[RFC PATCH 19/30] PCI: Cache PRI and PASID bits in pci_dev

Jean-Philippe Brucker
2017-02-27T19:54:30Z

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>
---
drivers/pci/ats.c | 23 +++++++++++++++++++++++
include/linux/pci.h | 2 ++
2 files changed, 25 insertions(+)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 331376e9bb8b..486dc2208119 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -153,6 +153,9 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
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, u32 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);
@@ -185,6 +190,9 @@ 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;
@@ -192,6 +200,8 @@ void pci_disable_pri(struct pci_dev *pdev)
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 *pdev, int features)
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 *pdev, int features)

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 *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);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index e606f289bf5f..47c353ca9957 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -351,6 +351,8 @@ 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;
--
2.11.0