[PATCH v6] PCI: Store PCIe bus address in struct of_pci_range
Gabriele Paoloni
gabriele.paoloni at huawei.com
Tue Aug 4 03:12:05 PDT 2015
> -----Original Message-----
> From: Jingoo Han [mailto:jingoohan1 at gmail.com]
> Sent: Tuesday, August 04, 2015 5:20 AM
> To: Gabriele Paoloni
> Cc: Rob Herring; Kishon Vijay Abraham I; Bjorn Helgaas; arnd at arndb.de;
> lorenzo.pieralisi at arm.com; Wangzhou (B); robh+dt at kernel.org;
> james.morse at arm.com; Liviu.Dudau at arm.com; linux-pci at vger.kernel.org;
> linux-arm-kernel at lists.infradead.org; devicetree at vger.kernel.org;
> Yuanzhichang; Zhudacai; zhangjukuo; qiuzhenfa; Liguozhu (Kenneth);
> Pratyush Anand; Arnd Bergmann; jingoohan1 at gmail.com
> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct
> of_pci_range
>
> On 2015. 8. 3., at PM 8:18, Gabriele Paoloni
> <gabriele.paoloni at huawei.com> wrote:
> >
> > Rob, Kishon what about the following solution?....
> >
> > ---
> > drivers/pci/host/pci-dra7xx.c | 12 ++++++++++++
> > drivers/pci/host/pcie-designware.c | 9 +++------
>
> Hi Paoloni,
>
> OK, it looks good.
> I want you to revert the following patch.
>
> commit "f4c55c5a3f7f (PCI: designware: Program ATU with untranslated
> address)"
>
> Would you remove all '*_mode_base's?
Hi Jingoo Han,
If I reverted the commit, in order to get designware working, dra7
should mask directly the CPU addresses stored in pp->cfg0_base,
pp->cfg1_base, pp->mem_base and pp->io_base.
The masking would happen at this point:
http://lxr.free-electrons.com/source/drivers/pci/host/pcie-designware.c#L493
Now:
- I see that pp->cfg<0/1>_base are used in devm_ioremap before that
point and nowhere else, so they should be ok.
- pp->mem_base is used in dw_pcie_setup_rc(); dw_pcie_setup_rc() is called
in dra7xx_pcie_host_init()...so here I should move the masking after
dw_pcie_setup() retuned, but I think it should be ok
- pp->io_base is used in pci_ioremap_io() in dw_pcie_setup(). Now currently
in designware this is called by pci_bios_init_hw(); this is after the
masking....so here we would have a the wrong value passed
Said that if you look at "[PATCH v5 2/5] PCI: designware: Add ARM64 support",
that is the patchset where this patch is needed, you can see that
dw_pcie_setup() is removed and pp->io_base is used in pci_remap_iospace() before
the masking would happen in dra7xx_pcie_host_init()...so for this patchset we
should be good to revert the commit.
I propose to add a new patch in the patchset "[PATCH v5 0/5] PCI: hisi: Add PCIe
host support for HiSilicon SoC Hip05" as the one I just posted in this
thread (this would not revert the commit but just moves the masking to dra7xx)
I would revert the commit in "[PATCH v5 2/5] PCI: designware: Add ARM64 support"
together with the rest of designware rework.
So we would have always a working version of designware...
Are you ok with this?
