diff options
Diffstat (limited to 'drivers/pci/ats.c')
| -rw-r--r-- | drivers/pci/ats.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c new file mode 100644 index 00000000000..f727a09eb72 --- /dev/null +++ b/drivers/pci/ats.c @@ -0,0 +1,438 @@ +/* + * 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> + * PASID support added by Joerg Roedel <joerg.roedel@amd.com> + */ + +#include <linux/pci-ats.h> +#include <linux/pci.h> + +#include "pci.h" + +static int ats_alloc_one(struct pci_dev *dev, int ps) +{ + int pos; + u16 cap; + struct pci_ats *ats; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); + if (!pos) + return -ENODEV; + + ats = kzalloc(sizeof(*ats), GFP_KERNEL); + if (!ats) + return -ENOMEM; + + ats->pos = pos; + ats->stu = ps; + pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap); + ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : + PCI_ATS_MAX_QDEP; + dev->ats = ats; + + return 0; +} + +static void ats_free_one(struct pci_dev *dev) +{ + kfree(dev->ats); + dev->ats = NULL; +} + +/** + * pci_enable_ats - enable the ATS capability + * @dev: the PCI device + * @ps: the IOMMU page shift + * + * Returns 0 on success, or negative on failure. + */ +int pci_enable_ats(struct pci_dev *dev, int ps) +{ + int rc; + u16 ctrl; + + BUG_ON(dev->ats && dev->ats->is_enabled); + + if (ps < PCI_ATS_MIN_STU) + return -EINVAL; + + if (dev->is_physfn || dev->is_virtfn) { + struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn; + + mutex_lock(&pdev->sriov->lock); + if (pdev->ats) + rc = pdev->ats->stu == ps ? 0 : -EINVAL; + else + rc = ats_alloc_one(pdev, ps); + + if (!rc) + pdev->ats->ref_cnt++; + mutex_unlock(&pdev->sriov->lock); + if (rc) + return rc; + } + + if (!dev->is_physfn) { + rc = ats_alloc_one(dev, ps); + if (rc) + return rc; + } + + ctrl = PCI_ATS_CTRL_ENABLE; + if (!dev->is_virtfn) + ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU); + pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl); + + dev->ats->is_enabled = 1; + + return 0; +} +EXPORT_SYMBOL_GPL(pci_enable_ats); + +/** + * pci_disable_ats - disable the ATS capability + * @dev: the PCI device + */ +void pci_disable_ats(struct pci_dev *dev) +{ + u16 ctrl; + + BUG_ON(!dev->ats || !dev->ats->is_enabled); + + pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl); + ctrl &= ~PCI_ATS_CTRL_ENABLE; + pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl); + + dev->ats->is_enabled = 0; + + if (dev->is_physfn || dev->is_virtfn) { + struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn; + + mutex_lock(&pdev->sriov->lock); + pdev->ats->ref_cnt--; + if (!pdev->ats->ref_cnt) + ats_free_one(pdev); + mutex_unlock(&pdev->sriov->lock); + } + + if (!dev->is_physfn) + ats_free_one(dev); +} +EXPORT_SYMBOL_GPL(pci_disable_ats); + +/** + * pci_ats_queue_depth - query the ATS Invalidate Queue Depth + * @dev: the PCI device + * + * Returns the queue depth on success, or negative on failure. + * + * The ATS spec uses 0 in the Invalidate Queue Depth field to + * indicate that the function can accept 32 Invalidate Request. + * But here we use the `real' values (i.e. 1~32) for the Queue + * Depth; and 0 indicates the function shares the Queue with + * other functions (doesn't exclusively own a Queue). + */ +int pci_ats_queue_depth(struct pci_dev *dev) +{ + int pos; + u16 cap; + + if (dev->is_virtfn) + return 0; + + if (dev->ats) + return dev->ats->qdep; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); + if (!pos) + return -ENODEV; + + pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap); + + return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : + 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 */ + +#ifdef CONFIG_PCI_PASID +/** + * pci_enable_pasid - Enable the PASID capability + * @pdev: PCI device structure + * @features: Features to enable + * + * Returns 0 on success, negative value on error. This function checks + * whether the features are actually supported by the device and returns + * an error if not. + */ +int pci_enable_pasid(struct pci_dev *pdev, int features) +{ + u16 control, supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, &control); + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + if (!(supported & PCI_PASID_ENABLE)) + return -EINVAL; + + supported &= PCI_PASID_EXEC | PCI_PASID_PRIV; + + /* User wants to enable anything unsupported? */ + if ((supported & features) != features) + return -EINVAL; + + control = PCI_PASID_ENABLE | features; + + pci_write_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, control); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_enable_pasid); + +/** + * pci_disable_pasid - Disable the PASID capability + * @pdev: PCI device structure + * + */ +void pci_disable_pasid(struct pci_dev *pdev) +{ + u16 control = 0; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return; + + pci_write_config_word(pdev, pos + PCI_PASID_CONTROL_OFF, control); +} +EXPORT_SYMBOL_GPL(pci_disable_pasid); + +/** + * pci_pasid_features - Check which PASID features are supported + * @pdev: PCI device structure + * + * Returns a negative value when no PASI capability is present. + * Otherwise is returns a bitmask with supported features. Current + * features reported are: + * PCI_PASID_ENABLE - PASID capability can be enabled + * PCI_PASID_EXEC - Execute permission supported + * PCI_PASID_PRIV - Priviledged mode supported + */ +int pci_pasid_features(struct pci_dev *pdev) +{ + u16 supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + supported &= PCI_PASID_ENABLE | PCI_PASID_EXEC | PCI_PASID_PRIV; + + return supported; +} +EXPORT_SYMBOL_GPL(pci_pasid_features); + +#define PASID_NUMBER_SHIFT 8 +#define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT) +/** + * pci_max_pasid - Get maximum number of PASIDs supported by device + * @pdev: PCI device structure + * + * Returns negative value when PASID capability is not present. + * Otherwise it returns the numer of supported PASIDs. + */ +int pci_max_pasids(struct pci_dev *pdev) +{ + u16 supported; + int pos; + + pos = pci_find_ext_capability(pdev, PCI_PASID_CAP); + if (!pos) + return -EINVAL; + + pci_read_config_word(pdev, pos + PCI_PASID_CAP_OFF, &supported); + + supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT; + + return (1 << supported); +} +EXPORT_SYMBOL_GPL(pci_max_pasids); +#endif /* CONFIG_PCI_PASID */ |