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path: root/drivers/pci/ats.c
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-rw-r--r--drivers/pci/ats.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
new file mode 100644
index 000000000..a8099d4d0
--- /dev/null
+++ b/drivers/pci/ats.c
@@ -0,0 +1,375 @@
+/*
+ * 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"
+
+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);
+
+void pci_restore_ats_state(struct pci_dev *dev)
+{
+ u16 ctrl;
+
+ if (!pci_ats_enabled(dev))
+ return;
+ if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS))
+ BUG();
+
+ 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->pos + 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)
+{
+ 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_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 */
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