On Thu, 14 Nov 2019 16:06:01 -0600
Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> Most of the ACS quirks have a similar pattern of:
>
> acs_flags &= ~( <controls provided by this device> );
> return acs_flags ? 0 : 1;
>
> Pull this out into a helper function to simplify the quirks slightly. The
> helper function is also a convenient place for comments about what the list
> of ACS controls means. No functional change intended.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/quirks.c | 67 +++++++++++++++++++++++++++++---------------
> 1 file changed, 45 insertions(+), 22 deletions(-)
Much cleaner, and looks equivalent to me. For both:
Reviewed-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Thanks!
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 59f73d084e1d..9a1051071a81 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -4296,6 +4296,24 @@ static void quirk_chelsio_T5_disable_root_port_attributes(struct pci_dev *pdev)
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
> quirk_chelsio_T5_disable_root_port_attributes);
>
> +/*
> + * pci_acs_ctrl_enabled - compare desired ACS controls with those provided
> + * by a device
> + * @acs_ctrl_req: Bitmask of desired ACS controls
> + * @acs_ctrl_ena: Bitmask of ACS controls enabled or provided implicitly by
> + * the hardware design
> + *
> + * Return 1 if all ACS controls in the @acs_ctrl_req bitmask are included
> + * in @acs_ctrl_ena, i.e., the device provides all the access controls the
> + * caller desires. Return 0 otherwise.
> + */
> +static int pci_acs_ctrl_enabled(u16 acs_ctrl_req, u16 acs_ctrl_ena)
> +{
> + if ((acs_ctrl_req & acs_ctrl_ena) == acs_ctrl_req)
> + return 1;
> + return 0;
> +}
> +
> /*
> * AMD has indicated that the devices below do not support peer-to-peer
> * in any system where they are found in the southbridge with an AMD
> @@ -4339,7 +4357,7 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
> /* Filter out flags not applicable to multifunction */
> acs_flags &= (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC | PCI_ACS_DT);
>
> - return acs_flags & ~(PCI_ACS_RR | PCI_ACS_CR) ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags, PCI_ACS_RR | PCI_ACS_CR);
> #else
> return -ENODEV;
> #endif
> @@ -4377,9 +4395,8 @@ static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
> * hardware implements and enables equivalent ACS functionality for
> * these flags.
> */
> - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> -
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> }
>
> static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
> @@ -4389,9 +4406,8 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
> * transactions with others, allowing masking out these bits as if they
> * were unimplemented in the ACS capability.
> */
> - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> -
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> }
>
> /*
> @@ -4443,17 +4459,16 @@ static bool pci_quirk_intel_pch_acs_match(struct pci_dev *dev)
> return false;
> }
>
> -#define INTEL_PCH_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
> -
> static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
> {
> if (!pci_quirk_intel_pch_acs_match(dev))
> return -ENOTTY;
>
> if (dev->dev_flags & PCI_DEV_FLAGS_ACS_ENABLED_QUIRK)
> - acs_flags &= ~(INTEL_PCH_ACS_FLAGS);
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
>
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags, 0);
> }
>
> /*
> @@ -4468,9 +4483,8 @@ static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
> */
> static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
> {
> - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> -
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> }
>
> static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
> @@ -4571,7 +4585,7 @@ static int pci_quirk_intel_spt_pch_acs(struct pci_dev *dev, u16 acs_flags)
>
> pci_read_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, &ctrl);
>
> - return acs_flags & ~ctrl ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags, ctrl);
> }
>
> static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags)
> @@ -4585,10 +4599,9 @@ static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags)
> * perform peer-to-peer with other functions, allowing us to mask out
> * these bits as if they were unimplemented in the ACS capability.
> */
> - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
> - PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
> -
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
> + PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
> }
>
> static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags)
> @@ -4599,9 +4612,8 @@ static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags)
> * Allow each Root Port to be in a separate IOMMU group by masking
> * SV/RR/CR/UF bits.
> */
> - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> -
> - return acs_flags ? 0 : 1;
> + return pci_acs_ctrl_enabled(acs_flags,
> + PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
> }
>
> static const struct pci_dev_acs_enabled {
> @@ -4703,6 +4715,17 @@ static const struct pci_dev_acs_enabled {
> { 0 }
> };
>
> +/*
> + * pci_dev_specific_acs_enabled - check whether device provides ACS controls
> + * @dev: PCI device
> + * @acs_flags: Bitmask of desired ACS controls
> + *
> + * Returns:
> + * -ENOTTY: No quirk applies to this device; we can't tell whether the
> + * device provides the desired controls
> + * 0: Device does not provide all the desired controls
> + * >0: Device provides all the controls in @acs_flags
> + */
> int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags)
> {
> const struct pci_dev_acs_enabled *i;
