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 <bart.vanassche@xxxxxxx>
> Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Cc: Brian King <brking@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/scsi/Kconfig | 1 +
> drivers/scsi/ipr.c | 49 ++++++++-----------------------------------------
> drivers/scsi/ipr.h | 2 +-
> 3 files changed, 10 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 41366339b950..d11e75e76195 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -1058,6 +1058,7 @@ config SCSI_IPR
> depends on PCI && SCSI && ATA
> select FW_LOADER
> select IRQ_POLL
> + select SGL_ALLOC
> ---help---
> This driver supports the IBM Power Linux family RAID adapters.
> This includes IBM pSeries 5712, 5703, 5709, and 570A, as well
> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
> index f838bd73befa..6fed5db6255e 100644
> --- a/drivers/scsi/ipr.c
> +++ b/drivers/scsi/ipr.c
> @@ -3815,10 +3815,8 @@ static struct device_attribute ipr_iopoll_weight_attr = {
> **/
> static struct ipr_sglist *ipr_alloc_ucode_buffer(int buf_len)
> {
> - int sg_size, order, bsize_elem, num_elem, i, j;
> + int sg_size, order;
> struct ipr_sglist *sglist;
> - struct scatterlist *scatterlist;
> - struct page *page;
>
> /* Get the minimum size per scatter/gather element */
> sg_size = buf_len / (IPR_MAX_SGLIST - 1);
> @@ -3826,45 +3824,18 @@ static struct ipr_sglist *ipr_alloc_ucode_buffer(int buf_len)
> /* Get the actual size per element */
> order = get_order(sg_size);
>
> - /* Determine the actual number of bytes per element */
> - bsize_elem = PAGE_SIZE * (1 << order);
> -
> - /* Determine the actual number of sg entries needed */
> - if (buf_len % bsize_elem)
> - num_elem = (buf_len / bsize_elem) + 1;
> - else
> - num_elem = buf_len / bsize_elem;
> -
> /* Allocate a scatter/gather list for the DMA */
> - sglist = kzalloc(sizeof(struct ipr_sglist) +
> - (sizeof(struct scatterlist) * (num_elem - 1)),
> - GFP_KERNEL);
> -
> + sglist = kzalloc(sizeof(struct ipr_sglist), GFP_KERNEL);
> if (sglist == NULL) {
> ipr_trace;
> return NULL;
> }
> -
> - scatterlist = sglist->scatterlist;
> - sg_init_table(scatterlist, num_elem);
> -
> sglist->order = order;
> - sglist->num_sg = num_elem;
> -
> - /* Allocate a bunch of sg elements */
> - for (i = 0; i < num_elem; i++) {
> - page = alloc_pages(GFP_KERNEL, order);
> - if (!page) {
> - ipr_trace;
> -
> - /* Free up what we already allocated */
> - for (j = i - 1; j >= 0; j--)
> - __free_pages(sg_page(&scatterlist[j]), order);
> - kfree(sglist);
> - return NULL;
> - }
> -
> - sg_set_page(&scatterlist[i], page, 0, 0);
> + sglist->scatterlist = sgl_alloc_order(buf_len, order, false, GFP_KERNEL,
> + &sglist->num_sg);
> + if (!sglist->scatterlist) {
> + kfree(sglist);
> + return NULL;
> }
>
> return sglist;
> @@ -3882,11 +3853,7 @@ static struct ipr_sglist *ipr_alloc_ucode_buffer(int buf_len)
> **/
> static void ipr_free_ucode_buffer(struct ipr_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);
> }
>
> diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
> index c7f0e9e3cd7d..93570734cbfb 100644
> --- a/drivers/scsi/ipr.h
> +++ b/drivers/scsi/ipr.h
> @@ -1454,7 +1454,7 @@ struct ipr_sglist {
> u32 num_sg;
> u32 num_dma_sg;
> u32 buffer_len;
> - struct scatterlist scatterlist[1];
> + struct scatterlist *scatterlist;
> };
>
> enum ipr_sdt_state {
>
Not sure if this is a valid conversion.
Originally the driver would allocate a single buffer; with this buffer
we have two distinct buffers.
Given that this is used to download the microcode I'm not sure if this
isn't a hardware-dependent structure which requires a single buffer
including the sglist.
Brian, can you shed some light here?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +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)
