/* * 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/export.h> #include <linux/pci-ats.h> #include <linux/pci.h> #include <linux/slab.h> #include "pci.h" void pci_ats_init(struct pci_dev *dev) { int pos; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); if (!pos) return; dev->ats_cap = pos; } /** * 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) { u16 ctrl; struct pci_dev *pdev; if (!dev->ats_cap) return -EINVAL; if (WARN_ON(dev->ats_enabled)) return -EBUSY; if (ps < PCI_ATS_MIN_STU) return -EINVAL; /* * Note that enabling ATS on a VF fails unless it's already enabled * with the same STU on the PF. */ ctrl = PCI_ATS_CTRL_ENABLE; if (dev->is_virtfn) { pdev = pci_physfn(dev); if (pdev->ats_stu != ps) return -EINVAL; atomic_inc(&pdev->ats_ref_cnt); /* count enabled VFs */ } else { dev->ats_stu = ps; ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU); } pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl); dev->ats_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) { struct pci_dev *pdev; u16 ctrl; if (WARN_ON(!dev->ats_enabled)) return; if (atomic_read(&dev->ats_ref_cnt)) return; /* VFs still enabled */ if (dev->is_virtfn) { pdev = pci_physfn(dev); atomic_dec(&pdev->ats_ref_cnt); } pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl); ctrl &= ~PCI_ATS_CTRL_ENABLE; pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl); dev->ats_enabled = 0; } EXPORT_SYMBOL_GPL(pci_disable_ats); void pci_restore_ats_state(struct pci_dev *dev) { u16 ctrl; if (!dev->ats_enabled) return; ctrl = PCI_ATS_CTRL_ENABLE; if (!dev->is_virtfn) ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU); pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl); } EXPORT_SYMBOL_GPL(pci_restore_ats_state); /** * 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) { u16 cap; if (!dev->ats_cap) return -EINVAL; if (dev->is_virtfn) return 0; pci_read_config_word(dev, dev->ats_cap + 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_EXT_CAP_ID_PRI); if (!pos) return -EINVAL; pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control); pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status); if ((control & PCI_PRI_CTRL_ENABLE) || !(status & PCI_PRI_STATUS_STOPPED)) return -EBUSY; pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests); reqs = min(max_requests, reqs); pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs); control |= PCI_PRI_CTRL_ENABLE; pci_write_config_word(pdev, pos + PCI_PRI_CTRL, 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_EXT_CAP_ID_PRI); if (!pos) return; pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control); control &= ~PCI_PRI_CTRL_ENABLE; pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); } EXPORT_SYMBOL_GPL(pci_disable_pri); /** * 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_EXT_CAP_ID_PRI); if (!pos) return -EINVAL; pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control); if (control & PCI_PRI_CTRL_ENABLE) return -EBUSY; control |= PCI_PRI_CTRL_RESET; pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control); return 0; } EXPORT_SYMBOL_GPL(pci_reset_pri); #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_EXT_CAP_ID_PASID); if (!pos) return -EINVAL; pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control); pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); if (control & PCI_PASID_CTRL_ENABLE) return -EINVAL; supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; /* User wants to enable anything unsupported? */ if ((supported & features) != features) return -EINVAL; control = PCI_PASID_CTRL_ENABLE | features; pci_write_config_word(pdev, pos + PCI_PASID_CTRL, 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_EXT_CAP_ID_PASID); if (!pos) return; pci_write_config_word(pdev, pos + PCI_PASID_CTRL, 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_CAP_EXEC - Execute permission supported * PCI_PASID_CAP_PRIV - Privileged mode supported */ int pci_pasid_features(struct pci_dev *pdev) { u16 supported; int pos; pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID); if (!pos) return -EINVAL; pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_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_EXT_CAP_ID_PASID); if (!pos) return -EINVAL; pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT; return (1 << supported); } EXPORT_SYMBOL_GPL(pci_max_pasids); #endif /* CONFIG_PCI_PASID */