drm/panthor: Don't add write fences to the shared BOs

[drm/drm-misc.git] / drivers / bus / fsl-mc / fsl-mc-bus.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Freescale Management Complex (MC) bus driver
 *
 * Copyright (C) 2014-2016 Freescale Semiconductor, Inc.
 * Copyright 2019-2020 NXP
 * Author: German Rivera <German.Rivera@freescale.com>
 *
 */

#define pr_fmt(fmt) "fsl-mc: " fmt

#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/limits.h>
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/acpi.h>
#include <linux/iommu.h>
#include <linux/dma-map-ops.h>

#include "fsl-mc-private.h"

/*
 * Default DMA mask for devices on a fsl-mc bus
 */
#define FSL_MC_DEFAULT_DMA_MASK (~0ULL)

static struct fsl_mc_version mc_version;

/**
 * struct fsl_mc - Private data of a "fsl,qoriq-mc" platform device
 * @root_mc_bus_dev: fsl-mc device representing the root DPRC
 * @num_translation_ranges: number of entries in addr_translation_ranges
 * @translation_ranges: array of bus to system address translation ranges
 * @fsl_mc_regs: base address of register bank
 */
struct fsl_mc {
        struct fsl_mc_device *root_mc_bus_dev;
        u8 num_translation_ranges;
        struct fsl_mc_addr_translation_range *translation_ranges;
        void __iomem *fsl_mc_regs;
};

/**
 * struct fsl_mc_addr_translation_range - bus to system address translation
 * range
 * @mc_region_type: Type of MC region for the range being translated
 * @start_mc_offset: Start MC offset of the range being translated
 * @end_mc_offset: MC offset of the first byte after the range (last MC
 * offset of the range is end_mc_offset - 1)
 * @start_phys_addr: system physical address corresponding to start_mc_addr
 */
struct fsl_mc_addr_translation_range {
        enum dprc_region_type mc_region_type;
        u64 start_mc_offset;
        u64 end_mc_offset;
        phys_addr_t start_phys_addr;
};

#define FSL_MC_GCR1     0x0
#define GCR1_P1_STOP    BIT(31)
#define GCR1_P2_STOP    BIT(30)

#define FSL_MC_FAPR     0x28
#define MC_FAPR_PL      BIT(18)
#define MC_FAPR_BMT     BIT(17)

static phys_addr_t mc_portal_base_phys_addr;

/**
 * fsl_mc_bus_match - device to driver matching callback
 * @dev: the fsl-mc device to match against
 * @drv: the device driver to search for matching fsl-mc object type
 * structures
 *
 * Returns 1 on success, 0 otherwise.
 */
static int fsl_mc_bus_match(struct device *dev, const struct device_driver *drv)
{
        const struct fsl_mc_device_id *id;
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
        const struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv);
        bool found = false;

        /* When driver_override is set, only bind to the matching driver */
        if (mc_dev->driver_override) {
                found = !strcmp(mc_dev->driver_override, mc_drv->driver.name);
                goto out;
        }

        if (!mc_drv->match_id_table)
                goto out;

        /*
         * If the object is not 'plugged' don't match.
         * Only exception is the root DPRC, which is a special case.
         */
        if ((mc_dev->obj_desc.state & FSL_MC_OBJ_STATE_PLUGGED) == 0 &&
            !fsl_mc_is_root_dprc(&mc_dev->dev))
                goto out;

        /*
         * Traverse the match_id table of the given driver, trying to find
         * a matching for the given device.
         */
        for (id = mc_drv->match_id_table; id->vendor != 0x0; id++) {
                if (id->vendor == mc_dev->obj_desc.vendor &&
                    strcmp(id->obj_type, mc_dev->obj_desc.type) == 0) {
                        found = true;

                        break;
                }
        }

out:
        dev_dbg(dev, "%smatched\n", found ? "" : "not ");
        return found;
}

/*
 * fsl_mc_bus_uevent - callback invoked when a device is added
 */
static int fsl_mc_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
        const struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        if (add_uevent_var(env, "MODALIAS=fsl-mc:v%08Xd%s",
                           mc_dev->obj_desc.vendor,
                           mc_dev->obj_desc.type))
                return -ENOMEM;

        return 0;
}

static int fsl_mc_dma_configure(struct device *dev)
{
        struct device *dma_dev = dev;
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
        struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);
        u32 input_id = mc_dev->icid;
        int ret;

        while (dev_is_fsl_mc(dma_dev))
                dma_dev = dma_dev->parent;

        if (dev_of_node(dma_dev))
                ret = of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id);
        else
                ret = acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id);

        if (!ret && !mc_drv->driver_managed_dma) {
                ret = iommu_device_use_default_domain(dev);
                if (ret)
                        arch_teardown_dma_ops(dev);
        }

        return ret;
}

static void fsl_mc_dma_cleanup(struct device *dev)
{
        struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);

