// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_iommu.h>
#include <linux/of_reserved_mem.h>
#include <linux/dma-direct.h> /* for bus_dma_region */
#include <linux/dma-map-ops.h>
#include <linux/init.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <linux/platform_device.h>

#include <asm/errno.h>
#include "of_private.h"

/**
 * of_match_device - Tell if a struct device matches an of_device_id list
 * @matches: array of of_device_id match structures to search in
 * @dev: the OF device structure to match against
 *
 * Used by a driver to check whether an platform_device present in the
 * system is in its list of supported devices.
 */
const struct of_device_id *of_match_device(const struct of_device_id *matches,
                                           const struct device *dev)
{
        if (!matches || !dev->of_node || dev->of_node_reused)
                return NULL;
        return of_match_node(matches, dev->of_node);
}
EXPORT_SYMBOL(of_match_device);

static void
of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
{
        struct device_node *of_node = dev->of_node;
        struct of_phandle_iterator it;
        int rc, i = 0;

        if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
                return;

        /*
         * If dev->of_node doesn't exist or doesn't contain memory-region, try
         * the OF node having DMA configuration.
         */
        if (!of_property_present(of_node, "memory-region"))
                of_node = np;

        of_for_each_phandle(&it, rc, of_node, "memory-region", NULL, 0) {
                /*
                 * There might be multiple memory regions, but only one
                 * restricted-dma-pool region is allowed.
                 */
                if (of_device_is_compatible(it.node, "restricted-dma-pool") &&
                    of_device_is_available(it.node)) {
                        if (of_reserved_mem_device_init_by_idx(dev, of_node, i))
                                dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
                        of_node_put(it.node);
                        break;
                }
                i++;
        }

}

/**
 * of_dma_configure_id - Setup DMA configuration
 * @dev:        Device to apply DMA configuration
 * @np:         Pointer to OF node having DMA configuration
 * @force_dma:  Whether device is to be set up by of_dma_configure() even if
 *              DMA capability is not explicitly described by firmware.
 * @id:         Optional const pointer value input id
 *
 * Try to get devices's DMA configuration from DT and update it
 * accordingly.
 *
 * If platform code needs to use its own special DMA configuration, it
 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
 * to fix up DMA configuration.
 */
int of_dma_configure_id(struct device *dev, struct device_node *np,
                        bool force_dma, const u32 *id)
{
        const struct bus_dma_region *map = NULL;
        struct device_node *bus_np;
        u64 mask, end = 0;
        bool coherent, set_map = false;
        int ret;

        if (dev->dma_range_map) {
                dev_dbg(dev, "dma_range_map already set\n");
                goto skip_map;
        }

        if (np == dev->of_node)
                bus_np = __of_get_dma_parent(np);
        else
                bus_np = of_node_get(np);

        ret = of_dma_get_range(bus_np, &map);
        of_node_put(bus_np);
        if (ret < 0) {
                /*
                 * For legacy reasons, we have to assume some devices need
                 * DMA configuration regardless of whether "dma-ranges" is
                 * correctly specified or not.
                 */
                if (!force_dma)
                        return ret == -ENODEV ? 0 : ret;
        } else {
                /* Determine the overall bounds of all DMA regions */
                end = dma_range_map_max(map);
                set_map = true;
        }
skip_map:
        /*
         * If @dev is expected to be DMA-capable then the bus code that created
         * it should have initialised its dma_mask pointer by this point. For
         * now, we'll continue the legacy behaviour of coercing it to the
         * coherent mask if not, but we'll no longer do so quietly.
         */
        if (!dev->dma_mask) {
                dev_warn(dev, "DMA mask not set\n");
                dev->dma_mask = &dev->coherent_dma_mask;
        }

        if (!end && dev->coherent_dma_mask)
                end = dev->coherent_dma_mask;
        else if (!end)
                end = (1ULL << 32) - 1;

