On Fri, Oct 04, 2024 at 02:07:42PM +0900, Damien Le Moal wrote:
> The function dw_pcie_prog_outbound_atu() used to program outbound ATU
> entries for mapping RC PCI addresses to local CPU addresses does not
> allow PCI addresses that are not aligned to struct dw_pcie->region_align
> (generally 64K).
I think that you should just remove the "generally 64K". This is totally
dependent on the hardware configuration set when synthesizing the DWC PCIe
controller.
See e.g. drivers/misc/pci_endpoint_test.c:
.alignment = SZ_4K,
.alignment = SZ_64K,
.alignment = 256,
In fact, the most common one, from looking at what the different PCI device
and vendor IDs, seems to be 4k.
Perhaps simply mention that the pci->region_align contains the value that was
read/determined from iATU hardware registers during detection time of the iATU
(done by dw_pcie_iatu_detect()), so this code is actually generic for all DWC
PCIe controllers, and should thus work regardless of the hardware configuration
used when synthesizing the DWC PCIe controller.
>
> Handle this constraint by defining the endpoint controller .map_align()
> operation to calculate a mapping size and the offset into the mapping
> based on the requested RC PCI address and size to map.
>
> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-designware-ep.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 43ba5c6738df..501e527c188e 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -268,6 +268,20 @@ static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
> return -EINVAL;
> }
>
> +static int dw_pcie_ep_map_align(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> + struct pci_epc_map *map)
> +{
> + struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> + struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> + size_t mask = pci->region_align - 1;
> +
> + map->map_pci_addr = map->pci_addr & ~mask;
> + map->map_ofst = map->pci_addr & mask;
> + map->map_size = ALIGN(map->map_ofst + map->pci_size, ep->page_size);
> +
> + return 0;
> +}
> +
> static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> phys_addr_t addr)
> {
> @@ -444,6 +458,7 @@ static const struct pci_epc_ops epc_ops = {
> .write_header = dw_pcie_ep_write_header,
> .set_bar = dw_pcie_ep_set_bar,
> .clear_bar = dw_pcie_ep_clear_bar,
> + .map_align = dw_pcie_ep_map_align,
> .map_addr = dw_pcie_ep_map_addr,
> .unmap_addr = dw_pcie_ep_unmap_addr,
> .set_msi = dw_pcie_ep_set_msi,
> --
> 2.46.2
>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
