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 <1558678046-4052-2-git-send-email-ley.foon.tan@intel.com> <20190530152548.GD13993@redmoon>
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From:   Ley Foon Tan <lftan.linux@gmail.com>
Date:   Wed, 12 Jun 2019 10:23:20 +0800
Message-ID: <CAFiDJ59Oa0_frzTYUfLdU-PfHRPGOHoYmBxRpS0ynue8e+21mg@mail.gmail.com>
Subject: Re: [PATCH 1/2] PCI: altera: Fix configuration type based on
 secondary number
To:     Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc:     Ley Foon Tan <ley.foon.tan@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-kernel@vger.kernel.org, linux-pci <linux-pci@vger.kernel.org>
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On Thu, May 30, 2019 at 11:25 PM Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
>
> On Fri, May 24, 2019 at 02:07:25PM +0800, Ley Foon Tan wrote:
> > This fix issue when access config from PCIe switch.
> >
> > Stratix 10 PCIe controller does not support Type 1 to Type 0 conversion
> > as previous version (V1) does.
> >
> > The PCIe controller need to send Type 0 config TLP if the targeting bus
> > matches with the secondary bus number, which is when the TLP is targeting
> > the immediate device on the link.
> >
> > The PCIe controller send Type 1 config TLP if the targeting bus is
> > larger than the secondary bus, which is when the TLP is targeting the
> > device not immediate on the link.
> >
> > Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
> > ---
> >  drivers/pci/controller/pcie-altera.c | 22 ++++++++++++++++++++--
> >  1 file changed, 20 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pcie-altera.c b/drivers/pci/controller/pcie-altera.c
> > index 27222071ace7..047bcc214f9b 100644
> > --- a/drivers/pci/controller/pcie-altera.c
> > +++ b/drivers/pci/controller/pcie-altera.c
> > @@ -44,6 +44,8 @@
> >  #define S10_RP_RXCPL_STATUS          0x200C
> >  #define S10_RP_CFG_ADDR(pcie, reg)   \
> >       (((pcie)->hip_base) + (reg) + (1 << 20))
> > +#define S10_RP_SECONDARY(pcie)               \
> > +     readb(S10_RP_CFG_ADDR(pcie, PCI_SECONDARY_BUS))
> >
> >  /* TLP configuration type 0 and 1 */
> >  #define TLP_FMTTYPE_CFGRD0           0x04    /* Configuration Read Type 0 */
> > @@ -63,6 +65,14 @@
> >       ((((bus == pcie->root_bus_nr) ? pcie->pcie_data->cfgwr0         \
> >                               : pcie->pcie_data->cfgwr1) << 24) |     \
> >                               TLP_PAYLOAD_SIZE)
> > +#define S10_TLP_CFGRD_DW0(pcie, bus)                                 \
> > +     (((((bus) > S10_RP_SECONDARY(pcie)) ? pcie->pcie_data->cfgrd0   \
> > +                             : pcie->pcie_data->cfgrd1) << 24) |     \
> > +                             TLP_PAYLOAD_SIZE)
> > +#define S10_TLP_CFGWR_DW0(pcie, bus)                                 \
> > +     (((((bus) > S10_RP_SECONDARY(pcie)) ? pcie->pcie_data->cfgwr0   \
> > +                             : pcie->pcie_data->cfgwr1) << 24) |     \
> > +                             TLP_PAYLOAD_SIZE)
> >  #define TLP_CFG_DW1(pcie, tag, be)   \
> >       (((TLP_REQ_ID(pcie->root_bus_nr,  RP_DEVFN)) << 16) | (tag << 8) | (be))
> >  #define TLP_CFG_DW2(bus, devfn, offset)      \
> > @@ -327,7 +337,11 @@ static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
> >  {
> >       u32 headers[TLP_HDR_SIZE];
> >
> > -     headers[0] = TLP_CFGRD_DW0(pcie, bus);
> > +     if (pcie->pcie_data->version == ALTERA_PCIE_V1)
> > +             headers[0] = TLP_CFGRD_DW0(pcie, bus);
> > +     else
> > +             headers[0] = S10_TLP_CFGRD_DW0(pcie, bus);
> > +
> >       headers[1] = TLP_CFG_DW1(pcie, TLP_READ_TAG, byte_en);
> >       headers[2] = TLP_CFG_DW2(bus, devfn, where);
> >
> > @@ -342,7 +356,11 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
> >       u32 headers[TLP_HDR_SIZE];
> >       int ret;
> >
> > -     headers[0] = TLP_CFGWR_DW0(pcie, bus);
> > +     if (pcie->pcie_data->version == ALTERA_PCIE_V1)
> > +             headers[0] = TLP_CFGWR_DW0(pcie, bus);
> > +     else
> > +             headers[0] = S10_TLP_CFGWR_DW0(pcie, bus);
> > +
>
> Why don't you rewrite all these macros as an eg:
>
> static inline u32 get_tlp_header()
> {}
>
> where you can also handle the version and everything needed to
> detect what header should be set-up ?
>
Okay, will change this.

Thanks.

Regards
Ley Foon