Implement managed PCI interface - pcim_enable_device(), pcim_pin_device() and pci_is_managed(). pcim_enable_device() is equivalent to pci_enable_device() except that it makes the PCI device managed. After pcim_enable_device(), PCI resources such as enabledness, msi/msix/intx status and BAR regions become managed. pcim_pin_device() is used by device drivers to ask PCI devres not to disable the device on driver detach. This function is to handle cases where a driver finds out that a device is otherwise busy and thus shouldn't be disabled on probe failure or driver detach. Signed-off-by: Tejun Heo <htejun@xxxxxxxxx> --- drivers/pci/pci.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++- include/linux/pci.h | 9 ++++ 2 files changed, 135 insertions(+), 1 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6bfb942..2ab2f8a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -744,6 +744,104 @@ int pci_enable_device(struct pci_dev *dev) return result; } +/* + * Managed PCI resources. This manages device on/off, intx/msi/msix + * on/off and BAR regions. pci_dev itself records msi/msix status, so + * there's no need to track it separately. pci_devres is initialized + * when a device is enabled using managed PCI device enable interface. + */ +struct pci_devres { + unsigned int disable:1; + unsigned int orig_intx:1; + unsigned int restore_intx:1; + u32 region_mask; +}; + +static void pcim_release(struct device *gendev, void *res) +{ + struct pci_dev *dev = container_of(gendev, struct pci_dev, dev); + struct pci_devres *this = res; + int i; + + if (dev->msi_enabled) + pci_disable_msi(dev); + if (dev->msix_enabled) + pci_disable_msix(dev); + + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) + if (this->region_mask & (1 << i)) + pci_release_region(dev, i); + + if (this->restore_intx) + pci_intx(dev, this->orig_intx); + + if (this->disable) + pci_disable_device(dev); +} + +static struct pci_devres * get_pci_dr(struct pci_dev *pdev) +{ + struct pci_devres *dr, *new_dr; + + dr = devres_find(&pdev->dev, pcim_release, NULL, NULL); + if (dr) + return dr; + + new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL); + if (!new_dr) + return NULL; + return devres_get(&pdev->dev, new_dr, NULL, NULL); +} + +static struct pci_devres * find_pci_dr(struct pci_dev *pdev) +{ + if (pci_is_managed(pdev)) + return devres_find(&pdev->dev, pcim_release, NULL, NULL); + return NULL; +} + +/** + * pcim_enable_device - Managed pci_enable_device() + * @pdev: PCI device to be initialized + * + * Managed pci_enable_device(). + */ +int pcim_enable_device(struct pci_dev *pdev) +{ + struct pci_devres *dr; + int rc; + + dr = get_pci_dr(pdev); + if (unlikely(!dr)) + return -ENOMEM; + WARN_ON(!!dr->disable); + + rc = pci_enable_device(pdev); + if (!rc) { + pdev->is_managed = 1; + dr->disable = 1; + } + return rc; +} + +/** + * pcim_pin_device - Pin managed PCI device + * @pdev: PCI device to pin + * + * Pin managed PCI device @pdev. Pinned device won't be disabled on + * driver detach. @pdev must have been enabled with + * pcim_enable_device(). + */ +void pcim_pin_device(struct pci_dev *pdev) +{ + struct pci_devres *dr; + + dr = find_pci_dr(pdev); + WARN_ON(!dr || !dr->disable); + if (dr) + dr->disable = 0; +} + /** * pcibios_disable_device - disable arch specific PCI resources for device dev * @dev: the PCI device to disable @@ -767,8 +865,13 @@ void __attribute__ ((weak)) pcibios_disable_device (struct pci_dev *dev) {} void pci_disable_device(struct pci_dev *dev) { + struct pci_devres *dr; u16 pci_command; + dr = find_pci_dr(dev); + if (dr) + dr->disable = 0; + if (atomic_sub_return(1, &dev->enable_cnt) != 0) return; @@ -867,6 +970,8 @@ pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge) */ void pci_release_region(struct pci_dev *pdev, int bar) { + struct pci_devres *dr; + if (pci_resource_len(pdev, bar) == 0) return; if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) @@ -875,6 +980,10 @@ void pci_release_region(struct pci_dev *pdev, int bar) else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) release_mem_region(pci_resource_start(pdev, bar), pci_resource_len(pdev, bar)); + + dr = find_pci_dr(pdev); + if (dr) + dr->region_mask &= ~(1 << bar); } /** @@ -893,6 +1002,8 @@ void pci_release_region(struct pci_dev *pdev, int bar) */ int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name) { + struct pci_devres *dr; + if (pci_resource_len(pdev, bar) == 0) return 0; @@ -906,7 +1017,11 @@ int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name) pci_resource_len(pdev, bar), res_name)) goto err_out; } - + + dr = find_pci_dr(pdev); + if (dr) + dr->region_mask |= 1 << bar; + return 0; err_out: @@ -1117,7 +1232,15 @@ pci_intx(struct pci_dev *pdev, int enable) } if (new != pci_command) { + struct pci_devres *dr; + pci_write_config_word(pdev, PCI_COMMAND, new); + + dr = find_pci_dr(pdev); + if (dr && !dr->restore_intx) { + dr->restore_intx = 1; + dr->orig_intx = !enable; + } } } @@ -1189,6 +1312,8 @@ EXPORT_SYMBOL(isa_bridge); EXPORT_SYMBOL_GPL(pci_restore_bars); EXPORT_SYMBOL(pci_enable_device_bars); EXPORT_SYMBOL(pci_enable_device); +EXPORT_SYMBOL(pcim_enable_device); +EXPORT_SYMBOL(pcim_pin_device); EXPORT_SYMBOL(pci_disable_device); EXPORT_SYMBOL(pci_find_capability); EXPORT_SYMBOL(pci_bus_find_capability); diff --git a/include/linux/pci.h b/include/linux/pci.h index f3c617e..1f82eb9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -167,6 +167,7 @@ struct pci_dev { unsigned int broken_parity_status:1; /* Device generates false positive parity */ unsigned int msi_enabled:1; unsigned int msix_enabled:1; + unsigned int is_managed:1; atomic_t enable_cnt; /* pci_enable_device has been called */ u32 saved_config_space[16]; /* config space saved at suspend time */ @@ -521,6 +522,14 @@ static inline int pci_write_config_dword(struct pci_dev *dev, int where, u32 val int __must_check pci_enable_device(struct pci_dev *dev); int __must_check pci_enable_device_bars(struct pci_dev *dev, int mask); +int __must_check pcim_enable_device(struct pci_dev *pdev); +void pcim_pin_device(struct pci_dev *pdev); + +static inline int pci_is_managed(struct pci_dev *pdev) +{ + return pdev->is_managed; +} + void pci_disable_device(struct pci_dev *dev); void pci_set_master(struct pci_dev *dev); #define HAVE_PCI_SET_MWI -- 1.4.4.3 - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html