        if (!mc_drv->driver_managed_dma)
                iommu_device_unuse_default_domain(dev);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        return sprintf(buf, "fsl-mc:v%08Xd%s\n", mc_dev->obj_desc.vendor,
                       mc_dev->obj_desc.type);
}
static DEVICE_ATTR_RO(modalias);

static ssize_t driver_override_store(struct device *dev,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
        int ret;

        if (WARN_ON(dev->bus != &fsl_mc_bus_type))
                return -EINVAL;

        ret = driver_set_override(dev, &mc_dev->driver_override, buf, count);
        if (ret)
                return ret;

        return count;
}

static ssize_t driver_override_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        return snprintf(buf, PAGE_SIZE, "%s\n", mc_dev->driver_override);
}
static DEVICE_ATTR_RW(driver_override);

static struct attribute *fsl_mc_dev_attrs[] = {
        &dev_attr_modalias.attr,
        &dev_attr_driver_override.attr,
        NULL,
};

ATTRIBUTE_GROUPS(fsl_mc_dev);

static int scan_fsl_mc_bus(struct device *dev, void *data)
{
        struct fsl_mc_device *root_mc_dev;
        struct fsl_mc_bus *root_mc_bus;

        if (!fsl_mc_is_root_dprc(dev))
                goto exit;

        root_mc_dev = to_fsl_mc_device(dev);
        root_mc_bus = to_fsl_mc_bus(root_mc_dev);
        mutex_lock(&root_mc_bus->scan_mutex);
        dprc_scan_objects(root_mc_dev, false);
        mutex_unlock(&root_mc_bus->scan_mutex);

exit:
        return 0;
}

static ssize_t rescan_store(const struct bus_type *bus,
                            const char *buf, size_t count)
{
        unsigned long val;

        if (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        if (val)
                bus_for_each_dev(bus, NULL, NULL, scan_fsl_mc_bus);

        return count;
}
static BUS_ATTR_WO(rescan);

static int fsl_mc_bus_set_autorescan(struct device *dev, void *data)
{
        struct fsl_mc_device *root_mc_dev;
        unsigned long val;
        char *buf = data;

        if (!fsl_mc_is_root_dprc(dev))
                goto exit;

        root_mc_dev = to_fsl_mc_device(dev);

        if (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        if (val)
                enable_dprc_irq(root_mc_dev);
        else
                disable_dprc_irq(root_mc_dev);

exit:
        return 0;
}

static int fsl_mc_bus_get_autorescan(struct device *dev, void *data)
{
        struct fsl_mc_device *root_mc_dev;
        char *buf = data;

        if (!fsl_mc_is_root_dprc(dev))
                goto exit;

        root_mc_dev = to_fsl_mc_device(dev);

        sprintf(buf, "%d\n", get_dprc_irq_state(root_mc_dev));
exit:
        return 0;
}

static ssize_t autorescan_store(const struct bus_type *bus,
                                const char *buf, size_t count)
{
        bus_for_each_dev(bus, NULL, (void *)buf, fsl_mc_bus_set_autorescan);

        return count;
}

static ssize_t autorescan_show(const struct bus_type *bus, char *buf)
{
        bus_for_each_dev(bus, NULL, (void *)buf, fsl_mc_bus_get_autorescan);
        return strlen(buf);
}

static BUS_ATTR_RW(autorescan);

static struct attribute *fsl_mc_bus_attrs[] = {
        &bus_attr_rescan.attr,
        &bus_attr_autorescan.attr,
        NULL,
};

ATTRIBUTE_GROUPS(fsl_mc_bus);

const struct bus_type fsl_mc_bus_type = {
        .name = "fsl-mc",
        .match = fsl_mc_bus_match,
        .uevent = fsl_mc_bus_uevent,
        .dma_configure  = fsl_mc_dma_configure,
        .dma_cleanup = fsl_mc_dma_cleanup,
        .dev_groups = fsl_mc_dev_groups,
        .bus_groups = fsl_mc_bus_groups,
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_type);

struct device_type fsl_mc_bus_dprc_type = {
        .name = "fsl_mc_bus_dprc"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dprc_type);

struct device_type fsl_mc_bus_dpni_type = {
        .name = "fsl_mc_bus_dpni"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpni_type);

struct device_type fsl_mc_bus_dpio_type = {
        .name = "fsl_mc_bus_dpio"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpio_type);

struct device_type fsl_mc_bus_dpsw_type = {
        .name = "fsl_mc_bus_dpsw"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpsw_type);

struct device_type fsl_mc_bus_dpbp_type = {
        .name = "fsl_mc_bus_dpbp"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpbp_type);

struct device_type fsl_mc_bus_dpcon_type = {
        .name = "fsl_mc_bus_dpcon"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpcon_type);

struct device_type fsl_mc_bus_dpmcp_type = {
        .name = "fsl_mc_bus_dpmcp"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpmcp_type);

struct device_type fsl_mc_bus_dpmac_type = {
        .name = "fsl_mc_bus_dpmac"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpmac_type);

struct device_type fsl_mc_bus_dprtc_type = {
        .name = "fsl_mc_bus_dprtc"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dprtc_type);

