Re: [PATCH v7 0/7] PCI: dwc: opitimaze RC Host/EP pci_fixup_addr()

Frank Li
2024-11-14T16:51:20Z

On Tue, Oct 29, 2024 at 12:36:33PM -0400, Frank Li wrote:

Mani:
Do you have chance to check dwc part?

Frank

> == RC side:
>
> ┌─────────┐ ┌────────────┐
> ┌─────┐ │ │ 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
> └────────────┘
>
> 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 = <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:
>
> Endpoint
> ┌───────────────────────────────────────────────┐
> │ pcie-ep@5f010000 │
> │ ┌────────────────┐│
> │ │ Endpoint ││
> │ │ PCIe ││
> │ │ Controller ││
> │ bus@5f000000 │ ││
> │ ┌──────────┐ │ ││
> │ │ │ Outbound Transfer ││
> │┌─────┐ │ Bus ┼─────►│ ATU ──────────┬┬─────►
> ││ │ │ Fabric │Bus │ ││PCI Addr
> ││ CPU ├───►│ │Addr │ ││0xA000_0000
> ││ │CPU │ │0x8000_0000 ││
> │└─────┘Addr└──────────┘ │ ││
> │ 0x7000_0000 └────────────────┘│
> └───────────────────────────────────────────────┘
>
> bus@5f000000 {
> compatible = "simple-bus";
> ranges = <0x80000000 0x0 0x70000000 0x10000000>;
>
> pcie-ep@5f010000 {
> reg = <0x5f010000 0x00010000>,
> <0x80000000 0x10000000>;
> reg-names = "dbi", "addr_space";
> ... ^^^^
> };
> ...
> };
>
> Add `bus_addr_base` to configure the outbound window address for CPU write.
> The BUS fabric generally passes the same address to the PCIe EP controller,
> but some BUS fabrics convert the address before sending it to the PCIe EP
> controller.
>
> Above diagram, CPU write data to outbound windows address 0x7000_0000,
> Bus fabric convert it to 0x8000_0000. ATU should use BUS address
> 0x8000_0000 as input address and convert to PCI address 0xA000_0000.
>
> Previously, `cpu_addr_fixup()` was used to handle address conversion. Now,
> the device tree provides this information.
>
> The both pave the road to eliminate ugle cpu_fixup_addr() callback function.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> Changes in v7:
> - fix
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202410291546.kvgEWJv7-lkp@intel.com/
> - Link to v6: https://lore.kernel.org/r/20241028-pci_fixup_addr-v6-0-ebebcd8fd4ff@nxp.com
>
> Changes in v6:
> - merge RC and EP to one thread!
> - Link to v5: https://lore.kernel.org/r/20241015-pci_fixup_addr-v5-0-ced556c85270@nxp.com
>
> Changes in v5:
> - update address order in diagram patches.
> - remove confused 0x5f00_0000 range
> - update patch1's commit message.
> - Link to v4: https://lore.kernel.org/r/20241008-pci_fixup_addr-v4-0-25e5200657bc@nxp.com
>
> Changes in v4:
> - Improve commit message by add driver source code path.
> - Link to v3: https://lore.kernel.org/r/20240930-pci_fixup_addr-v3-0-80ee70352fc7@nxp.com
>
> Changes in v3:
> - see each patch
> - Link to v2: https://lore.kernel.org/r/20240926-pci_fixup_addr-v2-0-e4524541edf4@nxp.com
>
> Changes in v2:
> - see each patch
> - Link to v1: https://lore.kernel.org/r/20240924-pci_fixup_addr-v1-0-57d14a91ec4f@nxp.com
>
> ---
> Frank Li (7):
> 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: dwc: ep: Add bus_addr_base for outbound window
> PCI: imx6: Remove cpu_addr_fixup()
> dt-bindings: PCI: fsl,imx6q-pcie-ep: Add compatible string fsl,imx8q-pcie-ep
> PCI: imx6: Pass correct sub mode when calling phy_set_mode_ext()
> PCI: imx6: Add i.MX8Q PCIe Endpoint (EP) support
>
> .../devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml | 38 ++++++++++++++-
> drivers/of/address.c | 2 +
> drivers/pci/controller/dwc/pci-imx6.c | 46 +++++++++---------
> drivers/pci/controller/dwc/pcie-designware-ep.c | 21 ++++++++-
> drivers/pci/controller/dwc/pcie-designware-host.c | 55 +++++++++++++++++++++-
> drivers/pci/controller/dwc/pcie-designware.h | 9 ++++
> include/linux/of_address.h | 1 +
> 7 files changed, 148 insertions(+), 24 deletions(-)
> ---
> base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
> change-id: 20240924-pci_fixup_addr-a8568f9bbb34
>
> Best regards,
> ---
> Frank Li <Frank.Li@nxp.com>
>