From da917d69d0ea63f5390716cba6e77f490ce96df9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 23 Sep 2007 13:14:12 +0900 Subject: [PATCH] libata-pmp-prep: implement qc_defer helpers Implement ap->nr_active_links (the number of links with active qcs), ap->excl_link (pointer to link which can be used by ->qc_defer and is cleared when a qc with ATA_QCFLAG_CLEAR_EXCL completes), and ata_link_active(). These can be used by ->qc_defer() to implement proper command exclusion. This set of helpers seem enough for both sil24 (ATAPI exclusion needed) and cmd-switching PMP. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 22 ++++++++++++++++++++-- drivers/ata/libata-eh.c | 5 +++++ include/linux/libata.h | 8 ++++++++ 3 files changed, 33 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index b666f51da7ed..376dbd80cc93 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1390,6 +1390,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev, struct ata_queued_cmd *qc; unsigned int tag, preempted_tag; u32 preempted_sactive, preempted_qc_active; + int preempted_nr_active_links; DECLARE_COMPLETION_ONSTACK(wait); unsigned long flags; unsigned int err_mask; @@ -1428,9 +1429,11 @@ unsigned ata_exec_internal_sg(struct ata_device *dev, preempted_tag = link->active_tag; preempted_sactive = link->sactive; preempted_qc_active = ap->qc_active; + preempted_nr_active_links = ap->nr_active_links; link->active_tag = ATA_TAG_POISON; link->sactive = 0; ap->qc_active = 0; + ap->nr_active_links = 0; /* prepare & issue qc */ qc->tf = *tf; @@ -1509,6 +1512,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev, link->active_tag = preempted_tag; link->sactive = preempted_sactive; ap->qc_active = preempted_qc_active; + ap->nr_active_links = preempted_nr_active_links; /* XXX - Some LLDDs (sata_mv) disable port on command failure. * Until those drivers are fixed, we detect the condition @@ -5408,10 +5412,19 @@ void __ata_qc_complete(struct ata_queued_cmd *qc) ata_sg_clean(qc); /* command should be marked inactive atomically with qc completion */ - if (qc->tf.protocol == ATA_PROT_NCQ) + if (qc->tf.protocol == ATA_PROT_NCQ) { link->sactive &= ~(1 << qc->tag); - else + if (!link->sactive) + ap->nr_active_links--; + } else { link->active_tag = ATA_TAG_POISON; + ap->nr_active_links--; + } + + /* clear exclusive status */ + if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL && + ap->excl_link == link)) + ap->excl_link = NULL; /* atapi: mark qc as inactive to prevent the interrupt handler * from completing the command twice later, before the error handler @@ -5590,9 +5603,14 @@ void ata_qc_issue(struct ata_queued_cmd *qc) if (qc->tf.protocol == ATA_PROT_NCQ) { WARN_ON(link->sactive & (1 << qc->tag)); + + if (!link->sactive) + ap->nr_active_links++; link->sactive |= 1 << qc->tag; } else { WARN_ON(link->sactive); + + ap->nr_active_links++; link->active_tag = qc->tag; } diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 1d3b0dccfb0a..5244723952c2 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -451,6 +451,7 @@ void ata_scsi_error(struct Scsi_Host *host) ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS; ap->pflags &= ~ATA_PFLAG_EH_PENDING; + ap->excl_link = NULL; /* don't maintain exclusion over EH */ spin_unlock_irqrestore(ap->lock, flags); @@ -2474,6 +2475,10 @@ void ata_eh_finish(struct ata_port *ap) } } } + + /* make sure nr_active_links is zero after EH */ + WARN_ON(ap->nr_active_links); + ap->nr_active_links = 0; } /** diff --git a/include/linux/libata.h b/include/linux/libata.h index b0d4ca0d27b4..f9f81fd93293 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -216,6 +216,7 @@ enum { ATA_QCFLAG_DMAMAP = ATA_QCFLAG_SG | ATA_QCFLAG_SINGLE, ATA_QCFLAG_IO = (1 << 3), /* standard IO command */ ATA_QCFLAG_RESULT_TF = (1 << 4), /* result TF requested */ + ATA_QCFLAG_CLEAR_EXCL = (1 << 5), /* clear excl_link on completion */ ATA_QCFLAG_FAILED = (1 << 16), /* cmd failed and is owned by EH */ ATA_QCFLAG_SENSE_VALID = (1 << 17), /* sense data valid */ @@ -579,11 +580,13 @@ struct ata_port { struct ata_queued_cmd qcmd[ATA_MAX_QUEUE]; unsigned long qc_allocated; unsigned int qc_active; + int nr_active_links; /* #links with active qcs */ struct ata_link link; /* host default link */ int nr_pmp_links; /* nr of available PMP links */ struct ata_link *pmp_link; /* array of PMP links */ + struct ata_link *excl_link; /* for PMP qc exclusion */ struct ata_port_stats stats; struct ata_host *host; @@ -1104,6 +1107,11 @@ static inline int ata_link_max_devices(const struct ata_link *link) return 1; } +static inline int ata_link_active(struct ata_link *link) +{ + return ata_tag_valid(link->active_tag) || link->sactive; +} + static inline struct ata_link *ata_port_first_link(struct ata_port *ap) { if (ap->nr_pmp_links)