struct device_type fsl_mc_bus_dpseci_type = {
        .name = "fsl_mc_bus_dpseci"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpseci_type);

struct device_type fsl_mc_bus_dpdmux_type = {
        .name = "fsl_mc_bus_dpdmux"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpdmux_type);

struct device_type fsl_mc_bus_dpdcei_type = {
        .name = "fsl_mc_bus_dpdcei"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpdcei_type);

struct device_type fsl_mc_bus_dpaiop_type = {
        .name = "fsl_mc_bus_dpaiop"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpaiop_type);

struct device_type fsl_mc_bus_dpci_type = {
        .name = "fsl_mc_bus_dpci"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpci_type);

struct device_type fsl_mc_bus_dpdmai_type = {
        .name = "fsl_mc_bus_dpdmai"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpdmai_type);

struct device_type fsl_mc_bus_dpdbg_type = {
        .name = "fsl_mc_bus_dpdbg"
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_dpdbg_type);

static struct device_type *fsl_mc_get_device_type(const char *type)
{
        static const struct {
                struct device_type *dev_type;
                const char *type;
        } dev_types[] = {
                { &fsl_mc_bus_dprc_type, "dprc" },
                { &fsl_mc_bus_dpni_type, "dpni" },
                { &fsl_mc_bus_dpio_type, "dpio" },
                { &fsl_mc_bus_dpsw_type, "dpsw" },
                { &fsl_mc_bus_dpbp_type, "dpbp" },
                { &fsl_mc_bus_dpcon_type, "dpcon" },
                { &fsl_mc_bus_dpmcp_type, "dpmcp" },
                { &fsl_mc_bus_dpmac_type, "dpmac" },
                { &fsl_mc_bus_dprtc_type, "dprtc" },
                { &fsl_mc_bus_dpseci_type, "dpseci" },
                { &fsl_mc_bus_dpdmux_type, "dpdmux" },
                { &fsl_mc_bus_dpdcei_type, "dpdcei" },
                { &fsl_mc_bus_dpaiop_type, "dpaiop" },
                { &fsl_mc_bus_dpci_type, "dpci" },
                { &fsl_mc_bus_dpdmai_type, "dpdmai" },
                { &fsl_mc_bus_dpdbg_type, "dpdbg" },
                { NULL, NULL }
        };
        int i;

        for (i = 0; dev_types[i].dev_type; i++)
                if (!strcmp(dev_types[i].type, type))
                        return dev_types[i].dev_type;

        return NULL;
}

static int fsl_mc_driver_probe(struct device *dev)
{
        struct fsl_mc_driver *mc_drv;
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
        int error;

        mc_drv = to_fsl_mc_driver(dev->driver);

        error = mc_drv->probe(mc_dev);
        if (error < 0) {
                if (error != -EPROBE_DEFER)
                        dev_err(dev, "%s failed: %d\n", __func__, error);
                return error;
        }

        return 0;
}

static int fsl_mc_driver_remove(struct device *dev)
{
        struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        mc_drv->remove(mc_dev);

        return 0;
}

static void fsl_mc_driver_shutdown(struct device *dev)
{
        struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        mc_drv->shutdown(mc_dev);
}

/*
 * __fsl_mc_driver_register - registers a child device driver with the
 * MC bus
 *
 * This function is implicitly invoked from the registration function of
 * fsl_mc device drivers, which is generated by the
 * module_fsl_mc_driver() macro.
 */
int __fsl_mc_driver_register(struct fsl_mc_driver *mc_driver,
                             struct module *owner)
{
        int error;

        mc_driver->driver.owner = owner;
        mc_driver->driver.bus = &fsl_mc_bus_type;

        if (mc_driver->probe)
                mc_driver->driver.probe = fsl_mc_driver_probe;

        if (mc_driver->remove)
                mc_driver->driver.remove = fsl_mc_driver_remove;

        if (mc_driver->shutdown)
                mc_driver->driver.shutdown = fsl_mc_driver_shutdown;

        error = driver_register(&mc_driver->driver);
        if (error < 0) {
                pr_err("driver_register() failed for %s: %d\n",
                       mc_driver->driver.name, error);
                return error;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(__fsl_mc_driver_register);

/*
 * fsl_mc_driver_unregister - unregisters a device driver from the
 * MC bus
 */
void fsl_mc_driver_unregister(struct fsl_mc_driver *mc_driver)
{
        driver_unregister(&mc_driver->driver);
}
EXPORT_SYMBOL_GPL(fsl_mc_driver_unregister);

