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From: sathyanarayanan.kuppuswamy@linux.intel.com
To: bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	ashok.raj@intel.com, keith.busch@intel.com,
	sathyanarayanan.kuppuswamy@linux.intel.com
Subject: [PATCH v7 3/7] PCI/ATS: Cache PASID capability check result
Date: Wed, 28 Aug 2019 15:14:03 -0700	[thread overview]
Message-ID: <4957778959fa34eab3e8b3065d1951989c61cb0f.1567029860.git.sathyanarayanan.kuppuswamy@linux.intel.com> (raw)
In-Reply-To: <cover.1567029860.git.sathyanarayanan.kuppuswamy@linux.intel.com>

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Currently, PASID capability checks are repeated across all PASID API's.
Instead, cache the capability check result in pci_pasid_init() and use
it in other PASID API's.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/ats.c   | 50 ++++++++++++++++++++++++++-------------------
 include/linux/pci.h |  1 +
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index b863562b6702..022698a85c98 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -29,6 +29,19 @@ static void pci_pri_init(struct pci_dev *pdev)
 #endif
 }
 
+static void pci_pasid_init(struct pci_dev *pdev)
+{
+#ifdef CONFIG_PCI_PASID
+	int pos;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+	if (!pos)
+		return;
+
+	pdev->pasid_cap = pos;
+#endif
+}
+
 void pci_ats_init(struct pci_dev *dev)
 {
 	int pos;
@@ -43,6 +56,8 @@ void pci_ats_init(struct pci_dev *dev)
 	dev->ats_cap = pos;
 
 	pci_pri_init(dev);
+
+	pci_pasid_init(dev);
 }
 
 /**
@@ -303,7 +318,6 @@ EXPORT_SYMBOL_GPL(pci_reset_pri);
 int pci_enable_pasid(struct pci_dev *pdev, int features)
 {
 	u16 control, supported;
-	int pos;
 
 	if (WARN_ON(pdev->pasid_enabled))
 		return -EBUSY;
@@ -311,11 +325,11 @@ 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 (!pdev->pasid_cap)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+	pci_read_config_word(pdev, pdev->pasid_cap + PCI_PASID_CAP,
+			     &supported);
 	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
 
 	/* User wants to enable anything unsupported? */
@@ -325,7 +339,7 @@ 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, pdev->pasid_cap + PCI_PASID_CTRL, control);
 
 	pdev->pasid_enabled = 1;
 
@@ -340,16 +354,14 @@ EXPORT_SYMBOL_GPL(pci_enable_pasid);
 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)
+	if (!pdev->pasid_cap)
 		return;
 
-	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+	pci_write_config_word(pdev, pdev->pasid_cap + PCI_PASID_CTRL, control);
 
 	pdev->pasid_enabled = 0;
 }
@@ -362,17 +374,15 @@ EXPORT_SYMBOL_GPL(pci_disable_pasid);
 void pci_restore_pasid_state(struct pci_dev *pdev)
 {
 	u16 control;
-	int pos;
 
 	if (!pdev->pasid_enabled)
 		return;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
-	if (!pos)
+	if (!pdev->pasid_cap)
 		return;
 
 	control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
-	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+	pci_write_config_word(pdev, pdev->pasid_cap + PCI_PASID_CTRL, control);
 }
 EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
 
@@ -389,13 +399,12 @@ EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
 int pci_pasid_features(struct pci_dev *pdev)
 {
 	u16 supported;
-	int pos;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
-	if (!pos)
+	if (!pdev->pasid_cap)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+	pci_read_config_word(pdev, pdev->pasid_cap + PCI_PASID_CAP,
+			     &supported);
 
 	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
 
@@ -445,13 +454,12 @@ EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
 int pci_max_pasids(struct pci_dev *pdev)
 {
 	u16 supported;
-	int pos;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
-	if (!pos)
+	if (!pdev->pasid_cap)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
+	pci_read_config_word(pdev, pdev->pasid_cap + PCI_PASID_CAP,
+			     &supported);
 
 	supported = (supported & PASID_NUMBER_MASK) >> PASID_NUMBER_SHIFT;
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 79991984c4cd..782bca667010 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -459,6 +459,7 @@ 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
-- 
2.21.0


  parent reply	other threads:[~2019-08-28 22:18 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-28 22:14 [PATCH v7 0/7] Fix PF/VF dependency issue sathyanarayanan.kuppuswamy
2019-08-28 22:14 ` [PATCH v7 1/7] PCI/ATS: Fix pci_prg_resp_pasid_required() dependency issues sathyanarayanan.kuppuswamy
2019-09-05 19:18   ` Bjorn Helgaas
2019-10-03 17:20     ` Kuppuswamy Sathyanarayanan
2019-10-03 19:04       ` Bjorn Helgaas
2019-10-03 20:37         ` Kuppuswamy Sathyanarayanan
2019-10-03 21:01           ` Bjorn Helgaas
2019-10-03 21:11             ` Kuppuswamy Sathyanarayanan
2019-10-04 12:49               ` Bjorn Helgaas
2019-08-28 22:14 ` [PATCH v7 2/7] PCI/ATS: Cache PRI capability check result sathyanarayanan.kuppuswamy
2019-08-28 22:14 ` sathyanarayanan.kuppuswamy [this message]
2019-08-28 22:14 ` [PATCH v7 4/7] PCI/ATS: Add PRI support for PCIe VF devices sathyanarayanan.kuppuswamy
2019-08-28 22:14 ` [PATCH v7 5/7] PCI/ATS: Add PASID " sathyanarayanan.kuppuswamy
2019-08-28 22:14 ` [PATCH v7 6/7] PCI/ATS: Disable PF/VF ATS service independently sathyanarayanan.kuppuswamy
2019-08-28 22:14 ` [PATCH v7 7/7] PCI: Skip Enhanced Allocation (EA) initialization for VF device sathyanarayanan.kuppuswamy
2019-10-03 17:21   ` Kuppuswamy Sathyanarayanan
2019-10-03 18:57     ` Bjorn Helgaas
2019-10-03 19:20       ` Raj, Ashok
2019-09-05 19:22 ` [PATCH v7 0/7] Fix PF/VF dependency issue Bjorn Helgaas

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