159 lines
3.3 KiB
C
159 lines
3.3 KiB
C
/*
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* drivers/pci/ats.c
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*
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* Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
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*
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* PCI Express I/O Virtualization (IOV) support.
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* Address Translation Service 1.0
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*/
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#include <linux/pci-ats.h>
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#include <linux/pci.h>
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#include "pci.h"
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static int ats_alloc_one(struct pci_dev *dev, int ps)
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{
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int pos;
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u16 cap;
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struct pci_ats *ats;
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pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
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if (!pos)
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return -ENODEV;
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ats = kzalloc(sizeof(*ats), GFP_KERNEL);
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if (!ats)
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return -ENOMEM;
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ats->pos = pos;
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ats->stu = ps;
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pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
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ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
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PCI_ATS_MAX_QDEP;
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dev->ats = ats;
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return 0;
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}
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static void ats_free_one(struct pci_dev *dev)
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{
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kfree(dev->ats);
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dev->ats = NULL;
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}
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/**
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* pci_enable_ats - enable the ATS capability
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* @dev: the PCI device
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* @ps: the IOMMU page shift
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*
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* Returns 0 on success, or negative on failure.
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*/
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int pci_enable_ats(struct pci_dev *dev, int ps)
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{
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int rc;
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u16 ctrl;
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BUG_ON(dev->ats && dev->ats->is_enabled);
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if (ps < PCI_ATS_MIN_STU)
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return -EINVAL;
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if (dev->is_physfn || dev->is_virtfn) {
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struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
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mutex_lock(&pdev->sriov->lock);
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if (pdev->ats)
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rc = pdev->ats->stu == ps ? 0 : -EINVAL;
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else
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rc = ats_alloc_one(pdev, ps);
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if (!rc)
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pdev->ats->ref_cnt++;
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mutex_unlock(&pdev->sriov->lock);
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if (rc)
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return rc;
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}
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if (!dev->is_physfn) {
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rc = ats_alloc_one(dev, ps);
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if (rc)
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return rc;
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}
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ctrl = PCI_ATS_CTRL_ENABLE;
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if (!dev->is_virtfn)
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ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
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pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
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dev->ats->is_enabled = 1;
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return 0;
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}
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EXPORT_SYMBOL_GPL(pci_enable_ats);
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/**
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* pci_disable_ats - disable the ATS capability
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* @dev: the PCI device
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*/
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void pci_disable_ats(struct pci_dev *dev)
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{
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u16 ctrl;
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BUG_ON(!dev->ats || !dev->ats->is_enabled);
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pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
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ctrl &= ~PCI_ATS_CTRL_ENABLE;
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pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
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dev->ats->is_enabled = 0;
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if (dev->is_physfn || dev->is_virtfn) {
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struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
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mutex_lock(&pdev->sriov->lock);
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pdev->ats->ref_cnt--;
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if (!pdev->ats->ref_cnt)
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ats_free_one(pdev);
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mutex_unlock(&pdev->sriov->lock);
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}
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if (!dev->is_physfn)
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ats_free_one(dev);
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}
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EXPORT_SYMBOL_GPL(pci_disable_ats);
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/**
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* pci_ats_queue_depth - query the ATS Invalidate Queue Depth
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* @dev: the PCI device
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*
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* Returns the queue depth on success, or negative on failure.
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*
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* The ATS spec uses 0 in the Invalidate Queue Depth field to
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* indicate that the function can accept 32 Invalidate Request.
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* But here we use the `real' values (i.e. 1~32) for the Queue
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* Depth; and 0 indicates the function shares the Queue with
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* other functions (doesn't exclusively own a Queue).
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*/
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int pci_ats_queue_depth(struct pci_dev *dev)
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{
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int pos;
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u16 cap;
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if (dev->is_virtfn)
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return 0;
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if (dev->ats)
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return dev->ats->qdep;
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pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
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if (!pos)
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return -ENODEV;
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pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
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return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
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PCI_ATS_MAX_QDEP;
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}
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EXPORT_SYMBOL_GPL(pci_ats_queue_depth);
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