/**
 * mc_get_version() - Retrieves the Management Complex firmware
 *                      version information
 * @mc_io:              Pointer to opaque I/O object
 * @cmd_flags:          Command flags; one or more of 'MC_CMD_FLAG_'
 * @mc_ver_info:        Returned version information structure
 *
 * Return:      '0' on Success; Error code otherwise.
 */
static int mc_get_version(struct fsl_mc_io *mc_io,
                          u32 cmd_flags,
                          struct fsl_mc_version *mc_ver_info)
{
        struct fsl_mc_command cmd = { 0 };
        struct dpmng_rsp_get_version *rsp_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPMNG_CMDID_GET_VERSION,
                                          cmd_flags,
                                          0);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dpmng_rsp_get_version *)cmd.params;
        mc_ver_info->revision = le32_to_cpu(rsp_params->revision);
        mc_ver_info->major = le32_to_cpu(rsp_params->version_major);
        mc_ver_info->minor = le32_to_cpu(rsp_params->version_minor);

        return 0;
}

/**
 * fsl_mc_get_version - function to retrieve the MC f/w version information
 *
 * Return:      mc version when called after fsl-mc-bus probe; NULL otherwise.
 */
struct fsl_mc_version *fsl_mc_get_version(void)
{
        if (mc_version.major)
                return &mc_version;

        return NULL;
}
EXPORT_SYMBOL_GPL(fsl_mc_get_version);

/*
 * fsl_mc_get_root_dprc - function to traverse to the root dprc
 */
void fsl_mc_get_root_dprc(struct device *dev,
                         struct device **root_dprc_dev)
{
        if (!dev) {
                *root_dprc_dev = NULL;
        } else if (!dev_is_fsl_mc(dev)) {
                *root_dprc_dev = NULL;
        } else {
                *root_dprc_dev = dev;
                while (dev_is_fsl_mc((*root_dprc_dev)->parent))
                        *root_dprc_dev = (*root_dprc_dev)->parent;
        }
}

static int get_dprc_attr(struct fsl_mc_io *mc_io,
                         int container_id, struct dprc_attributes *attr)
{
        u16 dprc_handle;
        int error;

        error = dprc_open(mc_io, 0, container_id, &dprc_handle);
        if (error < 0) {
                dev_err(mc_io->dev, "dprc_open() failed: %d\n", error);
                return error;
        }

        memset(attr, 0, sizeof(struct dprc_attributes));
        error = dprc_get_attributes(mc_io, 0, dprc_handle, attr);
        if (error < 0) {
                dev_err(mc_io->dev, "dprc_get_attributes() failed: %d\n",
                        error);
                goto common_cleanup;
        }

        error = 0;

common_cleanup:
        (void)dprc_close(mc_io, 0, dprc_handle);
        return error;
}

static int get_dprc_icid(struct fsl_mc_io *mc_io,
                         int container_id, u32 *icid)
{
        struct dprc_attributes attr;
        int error;

        error = get_dprc_attr(mc_io, container_id, &attr);
        if (error == 0)
                *icid = attr.icid;

        return error;
}

static int translate_mc_addr(struct fsl_mc_device *mc_dev,
                             enum dprc_region_type mc_region_type,
                             u64 mc_offset, phys_addr_t *phys_addr)
{
        int i;
        struct device *root_dprc_dev;
        struct fsl_mc *mc;

        fsl_mc_get_root_dprc(&mc_dev->dev, &root_dprc_dev);
        mc = dev_get_drvdata(root_dprc_dev->parent);

        if (mc->num_translation_ranges == 0) {
                /*
                 * Do identity mapping:
                 */
                *phys_addr = mc_offset;
                return 0;
        }

        for (i = 0; i < mc->num_translation_ranges; i++) {
                struct fsl_mc_addr_translation_range *range =
                        &mc->translation_ranges[i];

                if (mc_region_type == range->mc_region_type &&
                    mc_offset >= range->start_mc_offset &&
                    mc_offset < range->end_mc_offset) {
                        *phys_addr = range->start_phys_addr +
                                     (mc_offset - range->start_mc_offset);
                        return 0;
                }
        }

        return -EFAULT;
}

static int fsl_mc_device_get_mmio_regions(struct fsl_mc_device *mc_dev,
                                          struct fsl_mc_device *mc_bus_dev)
{
        int i;
        int error;
        struct resource *regions;
        struct fsl_mc_obj_desc *obj_desc = &mc_dev->obj_desc;
        struct device *parent_dev = mc_dev->dev.parent;
        enum dprc_region_type mc_region_type;

        if (is_fsl_mc_bus_dprc(mc_dev) ||
            is_fsl_mc_bus_dpmcp(mc_dev)) {
                mc_region_type = DPRC_REGION_TYPE_MC_PORTAL;
        } else if (is_fsl_mc_bus_dpio(mc_dev)) {
                mc_region_type = DPRC_REGION_TYPE_QBMAN_PORTAL;
        } else {
                /*
                 * This function should not have been called for this MC object
                 * type, as this object type is not supposed to have MMIO
                 * regions
                 */
                return -EINVAL;
        }

        regions = kmalloc_array(obj_desc->region_count,
                                sizeof(regions[0]), GFP_KERNEL);
        if (!regions)
                return -ENOMEM;

        for (i = 0; i < obj_desc->region_count; i++) {
                struct dprc_region_desc region_desc;

                error = dprc_get_obj_region(mc_bus_dev->mc_io,
                                            0,
                                            mc_bus_dev->mc_handle,
                                            obj_desc->type,
                                            obj_desc->id, i, &region_desc);
                if (error < 0) {
                        dev_err(parent_dev,
                                "dprc_get_obj_region() failed: %d\n", error);
                        goto error_cleanup_regions;
                }
                /*
                 * Older MC only returned region offset and no base address
                 * If base address is in the region_desc use it otherwise
                 * revert to old mechanism
                 */
                if (region_desc.base_address) {
                        regions[i].start = region_desc.base_address +
                                                region_desc.base_offset;
                } else {
                        error = translate_mc_addr(mc_dev, mc_region_type,
                                          region_desc.base_offset,
                                          &regions[i].start);

