From 4f1a22ee7b576a38dc5705837c9b0de0c7b5b064 Mon Sep 17 00:00:00 2001 From: John Garry Date: Fri, 8 Apr 2022 17:04:12 +0800 Subject: libata: Improve ATA queued command allocation Improve ATA queued command allocation as follows: - For attaining a qc tag for a SAS host we need to allocate a bit in ata_port.sas_tag_allocated bitmap. However we already have a unique tag per device in range [0, ATA_MAX_QUEUE -1] in the scsi cmnd budget token, so just use that instead. - It is a bit pointless to have ata_qc_new_init() in libata-core.c since it pokes scsi internals, so inline it in ata_scsi_qc_new() (in libata-scsi.c). Also update Doc accordingly. - Use standard SCSI helpers set_host_byte() and set_status_byte() in ata_scsi_qc_new(). Christoph Hellwig originally contributed the change to inline ata_qc_new_init(). Signed-off-by: John Garry Reviewed-by: Christoph Hellwig Signed-off-by: Damien Le Moal --- drivers/ata/libata-core.c | 48 +---------------------------------------------- 1 file changed, 1 insertion(+), 47 deletions(-) (limited to 'drivers/ata/libata-core.c') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index ca64837641be..23d1dc5faf73 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4566,42 +4566,6 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words) #endif /* __BIG_ENDIAN */ } -/** - * ata_qc_new_init - Request an available ATA command, and initialize it - * @dev: Device from whom we request an available command structure - * @tag: tag - * - * LOCKING: - * None. - */ - -struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag) -{ - struct ata_port *ap = dev->link->ap; - struct ata_queued_cmd *qc; - - /* no command while frozen */ - if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) - return NULL; - - /* libsas case */ - if (ap->flags & ATA_FLAG_SAS_HOST) { - tag = ata_sas_allocate_tag(ap); - if (tag < 0) - return NULL; - } - - qc = __ata_qc_from_tag(ap, tag); - qc->tag = qc->hw_tag = tag; - qc->scsicmd = NULL; - qc->ap = ap; - qc->dev = dev; - - ata_qc_reinit(qc); - - return qc; -} - /** * ata_qc_free - free unused ata_queued_cmd * @qc: Command to complete @@ -4614,19 +4578,9 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag) */ void ata_qc_free(struct ata_queued_cmd *qc) { - struct ata_port *ap; - unsigned int tag; - - WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */ - ap = qc->ap; - qc->flags = 0; - tag = qc->tag; - if (ata_tag_valid(tag)) { + if (ata_tag_valid(qc->tag)) qc->tag = ATA_TAG_POISON; - if (ap->flags & ATA_FLAG_SAS_HOST) - ata_sas_free_tag(tag, ap); - } } void __ata_qc_complete(struct ata_queued_cmd *qc) -- cgit v1.2.3-70-g09d2