From d274a9878bcd028712ea4f3d96db72b63d3eba4d Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 16 Oct 2007 11:20:52 +0200 Subject: ide-scsi: sg chaining support Acked-by: Bartlomiej Zolnierkiewicz Signed-off-by: Jens Axboe --- drivers/scsi/ide-scsi.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c index d81bb076a15..d297f64cd43 100644 --- a/drivers/scsi/ide-scsi.c +++ b/drivers/scsi/ide-scsi.c @@ -70,6 +70,7 @@ typedef struct idescsi_pc_s { u8 *buffer; /* Data buffer */ u8 *current_position; /* Pointer into the above buffer */ struct scatterlist *sg; /* Scatter gather table */ + struct scatterlist *last_sg; /* Last sg element */ int b_count; /* Bytes transferred from current entry */ struct scsi_cmnd *scsi_cmd; /* SCSI command */ void (*done)(struct scsi_cmnd *); /* Scsi completion routine */ @@ -173,12 +174,6 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne char *buf; while (bcount) { - if (pc->sg - scsi_sglist(pc->scsi_cmd) > - scsi_sg_count(pc->scsi_cmd)) { - printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n"); - idescsi_discard_data (drive, bcount); - return; - } count = min(pc->sg->length - pc->b_count, bcount); if (PageHighMem(pc->sg->page)) { unsigned long flags; @@ -197,10 +192,17 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne } bcount -= count; pc->b_count += count; if (pc->b_count == pc->sg->length) { - pc->sg++; + if (pc->sg == pc->last_sg) + break; + pc->sg = sg_next(pc->sg); pc->b_count = 0; } } + + if (bcount) { + printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n"); + idescsi_discard_data (drive, bcount); + } } static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigned int bcount) @@ -209,12 +211,6 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign char *buf; while (bcount) { - if (pc->sg - scsi_sglist(pc->scsi_cmd) > - scsi_sg_count(pc->scsi_cmd)) { - printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n"); - idescsi_output_zeros (drive, bcount); - return; - } count = min(pc->sg->length - pc->b_count, bcount); if (PageHighMem(pc->sg->page)) { unsigned long flags; @@ -233,10 +229,17 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign } bcount -= count; pc->b_count += count; if (pc->b_count == pc->sg->length) { - pc->sg++; + if (pc->sg == pc->last_sg) + break; + pc->sg = sg_next(pc->sg); pc->b_count = 0; } } + + if (bcount) { + printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n"); + idescsi_output_zeros (drive, bcount); + } } static void hexdump(u8 *x, int len) @@ -804,6 +807,7 @@ static int idescsi_queue (struct scsi_cmnd *cmd, memcpy (pc->c, cmd->cmnd, cmd->cmd_len); pc->buffer = NULL; pc->sg = scsi_sglist(cmd); + pc->last_sg = sg_last(pc->sg, cmd->use_sg); pc->b_count = 0; pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd); pc->scsi_cmd = cmd; -- cgit v1.2.3-70-g09d2