diff options
author | Adrian Hunter <adrian.hunter@nokia.com> | 2009-09-22 19:44:30 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 10:39:33 -0400 |
commit | 319a3f1429c91147058ac26c5f5bac8ec1730bc6 (patch) | |
tree | 4a39ff034f7e9b57b903997f818eee5304657991 /drivers/mmc/core/core.c | |
parent | 8ea926b22e2d13238e4d65d8f61c48fe424e6f4f (diff) |
mmc: allow host claim / release nesting
This change allows the MMC host to be claimed in situations where the host
may or may not have already been claimed. Also 'mmc_try_claim_host()' is
now exported.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mmc/core/core.c')
-rw-r--r-- | drivers/mmc/core/core.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index fb24a096dba..02f2b1871a3 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c | |||
@@ -461,16 +461,18 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) | |||
461 | while (1) { | 461 | while (1) { |
462 | set_current_state(TASK_UNINTERRUPTIBLE); | 462 | set_current_state(TASK_UNINTERRUPTIBLE); |
463 | stop = abort ? atomic_read(abort) : 0; | 463 | stop = abort ? atomic_read(abort) : 0; |
464 | if (stop || !host->claimed) | 464 | if (stop || !host->claimed || host->claimer == current) |
465 | break; | 465 | break; |
466 | spin_unlock_irqrestore(&host->lock, flags); | 466 | spin_unlock_irqrestore(&host->lock, flags); |
467 | schedule(); | 467 | schedule(); |
468 | spin_lock_irqsave(&host->lock, flags); | 468 | spin_lock_irqsave(&host->lock, flags); |
469 | } | 469 | } |
470 | set_current_state(TASK_RUNNING); | 470 | set_current_state(TASK_RUNNING); |
471 | if (!stop) | 471 | if (!stop) { |
472 | host->claimed = 1; | 472 | host->claimed = 1; |
473 | else | 473 | host->claimer = current; |
474 | host->claim_cnt += 1; | ||
475 | } else | ||
474 | wake_up(&host->wq); | 476 | wake_up(&host->wq); |
475 | spin_unlock_irqrestore(&host->lock, flags); | 477 | spin_unlock_irqrestore(&host->lock, flags); |
476 | remove_wait_queue(&host->wq, &wait); | 478 | remove_wait_queue(&host->wq, &wait); |
@@ -481,29 +483,43 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) | |||
481 | 483 | ||
482 | EXPORT_SYMBOL(__mmc_claim_host); | 484 | EXPORT_SYMBOL(__mmc_claim_host); |
483 | 485 | ||
484 | static int mmc_try_claim_host(struct mmc_host *host) | 486 | /** |
487 | * mmc_try_claim_host - try exclusively to claim a host | ||
488 | * @host: mmc host to claim | ||
489 | * | ||
490 | * Returns %1 if the host is claimed, %0 otherwise. | ||
491 | */ | ||
492 | int mmc_try_claim_host(struct mmc_host *host) | ||
485 | { | 493 | { |
486 | int claimed_host = 0; | 494 | int claimed_host = 0; |
487 | unsigned long flags; | 495 | unsigned long flags; |
488 | 496 | ||
489 | spin_lock_irqsave(&host->lock, flags); | 497 | spin_lock_irqsave(&host->lock, flags); |
490 | if (!host->claimed) { | 498 | if (!host->claimed || host->claimer == current) { |
491 | host->claimed = 1; | 499 | host->claimed = 1; |
500 | host->claimer = current; | ||
501 | host->claim_cnt += 1; | ||
492 | claimed_host = 1; | 502 | claimed_host = 1; |
493 | } | 503 | } |
494 | spin_unlock_irqrestore(&host->lock, flags); | 504 | spin_unlock_irqrestore(&host->lock, flags); |
495 | return claimed_host; | 505 | return claimed_host; |
496 | } | 506 | } |
507 | EXPORT_SYMBOL(mmc_try_claim_host); | ||
497 | 508 | ||
498 | static void mmc_do_release_host(struct mmc_host *host) | 509 | static void mmc_do_release_host(struct mmc_host *host) |
499 | { | 510 | { |
500 | unsigned long flags; | 511 | unsigned long flags; |
501 | 512 | ||
502 | spin_lock_irqsave(&host->lock, flags); | 513 | spin_lock_irqsave(&host->lock, flags); |
503 | host->claimed = 0; | 514 | if (--host->claim_cnt) { |
504 | spin_unlock_irqrestore(&host->lock, flags); | 515 | /* Release for nested claim */ |
505 | 516 | spin_unlock_irqrestore(&host->lock, flags); | |
506 | wake_up(&host->wq); | 517 | } else { |
518 | host->claimed = 0; | ||
519 | host->claimer = NULL; | ||
520 | spin_unlock_irqrestore(&host->lock, flags); | ||
521 | wake_up(&host->wq); | ||
522 | } | ||
507 | } | 523 | } |
508 | 524 | ||
509 | void mmc_host_deeper_disable(struct work_struct *work) | 525 | void mmc_host_deeper_disable(struct work_struct *work) |