From 302b4215daa0a704c843da40fd2529e5757a72da Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Mon, 18 May 2009 13:51:32 +0800 Subject: PCI: support the ATS capability The PCIe ATS capability makes the Endpoint be able to request the DMA address translation from the IOMMU and cache the translation in the device side, thus alleviate IOMMU pressure and improve the hardware performance in the I/O virtualization environment. Signed-off-by: Yu Zhao Acked-by: Jesse Barnes Signed-off-by: David Woodhouse --- drivers/pci/iov.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) (limited to 'drivers/pci/iov.c') diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index b497daab3d4..0a7a1b40286 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -5,6 +5,7 @@ * * PCI Express I/O Virtualization (IOV) support. * Single Root IOV 1.0 + * Address Translation Service 1.0 */ #include @@ -679,3 +680,107 @@ irqreturn_t pci_sriov_migration(struct pci_dev *dev) return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE; } EXPORT_SYMBOL_GPL(pci_sriov_migration); + +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); + + if (ps < PCI_ATS_MIN_STU) + return -EINVAL; + + rc = ats_alloc_one(dev, ps); + if (rc) + return rc; + + ctrl = PCI_ATS_CTRL_ENABLE; + ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU); + pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl); + + 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); + + 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); + + 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. + */ +int pci_ats_queue_depth(struct pci_dev *dev) +{ + int pos; + u16 cap; + + 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; +} -- cgit v1.2.3-18-g5258 From e277d2fc79d6abb86fafadb58dca0b9c498a9aa7 Mon Sep 17 00:00:00 2001 From: Yu Zhao Date: Mon, 18 May 2009 13:51:33 +0800 Subject: PCI: handle Virtual Function ATS enabling The SR-IOV spec requires that the Smallest Translation Unit and the Invalidate Queue Depth fields in the Virtual Function ATS capability are hardwired to 0. If a function is a Virtual Function, then and set its Physical Function's STU before enabling the ATS. Signed-off-by: Yu Zhao Acked-by: Jesse Barnes Signed-off-by: David Woodhouse --- drivers/pci/iov.c | 66 +++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 52 insertions(+), 14 deletions(-) (limited to 'drivers/pci/iov.c') diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 0a7a1b40286..415140499ff 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -491,10 +491,10 @@ found: if (pdev) iov->dev = pci_dev_get(pdev); - else { + else iov->dev = dev; - mutex_init(&iov->lock); - } + + mutex_init(&iov->lock); dev->sriov = iov; dev->is_physfn = 1; @@ -514,11 +514,11 @@ static void sriov_release(struct pci_dev *dev) { BUG_ON(dev->sriov->nr_virtfn); - if (dev == dev->sriov->dev) - mutex_destroy(&dev->sriov->lock); - else + if (dev != dev->sriov->dev) pci_dev_put(dev->sriov->dev); + mutex_destroy(&dev->sriov->lock); + kfree(dev->sriov); dev->sriov = NULL; } @@ -723,19 +723,40 @@ int pci_enable_ats(struct pci_dev *dev, int ps) int rc; u16 ctrl; - BUG_ON(dev->ats); + BUG_ON(dev->ats && dev->ats->is_enabled); if (ps < PCI_ATS_MIN_STU) return -EINVAL; - rc = ats_alloc_one(dev, ps); - if (rc) - return rc; + 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; - ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU); + 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; } @@ -747,13 +768,26 @@ void pci_disable_ats(struct pci_dev *dev) { u16 ctrl; - BUG_ON(!dev->ats); + 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); - ats_free_one(dev); + 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); } /** @@ -765,13 +799,17 @@ void pci_disable_ats(struct pci_dev *dev) * 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. + * 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; -- cgit v1.2.3-18-g5258