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authorBjorn Helgaas <bhelgaas@google.com>2019-10-10 00:07:51 +0300
committerBjorn Helgaas <bhelgaas@google.com>2019-10-16 00:39:10 +0300
commite5adf79a1d8086aefa56f48eeb08f8fe4e054a3d (patch)
treef053b77ce7824bd10bd5f99127159eb81663b5b8 /drivers/pci/ats.c
parent751035b8dc061ae434c3311bac9cd6d0e5e00f94 (diff)
downloadlinux-e5adf79a1d8086aefa56f48eeb08f8fe4e054a3d.tar.xz
PCI/ATS: Cache PRI PRG Response PASID Required bit
The PRG Response PASID Required bit in the PRI Capability is read-only. Read it once when we enumerate the device and cache the value so we don't need to read it again. Based-on-patch-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/ats.c')
-rw-r--r--drivers/pci/ats.c23
1 files changed, 10 insertions, 13 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index d5ac808cae21..76ae518d55f4 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -161,7 +161,16 @@ EXPORT_SYMBOL_GPL(pci_ats_page_aligned);
#ifdef CONFIG_PCI_PRI
void pci_pri_init(struct pci_dev *pdev)
{
+ u16 status;
+
pdev->pri_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+
+ if (!pdev->pri_cap)
+ return;
+
+ pci_read_config_word(pdev, pdev->pri_cap + PCI_PRI_STATUS, &status);
+ if (status & PCI_PRI_STATUS_PASID)
+ pdev->pasid_required = 1;
}
/**
@@ -301,22 +310,10 @@ EXPORT_SYMBOL_GPL(pci_reset_pri);
*/
int pci_prg_resp_pasid_required(struct pci_dev *pdev)
{
- u16 status;
- int pri;
-
if (pdev->is_virtfn)
pdev = pci_physfn(pdev);
- pri = pdev->pri_cap;
- if (!pri)
- return 0;
-
- pci_read_config_word(pdev, pri + PCI_PRI_STATUS, &status);
-
- if (status & PCI_PRI_STATUS_PASID)
- return 1;
-
- return 0;
+ return pdev->pasid_required;
}
EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
#endif /* CONFIG_PCI_PRI */