| Message ID | 20240930-pci_fixup_addr-v3-1-80ee70352fc7@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PCI: dwc: opitimaze RC host pci_fixup_addr() | expand |
On Mon, Sep 30, 2024 at 02:44:53PM -0400, Frank Li wrote: > Introduce field 'parent_bus_addr' in of_pci_range to retrieve untranslated > CPU address information. > > Refer to the diagram below to understand that the bus fabric in some > systems (like i.MX8QXP) does not use a 1:1 address map between input and > output. > > Currently, many drivers use .cpu_addr_fixup() callback hardcodes that s/drivers/controller drivers/ > translation in the code, e.g., "cpu_addr & CDNS_PLAT_CPU_TO_BUS_ADDR", > "cpu_addr + BUS_IATU_OFFSET", etc, even though those translations *should* > be described via DT. > It'd be useful to mention which driver has the mentioned fixup as an example. - Mani
diff --git a/drivers/of/address.c b/drivers/of/address.c index 286f0c161e332..1a0229ee4e0b2 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -811,6 +811,8 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser, else range->cpu_addr = of_translate_address(parser->node, parser->range + na); + + range->parent_bus_addr = of_read_number(parser->range + na, parser->pna); range->size = of_read_number(parser->range + parser->pna + na, ns); parser->range += np; diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 26a19daf0d092..13dd79186d02c 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -26,6 +26,7 @@ struct of_pci_range { u64 bus_addr; }; u64 cpu_addr; + u64 parent_bus_addr; u64 size; u32 flags; };
Introduce field 'parent_bus_addr' in of_pci_range to retrieve untranslated CPU address information. Refer to the diagram below to understand that the bus fabric in some systems (like i.MX8QXP) does not use a 1:1 address map between input and output. Currently, many drivers use .cpu_addr_fixup() callback hardcodes that translation in the code, e.g., "cpu_addr & CDNS_PLAT_CPU_TO_BUS_ADDR", "cpu_addr + BUS_IATU_OFFSET", etc, even though those translations *should* be described via DT. The .cpu_addr_fixup() can be eliminated if DT correct reflect hardware behavior and driver use 'parent_bus_addr' in of_pci_range. ┌─────────┐ ┌────────────┐ ┌─────┐ │ │ IA: 0x8ff0_0000 │ │ │ CPU ├───►│ ┌────►├─────────────────┐ │ PCI │ └─────┘ │ │ │ IA: 0x8ff8_0000 │ │ │ CPU Addr │ │ ┌─►├─────────────┐ │ │ Controller │ 0x7ff0_0000─┼───┘ │ │ │ │ │ │ │ │ │ │ │ │ │ PCI Addr 0x7ff8_0000─┼──────┘ │ │ └──► CfgSpace ─┼────────────► │ │ │ │ │ 0 0x7000_0000─┼────────►├─────────┐ │ │ │ └─────────┘ │ └──────► IOSpace ─┼────────────► BUS Fabric │ │ │ 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>; 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>; ... }; }; 'parent_bus_addr' in of_pci_range can indicate above diagram internal address (IA) address information. Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Frank Li <Frank.Li@nxp.com> --- Change from v2 to v3 - cpu_untranslate_addr -> parent_bus_addr - Add Rob's review tag I changed commit message base on Bjorn, if you have concern about review added tag, let me know. Change from v1 to v2 - add parent_bus_addr in of_pci_range, instead adding new API. --- drivers/of/address.c | 2 ++ include/linux/of_address.h | 1 + 2 files changed, 3 insertions(+)