_size = sizeof(Mpi2SGESimple32_t);
ioc->dma_mask = 32;
- } else
+ } else {
+ /* Try 64 bit, 32 bit failed */
+ consistent_dma_mask = DMA_BIT_MASK(64);
+ if (sizeof(dma_addr_t) > 4) {
+ const uint64_t required_mask =
+ dma_get_required_mask(&pdev->dev);
+ int consistent_mask =
+ pci_set_consistent_dma_mask(pdev,
+ consistent_dma_mask);
+
+ if ((required_mask > DMA_BIT_MASK(32)) &&
+ !pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) &&
+ !consistent_mask) {
+ ioc->base_add_sg_single =
+ &_base_add_sg_single_64;
+ ioc->sge_size = sizeof(Mpi2SGESimple64_t);
+ ioc->dma_mask = 64;
+ goto out;
+ }
+ }
return -ENODEV;

+ }
out:
si_meminfo(&s);
pr_info(MPT3SAS_FMT
--
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project