>
> Best regards,
> Jingoo Han
>
> > 2 files changed, 15 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-
> dra7xx.c
> > index 80db09e..bb2635f 100644
> > --- a/drivers/pci/host/pci-dra7xx.c
> > +++ b/drivers/pci/host/pci-dra7xx.c
> > @@ -61,6 +61,7 @@
> >
> > #define PCIECTRL_DRA7XX_CONF_PHY_CS 0x010C
> > #define LINK_UP BIT(16)
> > +#define CPU_TO_BUS_ADDR 0x0FFFFFFF
> >
> > struct dra7xx_pcie {
> > void __iomem *base;
> > @@ -138,6 +139,17 @@ static void dra7xx_pcie_enable_interrupts(struct
> pcie_port *pp)
> >
> > static void dra7xx_pcie_host_init(struct pcie_port *pp)
> > {
> > + if (pp->io_mod_base)
> > + pp->io_mod_base &= CPU_TO_BUS_ADDR;
> > +
> > + if (pp->mem_mod_base)
> > + pp->mem_mod_base &= CPU_TO_BUS_ADDR;
> > +
> > + if (pp->cfg0_mod_base) {
> > + pp->cfg0_mod_base &= CPU_TO_BUS_ADDR;
> > + pp->cfg1_mod_base &= CPU_TO_BUS_ADDR;
> > + }
> > +
> > dw_pcie_setup_rc(pp);
> > dra7xx_pcie_establish_link(pp);
> > if (IS_ENABLED(CONFIG_PCI_MSI))
> > diff --git a/drivers/pci/host/pcie-designware.c
> b/drivers/pci/host/pcie-designware.c
> > index 69486be..06c682b 100644
> > --- a/drivers/pci/host/pcie-designware.c
> > +++ b/drivers/pci/host/pcie-designware.c
> > @@ -416,8 +416,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
> > pp->io_base = range.cpu_addr;
> >
> > /* Find the untranslated IO space address */
> > - pp->io_mod_base = of_read_number(parser.range -
> > - parser.np + na, ns);
> > + pp->io_mod_base = range.cpu_addr;;
> > }
> > if (restype == IORESOURCE_MEM) {
> > of_pci_range_to_resource(&range, np, &pp->mem);
> > @@ -426,8 +425,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
> > pp->mem_bus_addr = range.pci_addr;
> >
> > /* Find the untranslated MEM space address */
> > - pp->mem_mod_base = of_read_number(parser.range -
> > - parser.np + na, ns);
> > + pp->mem_mod_base = range.cpu_addr;
> > }
> > if (restype == 0) {
> > of_pci_range_to_resource(&range, np, &pp->cfg);
> > @@ -437,8 +435,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
> > pp->cfg1_base = pp->cfg.start + pp->cfg0_size;
> >
> > /* Find the untranslated configuration space address */
> > - pp->cfg0_mod_base = of_read_number(parser.range -
> > - parser.np + na, ns);
> > + pp->cfg0_mod_base = range.cpu_addr;
> > pp->cfg1_mod_base = pp->cfg0_mod_base +
> > pp->cfg0_size;
> > }
> > --
> > 1.9.1
> >
> >
> >> -----Original Message-----
> >> From: linux-pci-owner at vger.kernel.org [mailto:linux-pci-
> >> owner at vger.kernel.org] On Behalf Of Rob Herring
> >> Sent: Friday, July 31, 2015 5:53 PM
> >> To: Kishon Vijay Abraham I
> >> Cc: Gabriele Paoloni; Bjorn Helgaas; arnd at arndb.de;
> >> lorenzo.pieralisi at arm.com; Wangzhou (B); robh+dt at kernel.org;
> >> james.morse at arm.com; Liviu.Dudau at arm.com; linux-pci at vger.kernel.org;
> >> linux-arm-kernel at lists.infradead.org; devicetree at vger.kernel.org;
> >> Yuanzhichang; Zhudacai; zhangjukuo; qiuzhenfa; Liguozhu (Kenneth);
> >> Jingoo Han; Pratyush Anand; Arnd Bergmann
> >> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct
> >> of_pci_range
> >>
> >> On Fri, Jul 31, 2015 at 9:57 AM, Kishon Vijay Abraham I
> <kishon at ti.com>
> >> wrote:
> >>> +Arnd
> >>>
> >>> Hi,
> >>>
> >>>> On Friday 31 July 2015 07:55 PM, Gabriele Paoloni wrote:
> >>>> [+cc Kishon]
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: linux-pci-owner at vger.kernel.org [mailto:linux-pci-
> >>>>> owner at vger.kernel.org] On Behalf Of Rob Herring
> >>>>> Sent: Thursday, July 30, 2015 9:42 PM
> >>>>> To: Gabriele Paoloni
> >>>>> Cc: Bjorn Helgaas; arnd at arndb.de; lorenzo.pieralisi at arm.com;
> >> Wangzhou
> >>>>> (B); robh+dt at kernel.org; james.morse at arm.com; Liviu.Dudau at arm.com;
> >>>>> linux-pci at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
> >>>>> devicetree at vger.kernel.org; Yuanzhichang; Zhudacai; zhangjukuo;
> >>>>> qiuzhenfa; Liguozhu (Kenneth); Jingoo Han; Pratyush Anand
> >>>>> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct
> >>>>> of_pci_range
> >>>>>
> >>>>> On Thu, Jul 30, 2015 at 12:34 PM, Gabriele Paoloni
> >>>>> <gabriele.paoloni at huawei.com> wrote:
> >>>>>>> -----Original Message-----
> >>>>>>> From: Bjorn Helgaas [mailto:bhelgaas at google.com]
> >>>>>>> Sent: 30 July 2015 18:15
> >>>>>>> On Thu, Jul 30, 2015 at 04:50:55PM +0000, Gabriele Paoloni
> wrote:
> >>>>>>>>> -----Original Message-----
> >>>>>>>>> From: linux-pci-owner at vger.kernel.org [mailto:linux-pci-
> >>>>>>>>> owner at vger.kernel.org] On Behalf Of Bjorn Helgaas
> >>>>>>>>> Sent: Thursday, July 30, 2015 5:15 PM
> >>>>>>>>> On Thu, Jul 30, 2015 at 01:52:13PM +0000, Gabriele Paoloni
> >> wrote:
> >>>>>
> >>>>> [...]