                        /*
                         * Some versions of the MC firmware wrongly report
                         * 0 for register base address of the DPMCP associated
                         * with child DPRC objects thus rendering them unusable.
                         * This is particularly troublesome in ACPI boot
                         * scenarios where the legacy way of extracting this
                         * base address from the device tree does not apply.
                         * Given that DPMCPs share the same base address,
                         * workaround this by using the base address extracted
                         * from the root DPRC container.
                         */
                        if (is_fsl_mc_bus_dprc(mc_dev) &&
                            regions[i].start == region_desc.base_offset)
                                regions[i].start += mc_portal_base_phys_addr;
                }

                if (error < 0) {
                        dev_err(parent_dev,
                                "Invalid MC offset: %#x (for %s.%d\'s region %d)\n",
                                region_desc.base_offset,
                                obj_desc->type, obj_desc->id, i);
                        goto error_cleanup_regions;
                }

                regions[i].end = regions[i].start + region_desc.size - 1;
                regions[i].name = "fsl-mc object MMIO region";
                regions[i].flags = region_desc.flags & IORESOURCE_BITS;
                regions[i].flags |= IORESOURCE_MEM;
        }

        mc_dev->regions = regions;
        return 0;

error_cleanup_regions:
        kfree(regions);
        return error;
}

/*
 * fsl_mc_is_root_dprc - function to check if a given device is a root dprc
 */
bool fsl_mc_is_root_dprc(struct device *dev)
{
        struct device *root_dprc_dev;

        fsl_mc_get_root_dprc(dev, &root_dprc_dev);
        if (!root_dprc_dev)
                return false;
        return dev == root_dprc_dev;
}

static void fsl_mc_device_release(struct device *dev)
{
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);

        kfree(mc_dev->regions);

        if (is_fsl_mc_bus_dprc(mc_dev))
                kfree(to_fsl_mc_bus(mc_dev));
        else
                kfree(mc_dev);
}

/*
 * Add a newly discovered fsl-mc device to be visible in Linux
 */
int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
                      struct fsl_mc_io *mc_io,
                      struct device *parent_dev,
                      struct fsl_mc_device **new_mc_dev)
{
        int error;
        struct fsl_mc_device *mc_dev = NULL;
        struct fsl_mc_bus *mc_bus = NULL;
        struct fsl_mc_device *parent_mc_dev;

        if (dev_is_fsl_mc(parent_dev))
                parent_mc_dev = to_fsl_mc_device(parent_dev);
        else
                parent_mc_dev = NULL;

        if (strcmp(obj_desc->type, "dprc") == 0) {
                /*
                 * Allocate an MC bus device object:
                 */
                mc_bus = kzalloc(sizeof(*mc_bus), GFP_KERNEL);
                if (!mc_bus)
                        return -ENOMEM;

                mutex_init(&mc_bus->scan_mutex);
                mc_dev = &mc_bus->mc_dev;
        } else {
                /*
                 * Allocate a regular fsl_mc_device object:
                 */
                mc_dev = kzalloc(sizeof(*mc_dev), GFP_KERNEL);
                if (!mc_dev)
                        return -ENOMEM;
        }

        mc_dev->obj_desc = *obj_desc;
        mc_dev->mc_io = mc_io;
        device_initialize(&mc_dev->dev);
        mc_dev->dev.parent = parent_dev;
        mc_dev->dev.bus = &fsl_mc_bus_type;
        mc_dev->dev.release = fsl_mc_device_release;
        mc_dev->dev.type = fsl_mc_get_device_type(obj_desc->type);
        if (!mc_dev->dev.type) {
                error = -ENODEV;
                dev_err(parent_dev, "unknown device type %s\n", obj_desc->type);
                goto error_cleanup_dev;
        }
        dev_set_name(&mc_dev->dev, "%s.%d", obj_desc->type, obj_desc->id);

        if (strcmp(obj_desc->type, "dprc") == 0) {
                struct fsl_mc_io *mc_io2;

                mc_dev->flags |= FSL_MC_IS_DPRC;

