Re: [PATCH] PCI: Enhance the ACS quirk for Cavium devices

[Robert Richter]

On 04.10.19 14:48:13, Bjorn Helgaas wrote:
> commit 37b22fbfec2d
> Author: George Cherian <george.cherian@xxxxxxxxxxx>
> Date:   Thu Sep 19 02:43:34 2019 +0000
> 
>     PCI: Apply Cavium ACS quirk to CN99xx and CN11xxx Root Ports
>     
>     Add an array of Cavium Root Port device IDs and apply the quirk only to the
>     listed devices.
>     
>     Instead of applying the quirk to all Root Ports where
>     "(dev->device & 0xf800) == 0xa000", apply it only to CN88xx 0xa180 and
>     0xa170 Root Ports.

No, this can't be removed. It is a match all for all CN8xxx variants
(note the 3 'x', all TX1 cores). So all device ids from 0xa000 to
0xa7FF are affected here and need the quirk.

>     
>     Also apply the quirk to CN99xx (0xaf84) and CN11xxx (0xb884) Root Ports.

I thought the quirk is CN8xxx specific, but I could be wrong here.

-Robert

>     
>     Link: https://urldefense.proofpoint.com/v2/url?u=https-3A__lore.kernel.org_r_20190919024319.GA8792-40dc5-2Deodlnx05.marvell.com&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=8vKOpC26NZGzQPAMiIlimxyEGCRSJiq-j8yyjPJ6VZ4&m=Vmml-rx3t63ZbbXZ0XaESAM9yAlexE29R-giTbcj4Qk&s=57jKIj8BAydbLpftLt5Ssva7vD6GuoCaIpjTi-sB5kU&e= 
>     Fixes: f2ddaf8dfd4a ("PCI: Apply Cavium ThunderX ACS quirk to more Root Ports")
>     Fixes: b404bcfbf035 ("PCI: Add ACS quirk for all Cavium devices")
>     Signed-off-by: George Cherian <george.cherian@xxxxxxxxxxx>
>     Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>     Cc: stable@xxxxxxxxxxxxxxx      # v4.12+
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 320255e5e8f8..4e5048cb5ec6 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -4311,17 +4311,24 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
>  #endif
>  }
>  
> +static const u16 pci_quirk_cavium_acs_ids[] = {
> +	0xa180, 0xa170,		/* CN88xx family of devices */
> +	0xaf84,			/* CN99xx family of devices */
> +	0xb884,			/* CN11xxx family of devices */
> +};
> +
>  static bool pci_quirk_cavium_acs_match(struct pci_dev *dev)
>  {
> -	/*
> -	 * Effectively selects all downstream ports for whole ThunderX 1
> -	 * family by 0xf800 mask (which represents 8 SoCs), while the lower
> -	 * bits of device ID are used to indicate which subdevice is used
> -	 * within the SoC.
> -	 */
> -	return (pci_is_pcie(dev) &&
> -		(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) &&
> -		((dev->device & 0xf800) == 0xa000));
> +	int i;
> +
> +	if (!pci_is_pcie(dev) || pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
> +		return false;
> +
> +	for (i = 0; i < ARRAY_SIZE(pci_quirk_cavium_acs_ids); i++)
> +		if (pci_quirk_cavium_acs_ids[i] == dev->device)
> +			return true;
> +
> +	return false;
>  }
>  
>  static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)