From: Hannes Reinecke Subject: Re: [PATCH v2 6/8] scsi/ipr: Use sgl_alloc_order() and sgl_free_order() Date: Tue, 17 Oct 2017 08:19:05 +0200 Message-ID: References: <20171016224940.1332-1-bart.vanassche@wdc.com> <20171016224940.1332-7-bart.vanassche@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org, linux-crypto@vger.kernel.org, "Martin K . Petersen" , Brian King To: Bart Van Assche , Jens Axboe Return-path: In-Reply-To: <20171016224940.1332-7-bart.vanassche@wdc.com> Content-Language: en-US Sender: linux-block-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org 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-scsi@vger.kernel.org > Cc: Martin K. Petersen > Cc: Brian King > --- > 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@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)