                /*
                 * To get the DPRC's ICID, we need to open the DPRC
                 * in get_dprc_icid(). For child DPRCs, we do so using the
                 * parent DPRC's MC portal instead of the child DPRC's MC
                 * portal, in case the child DPRC is already opened with
                 * its own portal (e.g., the DPRC used by AIOP).
                 *
                 * NOTE: There cannot be more than one active open for a
                 * given MC object, using the same MC portal.
                 */
                if (parent_mc_dev) {
                        /*
                         * device being added is a child DPRC device
                         */
                        mc_io2 = parent_mc_dev->mc_io;
                } else {
                        /*
                         * device being added is the root DPRC device
                         */
                        if (!mc_io) {
                                error = -EINVAL;
                                goto error_cleanup_dev;
                        }

                        mc_io2 = mc_io;
                }

                error = get_dprc_icid(mc_io2, obj_desc->id, &mc_dev->icid);
                if (error < 0)
                        goto error_cleanup_dev;
        } else {
                /*
                 * A non-DPRC object has to be a child of a DPRC, use the
                 * parent's ICID and interrupt domain.
                 */
                mc_dev->icid = parent_mc_dev->icid;
                mc_dev->dma_mask = FSL_MC_DEFAULT_DMA_MASK;
                mc_dev->dev.dma_mask = &mc_dev->dma_mask;
                mc_dev->dev.coherent_dma_mask = mc_dev->dma_mask;
                dev_set_msi_domain(&mc_dev->dev,
                                   dev_get_msi_domain(&parent_mc_dev->dev));
        }

        /*
         * Get MMIO regions for the device from the MC:
         *
         * NOTE: the root DPRC is a special case as its MMIO region is
         * obtained from the device tree
         */
        if (parent_mc_dev && obj_desc->region_count != 0) {
                error = fsl_mc_device_get_mmio_regions(mc_dev,
                                                       parent_mc_dev);
                if (error < 0)
                        goto error_cleanup_dev;
        }

        /*
         * The device-specific probe callback will get invoked by device_add()
         */
        error = device_add(&mc_dev->dev);
        if (error < 0) {
                dev_err(parent_dev,
                        "device_add() failed for device %s: %d\n",
                        dev_name(&mc_dev->dev), error);
                goto error_cleanup_dev;
        }

        dev_dbg(parent_dev, "added %s\n", dev_name(&mc_dev->dev));

        *new_mc_dev = mc_dev;
        return 0;

error_cleanup_dev:
        kfree(mc_dev->regions);
        kfree(mc_bus);
        kfree(mc_dev);

        return error;
}
EXPORT_SYMBOL_GPL(fsl_mc_device_add);

static struct notifier_block fsl_mc_nb;

/**
 * fsl_mc_device_remove - Remove an fsl-mc device from being visible to
 * Linux
 *
 * @mc_dev: Pointer to an fsl-mc device
 */
void fsl_mc_device_remove(struct fsl_mc_device *mc_dev)
{
        kfree(mc_dev->driver_override);
        mc_dev->driver_override = NULL;

        /*
         * The device-specific remove callback will get invoked by device_del()
         */
        device_del(&mc_dev->dev);
        put_device(&mc_dev->dev);
}
EXPORT_SYMBOL_GPL(fsl_mc_device_remove);

struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev,
                                          u16 if_id)
{
        struct fsl_mc_device *mc_bus_dev, *endpoint;
        struct fsl_mc_obj_desc endpoint_desc = {{ 0 }};
        struct dprc_endpoint endpoint1 = {{ 0 }};
        struct dprc_endpoint endpoint2 = {{ 0 }};
        int state, err;

        mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
        strcpy(endpoint1.type, mc_dev->obj_desc.type);
        endpoint1.id = mc_dev->obj_desc.id;
        endpoint1.if_id = if_id;

        err = dprc_get_connection(mc_bus_dev->mc_io, 0,
                                  mc_bus_dev->mc_handle,
                                  &endpoint1, &endpoint2,
                                  &state);

        if (err == -ENOTCONN || state == -1)
                return ERR_PTR(-ENOTCONN);

        if (err < 0) {
                dev_err(&mc_bus_dev->dev, "dprc_get_connection() = %d\n", err);
                return ERR_PTR(err);
        }

        strcpy(endpoint_desc.type, endpoint2.type);
        endpoint_desc.id = endpoint2.id;
        endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev);

        /*
         * We know that the device has an endpoint because we verified by
         * interrogating the firmware. This is the case when the device was not
         * yet discovered by the fsl-mc bus, thus the lookup returned NULL.
         * Force a rescan of the devices in this container and retry the lookup.
         */
        if (!endpoint) {
                struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);

                if (mutex_trylock(&mc_bus->scan_mutex)) {
                        err = dprc_scan_objects(mc_bus_dev, true);
                        mutex_unlock(&mc_bus->scan_mutex);
                }

                if (err < 0)
                        return ERR_PTR(err);
        }

        endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev);
        /*
         * This means that the endpoint might reside in a different isolation
         * context (DPRC/container). Not much to do, so return a permssion
         * error.
         */
        if (!endpoint)
                return ERR_PTR(-EPERM);

        return endpoint;
}
EXPORT_SYMBOL_GPL(fsl_mc_get_endpoint);

static int get_mc_addr_translation_ranges(struct device *dev,
                                          struct fsl_mc_addr_translation_range
                                                **ranges,
                                          u8 *num_ranges)
{
        struct fsl_mc_addr_translation_range *r;
        struct of_range_parser parser;
        struct of_range range;

        of_range_parser_init(&parser, dev->of_node);
        *num_ranges = of_range_count(&parser);
        if (!*num_ranges) {
                /*
                 * Missing or empty ranges property ("ranges;") for the
                 * 'fsl,qoriq-mc' node. In this case, identity mapping
                 * will be used.
                 */
                *ranges = NULL;
                return 0;
        }

