diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/pci/ats.c | 167 |
2 files changed, 176 insertions, 0 deletions
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 1d8ce839586..fb1e9707f91 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -85,6 +85,15 @@ config PCI_IOV If unsure, say N. +config PCI_PRI + bool "PCI PRI support" + select PCI_ATS + help + PRI is the PCI Page Request Interface. It allows PCI devices that are + behind an IOMMU to recover from page faults. + + If unsure, say N. + config PCI_IOAPIC bool depends on PCI diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 5ceff3e16e1..bf892a025d4 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -2,9 +2,11 @@ * drivers/pci/ats.c * * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com> + * Copyright (C) 2011 Advanced Micro Devices, * * PCI Express I/O Virtualization (IOV) support. * Address Translation Service 1.0 + * Page Request Interface added by Joerg Roedel <joerg.roedel@amd.com> */ #include <linux/pci-ats.h> @@ -156,3 +158,168 @@ int pci_ats_queue_depth(struct pci_dev *dev) PCI_ATS_MAX_QDEP; } EXPORT_SYMBOL_GPL(pci_ats_queue_depth); + +#ifdef CONFIG_PCI_PRI +/** + * pci_enable_pri - Enable PRI capability + * @ pdev: PCI device structure + * + * Returns 0 on success, negative value on error + */ +int pci_enable_pri(struct pci_dev *pdev, u32 reqs) +{ + u16 control, status; + u32 max_requests; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + pci_read_config_word(pdev, pos + PCI_PRI_STATUS_OFF, &status); + if ((control & PCI_PRI_ENABLE) || !(status & PCI_PRI_STATUS_STOPPED)) + return -EBUSY; + + pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ_OFF, &max_requests); + reqs = min(max_requests, reqs); + pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ_OFF, reqs); + + control |= PCI_PRI_ENABLE; + pci_write_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, control); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_enable_pri); + +/** + * pci_disable_pri - Disable PRI capability + * @pdev: PCI device structure + * + * Only clears the enabled-bit, regardless of its former value + */ +void pci_disable_pri(struct pci_dev *pdev) +{ + u16 control; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + control &= ~PCI_PRI_ENABLE; + pci_write_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, control); +} +EXPORT_SYMBOL_GPL(pci_disable_pri); + +/** + * pci_pri_enabled - Checks if PRI capability is enabled + * @pdev: PCI device structure + * + * Returns true if PRI is enabled on the device, false otherwise + */ +bool pci_pri_enabled(struct pci_dev *pdev) +{ + u16 control; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return false; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + + return (control & PCI_PRI_ENABLE) ? true : false; +} +EXPORT_SYMBOL_GPL(pci_pri_enabled); + +/** + * pci_reset_pri - Resets device's PRI state + * @pdev: PCI device structure + * + * The PRI capability must be disabled before this function is called. + * Returns 0 on success, negative value on error. + */ +int pci_reset_pri(struct pci_dev *pdev) +{ + u16 control; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + if (control & PCI_PRI_ENABLE) + return -EBUSY; + + control |= PCI_PRI_RESET; + + pci_write_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, control); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_reset_pri); + +/** + * pci_pri_stopped - Checks whether the PRI capability is stopped + * @pdev: PCI device structure + * + * Returns true if the PRI capability on the device is disabled and the + * device has no outstanding PRI requests, false otherwise. The device + * indicates this via the STOPPED bit in the status register of the + * capability. + * The device internal state can be cleared by resetting the PRI state + * with pci_reset_pri(). This can force the capability into the STOPPED + * state. + */ +bool pci_pri_stopped(struct pci_dev *pdev) +{ + u16 control, status; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return true; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + pci_read_config_word(pdev, pos + PCI_PRI_STATUS_OFF, &status); + + if (control & PCI_PRI_ENABLE) + return false; + + return (status & PCI_PRI_STATUS_STOPPED) ? true : false; +} +EXPORT_SYMBOL_GPL(pci_pri_stopped); + +/** + * pci_pri_status - Request PRI status of a device + * @pdev: PCI device structure + * + * Returns negative value on failure, status on success. The status can + * be checked against status-bits. Supported bits are currently: + * PCI_PRI_STATUS_RF: Response failure + * PCI_PRI_STATUS_UPRGI: Unexpected Page Request Group Index + * PCI_PRI_STATUS_STOPPED: PRI has stopped + */ +int pci_pri_status(struct pci_dev *pdev) +{ + u16 status, control; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PRI_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PRI_CONTROL_OFF, &control); + pci_read_config_word(pdev, pos + PCI_PRI_STATUS_OFF, &status); + + /* Stopped bit is undefined when enable == 1, so clear it */ + if (control & PCI_PRI_ENABLE) + status &= ~PCI_PRI_STATUS_STOPPED; + + return status; +} +EXPORT_SYMBOL_GPL(pci_pri_status); +#endif /* CONFIG_PCI_PRI */ |