Messages in this thread Patch in this message | | | Date | Tue, 24 Aug 2010 15:44:49 -0700 | From | Greg KH <> | Subject | [044/114] mtd: change struct flchip_shared spinlock locking into mutex |
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2.6.35-stable review patch. If anyone has any objections, please let us know.
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From: Stefani Seibold <stefani@seibold.net>
commit 8ae664184c45def51ff0b61d4bd6c6671db6cb4f upstream.
This patch prevent to schedule while atomic by changing the flchip_shared spinlock into a mutex. This should be save since no atomic path will use this lock.
It was suggested by Arnd Bergmann and Vasiliy Kulikov.
Signed-off-by: Stefani Seibold <stefani@seibold.net> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/mtd/chips/cfi_cmdset_0001.c | 20 ++++++++++---------- drivers/mtd/lpddr/lpddr_cmds.c | 20 ++++++++++---------- include/linux/mtd/flashchip.h | 2 +- 3 files changed, 21 insertions(+), 21 deletions(-)
--- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -717,7 +717,7 @@ static int cfi_intelext_partition_fixup( chip = &newcfi->chips[0]; for (i = 0; i < cfi->numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < numparts; j++) { *chip = cfi->chips[i]; chip->start += j << partshift; @@ -886,7 +886,7 @@ static int get_chip(struct map_info *map */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -899,7 +899,7 @@ static int get_chip(struct map_info *map * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -914,7 +914,7 @@ static int get_chip(struct map_info *map mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already * in FL_SYNCING state. Put contender and retry. */ @@ -930,7 +930,7 @@ static int get_chip(struct map_info *map * on this chip. Sleep. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -944,7 +944,7 @@ static int get_chip(struct map_info *map shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, adr, mode); if (ret == -EAGAIN) @@ -959,7 +959,7 @@ static void put_chip(struct map_info *ma if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -967,7 +967,7 @@ static void put_chip(struct map_info *ma /* give back ownership to who we loaned it from */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner, loaner->start); mutex_lock(&chip->mutex); @@ -985,11 +985,11 @@ static void put_chip(struct map_info *ma * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch(chip->oldstate) { --- a/drivers/mtd/lpddr/lpddr_cmds.c +++ b/drivers/mtd/lpddr/lpddr_cmds.c @@ -98,7 +98,7 @@ struct mtd_info *lpddr_cmdset(struct map numchips = lpddr->numchips / lpddr->qinfo->HWPartsNum; for (i = 0; i < numchips; i++) { shared[i].writing = shared[i].erasing = NULL; - spin_lock_init(&shared[i].lock); + mutex_init(&shared[i].lock); for (j = 0; j < lpddr->qinfo->HWPartsNum; j++) { *chip = lpddr->chips[i]; chip->start += j << lpddr->chipshift; @@ -217,7 +217,7 @@ static int get_chip(struct map_info *map */ struct flchip_shared *shared = chip->priv; struct flchip *contender; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); contender = shared->writing; if (contender && contender != chip) { /* @@ -230,7 +230,7 @@ static int get_chip(struct map_info *map * get_chip returns success we're clear to go ahead. */ ret = mutex_trylock(&contender->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); if (!ret) goto retry; mutex_unlock(&chip->mutex); @@ -245,7 +245,7 @@ static int get_chip(struct map_info *map mutex_unlock(&contender->mutex); return ret; } - spin_lock(&shared->lock); + mutex_lock(&shared->lock); /* We should not own chip if it is already in FL_SYNCING * state. Put contender and retry. */ @@ -261,7 +261,7 @@ static int get_chip(struct map_info *map Must sleep in such a case. */ if (mode == FL_ERASING && shared->erasing && shared->erasing->oldstate == FL_ERASING) { - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); @@ -275,7 +275,7 @@ static int get_chip(struct map_info *map shared->writing = chip; if (mode == FL_ERASING) shared->erasing = chip; - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } ret = chip_ready(map, chip, mode); @@ -348,7 +348,7 @@ static void put_chip(struct map_info *ma { if (chip->priv) { struct flchip_shared *shared = chip->priv; - spin_lock(&shared->lock); + mutex_lock(&shared->lock); if (shared->writing == chip && chip->oldstate == FL_READY) { /* We own the ability to write, but we're done */ shared->writing = shared->erasing; @@ -356,7 +356,7 @@ static void put_chip(struct map_info *ma /* give back the ownership */ struct flchip *loaner = shared->writing; mutex_lock(&loaner->mutex); - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); mutex_unlock(&chip->mutex); put_chip(map, loaner); mutex_lock(&chip->mutex); @@ -374,11 +374,11 @@ static void put_chip(struct map_info *ma * Don't let the switch below mess things up since * we don't have ownership to resume anything. */ - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); wake_up(&chip->wq); return; } - spin_unlock(&shared->lock); + mutex_unlock(&shared->lock); } switch (chip->oldstate) { --- a/include/linux/mtd/flashchip.h +++ b/include/linux/mtd/flashchip.h @@ -92,7 +92,7 @@ struct flchip { /* This is used to handle contention on write/erase operations between partitions of the same physical chip. */ struct flchip_shared { - spinlock_t lock; + struct mutex lock; struct flchip *writing; struct flchip *erasing; };
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