        *ranges = devm_kcalloc(dev, *num_ranges,
                               sizeof(struct fsl_mc_addr_translation_range),
                               GFP_KERNEL);
        if (!(*ranges))
                return -ENOMEM;

        r = *ranges;
        for_each_of_range(&parser, &range) {
                r->mc_region_type = range.flags;
                r->start_mc_offset = range.bus_addr;
                r->end_mc_offset = range.bus_addr + range.size;
                r->start_phys_addr = range.cpu_addr;
                r++;
        }

        return 0;
}

/*
 * fsl_mc_bus_probe - callback invoked when the root MC bus is being
 * added
 */
static int fsl_mc_bus_probe(struct platform_device *pdev)
{
        struct fsl_mc_obj_desc obj_desc;
        int error;
        struct fsl_mc *mc;
        struct fsl_mc_device *mc_bus_dev = NULL;
        struct fsl_mc_io *mc_io = NULL;
        int container_id;
        phys_addr_t mc_portal_phys_addr;
        u32 mc_portal_size, mc_stream_id;
        struct resource *plat_res;

        mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
        if (!mc)
                return -ENOMEM;

        platform_set_drvdata(pdev, mc);

        plat_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        if (plat_res) {
                mc->fsl_mc_regs = devm_ioremap_resource(&pdev->dev, plat_res);
                if (IS_ERR(mc->fsl_mc_regs))
                        return PTR_ERR(mc->fsl_mc_regs);
        }

        if (mc->fsl_mc_regs) {
                if (IS_ENABLED(CONFIG_ACPI) && !dev_of_node(&pdev->dev)) {
                        mc_stream_id = readl(mc->fsl_mc_regs + FSL_MC_FAPR);
                        /*
                         * HW ORs the PL and BMT bit, places the result in bit
                         * 14 of the StreamID and ORs in the ICID. Calculate it
                         * accordingly.
                         */
                        mc_stream_id = (mc_stream_id & 0xffff) |
                                ((mc_stream_id & (MC_FAPR_PL | MC_FAPR_BMT)) ?
                                        BIT(14) : 0);
                        error = acpi_dma_configure_id(&pdev->dev,
                                                      DEV_DMA_COHERENT,
                                                      &mc_stream_id);
                        if (error == -EPROBE_DEFER)
                                return error;
                        if (error)
                                dev_warn(&pdev->dev,
                                         "failed to configure dma: %d.\n",
                                         error);
                }

                /*
                 * Some bootloaders pause the MC firmware before booting the
                 * kernel so that MC will not cause faults as soon as the
                 * SMMU probes due to the fact that there's no configuration
                 * in place for MC.
                 * At this point MC should have all its SMMU setup done so make
                 * sure it is resumed.
                 */
                writel(readl(mc->fsl_mc_regs + FSL_MC_GCR1) &
                             (~(GCR1_P1_STOP | GCR1_P2_STOP)),
                       mc->fsl_mc_regs + FSL_MC_GCR1);
        }

        /*
         * Get physical address of MC portal for the root DPRC:
         */
        plat_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mc_portal_phys_addr = plat_res->start;
        mc_portal_size = resource_size(plat_res);
        mc_portal_base_phys_addr = mc_portal_phys_addr & ~0x3ffffff;

        error = fsl_create_mc_io(&pdev->dev, mc_portal_phys_addr,
                                 mc_portal_size, NULL,
                                 FSL_MC_IO_ATOMIC_CONTEXT_PORTAL, &mc_io);
        if (error < 0)
                return error;

        error = mc_get_version(mc_io, 0, &mc_version);
        if (error != 0) {
                dev_err(&pdev->dev,
                        "mc_get_version() failed with error %d\n", error);
                goto error_cleanup_mc_io;
        }

        dev_info(&pdev->dev, "MC firmware version: %u.%u.%u\n",
                 mc_version.major, mc_version.minor, mc_version.revision);

        if (dev_of_node(&pdev->dev)) {
                error = get_mc_addr_translation_ranges(&pdev->dev,
                                                &mc->translation_ranges,
                                                &mc->num_translation_ranges);
                if (error < 0)
                        goto error_cleanup_mc_io;
        }

        error = dprc_get_container_id(mc_io, 0, &container_id);
        if (error < 0) {
                dev_err(&pdev->dev,
                        "dprc_get_container_id() failed: %d\n", error);
                goto error_cleanup_mc_io;
        }

