Re: [Pv-drivers] [PATCH] VMW_PVSCSI: Fix the issue of DMA-API related warnings.

[Arvind Kumar <arvindkumar@vmware.com>]

Hi James,

I was wondering if you got time to get to this one. It would be great
if you could please help out with getting this patch in.

Thanks!
Arvind

On Mon, 2014-04-14 at 11:17 -0700, Arvind Kumar wrote:
> Hi James,
> 
> Could you please help getting this in?
> 
> Thanks!
> Arvind
> 
> ----- Original Message -----
> From: "Arvind Kumar" <arvindkumar@vmware.com>
> To: JBottomley@parallels.com, linux-scsi@vger.kernel.org
> Cc: pv-drivers@vmware.com, "Josh Boyer" <jwboyer@fedoraproject.org>
> Sent: Friday, March 21, 2014 11:08:32 AM
> Subject: [Pv-drivers] [PATCH] VMW_PVSCSI: Fix the issue of DMA-API related	warnings.
> 
> The driver is missing calls to pci_dma_mapping_error() after
> performing the DMA mapping, which caused DMA-API warning to
> show up in dmesg's output. Though that happens only when
> DMA_API_DEBUG option is enabled. This change fixes the issue
> and makes pvscsi_map_buffers() function more robust.
> 
> Signed-off-by: Arvind Kumar <arvindkumar@vmware.com>
> Cc: Josh Boyer <jwboyer@fedoraproject.org>
> ---
>  drivers/scsi/vmw_pvscsi.c |   45 +++++++++++++++++++++++++++++++++++++++------
>  drivers/scsi/vmw_pvscsi.h |    2 +-
>  2 files changed, 40 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
> index c88e146..9478a00 100644
> --- a/drivers/scsi/vmw_pvscsi.c
> +++ b/drivers/scsi/vmw_pvscsi.c
> @@ -349,9 +349,9 @@ static void pvscsi_create_sg(struct pvscsi_ctx *ctx,
>   * Map all data buffers for a command into PCI space and
>   * setup the scatter/gather list if needed.
>   */
> -static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
> -			       struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd,
> -			       struct PVSCSIRingReqDesc *e)
> +static int pvscsi_map_buffers(struct pvscsi_adapter *adapter,
> +			      struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd,
> +			      struct PVSCSIRingReqDesc *e)
>  {
>  	unsigned count;
>  	unsigned bufflen = scsi_bufflen(cmd);
> @@ -360,18 +360,30 @@ static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
>  	e->dataLen = bufflen;
>  	e->dataAddr = 0;
>  	if (bufflen == 0)
> -		return;
> +		return 0;
>  
>  	sg = scsi_sglist(cmd);
>  	count = scsi_sg_count(cmd);
>  	if (count != 0) {
>  		int segs = scsi_dma_map(cmd);
> -		if (segs > 1) {
> +
> +		if (segs == -ENOMEM) {
> +			scmd_printk(KERN_ERR, cmd,
> +				    "vmw_pvscsi: Failed to map cmd sglist for DMA.\n");
> +			return -1;
> +		} else if (segs > 1) {
>  			pvscsi_create_sg(ctx, sg, segs);
>  
>  			e->flags |= PVSCSI_FLAG_CMD_WITH_SG_LIST;
>  			ctx->sglPA = pci_map_single(adapter->dev, ctx->sgl,
>  						    SGL_SIZE, PCI_DMA_TODEVICE);
> +			if (pci_dma_mapping_error(adapter->dev, ctx->sglPA)) {
> +				scmd_printk(KERN_ERR, cmd,
> +					    "vmw_pvscsi: Failed to map ctx sglist for DMA.\n");
> +				scsi_dma_unmap(cmd);
> +				ctx->sglPA = 0;
> +				return -1;
> +			}
>  			e->dataAddr = ctx->sglPA;
>  		} else
>  			e->dataAddr = sg_dma_address(sg);
> @@ -382,8 +394,15 @@ static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
>  		 */
>  		ctx->dataPA = pci_map_single(adapter->dev, sg, bufflen,
>  					     cmd->sc_data_direction);
> +		if (pci_dma_mapping_error(adapter->dev, ctx->dataPA)) {
> +			scmd_printk(KERN_ERR, cmd,
> +				    "vmw_pvscsi: Failed to map direct data buffer for DMA.\n");
> +			return -1;
> +		}
>  		e->dataAddr = ctx->dataPA;
>  	}
> +
> +	return 0;
>  }
>  
>  static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
> @@ -712,6 +731,12 @@ static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
>  		ctx->sensePA = pci_map_single(adapter->dev, cmd->sense_buffer,
>  					      SCSI_SENSE_BUFFERSIZE,
>  					      PCI_DMA_FROMDEVICE);
> +		if (pci_dma_mapping_error(adapter->dev, ctx->sensePA)) {
> +			scmd_printk(KERN_ERR, cmd,
> +				    "vmw_pvscsi: Failed to map sense buffer for DMA.\n");
> +			ctx->sensePA = 0;
> +			return -1;
> +		}
>  		e->senseAddr = ctx->sensePA;
>  		e->senseLen = SCSI_SENSE_BUFFERSIZE;
>  	} else {
> @@ -737,7 +762,15 @@ static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
>  	else
>  		e->flags = 0;
>  
> -	pvscsi_map_buffers(adapter, ctx, cmd, e);
> +	if (pvscsi_map_buffers(adapter, ctx, cmd, e) != 0) {
> +		if (cmd->sense_buffer) {
> +			pci_unmap_single(adapter->dev, ctx->sensePA,
> +					 SCSI_SENSE_BUFFERSIZE,
> +					 PCI_DMA_FROMDEVICE);
> +			ctx->sensePA = 0;
> +		}
> +		return -1;
> +	}
>  
>  	e->context = pvscsi_map_context(adapter, ctx);
>  
> diff --git a/drivers/scsi/vmw_pvscsi.h b/drivers/scsi/vmw_pvscsi.h
> index ce45888..fe3b759 100644
> --- a/drivers/scsi/vmw_pvscsi.h
> +++ b/drivers/scsi/vmw_pvscsi.h
> @@ -26,7 +26,7 @@
>  
>  #include <linux/types.h>
>  
> -#define PVSCSI_DRIVER_VERSION_STRING   "1.0.5.0-k"
> +#define PVSCSI_DRIVER_VERSION_STRING   "1.0.6.0-k"
>  
>  #define PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT 128
>