/*
 * Copyright 2009 Jerome Glisse.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Jerome Glisse <glisse@freedesktop.org>
 *    Dave Airlie
 */
#include <linux/seq_file.h>
#include <asm/atomic.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/kref.h>
#include "drmP.h"
#include "drm.h"
#include "radeon_reg.h"
#include "radeon.h"

int radeon_fence_emit(struct radeon_device *rdev, struct radeon_fence *fence)
{
        unsigned long irq_flags;

        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        if (fence->emited) {
                write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
                return 0;
        }
        fence->seq = atomic_add_return(1, &rdev->fence_drv.seq);
        if (!rdev->cp.ready) {
                /* FIXME: cp is not running assume everythings is done right
                 * away
                 */
                WREG32(rdev->fence_drv.scratch_reg, fence->seq);
        } else
                radeon_fence_ring_emit(rdev, fence);

        fence->emited = true;
        fence->timeout = jiffies + ((2000 * HZ) / 1000);
        list_del(&fence->list);
        list_add_tail(&fence->list, &rdev->fence_drv.emited);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        return 0;
}

static bool radeon_fence_poll_locked(struct radeon_device *rdev)
{
        struct radeon_fence *fence;
        struct list_head *i, *n;
        uint32_t seq;
        bool wake = false;

        if (rdev == NULL) {
                return true;
        }
        if (rdev->shutdown) {
                return true;
        }
        seq = RREG32(rdev->fence_drv.scratch_reg);
        rdev->fence_drv.last_seq = seq;
        n = NULL;
        list_for_each(i, &rdev->fence_drv.emited) {
                fence = list_entry(i, struct radeon_fence, list);
                if (fence->seq == seq) {
                        n = i;
                        break;
                }
        }
        /* all fence previous to this one are considered as signaled */
        if (n) {
                i = n;
                do {
                        n = i->prev;
                        list_del(i);
                        list_add_tail(i, &rdev->fence_drv.signaled);
                        fence = list_entry(i, struct radeon_fence, list);
                        fence->signaled = true;
                        i = n;
                } while (i != &rdev->fence_drv.emited);
                wake = true;
        }
        return wake;
}

static void radeon_fence_destroy(struct kref *kref)
{
        unsigned long irq_flags;
        struct radeon_fence *fence;

        fence = container_of(kref, struct radeon_fence, kref);
        write_lock_irqsave(&fence->rdev->fence_drv.lock, irq_flags);
        list_del(&fence->list);
        fence->emited = false;
        write_unlock_irqrestore(&fence->rdev->fence_drv.lock, irq_flags);
        kfree(fence);
}

int radeon_fence_create(struct radeon_device *rdev, struct radeon_fence **fence)
{
        unsigned long irq_flags;

        *fence = kmalloc(sizeof(struct radeon_fence), GFP_KERNEL);
        if ((*fence) == NULL) {
                return -ENOMEM;
        }
        kref_init(&((*fence)->kref));
        (*fence)->rdev = rdev;
        (*fence)->emited = false;
        (*fence)->signaled = false;
        (*fence)->seq = 0;
        INIT_LIST_HEAD(&(*fence)->list);

        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        list_add_tail(&(*fence)->list, &rdev->fence_drv.created);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        return 0;
}


bool radeon_fence_signaled(struct radeon_fence *fence)
{
        struct radeon_device *rdev = fence->rdev;
        unsigned long irq_flags;
        bool signaled = false;

        if (rdev->gpu_lockup) {
                return true;
        }
        if (fence == NULL) {
                return true;
        }
        write_lock_irqsave(&fence->rdev->fence_drv.lock, irq_flags);
        signaled = fence->signaled;
        /* if we are shuting down report all fence as signaled */
        if (fence->rdev->shutdown) {
                signaled = true;
        }
        if (!fence->emited) {
                WARN(1, "Querying an unemited fence : %p !\n", fence);
                signaled = true;
        }
        if (!signaled) {
                radeon_fence_poll_locked(fence->rdev);
                signaled = fence->signaled;
        }
        write_unlock_irqrestore(&fence->rdev->fence_drv.lock, irq_flags);
        return signaled;
}

int r600_fence_wait(struct radeon_fence *fence,  bool intr, bool lazy)
{
        struct radeon_device *rdev;
        int ret = 0;

        rdev = fence->rdev;

