Re: [PATCH v6] PCI: quirks: update Cavium ThunderX ACS quirk implementation

Vadim Lomovtsev
2017-09-29T12:22:43Z

Hi Bjorn,

On Wed, Sep 27, 2017 at 02:18:54PM -0600, Alex Williamson wrote:
> On Wed, 27 Sep 2017 11:20:39 -0700
> Vadim Lomovtsev <Vadim.Lomovtsev@caviumnetworks.com> wrote:
>
> > This commit makes Cavium PCI ACS quirk applicable only to Cavium
> > ThunderX (CN8XXX) family PCIE Root Ports which has limited PCI capabilities
> > in terms of no ACS support advertisement. However, the RTL internally
> > implements similar protection as if ACS had completion/request redirection,
> > upstream forwarding and validation features enabled.
> >
> > Current quirk implementation doesn't take into account PCIERCs which
> > also needs to be quirked. So the pci device id check mask is updated
> > and check of device ID moved into separate function.
> >
> > Signed-off-by: Vadim Lomovtsev <Vadim.Lomovtsev@caviumnetworks.com>
> > ---
> > v5 -> v6: comment typo fix: change 0xa00 to 0xa000
>
> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
>

If there is no any objections, could you please take this patch ?

WBR,
Vadim

>
> > drivers/pci/quirks.c | 29 +++++++++++++++++++++--------
> > 1 file changed, 21 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index a4d3361..ed6c76d 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -4211,20 +4211,33 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
> > #endif
> > }
> >
> > -static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
> > +/*
> > + * The Cavium downstream ports doesn't advertise their ACS capability registers.
> > + * However, the RTL internally implements similar protection as if
> > + * ACS had completion redirection, forwarding and validation features enabled.
> > + * So by this flags we're asserting that the hardware implements and
> > + * enables equivalent ACS functionality for these flags.
> > + */
> > +#define CAVIUM_CN8XXX_ACS_FLAGS (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF)
> > +
> > +static __inline__ bool pci_quirk_cavium_acs_match(struct pci_dev *dev)
> > {
> > /*
> > - * Cavium devices matching this quirk do not perform peer-to-peer
> > - * with other functions, allowing masking out these bits as if they
> > - * were unimplemented in the ACS capability.
> > + * Effectively selects all downstream ports for whole ThunderX 1 family
> > + * by 0xa000 mask (which represents 8 SoCs), while the lower bits of device ID
> > + * are used to indicate which subdevice is used within the SoC.
> > */
> > - acs_flags &= ~(PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
> > - PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
> > + return (pci_is_pcie(dev) &&
> > + (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) &&
> > + ((dev->device & 0xf800) == 0xa000));
> > +}
> >
> > - if (!((dev->device >= 0xa000) && (dev->device <= 0xa0ff)))
> > +static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
> > +{
> > + if (!pci_quirk_cavium_acs_match(dev))
> > return -ENOTTY;
> >
> > - return acs_flags ? 0 : 1;
> > + return acs_flags & ~(CAVIUM_CN8XXX_ACS_FLAGS) ? 0 : 1;
> > }
> >
> > static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
>