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.
>
> ┌─────────┐ ┌────────────┐
> ┌─────┐ │ │ 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.
Rob
