uio: Convert uio_generic_pci to new intx masking API

The new PCI API provides both generic probing for 2.3 masking support
and check&mask in the interrupt handler.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c
index 56d00c6..0bd08ef 100644 (file)
--- 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) {