On Wed, 12 Jun 2024, daire.mcnamara@xxxxxxxxxxxxx wrote:
> From: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
>
> On Microchip PolarFire SoC the PCIe Root Port can be behind one of three
> general purpose Fabric Interface Controller (FIC) buses that encapsulates
> an AXI-S bus. Depending on which FIC(s) the Root Port is connected
> through to CPU space, and what address translation is done by that FIC,
> the Root Port driver's inbound address translation may vary.
>
> For all current supported designs and all future expected designs,
> inbound address translation done by a FIC on PolarFire SoC varies
> depending on whether PolarFire SoC in operating in dma-coherent mode or
> dma-noncoherent mode.
>
> The setup of the outbound address translation tables in the root port
> driver only needs to handle these two cases.
>
> Setup the inbound address translation tables to one of two address
> translations, depending on whether the rootport is marked as dma-coherent or
> dma-noncoherent.
>
> Fixes: 6f15a9c9f941 ("PCI: microchip: Add Microchip Polarfire PCIe controller driver")
>
> Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-microchip-host.c | 97 +++++++++++++++++++-
> 1 file changed, 92 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-microchip-host.c b/drivers/pci/controller/pcie-microchip-host.c
> index 853adce24492..d5021333e2aa 100644
> --- a/drivers/pci/controller/pcie-microchip-host.c
> +++ b/drivers/pci/controller/pcie-microchip-host.c
> @@ -30,6 +30,9 @@
> #define MC_PCIE_BRIDGE_ADDR (MC_PCIE1_BRIDGE_ADDR)
> #define MC_PCIE_CTRL_ADDR (MC_PCIE1_CTRL_ADDR)
>
> +#define MC_MAX_NUM_INBOUND_WINDOWS 8
> +#define MPFS_NC_BOUNCE_ADDR 0x80000000
> +
> /* PCIe Bridge Phy Regs */
> #define PCIE_PCI_IRQ_DW0 0xa8
> #define MSIX_CAP_MASK BIT(31)
> @@ -105,6 +108,7 @@
> #define ATR0_AXI4_SLV0_TRSL_PARAM 0x810u
> #define PCIE_TX_RX_INTERFACE 0x00000000u
> #define PCIE_CONFIG_INTERFACE 0x00000001u
> +#define TRSL_ID_AXI4_MASTER_0 0x00000004u
>
> #define ATR_ENTRY_SIZE 32
>
> @@ -931,6 +935,89 @@ static int mc_pcie_init_irq_domains(struct mc_pcie *port)
> return mc_allocate_msi_domains(port);
> }
>
> +static void mc_pcie_setup_inbound_atr(int window_index, u64 axi_addr, u64 pcie_addr, size_t size)
> +{
> + void __iomem *bridge_base_addr = port->axi_base_addr + MC_PCIE_BRIDGE_ADDR;
> + u32 table_offset = window_index * ATR_ENTRY_SIZE;
> + u32 atr_sz;
> + u32 val;
> +
> + atr_sz = ilog2(size) - 1;
> + atr_sz &= GENMASK(5, 0);
> + val = lower_32_bits(pcie_addr) & GENMASK(31, 12);
ALIGN_DOWN(, SZ_xx) ?
> + val |= (atr_sz << ATR_SIZE_SHIFT);
This looks like a named define + FIELD_PREP() would be more appropriate
here.
> + val |= ATR_IMPL_ENABLE;
> + writel(val, bridge_base_addr + table_offset + ATR0_PCIE_WIN0_SRCADDR_PARAM);
> +
> + writel(upper_32_bits(pcie_addr), bridge_base_addr + table_offset +
> + ATR0_PCIE_WIN0_SRC_ADDR);
> +
> + writel(lower_32_bits(axi_addr), bridge_base_addr + table_offset +
> + ATR0_PCIE_WIN0_TRSL_ADDR_LSB);
> + writel(upper_32_bits(axi_addr), bridge_base_addr + table_offset +
> + ATR0_PCIE_WIN0_TRSL_ADDR_UDW);
> +
> + writel(TRSL_ID_AXI4_MASTER_0, bridge_base_addr + table_offset +
> + ATR0_PCIE_WIN0_TRSL_PARAM);
Having a table_addr local variable instead would make these much less
repetitive and shorter.
