Re: [PATCH v2 8/8] scsi/pmcraid: Use sgl_alloc_order() and sgl_free_order()

[Hannes Reinecke]

On 10/17/2017 12:49 AM, Bart Van Assche wrote:
> Use the sgl_alloc_order() and sgl_free_order() functions instead
> of open coding these functions.
> 
> Signed-off-by: Bart Van Assche 
> Reviewed-by: Johannes Thumshirn 
> Cc: linux-s...@vger.kernel.org
> Cc: Martin K. Petersen 
> Cc: Anil Ravindranath 
> ---
>  drivers/scsi/Kconfig   |  1 +
>  drivers/scsi/pmcraid.c | 43 ---
>  drivers/scsi/pmcraid.h |  2 +-
>  3 files changed, 6 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index d11e75e76195..632200ec36a6 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -1576,6 +1576,7 @@ config ZFCP
>  config SCSI_PMCRAID
>   tristate "PMC SIERRA Linux MaxRAID adapter support"
>   depends on PCI && SCSI && NET
> + select SGL_ALLOC
>   ---help---
> This driver supports the PMC SIERRA MaxRAID adapters.
>  
> diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
> index b4d6cd8cd1ad..95fc0352f9bb 100644
> --- a/drivers/scsi/pmcraid.c
> +++ b/drivers/scsi/pmcraid.c
> @@ -3232,12 +3232,7 @@ static int pmcraid_build_ioadl(
>   */
>  static void pmcraid_free_sglist(struct pmcraid_sglist *sglist)
>  {
> - int i;
> -
> - for (i = 0; i < sglist->num_sg; i++)
> - __free_pages(sg_page(&(sglist->scatterlist[i])),
> -  sglist->order);
> -
> + sgl_free_order(sglist->scatterlist, sglist->order);
>   kfree(sglist);
>  }
>  
> @@ -3254,50 +3249,20 @@ static void pmcraid_free_sglist(struct pmcraid_sglist 
> *sglist)
>  static struct pmcraid_sglist *pmcraid_alloc_sglist(int buflen)
>  {
>   struct pmcraid_sglist *sglist;
> - struct scatterlist *scatterlist;
> - struct page *page;
> - int num_elem, i, j;
>   int sg_size;
>   int order;
> - int bsize_elem;
>  
>   sg_size = buflen / (PMCRAID_MAX_IOADLS - 1);
>   order = (sg_size > 0) ? get_order(sg_size) : 0;
> - bsize_elem = PAGE_SIZE * (1 << order);
> -
> - /* Determine the actual number of sg entries needed */
> - if (buflen % bsize_elem)
> - num_elem = (buflen / bsize_elem) + 1;
> - else
> - num_elem = buflen / bsize_elem;
>  
>   /* Allocate a scatter/gather list for the DMA */
> - sglist = kzalloc(sizeof(struct pmcraid_sglist) +
> -  (sizeof(struct scatterlist) * (num_elem - 1)),
> -  GFP_KERNEL);
> -
> + sglist = kzalloc(sizeof(struct pmcraid_sglist), GFP_KERNEL);
>   if (sglist == NULL)
>   return NULL;
>  
> - scatterlist = sglist->scatterlist;
> - sg_init_table(scatterlist, num_elem);
>   sglist->order = order;
> - sglist->num_sg = num_elem;
> - sg_size = buflen;
> -
> - for (i = 0; i < num_elem; i++) {
> - page = alloc_pages(GFP_KERNEL|GFP_DMA|__GFP_ZERO, order);
> - if (!page) {
> - for (j = i - 1; j >= 0; j--)
> - __free_pages(sg_page([j]), order);
> - kfree(sglist);
> - return NULL;
> - }
> -
> - sg_set_page([i], page,
> - sg_size < bsize_elem ? sg_size : bsize_elem, 0);
> - sg_size -= bsize_elem;
> - }
> + sgl_alloc_order(buflen, order, false,
> + GFP_KERNEL | GFP_DMA | __GFP_ZERO, >num_sg);
>  
>   return sglist;
>  }
> diff --git a/drivers/scsi/pmcraid.h b/drivers/scsi/pmcraid.h
> index 44da91712115..754ef30927e2 100644
> --- a/drivers/scsi/pmcraid.h
> +++ b/drivers/scsi/pmcraid.h
> @@ -542,7 +542,7 @@ struct pmcraid_sglist {
>   u32 order;
>   u32 num_sg;
>   u32 num_dma_sg;
> - struct scatterlist scatterlist[1];
> + struct scatterlist *scatterlist;
>  };
>  
>  /* page D0 inquiry data of focal point resource */
> 
The comment to ipr applied here, too.
We need input from the pmcraid folks if this is a valid conversion.

