[PATCH 2/2] nvme: improve cmb sysfs reporting

[PATCH 2/2] nvme: improve cmb sysfs reporting

[Stephen Bates]

Add more information to the NVMe CMB sysfs entry. This includes
information about the CMB size, location and capabilities.

Signed-off-by: Stephen Bates <sbates at raithlin.com>
---
 drivers/nvme/host/pci.c | 31 +++++++++++++++++++++++++++++--
 include/linux/nvme.h    |  8 ++++++++
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index be10860..1f70630 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -98,6 +98,7 @@ struct nvme_dev {
 	void __iomem *cmb;
 	dma_addr_t cmb_dma_addr;
 	u64 cmb_size;
+	u64 cmb_offset;
 	u32 cmbsz;
 	u32 cmbloc;
 	struct nvme_ctrl ctrl;
@@ -1326,14 +1327,39 @@ static int nvme_create_io_queues(struct nvme_dev *dev)
 	return ret >= 0 ? 0 : ret;
 }
 
+static const char * const cmb_caps[] = {
+	[NVME_CMB_CAP_SQS] = "SQS",
+	[NVME_CMB_CAP_CQS] = "CQS",
+	[NVME_CMB_CAP_LISTS] = "LISTS",
+	[NVME_CMB_CAP_RDS] = "RDS",
+	[NVME_CMB_CAP_WDS] = "WDS",
+};
+
 static ssize_t nvme_cmb_show(struct device *dev,
 			     struct device_attribute *attr,
 			     char *buf)
 {
 	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+	unsigned int i, len = 0;
+
+	len += scnprintf(buf+len, PAGE_SIZE-len,
+			"cmbloc  : 0x%08x\ncmbsz   : 0x%08x\n\n",
+			ndev->cmbloc, ndev->cmbsz);
+
+	len += scnprintf(buf+len, PAGE_SIZE-len,
+			"OFFSET   : 0x%016llx\nSIZE     : %llu Bytes\n" \
+			"DMA ADDR : %pad\n\n",
+			ndev->cmb_offset, ndev->cmb_size,
+			&ndev->cmb_dma_addr);
+
+	for (i = NVME_CMB_CAP_SQS; i <= NVME_CMB_CAP_WDS; i++)
+		len += scnprintf(buf+len, PAGE_SIZE-len, "%-7s: %s\n",
+				 cmb_caps[i],
+				 ((ndev->cmbsz) & (1<<i)) ? "SUPPORTED" :
+				 "NOT SUPPORTED");
+
+	return len;
 
-	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
-		       ndev->cmbloc, ndev->cmbsz);
 }
 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
 
@@ -1376,6 +1402,7 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
 
 	dev->cmb_dma_addr = dma_addr;
 	dev->cmb_size = size;
+	dev->cmb_offset = offset;
 	return cmb;
 }
 
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index fc3c242..cd0d324 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -121,6 +121,14 @@ enum {
 #define NVME_CMB_CQS(cmbsz)	((cmbsz) & 0x2)
 #define NVME_CMB_SQS(cmbsz)	((cmbsz) & 0x1)
 
+enum {
+	NVME_CMB_CAP_SQS = 0,
+	NVME_CMB_CAP_CQS,
+	NVME_CMB_CAP_LISTS,
+	NVME_CMB_CAP_RDS,
+	NVME_CMB_CAP_WDS,
+};
+
 /*
  * Submission and Completion Queue Entry Sizes for the NVM command set.
  * (In bytes and specified as a power of two (2^n)).
-- 
2.1.4

[PATCH 2/2] nvme: improve cmb sysfs reporting

[Jon Derrick]