        /*
         * Limit coherent and dma mask based on size and default mask
         * set by the driver.
         */
        mask = DMA_BIT_MASK(ilog2(end) + 1);
        dev->coherent_dma_mask &= mask;
        *dev->dma_mask &= mask;
        /* ...but only set bus limit and range map if we found valid dma-ranges earlier */
        if (set_map) {
                dev->bus_dma_limit = end;
                dev->dma_range_map = map;
        }

        coherent = of_dma_is_coherent(np);
        dev_dbg(dev, "device is%sdma coherent\n",
                coherent ? " " : " not ");

        ret = of_iommu_configure(dev, np, id);
        if (ret == -EPROBE_DEFER) {
                /* Don't touch range map if it wasn't set from a valid dma-ranges */
                if (set_map)
                        dev->dma_range_map = NULL;
                kfree(map);
                return -EPROBE_DEFER;
        }
        /* Take all other IOMMU errors to mean we'll just carry on without it */
        dev_dbg(dev, "device is%sbehind an iommu\n",
                !ret ? " " : " not ");

        arch_setup_dma_ops(dev, coherent);

        if (ret)
                of_dma_set_restricted_buffer(dev, np);

        return 0;
}
EXPORT_SYMBOL_GPL(of_dma_configure_id);

const void *of_device_get_match_data(const struct device *dev)
{
        const struct of_device_id *match;

        match = of_match_device(dev->driver->of_match_table, dev);
        if (!match)
                return NULL;

        return match->data;
}
EXPORT_SYMBOL(of_device_get_match_data);

/**
 * of_device_modalias - Fill buffer with newline terminated modalias string
 * @dev:        Calling device
 * @str:        Modalias string
 * @len:        Size of @str
 */
ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
{
        ssize_t sl;

        if (!dev || !dev->of_node || dev->of_node_reused)
                return -ENODEV;

        sl = of_modalias(dev->of_node, str, len - 2);
        if (sl < 0)
                return sl;
        if (sl > len - 2)
                return -ENOMEM;

        str[sl++] = '\n';
        str[sl] = 0;
        return sl;
}
EXPORT_SYMBOL_GPL(of_device_modalias);

/**
 * of_device_uevent - Display OF related uevent information
 * @dev:        Device to display the uevent information for
 * @env:        Kernel object's userspace event reference to fill up
 */
void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
        const char *compat, *type;
        struct alias_prop *app;
        struct property *p;
        int seen = 0;

        if ((!dev) || (!dev->of_node))
                return;

        add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
        add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
        type = of_node_get_device_type(dev->of_node);
        if (type)
                add_uevent_var(env, "OF_TYPE=%s", type);

        /* Since the compatible field can contain pretty much anything
         * it's not really legal to split it out with commas. We split it
         * up using a number of environment variables instead. */
        of_property_for_each_string(dev->of_node, "compatible", p, compat) {
                add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
                seen++;
        }
        add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);

        seen = 0;
        mutex_lock(&of_mutex);
        list_for_each_entry(app, &aliases_lookup, link) {
                if (dev->of_node == app->np) {
                        add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
                                       app->alias);
                        seen++;
                }
        }
        mutex_unlock(&of_mutex);
}
EXPORT_SYMBOL_GPL(of_device_uevent);

int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
{
        int sl;

        if ((!dev) || (!dev->of_node) || dev->of_node_reused)
                return -ENODEV;

        /* Devicetree modalias is tricky, we add it in 2 steps */
        if (add_uevent_var(env, "MODALIAS="))
                return -ENOMEM;

        sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
                         sizeof(env->buf) - env->buflen);
        if (sl < 0)
                return sl;
        if (sl >= (sizeof(env->buf) - env->buflen))
                return -ENOMEM;
        env->buflen += sl;

        return 0;
}
EXPORT_SYMBOL_GPL(of_device_uevent_modalias);

/**
 * of_device_make_bus_id - Use the device node data to assign a unique name
 * @dev: pointer to device structure that is linked to a device tree node
 *
 * This routine will first try using the translated bus address to
 * derive a unique name. If it cannot, then it will prepend names from
 * parent nodes until a unique name can be derived.
 */
void of_device_make_bus_id(struct device *dev)
{
        struct device_node *node = dev->of_node;
        const __be32 *reg;
        u64 addr;
        u32 mask;

        /* Construct the name, using parent nodes if necessary to ensure uniqueness */
        while (node->parent) {
                /*
                 * If the address can be translated, then that is as much
                 * uniqueness as we need. Make it the first component and return
                 */
                reg = of_get_property(node, "reg", NULL);
                if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
                        if (!of_property_read_u32(node, "mask", &mask))
                                dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
                                             addr, ffs(mask) - 1, node, dev_name(dev));

                        else
                                dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
                                             addr, node, dev_name(dev));
                        return;
                }

                /* format arguments only used if dev_name() resolves to NULL */
                dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
                             kbasename(node->full_name), dev_name(dev));
                node = node->parent;
        }
}
EXPORT_SYMBOL_GPL(of_device_make_bus_id);