scsi: ufs: core: Limit DMA alignment check

The three DMA memory regions allocated for the host memory space are
documented to require alignment of 128, 1024, and 1024 respectively, but
the returned address is checked for PAGE_SIZE alignment.

In the case where these allocations are serviced by e.g. the Arm SMMU, the
size and alignment will be determined by its supported page sizes. In most
cases SZ_4K and a few larger sizes are available.

In the typical configuration this does not cause problems, but in the event
that the system PAGE_SIZE is increased beyond 4k, it's no longer reasonable
to expect that the allocation will be PAGE_SIZE aligned.

Limit the DMA alignment check to the actual alignment requirements written
in the comments in the code, to avoid the UFS core refusing to initialize
with such configuration.

Link: https://lore.kernel.org/r/20230201034917.1902330-1-quic_bjorande@quicinc.com
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Asutosh Das <quic_asutoshd@quicinc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 89a78a0..ffa71c0 100644 (file)
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3726,12 +3726,9 @@ static int ufshcd_memory_alloc(struct ufs_hba *hba)
 
        /*
         * UFSHCI requires UTP command descriptor to be 128 byte aligned.
-        * make sure hba->ucdl_dma_addr is aligned to PAGE_SIZE
-        * if hba->ucdl_dma_addr is aligned to PAGE_SIZE, then it will
-        * be aligned to 128 bytes as well
         */
        if (!hba->ucdl_base_addr ||
-           WARN_ON(hba->ucdl_dma_addr & (PAGE_SIZE - 1))) {
+           WARN_ON(hba->ucdl_dma_addr & (128 - 1))) {
                dev_err(hba->dev,
                        "Command Descriptor Memory allocation failed\n");
                goto out;
@@ -3747,7 +3744,7 @@ static int ufshcd_memory_alloc(struct ufs_hba *hba)
                                                   &hba->utrdl_dma_addr,
                                                   GFP_KERNEL);
        if (!hba->utrdl_base_addr ||
-           WARN_ON(hba->utrdl_dma_addr & (PAGE_SIZE - 1))) {
+           WARN_ON(hba->utrdl_dma_addr & (1024 - 1))) {
                dev_err(hba->dev,
                        "Transfer Descriptor Memory allocation failed\n");
                goto out;
@@ -3771,7 +3768,7 @@ static int ufshcd_memory_alloc(struct ufs_hba *hba)
                                                    &hba->utmrdl_dma_addr,
                                                    GFP_KERNEL);
        if (!hba->utmrdl_base_addr ||
-           WARN_ON(hba->utmrdl_dma_addr & (PAGE_SIZE - 1))) {
+           WARN_ON(hba->utmrdl_dma_addr & (1024 - 1))) {
                dev_err(hba->dev,
                "Task Management Descriptor Memory allocation failed\n");
                goto out;