From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: [PATCH V3 10/15] scsi: aha152x: use sg helper to operate scatterlist Date: Fri, 14 Jun 2019 10:53:11 +0800 Message-ID: <20190614025316.7360-11-ming.lei@redhat.com> References: <20190614025316.7360-1-ming.lei@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190614025316.7360-1-ming.lei@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: Michael Schmitz , devel@driverdev.osuosl.org, Hannes Reinecke , Benjamin Block , Bart Van Assche , Greg Kroah-Hartman , linux-usb@vger.kernel.org, James Smart , "Ewan D . Milne" , Jim Gill , James Bottomley , Brian King , Finn Thain , "Juergen E . Fischer" , Ming Lei , Christoph Hellwig , Dan Carpenter List-Id: linux-scsi@vger.kernel.org Use the scatterlist iterators and remove direct indexing of the scatterlist array. This way allows us to pre-allocate one small scatterlist, which can be chained with one runtime allocated scatterlist if the pre-allocated one isn't enough for the whole request. Signed-off-by: Ming Lei --- drivers/scsi/aha152x.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/aha152x.c b/drivers/scsi/aha152x.c index 97872838b983..bc9d12aa7880 100644 --- a/drivers/scsi/aha152x.c +++ b/drivers/scsi/aha152x.c @@ -2033,7 +2033,7 @@ static void datai_run(struct Scsi_Host *shpnt) CURRENT_SC->SCp.buffers_residual > 0) { /* advance to next buffer */ CURRENT_SC->SCp.buffers_residual--; - CURRENT_SC->SCp.buffer++; + CURRENT_SC->SCp.buffer = sg_next(CURRENT_SC->SCp.buffer); CURRENT_SC->SCp.ptr = SG_ADDRESS(CURRENT_SC->SCp.buffer); CURRENT_SC->SCp.this_residual = CURRENT_SC->SCp.buffer->length; } @@ -2139,7 +2139,7 @@ static void datao_run(struct Scsi_Host *shpnt) if(CURRENT_SC->SCp.this_residual==0 && CURRENT_SC->SCp.buffers_residual>0) { /* advance to next buffer */ CURRENT_SC->SCp.buffers_residual--; - CURRENT_SC->SCp.buffer++; + CURRENT_SC->SCp.buffer = sg_next(CURRENT_SC->SCp.buffer); CURRENT_SC->SCp.ptr = SG_ADDRESS(CURRENT_SC->SCp.buffer); CURRENT_SC->SCp.this_residual = CURRENT_SC->SCp.buffer->length; } @@ -2160,20 +2160,29 @@ static void datao_end(struct Scsi_Host *shpnt) if(TESTLO(DMASTAT, DFIFOEMP)) { int data_count = (DATA_LEN - scsi_get_resid(CURRENT_SC)) - GETSTCNT(); + struct scatterlist *sg = scsi_sglist(CURRENT_SC); + int left, i = 0; CMD_INC_RESID(CURRENT_SC, data_count); data_count -= CURRENT_SC->SCp.ptr - SG_ADDRESS(CURRENT_SC->SCp.buffer); - while(data_count>0) { - CURRENT_SC->SCp.buffer--; - CURRENT_SC->SCp.buffers_residual++; - data_count -= CURRENT_SC->SCp.buffer->length; + + left = CURRENT_SC->transfersize - data_count; + for (i = 0; left > 0 && !sg_is_last(sg); i++, sg = sg_next(sg)) { + if (left < sg->length) + break; + left -= sg->length; + } + + if (data_count > 0) { + CURRENT_SC->SCp.buffers_residual += i; + CURRENT_SC->SCp.buffer = sg; + + CURRENT_SC->SCp.ptr = SG_ADDRESS(CURRENT_SC->SCp.buffer) + left; + CURRENT_SC->SCp.this_residual = CURRENT_SC->SCp.buffer->length - + left; } - CURRENT_SC->SCp.ptr = SG_ADDRESS(CURRENT_SC->SCp.buffer) - - data_count; - CURRENT_SC->SCp.this_residual = CURRENT_SC->SCp.buffer->length + - data_count; } SETPORT(SXFRCTL0, CH1|CLRCH1|CLRSTCNT); -- 2.20.1