linux-stable/include/linux/pci-ecam.h
Vidya Sagar 7f10074474 PCI: tegra: Add Tegra194 MCFG quirks for ECAM errata
The PCIe controller in Tegra194 SoC is not ECAM-compliant.  With the
current hardware design, ECAM can be enabled only for one controller (the
C5 controller) with bus numbers starting from 160 instead of 0. A different
approach is taken to avoid this abnormal way of enabling ECAM for just one
controller but to enable configuration space access for all the other
controllers. In this approach, ops are added through MCFG quirk mechanism
which access the configuration spaces by dynamically programming iATU
(internal AddressTranslation Unit) to generate respective configuration
accesses just like the way it is done in DesignWare core sub-system.

This issue is specific to Tegra194 and it would be fixed in the future
generations of Tegra SoCs.

Link: https://lore.kernel.org/r/20210416134537.19474-1-vidyas@nvidia.com
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-04-16 11:34:17 -05:00

96 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright 2016 Broadcom
*/
#ifndef DRIVERS_PCI_ECAM_H
#define DRIVERS_PCI_ECAM_H
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
/*
* Memory address shift values for the byte-level address that
* can be used when accessing the PCI Express Configuration Space.
*/
/*
* Enhanced Configuration Access Mechanism (ECAM)
*
* See PCI Express Base Specification, Revision 5.0, Version 1.0,
* Section 7.2.2, Table 7-1, p. 677.
*/
#define PCIE_ECAM_BUS_SHIFT 20 /* Bus number */
#define PCIE_ECAM_DEVFN_SHIFT 12 /* Device and Function number */
#define PCIE_ECAM_BUS_MASK 0xff
#define PCIE_ECAM_DEVFN_MASK 0xff
#define PCIE_ECAM_REG_MASK 0xfff /* Limit offset to a maximum of 4K */
#define PCIE_ECAM_BUS(x) (((x) & PCIE_ECAM_BUS_MASK) << PCIE_ECAM_BUS_SHIFT)
#define PCIE_ECAM_DEVFN(x) (((x) & PCIE_ECAM_DEVFN_MASK) << PCIE_ECAM_DEVFN_SHIFT)
#define PCIE_ECAM_REG(x) ((x) & PCIE_ECAM_REG_MASK)
#define PCIE_ECAM_OFFSET(bus, devfn, where) \
(PCIE_ECAM_BUS(bus) | \
PCIE_ECAM_DEVFN(devfn) | \
PCIE_ECAM_REG(where))
/*
* struct to hold pci ops and bus shift of the config window
* for a PCI controller.
*/
struct pci_config_window;
struct pci_ecam_ops {
unsigned int bus_shift;
struct pci_ops pci_ops;
int (*init)(struct pci_config_window *);
};
/*
* struct to hold the mappings of a config space window. This
* is expected to be used as sysdata for PCI controllers that
* use ECAM.
*/
struct pci_config_window {
struct resource res;
struct resource busr;
void *priv;
const struct pci_ecam_ops *ops;
union {
void __iomem *win; /* 64-bit single mapping */
void __iomem **winp; /* 32-bit per-bus mapping */
};
struct device *parent;/* ECAM res was from this dev */
};
/* create and free pci_config_window */
struct pci_config_window *pci_ecam_create(struct device *dev,
struct resource *cfgres, struct resource *busr,
const struct pci_ecam_ops *ops);
void pci_ecam_free(struct pci_config_window *cfg);
/* map_bus when ->sysdata is an instance of pci_config_window */
void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
int where);
/* default ECAM ops */
extern const struct pci_ecam_ops pci_generic_ecam_ops;
#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
extern const struct pci_ecam_ops pci_32b_ops; /* 32-bit accesses only */
extern const struct pci_ecam_ops pci_32b_read_ops; /* 32-bit read only */
extern const struct pci_ecam_ops hisi_pcie_ops; /* HiSilicon */
extern const struct pci_ecam_ops thunder_pem_ecam_ops; /* Cavium ThunderX 1.x & 2.x */
extern const struct pci_ecam_ops pci_thunder_ecam_ops; /* Cavium ThunderX 1.x */
extern const struct pci_ecam_ops xgene_v1_pcie_ecam_ops; /* APM X-Gene PCIe v1 */
extern const struct pci_ecam_ops xgene_v2_pcie_ecam_ops; /* APM X-Gene PCIe v2.x */
extern const struct pci_ecam_ops al_pcie_ops; /* Amazon Annapurna Labs PCIe */
extern const struct pci_ecam_ops tegra194_pcie_ops; /* Tegra194 PCIe */
#endif
#if IS_ENABLED(CONFIG_PCI_HOST_COMMON)
/* for DT-based PCI controllers that support ECAM */
int pci_host_common_probe(struct platform_device *pdev);
int pci_host_common_remove(struct platform_device *pdev);
#endif
#endif