> +}
> +
> +static int mc_pcie_setup_inbound_ranges(struct platform_device *pdev, struct mc_pcie *port)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *dn = dev->of_node;
> + struct of_range_parser parser;
> + struct of_range range;
> + int atr_index = 0;
> +
> + /*
> + * MPFS PCIe root port is 32-bit only, behind a Fabric Interface
> + * Controller FPGA logic block which contains the AXI-S interface.
> + *
> + * From the point of view of the PCIe root port, There are only
> + * two supported Root Port configurations
> + *
> + * Configuration 1: for use with fully coherent designs; supports a
> + * window from 0x0 (CPU space) to specified PCIe space.
> + *
> + * Configuration 2: for use with non-coherent designs; supports two
> + * 1 Gb wide windows to CPU space; one mapping cpu space 0 to pcie
> + * space 0x80000000 and mapping cpu space 0x40000000 to pcie
> + * space 0xc0000000. This cfg needs two windows because of how
> + * the MSI space is allocated in the AXI-S range on MPFS.
> + *
> + * The FIC interface outside the PCIe block *must* complete the inbound
> + * address translation as per MCHP MPFS FPGA design guidelines.
> + */
> + if (device_property_read_bool(dev, "dma-noncoherent")) {
> + /*
> + * Always need same two tables in this case. Need two tables
> + * due to hardware interactions between address and size.
> + */
> + mc_pcie_setup_inbound_atr(0, 0, MPFS_NC_BOUNCE_ADDR, SZ_1G);
> + mc_pcie_setup_inbound_atr(1, SZ_1G, MPFS_NC_BOUNCE_ADDR + SZ_1G, SZ_1G);
> + } else {
> + /* Find any dma-ranges */
> + if (of_pci_dma_range_parser_init(&parser, dn)) {
> + /* No dma-range property - setup default */
> + mc_pcie_setup_inbound_atr(0, 0, 0, SZ_4G);
> + return 0;
> + }
> +
> + for_each_of_range(&parser, &range) {
> + if (atr_index >= MC_MAX_NUM_INBOUND_WINDOWS) {
> + dev_err(dev, "too many inbound ranges; %d available tables\n",
> + MC_MAX_NUM_INBOUND_WINDOWS);
> + return -EINVAL;
You don't need to rollback anything when this error is encountered?
> + }
> + mc_pcie_setup_inbound_atr(atr_index, 0, range.pci_addr, range.size);
> + atr_index++;
> + }
> + }
> +
> + return 0;
> +}
> +
> static void mc_pcie_setup_window(void __iomem *bridge_base_addr, u32 index,
> phys_addr_t axi_addr, phys_addr_t pci_addr,
> u64 size)
> @@ -962,11 +1049,6 @@ static void mc_pcie_setup_window(void __iomem *bridge_base_addr, u32 index,
> val = upper_32_bits(pci_addr);
> writel(val, bridge_base_addr + (index * ATR_ENTRY_SIZE) +
> ATR0_AXI4_SLV0_TRSL_ADDR_UDW);
> -
> - val = readl(bridge_base_addr + ATR0_PCIE_WIN0_SRCADDR_PARAM);
> - val |= (ATR0_PCIE_ATR_SIZE << ATR0_PCIE_ATR_SIZE_SHIFT);
> - writel(val, bridge_base_addr + ATR0_PCIE_WIN0_SRCADDR_PARAM);
> - writel(0, bridge_base_addr + ATR0_PCIE_WIN0_SRC_ADDR);
> }
>
> static int mc_pcie_setup_windows(struct platform_device *pdev,
> @@ -1129,6 +1211,11 @@ static int mc_platform_init(struct pci_config_window *cfg)
> if (ret)
> return ret;
>
> + /* Configure inbound translation tables */
IMO, this comment adds 0 value over what the code tells all by itself so
it would be best to drop it.
> + ret = mc_pcie_setup_inbound_ranges(pdev, port);
> + if (ret)
> + return ret;
> +
> /* Address translation is up; safe to enable interrupts */
> ret = mc_init_interrupts(pdev, port);
> if (ret)
>
--
i.
