From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Date: Tue, 30 May 2017 09:25:48 -0700
Subject: PCI: Cache PRI and PASID bits in pci_dev
Git-commit: a4f4fa681add289ebfec6d776376ad7a2ffda669
Patch-mainline: v4.13-rc1
References: fate#322865

Device drivers need to check if an IOMMU enabled ATS, PRI and PASID in
order to know when they can use the SVM API.  Cache PRI and PASID bits in
the pci_dev structure, similarly to what is currently done for ATS.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/ats.c   | 23 +++++++++++++++++++++++
 include/linux/pci.h |  2 ++
 2 files changed, 25 insertions(+)

--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -153,6 +153,9 @@ int pci_enable_pri(struct pci_dev *pdev,
 	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;
@@ -170,6 +173,8 @@ int pci_enable_pri(struct pci_dev *pdev,
 	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);
@@ -185,6 +190,9 @@ void pci_disable_pri(struct pci_dev *pde
 	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;
@@ -192,6 +200,8 @@ void pci_disable_pri(struct pci_dev *pde
 	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);
 
@@ -207,6 +217,9 @@ 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;
@@ -239,6 +252,9 @@ int pci_enable_pasid(struct pci_dev *pde
 	u16 control, supported;
 	int pos;
 
+	if (WARN_ON(pdev->pasid_enabled))
+		return -EBUSY;
+
 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
 	if (!pos)
 		return -EINVAL;
@@ -259,6 +275,8 @@ int pci_enable_pasid(struct pci_dev *pde
 
 	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
 
+	pdev->pasid_enabled = 1;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pci_enable_pasid);
@@ -273,11 +291,16 @@ void pci_disable_pasid(struct pci_dev *p
 	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);
 
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -363,6 +363,8 @@ struct pci_dev {
 	unsigned int	msix_enabled:1;
 	unsigned int	ari_enabled:1;	/* ARI forwarding */
 	unsigned int	ats_enabled:1;	/* Address Translation Service */
+	unsigned int	pasid_enabled:1;	/* Process Address Space ID */
+	unsigned int	pri_enabled:1;		/* Page Request Interface */
 	unsigned int	is_managed:1;
 	unsigned int    needs_freset:1; /* Dev requires fundamental reset */
 	unsigned int	state_saved:1;