On Mon, 5 Jul 2021 20:07:39 +0530
Amey Narkhede [off-list ref] wrote:

On 21/07/05 07:51PM, Amey Narkhede wrote:

quoted

Add has_pcie_flr bitfield in struct pci_dev to indicate support for PCIe
FLR to avoid reading PCI_EXP_DEVCAP multiple times.

Currently there is separate function pcie_has_flr() to probe if PCIe FLR
is supported by the device which does not match the calling convention
followed by reset methods which use second function argument to decide
whether to probe or not. Add new function pcie_reset_flr() that follows
the calling convention of reset methods.

Signed-off-by: Amey Narkhede <redacted>
---
 drivers/crypto/cavium/nitrox/nitrox_main.c |  4 +-
 drivers/pci/pci.c                          | 59 +++++++++++-----------
 drivers/pci/pcie/aer.c                     | 12 ++---
 drivers/pci/probe.c                        |  6 ++-
 drivers/pci/quirks.c                       |  9 ++--
 include/linux/pci.h                        |  3 +-
 6 files changed, 45 insertions(+), 48 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c  

[...]

quoted

index 3a62d09b8..a95252113 100644

--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c

@@ -1487,6 +1487,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
 {
 	int pos;
 	u16 reg16;
+	u32 reg32;
 	int type;
 	struct pci_dev *parent;

@@ -1497,8 +1498,9 @@ 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, &reg32);
+	pdev->pcie_mpss = reg32 & PCI_EXP_DEVCAP_PAYLOAD;
+	pdev->has_pcie_flr = reg32 & PCI_EXP_DEVCAP_FLR ? 1 : 0;  

On the side note, removing ternary here as Alex suggested doesn't work
for some reason.

Probably I'm just incorrectly extrapolating boolean behavior to
bitfields, but indeed it doesn't work that way.  The other option is to
use the !! trick, ie. has_pcie_flr = !!(reg32 & PCI_EXP_DEVCAP_FLR),
but both solutions are used elsewhere in this file.

Reviewed-by: Alex Williamson <redacted>