┌─────────┐ ┌────────────┐
┌─────┐ │ │ 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/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 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@xxxxxxx
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@xxxxxxx
Changes in v3:
- see each patch
- 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: 9a3f54febedec23fde034d22bb19cf6f13143484
change-id: 20240924-pci_fixup_addr-a8568f9bbb34
Best regards,
---
Frank Li <Frank.Li@xxxxxxx>
