In addition to the comments from Damien: I think we should kill ata_qc_new_init as well. It is a bit pointless and having it in libata-core.c when it pokes into scsi internals also doesn't make sense. So maybe something like: diff --git a/Documentation/driver-api/libata.rst b/Documentation/driver-api/libata.rst index d477e296bda5f2..311af516a3fd9c 100644 --- a/Documentation/driver-api/libata.rst +++ b/Documentation/driver-api/libata.rst @@ -424,12 +424,6 @@ How commands are issued ----------------------- Internal commands - First, qc is allocated and initialized using :c:func:`ata_qc_new_init`. - Although :c:func:`ata_qc_new_init` doesn't implement any wait or retry - mechanism when qc is not available, internal commands are currently - issued only during initialization and error recovery, so no other - command is active and allocation is guaranteed to succeed. - Once allocated qc's taskfile is initialized for the command to be executed. qc currently has two mechanisms to notify completion. One is via ``qc->complete_fn()`` callback and the other is completion @@ -447,11 +441,6 @@ SCSI commands translated. No qc is involved in processing a simulated scmd. The result is computed right away and the scmd is completed. - For a translated scmd, :c:func:`ata_qc_new_init` is invoked to allocate a - qc and the scmd is translated into the qc. SCSI midlayer's - completion notification function pointer is stored into - ``qc->scsidone``. - ``qc->complete_fn()`` callback is used for completion notification. ATA commands use :c:func:`ata_scsi_qc_complete` while ATAPI commands use :c:func:`atapi_qc_complete`. Both functions end up calling ``qc->scsidone`` diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 0c854aebfe0bdc..811fceb4e647fa 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4563,42 +4563,6 @@ 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 @@ -4611,19 +4575,9 @@ 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) diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c index 071158c0c44c1d..13e2c0d28b6937 100644 --- a/drivers/ata/libata-sata.c +++ b/drivers/ata/libata-sata.c @@ -1268,31 +1268,6 @@ int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap) } EXPORT_SYMBOL_GPL(ata_sas_queuecmd); -int ata_sas_allocate_tag(struct ata_port *ap) -{ - unsigned int max_queue = ap->host->n_tags; - unsigned int i, tag; - - for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) { - tag = tag < max_queue ? tag : 0; - - /* the last tag is reserved for internal command. */ - if (ata_tag_internal(tag)) - continue; - - if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) { - ap->sas_last_tag = tag; - return tag; - } - } - return -1; -} - -void ata_sas_free_tag(unsigned int tag, struct ata_port *ap) -{ - clear_bit(tag, &ap->sas_tag_allocated); -} - /** * sata_async_notification - SATA async notification handler * @ap: ATA port where async notification is received diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index ed8be585a98f7c..5e0bc7b05a107e 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -638,24 +638,44 @@ EXPORT_SYMBOL_GPL(ata_scsi_ioctl); static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev, struct scsi_cmnd *cmd) { + struct ata_port *ap = dev->link->ap; struct ata_queued_cmd *qc; + int tag; - qc = ata_qc_new_init(dev, scsi_cmd_to_rq(cmd)->tag); - if (qc) { - qc->scsicmd = cmd; - qc->scsidone = scsi_done; - - qc->sg = scsi_sglist(cmd); - qc->n_elem = scsi_sg_count(cmd); + if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) + goto fail; - if (scsi_cmd_to_rq(cmd)->rq_flags & RQF_QUIET) - qc->flags |= ATA_QCFLAG_QUIET; + if (ap->flags & ATA_FLAG_SAS_HOST) { + /* XXX: add a comment here why SAS is different */ + if (WARN_ON_ONCE(cmd->budget_token >= ATA_MAX_QUEUE)) + goto fail; + tag = cmd->budget_token; } else { - cmd->result = (DID_OK << 16) | SAM_STAT_TASK_SET_FULL; - scsi_done(cmd); + tag = scsi_cmd_to_rq(cmd)->tag; } + 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); + + qc->scsicmd = cmd; + qc->scsidone = scsi_done; + + qc->sg = scsi_sglist(cmd); + qc->n_elem = scsi_sg_count(cmd); + + if (scsi_cmd_to_rq(cmd)->rq_flags & RQF_QUIET) + qc->flags |= ATA_QCFLAG_QUIET; return qc; + +fail: + cmd->result = (DID_OK << 16) | SAM_STAT_TASK_SET_FULL; + scsi_done(cmd); + return NULL; } static void ata_qc_set_pc_nbytes(struct ata_queued_cmd *qc) diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h index 51e01acdd24107..191f8bfe038656 100644 --- a/drivers/ata/libata.h +++ b/drivers/ata/libata.h @@ -44,7 +44,6 @@ static inline void ata_force_cbl(struct ata_port *ap) { } #endif extern u64 ata_tf_to_lba(const struct ata_taskfile *tf); extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf); -extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag); extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev, u64 block, u32 n_block, unsigned int tf_flags, unsigned int tag, int class); @@ -91,18 +90,6 @@ extern unsigned int ata_read_log_page(struct ata_device *dev, u8 log, #define to_ata_port(d) container_of(d, struct ata_port, tdev) -/* libata-sata.c */ -#ifdef CONFIG_SATA_HOST -int ata_sas_allocate_tag(struct ata_port *ap); -void ata_sas_free_tag(unsigned int tag, struct ata_port *ap); -#else -static inline int ata_sas_allocate_tag(struct ata_port *ap) -{ - return -EOPNOTSUPP; -} -static inline void ata_sas_free_tag(unsigned int tag, struct ata_port *ap) { } -#endif - /* libata-acpi.c */ #ifdef CONFIG_ATA_ACPI extern unsigned int ata_acpi_gtf_filter; diff --git a/include/linux/libata.h b/include/linux/libata.h index 7f99b4d788223b..3b9399f67b3902 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -814,7 +814,6 @@ struct ata_port { unsigned int cbl; /* cable type; ATA_CBL_xxx */ struct ata_queued_cmd qcmd[ATA_MAX_QUEUE + 1]; - unsigned long sas_tag_allocated; /* for sas tag allocation only */ u64 qc_active; int nr_active_links; /* #links with active qcs */ unsigned int sas_last_tag; /* track next tag hw expects */