block: inherit CPU completion on bio->rq and rq->rq merges

[linux-2.6/mini2440.git] / drivers / dma / dmatest.c

/*
 * DMA Engine test module
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/random.h>
#include <linux/wait.h>

static unsigned int test_buf_size = 16384;
module_param(test_buf_size, uint, S_IRUGO);
MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");

static char test_channel[BUS_ID_SIZE];
module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO);
MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");

static char test_device[BUS_ID_SIZE];
module_param_string(device, test_device, sizeof(test_device), S_IRUGO);
MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)");

static unsigned int threads_per_chan = 1;
module_param(threads_per_chan, uint, S_IRUGO);
MODULE_PARM_DESC(threads_per_chan,
                "Number of threads to start per channel (default: 1)");

static unsigned int max_channels;
module_param(max_channels, uint, S_IRUGO);
MODULE_PARM_DESC(nr_channels,
                "Maximum number of channels to use (default: all)");

/*
 * Initialization patterns. All bytes in the source buffer has bit 7
 * set, all bytes in the destination buffer has bit 7 cleared.
 *
 * Bit 6 is set for all bytes which are to be copied by the DMA
 * engine. Bit 5 is set for all bytes which are to be overwritten by
 * the DMA engine.
 *
 * The remaining bits are the inverse of a counter which increments by
 * one for each byte address.
 */
#define PATTERN_SRC             0x80
#define PATTERN_DST             0x00
#define PATTERN_COPY            0x40
#define PATTERN_OVERWRITE       0x20
#define PATTERN_COUNT_MASK      0x1f

struct dmatest_thread {
        struct list_head        node;
        struct task_struct      *task;
        struct dma_chan         *chan;
        u8                      *srcbuf;
        u8                      *dstbuf;
};

struct dmatest_chan {
        struct list_head        node;
        struct dma_chan         *chan;
        struct list_head        threads;
};

/*
 * These are protected by dma_list_mutex since they're only used by
 * the DMA client event callback
 */
static LIST_HEAD(dmatest_channels);
static unsigned int nr_channels;

static bool dmatest_match_channel(struct dma_chan *chan)
{
        if (test_channel[0] == '\0')
                return true;
        return strcmp(chan->dev.bus_id, test_channel) == 0;
}

static bool dmatest_match_device(struct dma_device *device)
{
        if (test_device[0] == '\0')
                return true;
        return strcmp(device->dev->bus_id, test_device) == 0;
}

static unsigned long dmatest_random(void)
{
        unsigned long buf;

        get_random_bytes(&buf, sizeof(buf));
        return buf;
}

static void dmatest_init_srcbuf(u8 *buf, unsigned int start, unsigned int len)
{
        unsigned int i;

        for (i = 0; i < start; i++)
                buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
        for ( ; i < start + len; i++)
                buf[i] = PATTERN_SRC | PATTERN_COPY
                        | (~i & PATTERN_COUNT_MASK);;
        for ( ; i < test_buf_size; i++)
                buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
}

static void dmatest_init_dstbuf(u8 *buf, unsigned int start, unsigned int len)
{
        unsigned int i;

        for (i = 0; i < start; i++)
                buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
        for ( ; i < start + len; i++)
                buf[i] = PATTERN_DST | PATTERN_OVERWRITE
                        | (~i & PATTERN_COUNT_MASK);
        for ( ; i < test_buf_size; i++)
                buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
}

static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
                unsigned int counter, bool is_srcbuf)
{
        u8              diff = actual ^ pattern;
        u8              expected = pattern | (~counter & PATTERN_COUNT_MASK);
        const char      *thread_name = current->comm;

        if (is_srcbuf)
                pr_warning("%s: srcbuf[0x%x] overwritten!"
                                " Expected %02x, got %02x\n",
                                thread_name, index, expected, actual);
        else if ((pattern & PATTERN_COPY)
                        && (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
                pr_warning("%s: dstbuf[0x%x] not copied!"
                                " Expected %02x, got %02x\n",
                                thread_name, index, expected, actual);
        else if (diff & PATTERN_SRC)
                pr_warning("%s: dstbuf[0x%x] was copied!"
                                " Expected %02x, got %02x\n",
                                thread_name, index, expected, actual);
        else
                pr_warning("%s: dstbuf[0x%x] mismatch!"
                                " Expected %02x, got %02x\n",
                                thread_name, index, expected, actual);
}

