2019-08-08 05:00:17

by Denis Efremov (Oracle)

Subject: [PATCH] liquidio: Use pcie_flr() instead of reimplementing it

octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
bit, which bypasses timing requirements imposed by the PCIe spec.
This patch fixes the function to use the pcie_flr() interface instead.

Signed-off-by: Denis Efremov <[email protected]>
---
drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
index 021d99cd1665..614d07be7181 100644
--- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
@@ -260,9 +260,7 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
dev_info(&oct->pci_dev->dev,
"got a request for FLR from VF that owns DPI ring %u\n",
mbox->q_no);
- pcie_capability_set_word(
- oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
- PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
+ pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
break;

case OCTEON_PF_CHANGED_VF_MACADDR:
--
2.21.0

2019-08-08 09:27:01

by Andrew Murray

Subject: Re: [PATCH] liquidio: Use pcie_flr() instead of reimplementing it

On Thu, Aug 08, 2019 at 07:57:53AM +0300, Denis Efremov wrote:
> octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
> bit, which bypasses timing requirements imposed by the PCIe spec.
> This patch fixes the function to use the pcie_flr() interface instead.
>
> Signed-off-by: Denis Efremov <[email protected]>
> ---
> drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> index 021d99cd1665..614d07be7181 100644
> --- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> +++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> @@ -260,9 +260,7 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
> dev_info(&oct->pci_dev->dev,
> "got a request for FLR from VF that owns DPI ring %u\n",
> mbox->q_no);
> - pcie_capability_set_word(
> - oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
> - PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
> + pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
> break;

It's possible for pcie_flr to fail if the device doesn't become ready soon
enough after reset in which case it returns ENOTTY. I think it's OK not to
test the return value here though, as pci_dev_wait will print a warning
anyway, and I'm not sure what you'd do with it anyway.

Reviewed-by: Andrew Murray <[email protected]>

>
> case OCTEON_PF_CHANGED_VF_MACADDR:
> --
> 2.21.0
>

2019-08-08 18:50:25

by Bjorn Helgaas

Subject: Re: [PATCH] liquidio: Use pcie_flr() instead of reimplementing it

On Thu, Aug 08, 2019 at 07:57:53AM +0300, Denis Efremov wrote:
> octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
> bit, which bypasses timing requirements imposed by the PCIe spec.
> This patch fixes the function to use the pcie_flr() interface instead.
>
> Signed-off-by: Denis Efremov <[email protected]>

Reviewed-by: Bjorn Helgaas <[email protected]>

Thanks for doing this, Denis. When possible it's better to use a PCI
core interface than to fiddle with PCI config space directly from a
driver.

> ---
> drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> index 021d99cd1665..614d07be7181 100644
> --- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> +++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> @@ -260,9 +260,7 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
> dev_info(&oct->pci_dev->dev,
> "got a request for FLR from VF that owns DPI ring %u\n",
> mbox->q_no);
> - pcie_capability_set_word(
> - oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
> - PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
> + pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
> break;
>
> case OCTEON_PF_CHANGED_VF_MACADDR:
> --
> 2.21.0
>

2019-08-09 05:42:15

by David Miller

Subject: Re: [PATCH] liquidio: Use pcie_flr() instead of reimplementing it

From: Denis Efremov <[email protected]>
Date: Thu, 8 Aug 2019 07:57:53 +0300

> octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
> bit, which bypasses timing requirements imposed by the PCIe spec.
> This patch fixes the function to use the pcie_flr() interface instead.
>
> Signed-off-by: Denis Efremov <[email protected]>

Applied to net-next.