diff options
| -rw-r--r-- | drivers/ide/ide-io.c | 105 | ||||
| -rw-r--r-- | include/linux/ide.h | 35 |
2 files changed, 69 insertions, 71 deletions
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 4ce793c0562..8f371821c61 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -666,45 +666,54 @@ void ide_stall_queue (ide_drive_t *drive, unsigned long timeout) } EXPORT_SYMBOL(ide_stall_queue); +static inline int ide_lock_port(ide_hwif_t *hwif) +{ + if (hwif->busy) + return 1; + + hwif->busy = 1; + + return 0; +} + +static inline void ide_unlock_port(ide_hwif_t *hwif) +{ + hwif->busy = 0; +} + +static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif) +{ + int rc = 0; + + if (host->host_flags & IDE_HFLAG_SERIALIZE) { + rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy); + if (rc == 0) { + /* for atari only */ + ide_get_lock(ide_intr, hwif); + } + } + return rc; +} + +static inline void ide_unlock_host(struct ide_host *host) +{ + if (host->host_flags & IDE_HFLAG_SERIALIZE) { + /* for atari only */ + ide_release_lock(); + clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy); + } +} + /* * Issue a new request to a drive from hwgroup - * - * A hwgroup is a serialized group of IDE interfaces. Usually there is - * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640) - * may have both interfaces in a single hwgroup to "serialize" access. - * Or possibly multiple ISA interfaces can share a common IRQ by being grouped - * together into one hwgroup for serialized access. - * - * Note also that several hwgroups can end up sharing a single IRQ, - * possibly along with many other devices. This is especially common in - * PCI-based systems with off-board IDE controller cards. - * - * The IDE driver uses a per-hwgroup lock to protect the hwgroup->busy flag. - * - * The first thread into the driver for a particular hwgroup sets the - * hwgroup->busy flag to indicate that this hwgroup is now active, - * and then initiates processing of the top request from the request queue. - * - * Other threads attempting entry notice the busy setting, and will simply - * queue their new requests and exit immediately. Note that hwgroup->busy - * remains set even when the driver is merely awaiting the next interrupt. - * Thus, the meaning is "this hwgroup is busy processing a request". - * - * When processing of a request completes, the completing thread or IRQ-handler - * will start the next request from the queue. If no more work remains, - * the driver will clear the hwgroup->busy flag and exit. - * - * The per-hwgroup spinlock is used to protect all access to the - * hwgroup->busy flag, but is otherwise not needed for most processing in - * the driver. This makes the driver much more friendlier to shared IRQs - * than previous designs, while remaining 100% (?) SMP safe and capable. */ void do_ide_request(struct request_queue *q) { ide_drive_t *drive = q->queuedata; ide_hwif_t *hwif = drive->hwif; + struct ide_host *host = hwif->host; ide_hwgroup_t *hwgroup = hwif->hwgroup; - struct request *rq; + struct request *rq = NULL; ide_startstop_t startstop; /* @@ -721,9 +730,13 @@ void do_ide_request(struct request_queue *q) blk_remove_plug(q); spin_unlock_irq(q->queue_lock); + + if (ide_lock_host(host, hwif)) + goto plug_device_2; + spin_lock_irq(&hwgroup->lock); - if (!ide_lock_hwgroup(hwgroup, hwif)) { + if (!ide_lock_port(hwif)) { ide_hwif_t *prev_port; repeat: prev_port = hwif->host->cur_port; @@ -731,7 +744,7 @@ repeat: if (drive->dev_flags & IDE_DFLAG_SLEEPING) { if (time_before(drive->sleep, jiffies)) { - ide_unlock_hwgroup(hwgroup); + ide_unlock_port(hwif); goto plug_device; } } @@ -761,7 +774,7 @@ repeat: spin_lock_irq(&hwgroup->lock); if (!rq) { - ide_unlock_hwgroup(hwgroup); + ide_unlock_port(hwif); goto out; } @@ -782,7 +795,7 @@ repeat: blk_pm_request(rq) == 0 && (rq->cmd_flags & REQ_PREEMPT) == 0) { /* there should be no pending command at this point */ - ide_unlock_hwgroup(hwgroup); + ide_unlock_port(hwif); goto plug_device; } @@ -798,11 +811,15 @@ repeat: goto plug_device; out: spin_unlock_irq(&hwgroup->lock); + if (rq == NULL) + ide_unlock_host(host); spin_lock_irq(q->queue_lock); return; plug_device: spin_unlock_irq(&hwgroup->lock); + ide_unlock_host(host); +plug_device_2: spin_lock_irq(q->queue_lock); if (!elv_queue_empty(q)) @@ -844,9 +861,9 @@ static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error) ide_dma_off_quietly(drive); /* - * un-busy drive etc (hwgroup->busy is cleared on return) and - * make sure request is sane + * un-busy drive etc and make sure request is sane */ + rq = HWGROUP(drive)->rq; if (!rq) @@ -895,6 +912,7 @@ static void ide_plug_device(ide_drive_t *drive) void ide_timer_expiry (unsigned long data) { ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data; + ide_hwif_t *uninitialized_var(hwif); ide_drive_t *uninitialized_var(drive); ide_handler_t *handler; ide_expiry_t *expiry; @@ -918,7 +936,6 @@ void ide_timer_expiry (unsigned long data) printk(KERN_ERR "%s: ->cur_dev was NULL\n", __func__); hwgroup->handler = NULL; } else { - ide_hwif_t *hwif; ide_startstop_t startstop = ide_stopped; if ((expiry = hwgroup->expiry) != NULL) { @@ -964,15 +981,17 @@ void ide_timer_expiry (unsigned long data) spin_lock_irq(&hwgroup->lock); enable_irq(hwif->irq); if (startstop == ide_stopped) { - ide_unlock_hwgroup(hwgroup); + ide_unlock_port(hwif); plug_device = 1; } } } spin_unlock_irqrestore(&hwgroup->lock, flags); - if (plug_device) + if (plug_device) { + ide_unlock_host(hwif->host); ide_plug_device(drive); + } } /** @@ -1150,7 +1169,7 @@ irqreturn_t ide_intr (int irq, void *dev_id) */ if (startstop == ide_stopped) { if (hwgroup->handler == NULL) { /* paranoia */ - ide_unlock_hwgroup(hwgroup); + ide_unlock_port(hwif); plug_device = 1; } else printk(KERN_ERR "%s: %s: huh? expected NULL handler " @@ -1161,8 +1180,10 @@ out_handled: out: spin_unlock_irqrestore(&hwgroup->lock, flags); out_early: - if (plug_device) + if (plug_device) { + ide_unlock_host(hwif->host); ide_plug_device(drive); + } return irq_ret; } diff --git a/include/linux/ide.h b/include/linux/ide.h index 8b74ccdd221..00df155b5a0 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -828,6 +828,7 @@ typedef struct hwif_s { unsigned present : 1; /* this interface exists */ unsigned sg_mapped : 1; /* sg_table and sg_nents are ready */ + unsigned busy : 1; /* serializes devices on a port */ struct device gendev; struct device *portdev; @@ -851,8 +852,13 @@ struct ide_host { unsigned long host_flags; void *host_priv; ide_hwif_t *cur_port; /* for hosts requiring serialization */ + + /* used for hosts requiring serialization */ + volatile long host_busy; }; +#define IDE_HOST_BUSY 0 + /* * internal ide interrupt handler type */ @@ -866,8 +872,6 @@ typedef struct hwgroup_s { /* irq handler, if active */ ide_startstop_t (*handler)(ide_drive_t *); - /* BOOL: protects all fields below */ - volatile int busy; /* BOOL: polling active & poll_timeout field valid */ unsigned int polling : 1; @@ -1271,26 +1275,6 @@ extern void ide_stall_queue(ide_drive_t *drive, unsigned long timeout); extern void ide_timer_expiry(unsigned long); extern irqreturn_t ide_intr(int irq, void *dev_id); - -static inline int ide_lock_hwgroup(ide_hwgroup_t *hwgroup, ide_hwif_t *hwif) -{ - if (hwgroup->busy) - return 1; - - hwgroup->busy = 1; - /* for atari only */ - ide_get_lock(ide_intr, hwif); - - return 0; -} - -static inline void ide_unlock_hwgroup(ide_hwgroup_t *hwgroup) -{ - /* for atari only */ - ide_release_lock(); - hwgroup->busy = 0; -} - extern void do_ide_request(struct request_queue *); void ide_init_disk(struct gendisk *, ide_drive_t *); @@ -1617,13 +1601,6 @@ static inline void ide_set_max_pio(ide_drive_t *drive) extern spinlock_t ide_lock; extern struct mutex ide_cfg_mtx; -/* - * Structure locking: - * - * ide_hwgroup_t->busy: hwgroup->lock - * ide_hwif_t->{hwgroup,mate}: constant, no locking - * ide_drive_t->hwif: constant, no locking - */ #define local_irq_set(flags) do { local_save_flags((flags)); local_irq_enable_in_hardirq(); } while (0) |