linux_kernel/drivers/pci/controller/pcie-cadence.c

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Cadence
// Cadence PCIe controller driver.
// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>

#include <linux/kernel.h>

#include "pcie-cadence.h"

void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 fn,
				   u32 r, bool is_io,
				   u64 cpu_addr, u64 pci_addr, size_t size)
{
	/*
	 * roundup_pow_of_two() returns an unsigned long, which is not suited
	 * for 64bit values.
	 */
	u64 sz = 1ULL << fls64(size - 1);
	int nbits = ilog2(sz);
	u32 addr0, addr1, desc0, desc1;

	if (nbits < 8)
		nbits = 8;

	/* Set the PCI address */
	addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(nbits) |
		(lower_32_bits(pci_addr) & GENMASK(31, 8));
	addr1 = upper_32_bits(pci_addr);

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(r), addr0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(r), addr1);

	/* Set the PCIe header descriptor */
	if (is_io)
		desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_IO;
	else
		desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_MEM;
	desc1 = 0;

	/*
	 * Whatever Bit [23] is set or not inside DESC0 register of the outbound
	 * PCIe descriptor, the PCI function number must be set into
	 * Bits [26:24] of DESC0 anyway.
	 *
	 * In Root Complex mode, the function number is always 0 but in Endpoint
	 * mode, the PCIe controller may support more than one function. This
	 * function number needs to be set properly into the outbound PCIe
	 * descriptor.
	 *
	 * Besides, setting Bit [23] is mandatory when in Root Complex mode:
	 * then the driver must provide the bus, resp. device, number in
	 * Bits [7:0] of DESC1, resp. Bits[31:27] of DESC0. Like the function
	 * number, the device number is always 0 in Root Complex mode.
	 *
	 * However when in Endpoint mode, we can clear Bit [23] of DESC0, hence
	 * the PCIe controller will use the captured values for the bus and
	 * device numbers.
	 */
	if (pcie->is_rc) {
		/* The device and function numbers are always 0. */
		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_HARDCODED_RID |
			 CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(0);
		desc1 |= CDNS_PCIE_AT_OB_REGION_DESC1_BUS(pcie->bus);
	} else {
		/*
		 * Use captured values for bus and device numbers but still
		 * need to set the function number.
		 */
		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(fn);
	}

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(r), desc0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(r), desc1);

	/* Set the CPU address */
	cpu_addr -= pcie->mem_res->start;
	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(nbits) |
		(lower_32_bits(cpu_addr) & GENMASK(31, 8));
	addr1 = upper_32_bits(cpu_addr);

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), addr0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), addr1);
}

void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie, u8 fn,
						  u32 r, u64 cpu_addr)
{
	u32 addr0, addr1, desc0, desc1;

	desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_NORMAL_MSG;
	desc1 = 0;

	/* See cdns_pcie_set_outbound_region() comments above. */
	if (pcie->is_rc) {
		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_HARDCODED_RID |
			 CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(0);
		desc1 |= CDNS_PCIE_AT_OB_REGION_DESC1_BUS(pcie->bus);
	} else {
		desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(fn);
	}

	/* Set the CPU address */
	cpu_addr -= pcie->mem_res->start;
	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(17) |
		(lower_32_bits(cpu_addr) & GENMASK(31, 8));
	addr1 = upper_32_bits(cpu_addr);

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(r), 0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(r), 0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(r), desc0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(r), desc1);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), addr0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), addr1);
}

void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
{
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(r), 0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(r), 0);

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(r), 0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(r), 0);

	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), 0);
	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), 0);
}