static unsigned int dmatest_verify(u8 *buf, unsigned int start,
                unsigned int end, unsigned int counter, u8 pattern,
                bool is_srcbuf)
{
        unsigned int i;
        unsigned int error_count = 0;
        u8 actual;

        for (i = start; i < end; i++) {
                actual = buf[i];
                if (actual != (pattern | (~counter & PATTERN_COUNT_MASK))) {
                        if (error_count < 32)
                                dmatest_mismatch(actual, pattern, i, counter,
                                                is_srcbuf);
                        error_count++;
                }
                counter++;
        }

        if (error_count > 32)
                pr_warning("%s: %u errors suppressed\n",
                        current->comm, error_count - 32);

        return error_count;
}

/*
 * This function repeatedly tests DMA transfers of various lengths and
 * offsets until it is told to exit by kthread_stop(). There may be
 * multiple threads running this function in parallel for a single
 * channel, and there may be multiple channels being tested in
 * parallel.
 *
 * Before each test, the source and destination buffer is initialized
 * with a known pattern. This pattern is different depending on
 * whether it's in an area which is supposed to be copied or
 * overwritten, and different in the source and destination buffers.
 * So if the DMA engine doesn't copy exactly what we tell it to copy,
 * we'll notice.
 */
static int dmatest_func(void *data)
{
        struct dmatest_thread   *thread = data;
        struct dma_chan         *chan;
        const char              *thread_name;
        unsigned int            src_off, dst_off, len;
        unsigned int            error_count;
        unsigned int            failed_tests = 0;
        unsigned int            total_tests = 0;
        dma_cookie_t            cookie;
        enum dma_status         status;
        int                     ret;

        thread_name = current->comm;

        ret = -ENOMEM;
        thread->srcbuf = kmalloc(test_buf_size, GFP_KERNEL);
        if (!thread->srcbuf)
                goto err_srcbuf;
        thread->dstbuf = kmalloc(test_buf_size, GFP_KERNEL);
        if (!thread->dstbuf)
                goto err_dstbuf;

        smp_rmb();
        chan = thread->chan;
        dma_chan_get(chan);

        while (!kthread_should_stop()) {
                total_tests++;

                len = dmatest_random() % test_buf_size + 1;
                src_off = dmatest_random() % (test_buf_size - len + 1);
                dst_off = dmatest_random() % (test_buf_size - len + 1);

                dmatest_init_srcbuf(thread->srcbuf, src_off, len);
                dmatest_init_dstbuf(thread->dstbuf, dst_off, len);

                cookie = dma_async_memcpy_buf_to_buf(chan,
                                thread->dstbuf + dst_off,
                                thread->srcbuf + src_off,
                                len);
                if (dma_submit_error(cookie)) {
                        pr_warning("%s: #%u: submit error %d with src_off=0x%x "
                                        "dst_off=0x%x len=0x%x\n",
                                        thread_name, total_tests - 1, cookie,
                                        src_off, dst_off, len);
                        msleep(100);
                        failed_tests++;
                        continue;
                }
                dma_async_memcpy_issue_pending(chan);

                do {
                        msleep(1);
                        status = dma_async_memcpy_complete(
                                        chan, cookie, NULL, NULL);
                } while (status == DMA_IN_PROGRESS);

                if (status == DMA_ERROR) {
                        pr_warning("%s: #%u: error during copy\n",
                                        thread_name, total_tests - 1);
                        failed_tests++;
                        continue;
                }

                error_count = 0;

                pr_debug("%s: verifying source buffer...\n", thread_name);
                error_count += dmatest_verify(thread->srcbuf, 0, src_off,
                                0, PATTERN_SRC, true);
                error_count += dmatest_verify(thread->srcbuf, src_off,
                                src_off + len, src_off,
                                PATTERN_SRC | PATTERN_COPY, true);
                error_count += dmatest_verify(thread->srcbuf, src_off + len,
                                test_buf_size, src_off + len,
                                PATTERN_SRC, true);

                pr_debug("%s: verifying dest buffer...\n",
                                thread->task->comm);
                error_count += dmatest_verify(thread->dstbuf, 0, dst_off,
                                0, PATTERN_DST, false);
                error_count += dmatest_verify(thread->dstbuf, dst_off,
                                dst_off + len, src_off,
                                PATTERN_SRC | PATTERN_COPY, false);
                error_count += dmatest_verify(thread->dstbuf, dst_off + len,
                                test_buf_size, dst_off + len,
                                PATTERN_DST, false);

