Re: [PATCH v2 2/2] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

[Jon Mason]

On Mon, Dec 18, 2017 at 11:25:06AM -0700, Logan Gunthorpe wrote:
> With Switchtec hardware, the buffer used for a memory window must be
> aligned to its size (the hardware only replaces the lower bits). In
> certain circumstances dma_alloc_coherent() will not provide a buffer
> that adheres to this requirement like when using the CMA and
> CONFIG_CMA_ALIGNMENT is set lower than the buffer size.
> 
> When we get an unaligned buffer mw_set_trans() should return an error.
> We also log an error so we know the cause of the problem.
> 

Applied to ntb-next.

Thanks,
Jon

> Signed-off-by: Logan Gunthorpe 
> Cc: Jon Mason 
> ---
> 
> v2: Use IS_ALIGNED macro as suggested by Allen
> 
>  drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c 
> b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> index bcd5b6fb3800..6c6f991999b5 100644
> --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> @@ -320,6 +320,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev 
> *ntb, int pidx, int widx,
>   if (xlate_pos < 12)
>   return -EINVAL;
> 
> + if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
> + /*
> +  * In certain circumstances we can get a buffer that is
> +  * not aligned to its size. (Most of the time
> +  * dma_alloc_coherent ensures this). This can happen when
> +  * using large buffers allocated by the CMA
> +  * (see CMA_CONFIG_ALIGNMENT)
> +  */
> + dev_err(>stdev->dev,
> + "ERROR: Memory window address is not aligned to it's 
> size!\n");
> + return -EINVAL;
> + }
> +
>   rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
>  NTB_CTRL_PART_STATUS_LOCKED);
>   if (rc)
> --
> 2.11.0
> 
> -- 
> You received this message because you are subscribed to the Google Groups 
> "linux-ntb" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to linux-ntb+unsubscr...@googlegroups.com.
> To post to this group, send email to linux-...@googlegroups.com.
> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/linux-ntb/20171218182506.5219-2-logang%40deltatee.com.
> For more options, visit https://groups.google.com/d/optout.

Re: [PATCH v2 2/2] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

[Jon Mason]

On Mon, Dec 18, 2017 at 11:25:06AM -0700, Logan Gunthorpe wrote:
> With Switchtec hardware, the buffer used for a memory window must be
> aligned to its size (the hardware only replaces the lower bits). In
> certain circumstances dma_alloc_coherent() will not provide a buffer
> that adheres to this requirement like when using the CMA and
> CONFIG_CMA_ALIGNMENT is set lower than the buffer size.
> 
> When we get an unaligned buffer mw_set_trans() should return an error.
> We also log an error so we know the cause of the problem.
> 

Applied to ntb-next.

Thanks,
Jon

> Signed-off-by: Logan Gunthorpe 
> Cc: Jon Mason 
> ---
> 
> v2: Use IS_ALIGNED macro as suggested by Allen
> 
>  drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c 
> b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> index bcd5b6fb3800..6c6f991999b5 100644
> --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
> @@ -320,6 +320,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev 
> *ntb, int pidx, int widx,
>   if (xlate_pos < 12)
>   return -EINVAL;
> 
> + if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
> + /*
> +  * In certain circumstances we can get a buffer that is
> +  * not aligned to its size. (Most of the time
> +  * dma_alloc_coherent ensures this). This can happen when
> +  * using large buffers allocated by the CMA
> +  * (see CMA_CONFIG_ALIGNMENT)
> +  */
> + dev_err(>stdev->dev,
> + "ERROR: Memory window address is not aligned to it's 
> size!\n");
> + return -EINVAL;
> + }
> +
>   rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
>  NTB_CTRL_PART_STATUS_LOCKED);
>   if (rc)
> --
> 2.11.0
> 
> -- 
> You received this message because you are subscribed to the Google Groups 
> "linux-ntb" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to linux-ntb+unsubscr...@googlegroups.com.
> To post to this group, send email to linux-...@googlegroups.com.
> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/linux-ntb/20171218182506.5219-2-logang%40deltatee.com.
> For more options, visit https://groups.google.com/d/optout.

[PATCH v2 2/2] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

[Logan Gunthorpe]

With Switchtec hardware, the buffer used for a memory window must be
aligned to its size (the hardware only replaces the lower bits). In
certain circumstances dma_alloc_coherent() will not provide a buffer
that adheres to this requirement like when using the CMA and
CONFIG_CMA_ALIGNMENT is set lower than the buffer size.

When we get an unaligned buffer mw_set_trans() should return an error.
We also log an error so we know the cause of the problem.

Signed-off-by: Logan Gunthorpe 
Cc: Jon Mason 
---

v2: Use IS_ALIGNED macro as suggested by Allen

 drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +
 1 file changed, 13 insertions(+)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c 
b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index bcd5b6fb3800..6c6f991999b5 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -320,6 +320,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, 
int pidx, int widx,
if (xlate_pos < 12)
return -EINVAL;

+   if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
+   /*
+* In certain circumstances we can get a buffer that is
+* not aligned to its size. (Most of the time
+* dma_alloc_coherent ensures this). This can happen when
+* using large buffers allocated by the CMA
+* (see CMA_CONFIG_ALIGNMENT)
+*/
+   dev_err(>stdev->dev,
+   "ERROR: Memory window address is not aligned to it's 
size!\n");
+   return -EINVAL;
+   }
+
rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
   NTB_CTRL_PART_STATUS_LOCKED);
if (rc)
--
2.11.0

[PATCH v2 2/2] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

[Logan Gunthorpe]

With Switchtec hardware, the buffer used for a memory window must be
aligned to its size (the hardware only replaces the lower bits). In
certain circumstances dma_alloc_coherent() will not provide a buffer
that adheres to this requirement like when using the CMA and
CONFIG_CMA_ALIGNMENT is set lower than the buffer size.

When we get an unaligned buffer mw_set_trans() should return an error.
We also log an error so we know the cause of the problem.

Signed-off-by: Logan Gunthorpe 
Cc: Jon Mason 
---

v2: Use IS_ALIGNED macro as suggested by Allen

 drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +
 1 file changed, 13 insertions(+)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c 
b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index bcd5b6fb3800..6c6f991999b5 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -320,6 +320,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, 
int pidx, int widx,
if (xlate_pos < 12)
return -EINVAL;

+   if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
+   /*
+* In certain circumstances we can get a buffer that is
+* not aligned to its size. (Most of the time
+* dma_alloc_coherent ensures this). This can happen when
+* using large buffers allocated by the CMA
+* (see CMA_CONFIG_ALIGNMENT)
+*/
+   dev_err(>stdev->dev,
+   "ERROR: Memory window address is not aligned to it's 
size!\n");
+   return -EINVAL;
+   }
+
rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
   NTB_CTRL_PART_STATUS_LOCKED);
if (rc)
--
2.11.0