diff mbox series

[2/2] PCI: microchip: Fix inbound address translation tables

Message ID 20240531085333.2501399-3-daire.mcnamara@microchip.com (mailing list archive)
State Superseded
Delegated to: Krzysztof WilczyƄski
Headers show
Series Fix address translations on MPFS PCIe controller | expand

Commit Message

Daire McNamara May 31, 2024, 8:53 a.m. UTC
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@microchip.com>
---
 drivers/pci/controller/pcie-microchip-host.c | 97 +++++++++++++++++++-
 1 file changed, 92 insertions(+), 5 deletions(-)

Comments

Conor Dooley June 10, 2024, 9:44 a.m. UTC | #1
On Fri, May 31, 2024 at 09:53:33AM +0100, Daire McNamara wrote:
> 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.

Since we're talking about dma-noncoherent here, I think this series
should contain a patch that adds the property to the binding for PCIe:

-- >8 --

From af066543b8f8b8b0b37e0844979f0c3e28f30513 Mon Sep 17 00:00:00 2001
From: Conor Dooley <conor.dooley@microchip.com>
Date: Mon, 20 Mar 2023 11:02:11 +0000
Subject: [PATCH] dt-bindings: PCI: microchip,pcie-host: allow dma-noncoherent

PolarFire SoC may be configured in a way that requires non-coherent DMA
handling. On RISC-V, buses are coherent by default & the dma-noncoherent
property is required to denote buses or devices that are non-coherent.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml b/Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml
index 45c14b6e4aa4..2f21109c3580 100644
--- a/Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml
+++ b/Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml
@@ -53,6 +53,8 @@ properties:
     items:
       pattern: '^fic[0-3]$'
 
+  dma-noncoherent: true
+
   interrupts:
     minItems: 1
     items:
diff mbox series

Patch

diff --git a/drivers/pci/controller/pcie-microchip-host.c b/drivers/pci/controller/pcie-microchip-host.c
index 0795cd122a4a..3042e00cc44e 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);
+	val |= (atr_sz << ATR_SIZE_SHIFT);
+	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);
+}
+
+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;
+			}
+			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,
 				 size_t 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,
@@ -1130,6 +1212,11 @@  static int mc_platform_init(struct pci_config_window *cfg)
 	if (ret)
 		return ret;
 
+	/* Configure inbound translation tables */
+	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)