On Wed, Sep 25, 2024 at 09:26:10PM -0500, Rob Herring wrote:
> On Tue, Sep 24, 2024 at 05:54:19PM -0400, Frank Li wrote:
> > Introduce `for_each_of_range_untranslate()` to retrieve untranslated CPU
> > address information, similar to `of_property_read_reg()`. This is required
> > for hardware like i.MX8QXP to configure the PCIe controller ATU and
> > eliminate the need for workaround address fixups in drivers. Currently,
> > many drivers use hardcoded CPU addresses for fixups, but this information
> > is already described in the Device Tree. With correct hardware
> > descriptions, such fixups can be removed.
>
> Just to be clear, you don't have to change the DT to add the
> intermediate bus? If you do, then that's an ABI issue.
imx8q's pci dts is still not upstreamed. We are working on it. I think use
this way is more reasonable.
>
> >
> > ┌─────────┐ ┌────────────┐
> > ┌─────┐ │ │ IA: 0x8ff0_0000 │ │
> > │ CPU ├───►│ BUS ├─────────────────┐ │ PCI │
> > └─────┘ │ │ IA: 0x8ff8_0000 │ │ │
> > CPU Addr │ Fabric ├─────────────┐ │ │ Controller │
> > 0x7000_0000 │ │ │ │ │ │
> > │ │ │ │ │ │ PCI Addr
> > │ │ │ └──► CfgSpace ─┼────────────►
> > │ ├─────────┐ │ │ │ 0
> > │ │ │ │ │ │
> > └─────────┘ │ └──────► IOSpace ─┼────────────►
> > │ │ │ 0
> > │ │ │
> > └──────────► MemSpace ─┼────────────►
> > IA: 0x8000_0000 │ │ 0x8000_0000
> > └────────────┘
> >
> > bus@5f000000 {
> > compatible = "simple-bus";
> > #address-cells = <1>;
> > #size-cells = <1>;
> > ranges = <0x5f000000 0x0 0x5f000000 0x21000000>,
> > <0x80000000 0x0 0x70000000 0x10000000>;
> >
> > pcieb: pcie@5f010000 {
> > compatible = "fsl,imx8q-pcie";
> > reg = <0x5f010000 0x10000>, <0x8ff00000 0x80000>;
> > reg-names = "dbi", "config";
> > #address-cells = <3>;
> > #size-cells = <2>;
> > device_type = "pci";
> > bus-range = <0x00 0xff>;
> > ranges = <0x81000000 0 0x00000000 0x8ff80000 0 0x00010000>,
> > <0x82000000 0 0x80000000 0x80000000 0 0x0ff00000>;
> > ...
> > };
> > };
> >
> > Currently all function related 'range' return CPU address. THe new help
> > function for_each_of_range_untranslate() can get above diagram IA address
> > informaiton.
> >
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > drivers/of/address.c | 33 +++++++++++++++++++++++----------
> > include/linux/of_address.h | 9 ++++++++-
> > 2 files changed, 31 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> > index 286f0c161e332..09c73936e573f 100644
> > --- a/drivers/of/address.c
> > +++ b/drivers/of/address.c
> > @@ -787,8 +787,9 @@ int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
> > EXPORT_SYMBOL_GPL(of_pci_dma_range_parser_init);
> > #define of_dma_range_parser_init of_pci_dma_range_parser_init
> >
> > -struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
> > - struct of_pci_range *range)
> > +struct of_pci_range *of_pci_range_parser_one_common(struct of_pci_range_parser *parser,
> > + struct of_pci_range *range,
> > + bool translate)
> > {
> > int na = parser->na;
> > int ns = parser->ns;
> > @@ -806,11 +807,13 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
> > range->bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
> >
> > if (parser->dma)
> > - range->cpu_addr = of_translate_dma_address(parser->node,
> > - parser->range + na);
> > + range->cpu_addr = translate ? of_translate_dma_address(parser->node,
> > + parser->range + na) :
> > + of_read_number(parser->range + na, parser->pna);
> > else
> > - range->cpu_addr = of_translate_address(parser->node,
> > - parser->range + na);
> > + range->cpu_addr = translate ? of_translate_address(parser->node,
> > + parser->range + na) :
> > + of_read_number(parser->range + na, parser->pna);
> > range->size = of_read_number(parser->range + parser->pna + na, ns);
> >
> > parser->range += np;
> > @@ -823,11 +826,13 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
> > flags = parser->bus->get_flags(parser->range);
> > bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
> > if (parser->dma)
> > - cpu_addr = of_translate_dma_address(parser->node,
> > - parser->range + na);
> > + cpu_addr = translate ? of_translate_dma_address(parser->node,
> > + parser->range + na) :
> > + of_read_number(parser->range + np, np);
> > else
> > - cpu_addr = of_translate_address(parser->node,
> > - parser->range + na);
> > + cpu_addr = translate ? of_translate_address(parser->node,
> > + parser->range + na) :
> > + of_read_number(parser->range + np, np);
> > size = of_read_number(parser->range + parser->pna + na, ns);
> >
> > if (flags != range->flags)
> > @@ -842,6 +847,14 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
> >
> > return range;
> > }
> > +EXPORT_SYMBOL_GPL(of_pci_range_parser_one_common);
> > +
> > +struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
> > + struct of_pci_range *range)
> > +{
> > + return of_pci_range_parser_one_common(parser, range, true);
> > +}
> > +
> > EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
> >
> > static u64 of_translate_ioport(struct device_node *dev, const __be32 *in_addr,
> > diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> > index 26a19daf0d092..692aae853217a 100644
> > --- a/include/linux/of_address.h
> > +++ b/include/linux/of_address.h
> > @@ -32,8 +32,11 @@ struct of_pci_range {
> > #define of_range of_pci_range
> >
> > #define for_each_of_pci_range(parser, range) \
> > - for (; of_pci_range_parser_one(parser, range);)
> > + for (; of_pci_range_parser_one_common(parser, range, true);)
> > +#define for_each_of_pci_range_untranslate(parser, range) \
> > + for (; of_pci_range_parser_one_common(parser, range, false);)
> > #define for_each_of_range for_each_of_pci_range
> > +#define for_each_of_range_untranslate for_each_of_pci_range_untranslate
>
> You may want both the translated and untranslated address, so I would
> just add the untranslated address to the of_pci_range struct and return
> both with the existing iterator.
Yes, let me try it.
Frank
>
> Rob
