diff options
Diffstat (limited to 'drivers/uio/uio_pci_generic.c')
| -rw-r--r-- | drivers/uio/uio_pci_generic.c | 116 |
1 files changed, 18 insertions, 98 deletions
diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c index 313da35984a..077ae12269c 100644 --- a/drivers/uio/uio_pci_generic.c +++ b/drivers/uio/uio_pci_generic.c @@ -22,8 +22,8 @@ #include <linux/device.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/slab.h> #include <linux/uio_driver.h> -#include <linux/spinlock.h> #define DRIVER_VERSION "0.01.0" #define DRIVER_AUTHOR "Michael S. Tsirkin <mst@redhat.com>" @@ -32,7 +32,6 @@ struct uio_pci_generic_dev { struct uio_info info; struct pci_dev *pdev; - spinlock_t lock; /* guards command register accesses */ }; static inline struct uio_pci_generic_dev * @@ -46,93 +45,20 @@ 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); - - spin_lock_irq(&gdev->lock); - pci_block_user_cfg_access(pdev); - - /* 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_unblock_user_cfg_access(pdev); - spin_unlock_irq(&gdev->lock); - 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_block_user_cfg_access(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_unblock_user_cfg_access(pdev); - return err; + /* UIO core will signal the user process. */ + return IRQ_HANDLED; } -static int __devinit probe(struct pci_dev *pdev, +static int probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct uio_pci_generic_dev *gdev; int err; - if (!pdev->irq) { - dev_warn(&pdev->dev, "No IRQ assigned to device: " - "no support for interrupts?\n"); - return -ENODEV; - } - err = pci_enable_device(pdev); if (err) { dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n", @@ -140,9 +66,17 @@ static int __devinit probe(struct pci_dev *pdev, return err; } - err = verify_pci_2_3(pdev); - if (err) + if (!pdev->irq) { + dev_warn(&pdev->dev, "No IRQ assigned to device: " + "no support for interrupts?\n"); + pci_disable_device(pdev); + return -ENODEV; + } + + if (!pci_intx_mask_supported(pdev)) { + err = -ENODEV; goto err_verify; + } gdev = kzalloc(sizeof(struct uio_pci_generic_dev), GFP_KERNEL); if (!gdev) { @@ -156,7 +90,6 @@ static int __devinit probe(struct pci_dev *pdev, gdev->info.irq_flags = IRQF_SHARED; gdev->info.handler = irqhandler; gdev->pdev = pdev; - spin_lock_init(&gdev->lock); if (uio_register_device(&pdev->dev, &gdev->info)) goto err_register; @@ -180,27 +113,14 @@ static void remove(struct pci_dev *pdev) kfree(gdev); } -static struct pci_driver driver = { +static struct pci_driver uio_pci_driver = { .name = "uio_pci_generic", .id_table = NULL, /* only dynamic id's */ .probe = probe, .remove = remove, }; -static int __init init(void) -{ - pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); - return pci_register_driver(&driver); -} - -static void __exit cleanup(void) -{ - pci_unregister_driver(&driver); -} - -module_init(init); -module_exit(cleanup); - +module_pci_driver(uio_pci_driver); MODULE_VERSION(DRIVER_VERSION); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR(DRIVER_AUTHOR); |