[PATCH v12 12/13] PCI: dwc: Use parent_bus_offset to remove need for .cpu_addr_fixup()

Bjorn Helgaas
2025-03-15T20:39:06Z

From: Frank Li <Frank.Li@nxp.com>

We know the parent_bus_offset, either computed from a DT reg property (the
offset is the CPU physical addr - the 'config'/'addr_space' address on the
parent bus) or from a .cpu_addr_fixup() (which may have used a host bridge
window offset).

Apply that parent_bus_offset instead of calling .cpu_addr_fixup() when
programming the ATU.

This assumes all intermediate addresses are at the same offset from the CPU
physical addresses.

Link: https://lore.kernel.org/r/20250313-pci_fixup_addr-v11-9-01d2313502ab@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 5 +++--
drivers/pci/controller/dwc/pcie-designware-host.c | 12 ++++++------
drivers/pci/controller/dwc/pcie-designware.c | 3 ---
3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 2ef9964fa080..c1feaadb046a 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -314,7 +314,8 @@ static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
struct dw_pcie_ep *ep = epc_get_drvdata(epc);
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

- ret = dw_pcie_find_index(ep, addr, &atu_index);
+ ret = dw_pcie_find_index(ep, addr - pci->parent_bus_offset,
+ &atu_index);
if (ret < 0)
return;

@@ -333,7 +334,7 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,

atu.func_no = func_no;
atu.type = PCIE_ATU_TYPE_MEM;
- atu.parent_bus_addr = addr;
+ atu.parent_bus_addr = addr - pci->parent_bus_offset;
atu.pci_addr = pci_addr;
atu.size = size;
ret = dw_pcie_ep_outbound_atu(ep, &atu);
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 9e38ac7d1bcb..d760abcbb785 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -635,7 +635,7 @@ static void __iomem *dw_pcie_other_conf_map_bus(struct pci_bus *bus,
type = PCIE_ATU_TYPE_CFG1;

atu.type = type;
- atu.parent_bus_addr = pp->cfg0_base;
+ atu.parent_bus_addr = pp->cfg0_base - pci->parent_bus_offset;
atu.pci_addr = busdev;
atu.size = pp->cfg0_size;

@@ -660,7 +660,7 @@ static int dw_pcie_rd_other_conf(struct pci_bus *bus, unsigned int devfn,

if (pp->cfg0_io_shared) {
atu.type = PCIE_ATU_TYPE_IO;
- atu.parent_bus_addr = pp->io_base;
+ atu.parent_bus_addr = pp->io_base - pci->parent_bus_offset;
atu.pci_addr = pp->io_bus_addr;
atu.size = pp->io_size;

@@ -686,7 +686,7 @@ static int dw_pcie_wr_other_conf(struct pci_bus *bus, unsigned int devfn,

if (pp->cfg0_io_shared) {
atu.type = PCIE_ATU_TYPE_IO;
- atu.parent_bus_addr = pp->io_base;
+ atu.parent_bus_addr = pp->io_base - pci->parent_bus_offset;
atu.pci_addr = pp->io_bus_addr;
atu.size = pp->io_size;

@@ -755,7 +755,7 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp)

atu.index = i;
atu.type = PCIE_ATU_TYPE_MEM;
- atu.parent_bus_addr = entry->res->start;
+ atu.parent_bus_addr = entry->res->start - pci->parent_bus_offset;
atu.pci_addr = entry->res->start - entry->offset;

/* Adjust iATU size if MSG TLP region was allocated before */
@@ -777,7 +777,7 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp)
if (pci->num_ob_windows > ++i) {
atu.index = i;
atu.type = PCIE_ATU_TYPE_IO;
- atu.parent_bus_addr = pp->io_base;
+ atu.parent_bus_addr = pp->io_base - pci->parent_bus_offset;
atu.pci_addr = pp->io_bus_addr;
atu.size = pp->io_size;

@@ -921,7 +921,7 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
atu.size = resource_size(pci->pp.msg_res);
atu.index = pci->pp.msg_atu_index;

- atu.parent_bus_addr = pci->pp.msg_res->start;
+ atu.parent_bus_addr = pci->pp.msg_res->start - pci->parent_bus_offset;

ret = dw_pcie_prog_outbound_atu(pci, &atu);
if (ret)
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 985264c88b92..d9d2090f380c 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -475,9 +475,6 @@ int dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
u32 retries, val;
u64 limit_addr;

- if (pci->ops && pci->ops->cpu_addr_fixup)
- parent_bus_addr = pci->ops->cpu_addr_fixup(pci, parent_bus_addr);
-
limit_addr = parent_bus_addr + atu->size - 1;

if ((limit_addr & ~pci->region_limit) != (parent_bus_addr & ~pci->region_limit) ||
--
2.34.1