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PCI/ATS: Cache PASID Capability offset
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Previously each PASID interface searched for the PASID Capability.  Cache
the capability offset the first time we use it instead of searching each
time.

[bhelgaas: commit log, reorder patch to later, call pci_pasid_init() from
pci_init_capabilities()]
Link: https://lore.kernel.org/r/4957778959fa34eab3e8b3065d1951989c61cb0f.1567029860.git.sathyanarayanan.kuppuswamy@linux.intel.com
Link: https://lore.kernel.org/r/20190905193146.90250-6-helgaas@kernel.org
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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Kuppuswamy Sathyanarayanan authored and Bjorn Helgaas committed Oct 15, 2019
1 parent c065190 commit 751035b
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Showing 4 changed files with 31 additions and 21 deletions.
42 changes: 21 additions & 21 deletions drivers/pci/ats.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -322,6 +322,11 @@ EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
#endif /* CONFIG_PCI_PRI */

#ifdef CONFIG_PCI_PASID
void pci_pasid_init(struct pci_dev *pdev)
{
pdev->pasid_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
}

/**
* pci_enable_pasid - Enable the PASID capability
* @pdev: PCI device structure
Expand All @@ -334,7 +339,7 @@ EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
int pci_enable_pasid(struct pci_dev *pdev, int features)
{
u16 control, supported;
int pos;
int pasid = pdev->pasid_cap;

/*
* VFs must not implement the PASID Capability, but if a PF
Expand All @@ -352,11 +357,10 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
if (!pdev->eetlp_prefix_path)
return -EINVAL;

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
if (!pasid)
return -EINVAL;

pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);
supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;

/* User wants to enable anything unsupported? */
Expand All @@ -366,7 +370,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
control = PCI_PASID_CTRL_ENABLE | features;
pdev->pasid_features = features;

pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);

pdev->pasid_enabled = 1;

Expand All @@ -381,7 +385,7 @@ EXPORT_SYMBOL_GPL(pci_enable_pasid);
void pci_disable_pasid(struct pci_dev *pdev)
{
u16 control = 0;
int pos;
int pasid = pdev->pasid_cap;

/* VFs share the PF PASID configuration */
if (pdev->is_virtfn)
Expand All @@ -390,11 +394,10 @@ void pci_disable_pasid(struct pci_dev *pdev)
if (WARN_ON(!pdev->pasid_enabled))
return;

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
if (!pasid)
return;

pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);

pdev->pasid_enabled = 0;
}
Expand All @@ -407,20 +410,19 @@ EXPORT_SYMBOL_GPL(pci_disable_pasid);
void pci_restore_pasid_state(struct pci_dev *pdev)
{
u16 control;
int pos;
int pasid = pdev->pasid_cap;

if (pdev->is_virtfn)
return;

if (!pdev->pasid_enabled)
return;

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
if (!pasid)
return;

control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
pci_write_config_word(pdev, pasid + PCI_PASID_CTRL, control);
}
EXPORT_SYMBOL_GPL(pci_restore_pasid_state);

Expand All @@ -437,16 +439,15 @@ EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
int pci_pasid_features(struct pci_dev *pdev)
{
u16 supported;
int pos;
int pasid = pdev->pasid_cap;

if (pdev->is_virtfn)
pdev = pci_physfn(pdev);

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
if (!pasid)
return -EINVAL;

pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);

supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;

Expand All @@ -466,16 +467,15 @@ EXPORT_SYMBOL_GPL(pci_pasid_features);
int pci_max_pasids(struct pci_dev *pdev)
{
u16 supported;
int pos;
int pasid = pdev->pasid_cap;

if (pdev->is_virtfn)
pdev = pci_physfn(pdev);

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
if (!pos)
if (!pasid)
return -EINVAL;

pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported);

supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT;

Expand Down
6 changes: 6 additions & 0 deletions drivers/pci/pci.h
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Original file line number Diff line number Diff line change
Expand Up @@ -462,6 +462,12 @@ void pci_pri_init(struct pci_dev *dev);
static inline void pci_pri_init(struct pci_dev *dev) { }
#endif

#ifdef CONFIG_PCI_PASID
void pci_pasid_init(struct pci_dev *dev);
#else
static inline void pci_pasid_init(struct pci_dev *dev) { }
#endif

#ifdef CONFIG_PCI_IOV
int pci_iov_init(struct pci_dev *dev);
void pci_iov_release(struct pci_dev *dev);
Expand Down
3 changes: 3 additions & 0 deletions drivers/pci/probe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2327,6 +2327,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
/* Page Request Interface */
pci_pri_init(dev);

/* Process Address Space ID */
pci_pasid_init(dev);

/* Enable ACS P2P upstream forwarding */
pci_enable_acs(dev);

Expand Down
1 change: 1 addition & 0 deletions include/linux/pci.h
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Original file line number Diff line number Diff line change
Expand Up @@ -458,6 +458,7 @@ struct pci_dev {
u32 pri_reqs_alloc; /* Number of PRI requests allocated */
#endif
#ifdef CONFIG_PCI_PASID
u16 pasid_cap; /* PASID Capability offset */
u16 pasid_features;
#endif
#ifdef CONFIG_PCI_P2PDMA
Expand Down

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