Re: [PATCH v3 0/3] PCI: dwc: opitimaze RC host pci_fixup_addr()

[Manivannan Sadhasivam]

On Mon, Sep 30, 2024 at 02:44:52PM -0400, Frank Li wrote:
> ┌─────────┐                    ┌────────────┐
>  ┌─────┐    │         │ 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
>                                            └────────────┘
> 
> Current dwc implimemnt, pci_fixup_addr() call back is needed when bus
> fabric convert cpu address before send to PCIe controller.
> 
>     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>;
>             ...
>             };
>     };
> 
> Device tree already can descript all address translate. Some hardware
> driver implement fixup function by mask some bits of cpu address. Last
> pci-imx6.c are little bit better by fetch memory resource's offset to do
> fixup.
> 
> static u64 imx_pcie_cpu_addr_fixup(struct dw_pcie *pcie, u64 cpu_addr)
> {
> 	...
> 	entry = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM);
> 	return cpu_addr - entry->offset;
> }
> 
> But it is not good by using IORESOURCE_MEM to fix up io/cfg address map
> although address translate is the same as IORESOURCE_MEM.
> 
> This patches to fetch untranslate range information for PCIe controller
> (pcie@5f010000: ranges). So current config ATU without cpu_fixup_addr().
> 
> EP side patch:
> https://lore.kernel.org/linux-pci/20240923-pcie_ep_range-v2-0-78d2ea434d9f@xxxxxxx/T/#mfc73ca113a69ad2c0294a2e629ecee3105b72973
> 
> The both pave the road to eliminate ugle cpu_fixup_addr() callback function.
> 
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> ---
> Changes in v3:
> - see each patch

You should make the life easier for the reviewer, not hard. Please summarise
what has changed since the last version.

- Mani

> - Link to v2: https://lore.kernel.org/r/20240926-pci_fixup_addr-v2-0-e4524541edf4@xxxxxxx
> 
> Changes in v2:
> - see each patch
> - Link to v1: https://lore.kernel.org/r/20240924-pci_fixup_addr-v1-0-57d14a91ec4f@xxxxxxx
> 
> ---
> Frank Li (3):
>       of: address: Add parent_bus_addr to struct of_pci_range
>       PCI: dwc: Using parent_bus_addr in of_range to eliminate cpu_addr_fixup()
>       PCI: imx6: Remove cpu_addr_fixup()
> 
>  drivers/of/address.c                              |  2 ++
>  drivers/pci/controller/dwc/pci-imx6.c             | 22 ++----------
>  drivers/pci/controller/dwc/pcie-designware-host.c | 42 +++++++++++++++++++++++
>  drivers/pci/controller/dwc/pcie-designware.h      |  8 +++++
>  include/linux/of_address.h                        |  1 +
>  5 files changed, 55 insertions(+), 20 deletions(-)
> ---
> base-commit: 69940764dc1c429010d37cded159fadf1347d318
> change-id: 20240924-pci_fixup_addr-a8568f9bbb34
> 
> Best regards,
> ---
> Frank Li <Frank.Li@xxxxxxx>
> 

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