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

[Frank Li <Frank.li@nxp.com>]

On Sat, Mar 15, 2025 at 03:15:47PM -0500, Bjorn Helgaas wrote:
> 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>

look good

Frank
> ---
>  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
>