Minor nit below

On Fri, Dec 16, 2016@11:54:51AM -0700, Stephen Bates wrote:
> Add more information to the NVMe CMB sysfs entry. This includes
> information about the CMB size, location and capabilities.
> 
> Signed-off-by: Stephen Bates <sbates at raithlin.com>
> ---
>  drivers/nvme/host/pci.c | 31 +++++++++++++++++++++++++++++--
>  include/linux/nvme.h    |  8 ++++++++
>  2 files changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index be10860..1f70630 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -98,6 +98,7 @@ struct nvme_dev {
>  	void __iomem *cmb;
>  	dma_addr_t cmb_dma_addr;
>  	u64 cmb_size;
> +	u64 cmb_offset;
>  	u32 cmbsz;
>  	u32 cmbloc;
>  	struct nvme_ctrl ctrl;
> @@ -1326,14 +1327,39 @@ static int nvme_create_io_queues(struct nvme_dev *dev)
>  	return ret >= 0 ? 0 : ret;
>  }
>  
> +static const char * const cmb_caps[] = {
> +	[NVME_CMB_CAP_SQS] = "SQS",
> +	[NVME_CMB_CAP_CQS] = "CQS",
> +	[NVME_CMB_CAP_LISTS] = "LISTS",
> +	[NVME_CMB_CAP_RDS] = "RDS",
> +	[NVME_CMB_CAP_WDS] = "WDS",
> +};
> +
>  static ssize_t nvme_cmb_show(struct device *dev,
>  			     struct device_attribute *attr,
>  			     char *buf)
>  {
>  	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
> +	unsigned int i, len = 0;
> +
> +	len += scnprintf(buf+len, PAGE_SIZE-len,
> +			"cmbloc  : 0x%08x\ncmbsz   : 0x%08x\n\n",
> +			ndev->cmbloc, ndev->cmbsz);
> +
> +	len += scnprintf(buf+len, PAGE_SIZE-len,
> +			"OFFSET   : 0x%016llx\nSIZE     : %llu Bytes\n" \
> +			"DMA ADDR : %pad\n\n",
> +			ndev->cmb_offset, ndev->cmb_size,
> +			&ndev->cmb_dma_addr);
> +
> +	for (i = NVME_CMB_CAP_SQS; i <= NVME_CMB_CAP_WDS; i++)
I'd prefer seeing (i = 0; i < ARRAY_SIZE(..); i++) because it provides
automatic bounds checking against future code.

> +		len += scnprintf(buf+len, PAGE_SIZE-len, "%-7s: %s\n",
> +				 cmb_caps[i],
> +				 ((ndev->cmbsz) & (1<<i)) ? "SUPPORTED" :
> +				 "NOT SUPPORTED");
> +
> +	return len;
>  
> -	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
> -		       ndev->cmbloc, ndev->cmbsz);
>  }
>  static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
>  
> @@ -1376,6 +1402,7 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
>  
>  	dev->cmb_dma_addr = dma_addr;
>  	dev->cmb_size = size;
> +	dev->cmb_offset = offset;
>  	return cmb;
>  }
>  
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index fc3c242..cd0d324 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -121,6 +121,14 @@ enum {
>  #define NVME_CMB_CQS(cmbsz)	((cmbsz) & 0x2)
>  #define NVME_CMB_SQS(cmbsz)	((cmbsz) & 0x1)
>  
> +enum {
> +	NVME_CMB_CAP_SQS = 0,
> +	NVME_CMB_CAP_CQS,
> +	NVME_CMB_CAP_LISTS,
> +	NVME_CMB_CAP_RDS,
> +	NVME_CMB_CAP_WDS,
> +};
> +
>  /*
>   * Submission and Completion Queue Entry Sizes for the NVM command set.
>   * (In bytes and specified as a power of two (2^n)).
> -- 
> 2.1.4
> 

[PATCH 2/2] nvme: improve cmb sysfs reporting

[Stephen Bates]

> Minor nit below
>
>
>> +
>> +	for (i = NVME_CMB_CAP_SQS; i <= NVME_CMB_CAP_WDS; i++)
>>
> I'd prefer seeing (i = 0; i < ARRAY_SIZE(..); i++) because it provides
> automatic bounds checking against future code.
>

Thanks Jon, I will take a look at doing this in a V1.