> >>>>>
> >>>>>>>>>> I don’t think we should rely on [CPU] addresses...what if
> the
> >>>>>>>>> intermediate
> >>>>>>>>>> translation layer changes the lower significant bits of the
> >>>>> "bus
> >>>>>>>>> address"
> >>>>>>>>>> to translate into a cpu address?
> >>>>>>>>>
> >>>>>>>>> Is it really a possiblity that the lower bits could be
> changed?
> >>>>>>>>
> >>>>>>>> I've checked all the current deignware users DTs except "pci-
> >>>>>>> layerscape"
> >>>>>>>> that I could not find:
> >>>>>>>> spear1310.dtsi
> >>>>>>>> spear1340.dtsi
> >>>>>>>> dra7.dtsi
> >>>>>>>> imx6qdl.dtsi
> >>>>>>>> imx6sx.dtsi
> >>>>>>>> keystone.dtsi
> >>>>>>>> exynos5440.dtsi
> >>>>>>>>
> >>>>>>>> None of them modifies the lower bits. To be more precise the
> >> only
> >>>>> guy
> >>>>>>>> that provides another translation layer is "dra7.dtsi":
> >>>>>>>> axi0
> >>>>>>>> http://lxr.free-
> >>>>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L207
> >>>>>>>>
> >>>>>>>> axi1
> >>>>>>>> http://lxr.free-
> >>>>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L241
> >>>>>>>>
> >>>>>>>> For this case masking the top 4bits (bits28 to 31) should make
> >> the
> >>>>> job.
> >>>>>
> >>>>> IMO, we should just fix this case. After further study, I don't
> >> think
> >>>>> this is a DW issue, but rather an SOC integration issue.
> >>>>>
> >>>>> I believe you can just fixup the address in the pp->ops-
> >host_init
> >> hook.
> >>>>
> >>>> Yes I guess that I could just assign pp->(*)_mod_base to the CPU
> >> address
> >>>> in DW and mask it out in dra7xx_pcie_host_init()...
> >>>>
> >>>> Kishon, would you be ok with that?
> >>>
> >>> Initially I was using *base-mask* property from dt. Me and Arnd
> >> (cc'ed) had
> >>> this discussion [1] before we decided the current approach. It'll
> be
> >> good to
> >>> check with Arnd too.
> >>>
> >>> [1] -> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-
> >> May/253528.html
> >>
> >> The problem I have here is the use of ranges does not necessarily
> mean
> >> fewer address bits are available. It can be used just for
> convenience
> >> of not putting the full address into every node's reg property. And
> >> vice versa, there are probably plenty of cases where we have the
> full
> >> address in the nodes, but really only some of the address bits are
> >> decoded at the IP block. Whether the address bits are present is
> >> rarely cared about or known by s/w folks until you hit a problem
> like
> >> this. Given this is an isolated case ATM, I would fix it in an
> >> isolated way. It does not affect the binding and could be changed in
> >> the kernel later if this becomes a common need.
> >>
> >> Rob
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-pci"
> in
> >> the body of a message to majordomo at vger.kernel.org
> >> More majordomo info at http://vger.kernel.org/majordomo-info.html
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