                if (error_count) {
                        pr_warning("%s: #%u: %u errors with "
                                "src_off=0x%x dst_off=0x%x len=0x%x\n",
                                thread_name, total_tests - 1, error_count,
                                src_off, dst_off, len);
                        failed_tests++;
                } else {
                        pr_debug("%s: #%u: No errors with "
                                "src_off=0x%x dst_off=0x%x len=0x%x\n",
                                thread_name, total_tests - 1,
                                src_off, dst_off, len);
                }
        }

        ret = 0;
        dma_chan_put(chan);
        kfree(thread->dstbuf);
err_dstbuf:
        kfree(thread->srcbuf);
err_srcbuf:
        pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
                        thread_name, total_tests, failed_tests, ret);
        return ret;
}

static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
{
        struct dmatest_thread   *thread;
        struct dmatest_thread   *_thread;
        int                     ret;

        list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
                ret = kthread_stop(thread->task);
                pr_debug("dmatest: thread %s exited with status %d\n",
                                thread->task->comm, ret);
                list_del(&thread->node);
                kfree(thread);
        }
        kfree(dtc);
}

static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
{
        struct dmatest_chan     *dtc;
        struct dmatest_thread   *thread;
        unsigned int            i;

        dtc = kmalloc(sizeof(struct dmatest_chan), GFP_ATOMIC);
        if (!dtc) {
                pr_warning("dmatest: No memory for %s\n", chan->dev.bus_id);
                return DMA_NAK;
        }

        dtc->chan = chan;
        INIT_LIST_HEAD(&dtc->threads);

        for (i = 0; i < threads_per_chan; i++) {
                thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
                if (!thread) {
                        pr_warning("dmatest: No memory for %s-test%u\n",
                                        chan->dev.bus_id, i);
                        break;
                }
                thread->chan = dtc->chan;
                smp_wmb();
                thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
                                chan->dev.bus_id, i);
                if (IS_ERR(thread->task)) {
                        pr_warning("dmatest: Failed to run thread %s-test%u\n",
                                        chan->dev.bus_id, i);
                        kfree(thread);
                        break;
                }

                /* srcbuf and dstbuf are allocated by the thread itself */

                list_add_tail(&thread->node, &dtc->threads);
        }

        pr_info("dmatest: Started %u threads using %s\n", i, chan->dev.bus_id);

        list_add_tail(&dtc->node, &dmatest_channels);
        nr_channels++;

        return DMA_ACK;
}

static enum dma_state_client dmatest_remove_channel(struct dma_chan *chan)
{
        struct dmatest_chan     *dtc, *_dtc;

        list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
                if (dtc->chan == chan) {
                        list_del(&dtc->node);
                        dmatest_cleanup_channel(dtc);
                        pr_debug("dmatest: lost channel %s\n",
                                        chan->dev.bus_id);
                        return DMA_ACK;
                }
        }

        return DMA_DUP;
}

/*
 * Start testing threads as new channels are assigned to us, and kill
 * them when the channels go away.
 *
 * When we unregister the client, all channels are removed so this
 * will also take care of cleaning things up when the module is
 * unloaded.
 */
static enum dma_state_client
dmatest_event(struct dma_client *client, struct dma_chan *chan,
                enum dma_state state)
{
        enum dma_state_client   ack = DMA_NAK;

        switch (state) {
        case DMA_RESOURCE_AVAILABLE:
                if (!dmatest_match_channel(chan)
                                || !dmatest_match_device(chan->device))
                        ack = DMA_DUP;
                else if (max_channels && nr_channels >= max_channels)
                        ack = DMA_NAK;
                else
                        ack = dmatest_add_channel(chan);
                break;

        case DMA_RESOURCE_REMOVED:
                ack = dmatest_remove_channel(chan);
                break;

        default:
                pr_info("dmatest: Unhandled event %u (%s)\n",
                                state, chan->dev.bus_id);
                break;
        }

        return ack;
}

static struct dma_client dmatest_client = {
        .event_callback = dmatest_event,
};

static int __init dmatest_init(void)
{
        dma_cap_set(DMA_MEMCPY, dmatest_client.cap_mask);
        dma_async_client_register(&dmatest_client);
        dma_async_client_chan_request(&dmatest_client);

        return 0;
}
module_init(dmatest_init);

static void __exit dmatest_exit(void)
{
        dma_async_client_unregister(&dmatest_client);
}
module_exit(dmatest_exit);

MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
MODULE_LICENSE("GPL v2");