Cheers,

Hannes
-- 
Dr. Hannes ReineckeTeamlead Storage & Networking
h...@suse.de   +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

[PATCH v2 8/8] scsi/pmcraid: Use sgl_alloc_order() and sgl_free_order()

[Bart Van Assche]

Use the sgl_alloc_order() and sgl_free_order() functions instead
of open coding these functions.

Signed-off-by: Bart Van Assche 
Reviewed-by: Johannes Thumshirn 
Cc: linux-s...@vger.kernel.org
Cc: Martin K. Petersen 
Cc: Anil Ravindranath 
---
 drivers/scsi/Kconfig   |  1 +
 drivers/scsi/pmcraid.c | 43 ---
 drivers/scsi/pmcraid.h |  2 +-
 3 files changed, 6 insertions(+), 40 deletions(-)

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index d11e75e76195..632200ec36a6 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1576,6 +1576,7 @@ config ZFCP
 config SCSI_PMCRAID
tristate "PMC SIERRA Linux MaxRAID adapter support"
depends on PCI && SCSI && NET
+   select SGL_ALLOC
---help---
  This driver supports the PMC SIERRA MaxRAID adapters.
 
diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index b4d6cd8cd1ad..95fc0352f9bb 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -3232,12 +3232,7 @@ static int pmcraid_build_ioadl(
  */
 static void pmcraid_free_sglist(struct pmcraid_sglist *sglist)
 {
-   int i;
-
-   for (i = 0; i < sglist->num_sg; i++)
-   __free_pages(sg_page(&(sglist->scatterlist[i])),
-sglist->order);
-
+   sgl_free_order(sglist->scatterlist, sglist->order);
kfree(sglist);
 }
 
@@ -3254,50 +3249,20 @@ static void pmcraid_free_sglist(struct pmcraid_sglist 
*sglist)
 static struct pmcraid_sglist *pmcraid_alloc_sglist(int buflen)
 {
struct pmcraid_sglist *sglist;
-   struct scatterlist *scatterlist;
-   struct page *page;
-   int num_elem, i, j;
int sg_size;
int order;
-   int bsize_elem;
 
sg_size = buflen / (PMCRAID_MAX_IOADLS - 1);
order = (sg_size > 0) ? get_order(sg_size) : 0;
-   bsize_elem = PAGE_SIZE * (1 << order);
-
-   /* Determine the actual number of sg entries needed */
-   if (buflen % bsize_elem)
-   num_elem = (buflen / bsize_elem) + 1;
-   else
-   num_elem = buflen / bsize_elem;
 
/* Allocate a scatter/gather list for the DMA */
-   sglist = kzalloc(sizeof(struct pmcraid_sglist) +
-(sizeof(struct scatterlist) * (num_elem - 1)),
-GFP_KERNEL);
-
+   sglist = kzalloc(sizeof(struct pmcraid_sglist), GFP_KERNEL);
if (sglist == NULL)
return NULL;
 
-   scatterlist = sglist->scatterlist;
-   sg_init_table(scatterlist, num_elem);
sglist->order = order;
-   sglist->num_sg = num_elem;
-   sg_size = buflen;
-
-   for (i = 0; i < num_elem; i++) {
-   page = alloc_pages(GFP_KERNEL|GFP_DMA|__GFP_ZERO, order);
-   if (!page) {
-   for (j = i - 1; j >= 0; j--)
-   __free_pages(sg_page([j]), order);
-   kfree(sglist);
-   return NULL;
-   }
-
-   sg_set_page([i], page,
-   sg_size < bsize_elem ? sg_size : bsize_elem, 0);
-   sg_size -= bsize_elem;
-   }
+   sgl_alloc_order(buflen, order, false,
+   GFP_KERNEL | GFP_DMA | __GFP_ZERO, >num_sg);
 
return sglist;
 }
diff --git a/drivers/scsi/pmcraid.h b/drivers/scsi/pmcraid.h
index 44da91712115..754ef30927e2 100644
--- a/drivers/scsi/pmcraid.h
+++ b/drivers/scsi/pmcraid.h
@@ -542,7 +542,7 @@ struct pmcraid_sglist {
u32 order;
u32 num_sg;
u32 num_dma_sg;
-   struct scatterlist scatterlist[1];
+   struct scatterlist *scatterlist;
 };
 
 /* page D0 inquiry data of focal point resource */
-- 
2.14.2