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Staging: ipack/bridges/tpci200: Protect device registers with spinlock.

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Some of the device registers are accessed from both interrupt and
non-interrupt context.  To ensure proper read-modify-write modification
of these registers we can not use the  "global" tpci200 mutex.  Instead
a spin-lock is used.

Signed-off-by: Jens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jens Taprogge 2012-09-12 14:55:33 +02:00 committed by Greg Kroah-Hartman
parent b8d61d49b2
commit 487e0a608d
2 changed files with 15 additions and 19 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

33
drivers/staging/ipack/bridges/tpci200.c
View file

@ -53,30 +53,22 @@ static struct tpci200_board *check_slot(struct ipack_device *dev)
return tpci200;
}
static void __tpci200_clear_mask(__le16 __iomem *addr, u16 mask)
{
iowrite16(ioread16(addr) & (~mask), addr);
}
static void tpci200_clear_mask(struct tpci200_board *tpci200,
__le16 __iomem *addr, u16 mask)
{
mutex_lock(&tpci200->mutex);
__tpci200_clear_mask(addr, mask);
mutex_unlock(&tpci200->mutex);
}
static void __tpci200_set_mask(__le16 __iomem *addr, u16 mask)
{
iowrite16(ioread16(addr) | mask, addr);
unsigned long flags;
spin_lock_irqsave(&tpci200->regs_lock, flags);
iowrite16(ioread16(addr) & (~mask), addr);
spin_unlock_irqrestore(&tpci200->regs_lock, flags);
}
static void tpci200_set_mask(struct tpci200_board *tpci200,
__le16 __iomem *addr, u16 mask)
{
mutex_lock(&tpci200->mutex);
__tpci200_set_mask(addr, mask);
mutex_unlock(&tpci200->mutex);
unsigned long flags;
spin_lock_irqsave(&tpci200->regs_lock, flags);
iowrite16(ioread16(addr) | mask, addr);
spin_unlock_irqrestore(&tpci200->regs_lock, flags);
}
static void tpci200_unregister(struct tpci200_board *tpci200)
@ -143,7 +135,7 @@ static irqreturn_t tpci200_interrupt(int irq, void *dev_id)
dev_info(&tpci200->info->pdev->dev,
"No registered ISR for slot [%d:%d]!. IRQ will be disabled.\n",
tpci200->number, i);
__tpci200_clear_mask(
tpci200_clear_mask(tpci200,
&tpci200->info->interface_regs->control[i],
TPCI200_INT0_EN | TPCI200_INT1_EN);
}
@ -213,6 +205,9 @@ static int tpci200_register(struct tpci200_board *tpci200)
TPCI200_MEM8_SPACE_BAR),
TPCI200_MEM8_SIZE);
/* Initialize lock that protects interface_regs */
spin_lock_init(&tpci200->regs_lock);
ioidint_base = pci_resource_start(tpci200->info->pdev,
TPCI200_IO_ID_INT_SPACES_BAR);
mem_base = pci_resource_start(tpci200->info->pdev,
@ -272,7 +267,7 @@ static int tpci200_register(struct tpci200_board *tpci200)
static int __tpci200_request_irq(struct tpci200_board *tpci200,
struct ipack_device *dev)
{
__tpci200_set_mask(
tpci200_set_mask(tpci200,
&tpci200->info->interface_regs->control[dev->slot],
TPCI200_INT0_EN | TPCI200_INT1_EN);
return 0;
@ -281,7 +276,7 @@ static int __tpci200_request_irq(struct tpci200_board *tpci200,
static void __tpci200_free_irq(struct tpci200_board *tpci200,
struct ipack_device *dev)
{
__tpci200_clear_mask(
tpci200_clear_mask(tpci200,
&tpci200->info->interface_regs->control[dev->slot],
TPCI200_INT0_EN | TPCI200_INT1_EN);
}

1
drivers/staging/ipack/bridges/tpci200.h
View file

@ -163,6 +163,7 @@ struct tpci200_infos {
struct tpci200_board {
unsigned int number;
struct mutex mutex;
spinlock_t regs_lock;
struct tpci200_slot *slots;
struct tpci200_infos *info;
};