diff options
| author | Frank Li <Frank.Li@nxp.com> | 2024-11-19 14:44:19 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-01-18 15:04:23 -0600 |
| commit | 4dbf0155dfcfa65440b5f70d3e905261208b387e (patch) | |
| tree | 4fd2fce3d16515ce7c0a3e09800e32982702f550 /drivers/of | |
| parent | 9d6b1bd6b3c83e36810570024ce4bbb8ec24f64e (diff) | |
of: address: Add parent_bus_addr to struct of_pci_range
Add a new field called 'parent_bus_addr' to struct of_pci_range to use
when retrieving parent bus address information.
Refer to the diagram below to better understand that the bus fabric in
some systems (like i.MX8QXP) does not always use a 1:1 address map
between input and output.
Currently, many controller drivers use the cpu_addr_fixup() callback
that would often hardcode address translation directly in the code, e.g.,
"cpu_addr & CDNS_PLAT_CPU_TO_BUS_ADDR" or "cpu_addr + BUS_IATU_OFFSET",
etc., even though those translations *should* be described via DT.
However, the cpu_addr_fixup() can be eliminated if DT correctly reflects
hardware behavior and drivers use 'parent_bus_addr' in struct of_pci_range.
┌─────────┐ ┌────────────┐
┌─────┐ │ │ IA: 0x8ff8_0000 │ │
│ CPU ├───►│ ┌────►├─────────────────┐ │ PCI │
└─────┘ │ │ │ IA: 0x8ff0_0000 │ │ │
CPU Addr │ │ ┌─►├─────────────┐ │ │ Controller │
0x7ff8_0000─┼───┘ │ │ │ │ │ │
│ │ │ │ │ │ │ PCI Addr
0x7ff0_0000─┼──────┘ │ │ └──► IOSpace ─┼────────────►
│ │ │ │ │ 0
0x7000_0000─┼────────►├─────────┐ │ │ │
└─────────┘ │ └──────► CfgSpace ─┼────────────►
BUS Fabric │ │ │ 0
│ │ │
└──────────► MemSpace ─┼────────────►
IA: 0x8000_0000 │ │ 0x8000_0000
└────────────┘
bus@5f000000 {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <1>;
ranges = <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>;
...
};
};
In the diagram above, the 'parent_bus_addr' field in struct of_pci_range
can indicate internal address (IA) address information.
Link: https://lore.kernel.org/r/20241119-pci_fixup_addr-v8-1-c4bfa5193288@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/address.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index c5b925ac469f..6373e69ebb08 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -815,6 +815,8 @@ 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; |