        memset(&obj_desc, 0, sizeof(struct fsl_mc_obj_desc));
        error = dprc_get_api_version(mc_io, 0,
                                     &obj_desc.ver_major,
                                     &obj_desc.ver_minor);
        if (error < 0)
                goto error_cleanup_mc_io;

        obj_desc.vendor = FSL_MC_VENDOR_FREESCALE;
        strcpy(obj_desc.type, "dprc");
        obj_desc.id = container_id;
        obj_desc.irq_count = 1;
        obj_desc.region_count = 0;

        error = fsl_mc_device_add(&obj_desc, mc_io, &pdev->dev, &mc_bus_dev);
        if (error < 0)
                goto error_cleanup_mc_io;

        mc->root_mc_bus_dev = mc_bus_dev;
        mc_bus_dev->dev.fwnode = pdev->dev.fwnode;
        return 0;

error_cleanup_mc_io:
        fsl_destroy_mc_io(mc_io);
        return error;
}

/*
 * fsl_mc_bus_remove - callback invoked when the root MC bus is being
 * removed
 */
static void fsl_mc_bus_remove(struct platform_device *pdev)
{
        struct fsl_mc *mc = platform_get_drvdata(pdev);
        struct fsl_mc_io *mc_io;

        mc_io = mc->root_mc_bus_dev->mc_io;
        fsl_mc_device_remove(mc->root_mc_bus_dev);
        fsl_destroy_mc_io(mc_io);

        bus_unregister_notifier(&fsl_mc_bus_type, &fsl_mc_nb);

        if (mc->fsl_mc_regs) {
                /*
                 * Pause the MC firmware so that it doesn't crash in certain
                 * scenarios, such as kexec.
                 */
                writel(readl(mc->fsl_mc_regs + FSL_MC_GCR1) |
                       (GCR1_P1_STOP | GCR1_P2_STOP),
                       mc->fsl_mc_regs + FSL_MC_GCR1);
        }
}

static const struct of_device_id fsl_mc_bus_match_table[] = {
        {.compatible = "fsl,qoriq-mc",},
        {},
};

MODULE_DEVICE_TABLE(of, fsl_mc_bus_match_table);

static const struct acpi_device_id fsl_mc_bus_acpi_match_table[] = {
        {"NXP0008", 0 },
        { }
};
MODULE_DEVICE_TABLE(acpi, fsl_mc_bus_acpi_match_table);

static struct platform_driver fsl_mc_bus_driver = {
        .driver = {
                   .name = "fsl_mc_bus",
                   .pm = NULL,
                   .of_match_table = fsl_mc_bus_match_table,
                   .acpi_match_table = fsl_mc_bus_acpi_match_table,
                   },
        .probe = fsl_mc_bus_probe,
        .remove_new = fsl_mc_bus_remove,
        .shutdown = fsl_mc_bus_remove,
};

static int fsl_mc_bus_notifier(struct notifier_block *nb,
                               unsigned long action, void *data)
{
        struct device *dev = data;
        struct resource *res;
        void __iomem *fsl_mc_regs;

        if (action != BUS_NOTIFY_ADD_DEVICE)
                return 0;

        if (!of_match_device(fsl_mc_bus_match_table, dev) &&
            !acpi_match_device(fsl_mc_bus_acpi_match_table, dev))
                return 0;

        res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 1);
        if (!res)
                return 0;

        fsl_mc_regs = ioremap(res->start, resource_size(res));
        if (!fsl_mc_regs)
                return 0;

        /*
         * Make sure that the MC firmware is paused before the IOMMU setup for
         * it is done or otherwise the firmware will crash right after the SMMU
         * gets probed and enabled.
         */
        writel(readl(fsl_mc_regs + FSL_MC_GCR1) | (GCR1_P1_STOP | GCR1_P2_STOP),
               fsl_mc_regs + FSL_MC_GCR1);
        iounmap(fsl_mc_regs);

        return 0;
}

static struct notifier_block fsl_mc_nb = {
        .notifier_call = fsl_mc_bus_notifier,
};

static int __init fsl_mc_bus_driver_init(void)
{
        int error;

        error = bus_register(&fsl_mc_bus_type);
        if (error < 0) {
                pr_err("bus type registration failed: %d\n", error);
                goto error_cleanup_cache;
        }

        error = platform_driver_register(&fsl_mc_bus_driver);
        if (error < 0) {
                pr_err("platform_driver_register() failed: %d\n", error);
                goto error_cleanup_bus;
        }

        error = dprc_driver_init();
        if (error < 0)
                goto error_cleanup_driver;

        error = fsl_mc_allocator_driver_init();
        if (error < 0)
                goto error_cleanup_dprc_driver;

        return bus_register_notifier(&platform_bus_type, &fsl_mc_nb);

error_cleanup_dprc_driver:
        dprc_driver_exit();

error_cleanup_driver:
        platform_driver_unregister(&fsl_mc_bus_driver);

error_cleanup_bus:
        bus_unregister(&fsl_mc_bus_type);

error_cleanup_cache:
        return error;
}
postcore_initcall(fsl_mc_bus_driver_init);