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| author | Jeff Garzik <jeff@garzik.org> | 2007-10-19 00:21:18 +0400 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-10-19 00:21:18 +0400 |
| commit | 3be6cbd73f74b4a3da82cc7d6e1688a4ae595fc7 (patch) | |
| tree | a077cf70d1cd438db34f5def23dd8f72f42b5a8c /drivers/ata/sata_mv.c | |
| parent | 858c9c406688bc7244986b5836265071edfd1d3f (diff) | |
| download | linux-3be6cbd73f74b4a3da82cc7d6e1688a4ae595fc7.tar.xz | |
[libata] kill ata_sg_is_last()
Short term, this works around a bug introduced by early sg-chaining
work.
Long term, removing this function eliminates a branch from a hot
path loop in each scatter/gather table build. Also, as this code
demonstrates, we don't need to _track_ the end of the s/g list, as
long as we mark it in some way. And doing so programatically is nice.
So its a useful cleanup, regardless of its short term effects.
Based conceptually on a quick patch by Jens Axboe.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/sata_mv.c')
| -rw-r--r-- | drivers/ata/sata_mv.c | 26 |
1 files changed, 7 insertions, 19 deletions
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c index 4df8311968e9..7f1b13e89cf7 100644 --- a/drivers/ata/sata_mv.c +++ b/drivers/ata/sata_mv.c @@ -421,7 +421,6 @@ static void mv_error_handler(struct ata_port *ap); static void mv_post_int_cmd(struct ata_queued_cmd *qc); static void mv_eh_freeze(struct ata_port *ap); static void mv_eh_thaw(struct ata_port *ap); -static int mv_slave_config(struct scsi_device *sdev); static int mv_init_one(struct pci_dev *pdev, const struct pci_device_id *ent); static void mv5_phy_errata(struct mv_host_priv *hpriv, void __iomem *mmio, @@ -459,7 +458,7 @@ static struct scsi_host_template mv5_sht = { .use_clustering = 1, .proc_name = DRV_NAME, .dma_boundary = MV_DMA_BOUNDARY, - .slave_configure = mv_slave_config, + .slave_configure = ata_scsi_slave_config, .slave_destroy = ata_scsi_slave_destroy, .bios_param = ata_std_bios_param, }; @@ -477,7 +476,7 @@ static struct scsi_host_template mv6_sht = { .use_clustering = 1, .proc_name = DRV_NAME, .dma_boundary = MV_DMA_BOUNDARY, - .slave_configure = mv_slave_config, + .slave_configure = ata_scsi_slave_config, .slave_destroy = ata_scsi_slave_destroy, .bios_param = ata_std_bios_param, }; @@ -756,17 +755,6 @@ static void mv_irq_clear(struct ata_port *ap) { } -static int mv_slave_config(struct scsi_device *sdev) -{ - int rc = ata_scsi_slave_config(sdev); - if (rc) - return rc; - - blk_queue_max_phys_segments(sdev->request_queue, MV_MAX_SG_CT / 2); - - return 0; /* scsi layer doesn't check return value, sigh */ -} - static void mv_set_edma_ptrs(void __iomem *port_mmio, struct mv_host_priv *hpriv, struct mv_port_priv *pp) @@ -1138,7 +1126,7 @@ static void mv_fill_sg(struct ata_queued_cmd *qc) { struct mv_port_priv *pp = qc->ap->private_data; struct scatterlist *sg; - struct mv_sg *mv_sg; + struct mv_sg *mv_sg, *last_sg = NULL; mv_sg = pp->sg_tbl; ata_for_each_sg(sg, qc) { @@ -1159,13 +1147,13 @@ static void mv_fill_sg(struct ata_queued_cmd *qc) sg_len -= len; addr += len; - if (!sg_len && ata_sg_is_last(sg, qc)) - mv_sg->flags_size |= cpu_to_le32(EPRD_FLAG_END_OF_TBL); - + last_sg = mv_sg; mv_sg++; } - } + + if (likely(last_sg)) + last_sg->flags_size |= cpu_to_le32(EPRD_FLAG_END_OF_TBL); } static inline void mv_crqb_pack_cmd(__le16 *cmdw, u8 data, u8 addr, unsigned last) |