/* SPDX-License-Identifier: GPL-2.0 */
/*
 * The contents of this file are private to DMA engine drivers, and is not
 * part of the API to be used by DMA engine users.
 */
#ifndef DMAENGINE_H
#define DMAENGINE_H

#include <linux/bug.h>
#include <linux/dmaengine.h>

/**
 * dma_cookie_init - initialize the cookies for a DMA channel
 * @chan: dma channel to initialize
 */
static inline void dma_cookie_init(struct dma_chan *chan)
{
        chan->cookie = DMA_MIN_COOKIE;
        chan->completed_cookie = DMA_MIN_COOKIE;
}

/**
 * dma_cookie_assign - assign a DMA engine cookie to the descriptor
 * @tx: descriptor needing cookie
 *
 * Assign a unique non-zero per-channel cookie to the descriptor.
 * Note: caller is expected to hold a lock to prevent concurrency.
 */
static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
{
        struct dma_chan *chan = tx->chan;
        dma_cookie_t cookie;

        cookie = chan->cookie + 1;
        if (cookie < DMA_MIN_COOKIE)
                cookie = DMA_MIN_COOKIE;
        tx->cookie = chan->cookie = cookie;

        return cookie;
}

/**
 * dma_cookie_complete - complete a descriptor
 * @tx: descriptor to complete
 *
 * Mark this descriptor complete by updating the channels completed
 * cookie marker.  Zero the descriptors cookie to prevent accidental
 * repeated completions.
 *
 * Note: caller is expected to hold a lock to prevent concurrency.
 */
static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
{
        BUG_ON(tx->cookie < DMA_MIN_COOKIE);
        tx->chan->completed_cookie = tx->cookie;
        tx->cookie = 0;
}

/**
 * dma_cookie_status - report cookie status
 * @chan: dma channel
 * @cookie: cookie we are interested in
 * @state: dma_tx_state structure to return last/used cookies
 *
 * Report the status of the cookie, filling in the state structure if
 * non-NULL.  No locking is required.
 */
static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
        dma_cookie_t cookie, struct dma_tx_state *state)
{
        dma_cookie_t used, complete;

        used = chan->cookie;
        complete = chan->completed_cookie;
        barrier();
        if (state) {
                state->last = complete;
                state->used = used;
                state->residue = 0;
                state->in_flight_bytes = 0;
        }
        return dma_async_is_complete(cookie, complete, used);
}

static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
{
        if (state)
                state->residue = residue;
}

static inline void dma_set_in_flight_bytes(struct dma_tx_state *state,
                                           u32 in_flight_bytes)
{
        if (state)
                state->in_flight_bytes = in_flight_bytes;
}

struct dmaengine_desc_callback {
        dma_async_tx_callback callback;
        dma_async_tx_callback_result callback_result;
        void *callback_param;
};

/**
 * dmaengine_desc_get_callback - get the passed in callback function
 * @tx: tx descriptor
 * @cb: temp struct to hold the callback info
 *
 * Fill the passed in cb struct with what's available in the passed in
 * tx descriptor struct
 * No locking is required.
 */
static inline void
dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
                            struct dmaengine_desc_callback *cb)
{
        cb->callback = tx->callback;
        cb->callback_result = tx->callback_result;
        cb->callback_param = tx->callback_param;
}

/**
 * dmaengine_desc_callback_invoke - call the callback function in cb struct
 * @cb: temp struct that is holding the callback info
 * @result: transaction result
 *
 * Call the callback function provided in the cb struct with the parameter
 * in the cb struct.
 * Locking is dependent on the driver.
 */
static inline void
dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
                               const struct dmaengine_result *result)
{
        struct dmaengine_result dummy_result = {
                .result = DMA_TRANS_NOERROR,
                .residue = 0
        };

        if (cb->callback_result) {
                if (!result)
                        result = &dummy_result;
                cb->callback_result(cb->callback_param, result);
        } else if (cb->callback) {
                cb->callback(cb->callback_param);
        }
}

/**
 * dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
 *                                      then immediately call the callback.
 * @tx: dma async tx descriptor
 * @result: transaction result
 *
 * Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
 * in a single function since no work is necessary in between for the driver.
 * Locking is dependent on the driver.
 */
static inline void
dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
                                   const struct dmaengine_result *result)
{
        struct dmaengine_desc_callback cb;

        dmaengine_desc_get_callback(tx, &cb);
        dmaengine_desc_callback_invoke(&cb, result);
}

/**
 * dmaengine_desc_callback_valid - verify the callback is valid in cb
 * @cb: callback info struct
 *
 * Return a bool that verifies whether callback in cb is valid or not.
 * No locking is required.
 */
static inline bool
dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
{
        return (cb->callback) ? true : false;
}

struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
struct dma_chan *dma_get_any_slave_channel(struct dma_device *device);

#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>

static inline struct dentry *
dmaengine_get_debugfs_root(struct dma_device *dma_dev) {
        return dma_dev->dbg_dev_root;
}
#else
struct dentry;
static inline struct dentry *
dmaengine_get_debugfs_root(struct dma_device *dma_dev)
{
        return NULL;
}
#endif /* CONFIG_DEBUG_FS */

#endif