diff options
| -rw-r--r-- | drivers/uio/uio_pci_generic.c | 79 |
1 files changed, 7 insertions, 72 deletions
diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c index 56d00c6258f0..0bd08ef2b394 100644 --- a/drivers/uio/uio_pci_generic.c +++ b/drivers/uio/uio_pci_generic.c @@ -45,78 +45,12 @@ to_uio_pci_generic_dev(struct uio_info *info) static irqreturn_t irqhandler(int irq, struct uio_info *info) { struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); - struct pci_dev *pdev = gdev->pdev; - irqreturn_t ret = IRQ_NONE; - u32 cmd_status_dword; - u16 origcmd, newcmd, status; - - /* We do a single dword read to retrieve both command and status. - * Document assumptions that make this possible. */ - BUILD_BUG_ON(PCI_COMMAND % 4); - BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS); - - if (!pci_cfg_access_trylock(pdev)) - goto error; - - /* Read both command and status registers in a single 32-bit operation. - * Note: we could cache the value for command and move the status read - * out of the lock if there was a way to get notified of user changes - * to command register through sysfs. Should be good for shared irqs. */ - pci_read_config_dword(pdev, PCI_COMMAND, &cmd_status_dword); - origcmd = cmd_status_dword; - status = cmd_status_dword >> 16; - - /* Check interrupt status register to see whether our device - * triggered the interrupt. */ - if (!(status & PCI_STATUS_INTERRUPT)) - goto done; - - /* We triggered the interrupt, disable it. */ - newcmd = origcmd | PCI_COMMAND_INTX_DISABLE; - if (newcmd != origcmd) - pci_write_config_word(pdev, PCI_COMMAND, newcmd); - /* UIO core will signal the user process. */ - ret = IRQ_HANDLED; -done: - - pci_cfg_access_lock(pdev); - return ret; -} + if (!pci_check_and_mask_intx(gdev->pdev)) + return IRQ_NONE; -/* Verify that the device supports Interrupt Disable bit in command register, - * per PCI 2.3, by flipping this bit and reading it back: this bit was readonly - * in PCI 2.2. */ -static int __devinit verify_pci_2_3(struct pci_dev *pdev) -{ - u16 orig, new; - int err = 0; - - pci_cfg_access_lock(pdev); - pci_read_config_word(pdev, PCI_COMMAND, &orig); - pci_write_config_word(pdev, PCI_COMMAND, - orig ^ PCI_COMMAND_INTX_DISABLE); - pci_read_config_word(pdev, PCI_COMMAND, &new); - /* There's no way to protect against - * hardware bugs or detect them reliably, but as long as we know - * what the value should be, let's go ahead and check it. */ - if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) { - err = -EBUSY; - dev_err(&pdev->dev, "Command changed from 0x%x to 0x%x: " - "driver or HW bug?\n", orig, new); - goto err; - } - if (!((new ^ orig) & PCI_COMMAND_INTX_DISABLE)) { - dev_warn(&pdev->dev, "Device does not support " - "disabling interrupts: unable to bind.\n"); - err = -ENODEV; - goto err; - } - /* Now restore the original value. */ - pci_write_config_word(pdev, PCI_COMMAND, orig); -err: - pci_cfg_access_unlock(pdev); - return err; + /* UIO core will signal the user process. */ + return IRQ_HANDLED; } static int __devinit probe(struct pci_dev *pdev, @@ -139,9 +73,10 @@ static int __devinit probe(struct pci_dev *pdev, return -ENODEV; } - err = verify_pci_2_3(pdev); - if (err) + if (!pci_intx_mask_supported(pdev)) { + err = -ENODEV; goto err_verify; + } gdev = kzalloc(sizeof(struct uio_pci_generic_dev), GFP_KERNEL); if (!gdev) { |