linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright 2016 Broadcom

 */

​

#include <linux/device.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/pci.h>

#include <linux/pci-ecam.h>

#include <linux/slab.h>

​

/*

 * On 64-bit systems, we do a single ioremap for the whole config space

 * since we have enough virtual address range available.  On 32-bit, we

 * ioremap the config space for each bus individually.

 */

static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);

​

/*

 * Create a PCI config space window

 *  - reserve mem region

 *  - alloc struct pci_config_window with space for all mappings

 *  - ioremap the config space

 */

struct pci_config_window *pci_ecam_create(struct device *dev,

        struct resource *cfgres, struct resource *busr,

        struct pci_ecam_ops *ops)

{

    struct pci_config_window *cfg;

    unsigned int bus_range, bus_range_max, bsz;

    struct resource *conflict;

    int i, err;

​

    if (busr->start > busr->end)

        return ERR_PTR(-EINVAL);

​

    cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);

    if (!cfg)

        return ERR_PTR(-ENOMEM);

​

    cfg->parent = dev;

    cfg->ops = ops;

    cfg->busr.start = busr->start;

    cfg->busr.end = busr->end;

    cfg->busr.flags = IORESOURCE_BUS;

    bus_range = resource_size(&cfg->busr);

    bus_range_max = resource_size(cfgres) >> ops->bus_shift;

    if (bus_range > bus_range_max) {

        bus_range = bus_range_max;

        cfg->busr.end = busr->start + bus_range - 1;

        dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n",

             cfgres, &cfg->busr, busr);

    }

    bsz = 1 << ops->bus_shift;

​

    cfg->res.start = cfgres->start;

    cfg->res.end = cfgres->end;

    cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;

    cfg->res.name = "PCI ECAM";

​

    conflict = request_resource_conflict(&iomem_resource, &cfg->res);