Re: [PATCH v6 1/3] PCI: microchip: Fix outbound address translation tables

From: Ilpo Järvinen
Date: Mon Jul 08 2024 - 05:04:55 EST


On Fri, 28 Jun 2024, daire.mcnamara@xxxxxxxxxxxxx wrote:

> From: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
>
> On Microchip PolarFire SoC (MPFS) the PCIe Root Port can be behind one of
> three general-purpose Fabric Interface Controller (FIC) buses that
> encapsulate an AXI-M interface. That FIC is responsible for managing
> the translations of the upper 32-bits of the AXI-M address. On MPFS,
> the Root Port driver needs to take account of that outbound address
> translation done by the parent FIC bus before setting up its own
> outbound address translation tables. In all cases on MPFS,
> the remaining outbound address translation tables are 32-bit only.
>
> Limit the outbound address translation tables to 32-bit only.
>
> This necessitates changing a size_t in mc_pcie_setup_window
> to a resource_size_t to avoid a compile error on 32-bit platforms.

Do you really mean "a compile error" here, that is, building 32-bit kernel
fails during compile stage? If not, it would be good to rephrase this line.

Other than that,

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

--
i.

> Fixes: 6f15a9c9f941 ("PCI: microchip: Add Microchip Polarfire PCIe controller driver")
> Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-microchip-host.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-microchip-host.c b/drivers/pci/controller/pcie-microchip-host.c
> index 137fb8570ba2..47c397ae515a 100644
> --- a/drivers/pci/controller/pcie-microchip-host.c
> +++ b/drivers/pci/controller/pcie-microchip-host.c
> @@ -23,6 +23,8 @@
> /* Number of MSI IRQs */
> #define MC_MAX_NUM_MSI_IRQS 32
>
> +#define MC_OUTBOUND_TRANS_TBL_MASK GENMASK(31, 0)
> +
> /* PCIe Bridge Phy and Controller Phy offsets */
> #define MC_PCIE1_BRIDGE_ADDR 0x00008000u
> #define MC_PCIE1_CTRL_ADDR 0x0000a000u
> @@ -933,7 +935,7 @@ static int mc_pcie_init_irq_domains(struct mc_pcie *port)
>
> static void mc_pcie_setup_window(void __iomem *bridge_base_addr, u32 index,
> phys_addr_t axi_addr, phys_addr_t pci_addr,
> - size_t size)
> + resource_size_t size)
> {
> u32 atr_sz = ilog2(size) - 1;
> u32 val;
> @@ -983,7 +985,8 @@ static int mc_pcie_setup_windows(struct platform_device *pdev,
> if (resource_type(entry->res) == IORESOURCE_MEM) {
> pci_addr = entry->res->start - entry->offset;
> mc_pcie_setup_window(bridge_base_addr, index,
> - entry->res->start, pci_addr,
> + entry->res->start & MC_OUTBOUND_TRANS_TBL_MASK,
> + pci_addr,
> resource_size(entry->res));
> index++;
> }
> @@ -1117,9 +1120,8 @@ static int mc_platform_init(struct pci_config_window *cfg)
> int ret;
>
> /* Configure address translation table 0 for PCIe config space */
> - mc_pcie_setup_window(bridge_base_addr, 0, cfg->res.start,
> - cfg->res.start,
> - resource_size(&cfg->res));
> + mc_pcie_setup_window(bridge_base_addr, 0, cfg->res.start & MC_OUTBOUND_TRANS_TBL_MASK,
> + 0, resource_size(&cfg->res));
>
> /* Need some fixups in config space */
> mc_pcie_enable_msi(port, cfg->win);