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

Manivannan Sadhasivam
2024-11-14T17:29:27Z

On Thu, Nov 14, 2024 at 11:49:44AM -0500, Frank Li wrote:
> On Tue, Oct 29, 2024 at 12:36:33PM -0400, Frank Li wrote:
>
> Mani:
> Do you have chance to check dwc part?
>

Frank,

Sorry for the delay. I plan to look into this (and other series) tomorrow.

- Mani

> 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>
> >

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