diff options
Diffstat (limited to 'drivers/pci/ats.c')
| -rw-r--r-- | drivers/pci/ats.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c new file mode 100644 index 000000000000..ae4bf87afb09 --- /dev/null +++ b/drivers/pci/ats.c @@ -0,0 +1,155 @@ +/* + * drivers/pci/ats.c + * + * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com> + * + * PCI Express I/O Virtualization (IOV) support. + * Address Translation Service 1.0 + */ + +#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; +} + +/** + * 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); +} + +/** + * 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; +} |