Hi Bjorn,
Thanks for looking into this patch set.
On 9/5/19 12:18 PM, Bjorn Helgaas wrote:
On Wed, Aug 28, 2019 at 03:14:01PM -0700, sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx wrote:
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Since pci_prg_resp_pasid_required() function has dependency on both
PASID and PRI, define it only if both CONFIG_PCI_PRI and
CONFIG_PCI_PASID config options are enabled.
Fixes: e5567f5f6762 ("PCI/ATS: Add pci_prg_resp_pasid_required()
interface.")
[Don't split tags, including "Fixes:" across lines]
This definitely doesn't fix e5567f5f6762. That commit added
pci_prg_resp_pasid_required(), but with no dependency on
CONFIG_PCI_PRI or CONFIG_PCI_PASID.
This patch is only required when a subsequent patch is applied. It
should be squashed into the commit that requires it so it's obvious
why it's needed.
I've been poking at this series, and I'll post a v8 soon with this and
other fixes.
In your v8 submission you did not merge this patch. You did not use
pri_cap or pasid_cap cached values. Instead you have re-read the
value from register. Is this intentional?
Since this function will be called for every VF device we might loose
some performance benefit.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
---
drivers/pci/ats.c | 10 ++++++----
include/linux/pci-ats.h | 12 +++++++++---
2 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index e18499243f84..cdd936d10f68 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -395,6 +395,8 @@ int pci_pasid_features(struct pci_dev *pdev)
}
EXPORT_SYMBOL_GPL(pci_pasid_features);
+#ifdef CONFIG_PCI_PRI
+
/**
* pci_prg_resp_pasid_required - Return PRG Response PASID Required bit
* status.
@@ -402,10 +404,8 @@ EXPORT_SYMBOL_GPL(pci_pasid_features);
*
* Returns 1 if PASID is required in PRG Response Message, 0 otherwise.
*
- * Even though the PRG response PASID status is read from PRI Status
- * Register, since this API will mainly be used by PASID users, this
- * function is defined within #ifdef CONFIG_PCI_PASID instead of
- * CONFIG_PCI_PRI.
+ * Since this API has dependency on both PRI and PASID, protect it
+ * with both CONFIG_PCI_PRI and CONFIG_PCI_PASID.
*/
int pci_prg_resp_pasid_required(struct pci_dev *pdev)
{
@@ -425,6 +425,8 @@ int pci_prg_resp_pasid_required(struct pci_dev *pdev)
}
EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
+#endif
+
#define PASID_NUMBER_SHIFT 8
#define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT)
/**
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 1ebb88e7c184..1a0bdaee2f32 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -40,7 +40,6 @@ void pci_disable_pasid(struct pci_dev *pdev);
void pci_restore_pasid_state(struct pci_dev *pdev);
int pci_pasid_features(struct pci_dev *pdev);
int pci_max_pasids(struct pci_dev *pdev);
-int pci_prg_resp_pasid_required(struct pci_dev *pdev);
#else /* CONFIG_PCI_PASID */
@@ -67,11 +66,18 @@ static inline int pci_max_pasids(struct pci_dev *pdev)
return -EINVAL;
}
+#endif /* CONFIG_PCI_PASID */
+
+#if defined(CONFIG_PCI_PRI) && defined(CONFIG_PCI_PASID)
+
+int pci_prg_resp_pasid_required(struct pci_dev *pdev);
+
+#else /* CONFIG_PCI_PASID && CONFIG_PCI_PRI */
+
static inline int pci_prg_resp_pasid_required(struct pci_dev *pdev)
{
return 0;
}
-#endif /* CONFIG_PCI_PASID */
-
+#endif
#endif /* LINUX_PCI_ATS_H*/
--
2.21.0
--
Sathyanarayanan Kuppuswamy
Linux kernel developer
