[v5,0/3] PCI: dwc: opitimaze RC host pci_fixup_addr()

Message

Frank Li Oct. 15, 2024, 7:17 p.m. UTC

┌─────────┐                    ┌────────────┐
 ┌─────┐    │         │ 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 patch:
https://lore.kernel.org/linux-pci/[e-mail]/T/#mfc73ca113a69ad2c0294a2e629ecee3105b72973

The both pave the road to eliminate ugle cpu_fixup_addr() callback function.

Signed-off-by: Frank Li <[e-mail]>
---
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/[e-mail]

Changes in v4:
- Improve commit message by add driver source code path.
- Link to v3: https://lore.kernel.org/r/[e-mail]

Changes in v3:
- see each patch
- Link to v2: https://lore.kernel.org/r/[e-mail]

Changes in v2:
- see each patch
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
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: 9a3f54febedec23fde034d22bb19cf6f13143484
change-id: 20240924-pci_fixup_addr-a8568f9bbb34

Best regards,
---
Frank Li <[e-mail]>