Stephen

[PATCH 0/2] nvme: Improvements in sysfs entry for NVMe CMBs

[Jens Axboe]

On 12/16/2016 11:54 AM, Stephen Bates wrote:
> Hi
> 
> This series adds some more verbosity to the NVMe CMB sysfs entry.
> 
> Jens I based this off v4.9 because for some reason your for-4.10/block
> is missing my original CMB commit (202021c1a63c6)?

for-4.10/block was forked off v4.9-rc1, and that patch didn't make it
in until v4.9-rc2. Since for-4.10/block has been merged, any patches
for this series or next should be based on my for-linus, or just master.

Assuming these two apply directly to master as well?

-- 
Jens Axboe

[PATCH 0/2] nvme: Improvements in sysfs entry for NVMe CMBs

[Stephen Bates]

>> Jens I based this off v4.9 because for some reason your for-4.10/block
>> is missing my original CMB commit (202021c1a63c6)?
>
> for-4.10/block was forked off v4.9-rc1, and that patch didn't make it in
> until v4.9-rc2. Since for-4.10/block has been merged, any patches for this
> series or next should be based on my for-linus, or just master.
>
> Assuming these two apply directly to master as well?
>
>

Ah thanks for clearing up my confusion ;-). Yes, this series applies
cleanly to both your master and for-linus branches.


Stephen

[PATCH 1/2] nvme : Use correct scnprintf in cmb show

[Jon Derrick]

Looks good. Thanks Stephen.

Reviewed-by Jon Derrick: <jonathan.derrick at intel.com>

On Fri, Dec 16, 2016@11:54:50AM -0700, Stephen Bates wrote:
> Make sure we are using the correct scnprintf in the sysfs show
> function for the CMB.
> 
> Signed-off-by: Stephen Bates <sbates at raithlin.com>
> ---
>  drivers/nvme/host/pci.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 5e52034..be10860 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -50,7 +50,7 @@
>  #define NVME_AQ_DEPTH		256
>  #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
>  #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
> -		
> +
>  /*
>   * We handle AEN commands ourselves and don't even let the
>   * block layer know about them.
> @@ -1332,7 +1332,7 @@ static ssize_t nvme_cmb_show(struct device *dev,
>  {
>  	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
>  
> -	return snprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
> +	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
>  		       ndev->cmbloc, ndev->cmbsz);
>  }
>  static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
> -- 
> 2.1.4
> 

[PATCH 0/2] nvme: Improvements in sysfs entry for NVMe CMBs

[Jens Axboe]

On 12/16/2016 11:54 AM, Stephen Bates wrote:
> Hi
> 
> This series adds some more verbosity to the NVMe CMB sysfs entry.
> 
> Jens I based this off v4.9 because for some reason your for-4.10/block
> is missing my original CMB commit (202021c1a63c6)?
> 
> Stephen
> 
> Stephen Bates (2):
>   nvme : Use correct scnprintf in cmb show
>   nvme: improve cmb sysfs reporting
> 
>  drivers/nvme/host/pci.c | 33 ++++++++++++++++++++++++++++++---
>  include/linux/nvme.h    |  8 ++++++++
>  2 files changed, 38 insertions(+), 3 deletions(-)

I have added 1/2, since that one is a no-brainer. For 2/2, not so sure.
Generally we try to avoid having sysfs file that aren't single value
output. That isn't a super hard rule, but it is preferable.

-- 
Jens Axboe

[PATCH 0/2] nvme: Improvements in sysfs entry for NVMe CMBs

[Stephen Bates]

>
> I have added 1/2, since that one is a no-brainer. For 2/2, not so sure.
> Generally we try to avoid having sysfs file that aren't single value
> output. That isn't a super hard rule, but it is preferable.
>
> --
> Jens Axboe
>

Thanks Jens and sorry for the delay (extended vacation). Thanks for
pulling 1/2. I will go take a look at 2/2.

Stephen