parent_bus_offset in resource_entry can indicate address information just
ahead of PCIe controller. Most system's bus fabric use 1:1 map between
input and output address. but some hardware like i.MX8QXP doesn't use 1:1
map. See below diagram:
┌─────────┐ ┌────────────┐
┌─────┐ │ │ 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
└────────────┘
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>;
...
};
};
Term Intermediate address (IA) here means the address just before PCIe
controller. After ATU use this IA instead CPU address, cpu_addr_fixup() can
be removed.
Use reg-name "config" to detect parent_bus_addr_offset. Suppose the offset
is the same for all kinds of address translation.
Just set parent_bus_offset, but doesn't use it, so no functional change
intended yet.
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
change from v9 to v10
- call helper dw_pcie_init_parent_bus_offset()
chagne from v8 to v9
- use resoure_entry parent_bus_offset to simple code logic
- add check for use_parent_dt_ranges and cpu_addr_fixup to make sure only
one set.
Change from v7 to v8
- Add dev_warning_once at dw_pcie_iatu_detect() to reminder
cpu_addr_fixup() user to correct their code
- use 'use_parent_dt_ranges' control enable use dt parent bus node ranges.
- rename dw_pcie_get_untranslate_addr to dw_pcie_get_parent_addr().
- of_property_read_reg() already have comments, so needn't add more.
- return actual err code from function
Change from v6 to v7
Add a resource_size_t parent_bus_addr local varible to fix 32bit build
error.
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410291546.kvgEWJv7-lkp@xxxxxxxxx/
Chagne from v5 to v6
-add comments for of_property_read_reg().
Change from v4 to v5
- remove confused 0x5f00_0000 range in sample dts.
- reorder address at above diagram.
Change from v3 to v4
- none
Change from v2 to v3
- %s/cpu_untranslate_addr/parent_bus_addr/g
- update diagram.
- improve commit message.
Change from v1 to v2
- update because patch1 change get untranslate address method.
- add using_dtbus_info in case break back compatibility for exited platform.
---
drivers/pci/controller/dwc/pcie-designware-host.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index c57831902686e..eaa6dd4c7edda 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -478,6 +478,15 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
bridge->ops = &dw_pcie_ops;
bridge->child_ops = &dw_child_pcie_ops;
+ /*
+ * visconti_pcie_cpu_addr_fixup() use pp->io_base,
+ * so have to call dw_pcie_init_parent_bus_offset() after init
+ * pp->io_base.
+ */
+ ret = dw_pcie_init_parent_bus_offset(pci, "config", pp->cfg0_base);
+ if (ret)
+ return ret;
+
if (pp->ops->init) {
ret = pp->ops->init(pp);
if (ret)
--
2.34.1
