Re: [PATCH 2/2] PCI: designware: use iATU0 for cfg and IO, iATU1 for MEM

Jisheng Zhang
2015-04-23T07:51:22Z

Hi Fabrice,

On Thu, 23 Apr 2015 00:35:10 -0700
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> Hi Jisheng,
>
> On 04/22/2015 02:58 PM, Jisheng Zhang wrote:
> > Most transactions' type are cfg0 and MEM, so the Current iATU usage is not
> > balanced, iATU0 is hot while iATU1 is rarely used. This patch refactors
> > the iATU usage: iATU0 for cfg and IO, iATU1 for MEM. This allocation
> > ideas comes from Minghuan Lian<Minghuan.Lian@freescale.com>:
> >
> > http://www.spinics.net/lists/linux-pci/msg40440.html
> >
> > Signed-off-by: Jisheng Zhang<jszhang@marvell.com>
> > ---
> > drivers/pci/host/pcie-designware.c | 83 +++++++++++++++++++++-----------------
> > 1 file changed, 47 insertions(+), 36 deletions(-)
> >
> > diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> > index 1da1446..bb81c8ad 100644
> > --- a/drivers/pci/host/pcie-designware.c
> > +++ b/drivers/pci/host/pcie-designware.c
> > @@ -508,6 +508,13 @@ int dw_pcie_host_init(struct pcie_port *pp)
> > if (pp->ops->host_init)
> > pp->ops->host_init(pp);
> >
> > + dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
> > + PCIE_ATU_TYPE_IO, pp->io_mod_base,
> > + pp->io_bus_addr, pp->io_size);
> > + dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
> > + PCIE_ATU_TYPE_MEM, pp->mem_mod_base,
> > + pp->mem_bus_addr, pp->mem_size);
> > +
> Some platforms doesn't have support for ATU. I think this is the reason
> to have
> rd_other_conf / wr_other_conf ops in the driver.

oops. Thanks for the information. So what about something like:

if (!pp->ops->rd_other_conf) {
dw_pcie_prog_outbound_atu(...);
dw_pcie_prog_outbound_atu(...);
}

Thanks,
Jisheng

> IMO, this is not suitable to have this in the initialization routine for
> all platforms.
>
> Regards,
> Fabrice