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Commit 487e0a60 authored by Jens Taprogge's avatar Jens Taprogge Committed by Greg Kroah-Hartman
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Staging: ipack/bridges/tpci200: Protect device registers with spinlock. 



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: default avatarJens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: default avatarSamuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b8d61d49

drivers/staging/ipack/bridges/tpci200.c

+14 −19
Original line number Diff line number Diff line
@@ -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);

}

drivers/staging/ipack/bridges/tpci200.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

};