1 files changed, 396 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
new file mode 100644
index 000000000..5b78f3b1b
--- /dev/null
+++ b/drivers/pci/ats.c
@@ -0,0 +1,396 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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>
+ *
+ * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
+ * Copyright (C) 2011 Advanced Micro Devices,
+ */
+
+#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;
+
+	if (pci_ats_disabled())
+		return;
+
+	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;
+
+	if (WARN_ON(pdev->pri_enabled))
+		return -EBUSY;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+	if (!pos)
+		return -EINVAL;
+
+	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
+	if (!(status & PCI_PRI_STATUS_STOPPED))
+		return -EBUSY;
+
+	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
+	reqs = min(max_requests, reqs);
+	pdev->pri_reqs_alloc = 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);
+
+	pdev->pri_enabled = 1;
+
+	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;
+
+	if (WARN_ON(!pdev->pri_enabled))
+		return;
+
+	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);
+
+	pdev->pri_enabled = 0;
+}
+EXPORT_SYMBOL_GPL(pci_disable_pri);
+
+/**
+ * pci_restore_pri_state - Restore PRI
+ * @pdev: PCI device structure
+ */
+void pci_restore_pri_state(struct pci_dev *pdev)
+{
+	u16 control = PCI_PRI_CTRL_ENABLE;
+	u32 reqs = pdev->pri_reqs_alloc;
+	int pos;
+
+	if (!pdev->pri_enabled)
+		return;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+	if (!pos)
+		return;
+
+	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
+	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pri_state);
+
+/**
+ * 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;
+
+	if (WARN_ON(pdev->pri_enabled))
+		return -EBUSY;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+	if (!pos)
+		return -EINVAL;
+
+	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;
+
+	if (WARN_ON(pdev->pasid_enabled))
+		return -EBUSY;
+
+	if (!pdev->eetlp_prefix_path)
+		return -EINVAL;
+
+	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;
+
+	/* User wants to enable anything unsupported? */
+	if ((supported & features) != features)
+		return -EINVAL;
+
+	control = PCI_PASID_CTRL_ENABLE | features;
+	pdev->pasid_features = features;
+
+	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+
+	pdev->pasid_enabled = 1;
+
+	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;
+
+	if (WARN_ON(!pdev->pasid_enabled))
+		return;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+	if (!pos)
+		return;
+
+	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+
+	pdev->pasid_enabled = 0;
+}
+EXPORT_SYMBOL_GPL(pci_disable_pasid);
+
+/**
+ * pci_restore_pasid_state - Restore PASID capabilities
+ * @pdev: PCI device structure
+ */
+void pci_restore_pasid_state(struct pci_dev *pdev)
+{
+	u16 control;
+	int pos;
+
+	if (!pdev->pasid_enabled)
+		return;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+	if (!pos)
+		return;
+
+	control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
+	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
+
+/**
+ * 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 */