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From: Amey Narkhede <ameynarkhede03@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: alex.williamson@redhat.com,
	Raphael Norwitz <raphael.norwitz@nutanix.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	kw@linux.com, Shanker Donthineni <sdonthineni@nvidia.com>,
	Sinan Kaya <okaya@kernel.org>, Len Brown <lenb@kernel.org>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Amey Narkhede <ameynarkhede03@gmail.com>
Subject: [PATCH v14 1/9] PCI: Cache PCIe FLR capability
Date: Thu,  5 Aug 2021 02:11:53 +0530	[thread overview]
Message-ID: <20210804204201.1282-2-ameynarkhede03@gmail.com> (raw)
In-Reply-To: <20210804204201.1282-1-ameynarkhede03@gmail.com>

Add a new member called devcap in struct pci_dev for caching the device
capabilities to avoid reading PCI_EXP_DEVCAP multiple times.

Refactor pcie_has_flr() to use cached device capabilities.

Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/pci/pci.c   | 6 ++----
 drivers/pci/probe.c | 5 +++--
 include/linux/pci.h | 1 +
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 452351025a09..1fafd05caa41 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -31,6 +31,7 @@
 #include <linux/vmalloc.h>
 #include <asm/dma.h>
 #include <linux/aer.h>
+#include <linux/bitfield.h>
 #include "pci.h"
 
 DEFINE_MUTEX(pci_slot_mutex);
@@ -4620,13 +4621,10 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
  */
 bool pcie_has_flr(struct pci_dev *dev)
 {
-	u32 cap;
-
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return false;
 
-	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
-	return cap & PCI_EXP_DEVCAP_FLR;
+	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
 }
 EXPORT_SYMBOL_GPL(pcie_has_flr);
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3a62d09b8869..df3f9db6e151 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -19,6 +19,7 @@
 #include <linux/hypervisor.h>
 #include <linux/irqdomain.h>
 #include <linux/pm_runtime.h>
+#include <linux/bitfield.h>
 #include "pci.h"
 
 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
@@ -1497,8 +1498,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
 	pdev->pcie_cap = pos;
 	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
 	pdev->pcie_flags_reg = reg16;
-	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
-	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
+	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
+	pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
 
 	parent = pci_upstream_bridge(pdev);
 	if (!parent)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c20211e59a57..697b1f085c7b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -333,6 +333,7 @@ struct pci_dev {
 	struct rcec_ea	*rcec_ea;	/* RCEC cached endpoint association */
 	struct pci_dev  *rcec;          /* Associated RCEC device */
 #endif
+	u32		devcap;		/* PCIe device capabilities */
 	u8		pcie_cap;	/* PCIe capability offset */
 	u8		msi_cap;	/* MSI capability offset */
 	u8		msix_cap;	/* MSI-X capability offset */
-- 
2.32.0


  reply	other threads:[~2021-08-04 20:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 20:41 [PATCH v14 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
2021-08-04 20:41 ` Amey Narkhede [this message]
2021-08-04 20:41 ` [PATCH v14 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
2021-08-04 20:41 ` [PATCH v14 3/9] PCI: Add new array for keeping track of ordering of " Amey Narkhede
2021-08-04 20:41 ` [PATCH v14 4/9] PCI: Remove reset_fn field from pci_dev Amey Narkhede
2021-08-04 20:41 ` [PATCH v14 5/9] PCI: Allow userspace to query and set device reset mechanism Amey Narkhede
2021-08-05  3:55   ` Shanker R Donthineni
2021-08-04 20:41 ` [PATCH v14 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
2021-08-05  3:19   ` Shanker R Donthineni
2021-08-04 20:41 ` [PATCH v14 7/9] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
2021-08-04 20:42 ` [PATCH v14 8/9] PCI: Add support for ACPI _RST reset method Amey Narkhede
2021-08-04 20:42 ` [PATCH v14 9/9] PCI: Change the type of probe argument in reset functions Amey Narkhede

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