        __set_current_state(intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);

        while (1) {
                if (radeon_fence_signaled(fence))
                        break;

                if (time_after_eq(jiffies, fence->timeout)) {
                        ret = -EBUSY;
                        break;
                }

                if (lazy)
                        schedule_timeout(1);

                if (intr && signal_pending(current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
        }
        __set_current_state(TASK_RUNNING);
        return ret;
}


int radeon_fence_wait(struct radeon_fence *fence, bool intr)
{
        struct radeon_device *rdev;
        unsigned long cur_jiffies;
        unsigned long timeout;
        bool expired = false;
        int r;

        if (fence == NULL) {
                WARN(1, "Querying an invalid fence : %p !\n", fence);
                return 0;
        }
        rdev = fence->rdev;
        if (radeon_fence_signaled(fence)) {
                return 0;
        }

        if (rdev->family >= CHIP_R600) {
                r = r600_fence_wait(fence, intr, 0);
                if (r == -ERESTARTSYS)
                        return -EBUSY;
                return r;
        }

retry:
        cur_jiffies = jiffies;
        timeout = HZ / 100;
        if (time_after(fence->timeout, cur_jiffies)) {
                timeout = fence->timeout - cur_jiffies;
        }

        if (intr) {
                r = wait_event_interruptible_timeout(rdev->fence_drv.queue,
                                radeon_fence_signaled(fence), timeout);
                if (unlikely(r == -ERESTARTSYS)) {
                        return -EBUSY;
                }
        } else {
                r = wait_event_timeout(rdev->fence_drv.queue,
                         radeon_fence_signaled(fence), timeout);
        }
        if (unlikely(!radeon_fence_signaled(fence))) {
                if (unlikely(r == 0)) {
                        expired = true;
                }
                if (unlikely(expired)) {
                        timeout = 1;
                        if (time_after(cur_jiffies, fence->timeout)) {
                                timeout = cur_jiffies - fence->timeout;
                        }
                        timeout = jiffies_to_msecs(timeout);
                        if (timeout > 500) {
                                DRM_ERROR("fence(%p:0x%08X) %lums timeout "
                                          "going to reset GPU\n",
                                          fence, fence->seq, timeout);
                                radeon_gpu_reset(rdev);
                                WREG32(rdev->fence_drv.scratch_reg, fence->seq);
                        }
                }
                goto retry;
        }
        if (unlikely(expired)) {
                rdev->fence_drv.count_timeout++;
                cur_jiffies = jiffies;
                timeout = 1;
                if (time_after(cur_jiffies, fence->timeout)) {
                        timeout = cur_jiffies - fence->timeout;
                }
                timeout = jiffies_to_msecs(timeout);
                DRM_ERROR("fence(%p:0x%08X) %lums timeout\n",
                          fence, fence->seq, timeout);
                DRM_ERROR("last signaled fence(0x%08X)\n",
                          rdev->fence_drv.last_seq);
        }
        return 0;
}

int radeon_fence_wait_next(struct radeon_device *rdev)
{
        unsigned long irq_flags;
        struct radeon_fence *fence;
        int r;

        if (rdev->gpu_lockup) {
                return 0;
        }
        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        if (list_empty(&rdev->fence_drv.emited)) {
                write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
                return 0;
        }
        fence = list_entry(rdev->fence_drv.emited.next,
                           struct radeon_fence, list);
        radeon_fence_ref(fence);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        r = radeon_fence_wait(fence, false);
        radeon_fence_unref(&fence);
        return r;
}

int radeon_fence_wait_last(struct radeon_device *rdev)
{
        unsigned long irq_flags;
        struct radeon_fence *fence;
        int r;

        if (rdev->gpu_lockup) {
                return 0;
        }
        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        if (list_empty(&rdev->fence_drv.emited)) {
                write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
                return 0;
        }
        fence = list_entry(rdev->fence_drv.emited.prev,
                           struct radeon_fence, list);
        radeon_fence_ref(fence);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        r = radeon_fence_wait(fence, false);
        radeon_fence_unref(&fence);
        return r;
}

struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
{
        kref_get(&fence->kref);
        return fence;
}

void radeon_fence_unref(struct radeon_fence **fence)
{
        struct radeon_fence *tmp = *fence;

        *fence = NULL;
        if (tmp) {
                kref_put(&tmp->kref, &radeon_fence_destroy);
        }
}

void radeon_fence_process(struct radeon_device *rdev)
{
        unsigned long irq_flags;
        bool wake;

        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        wake = radeon_fence_poll_locked(rdev);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        if (wake) {
                wake_up_all(&rdev->fence_drv.queue);
        }
}

int radeon_fence_driver_init(struct radeon_device *rdev)
{
        unsigned long irq_flags;
        int r;

        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        r = radeon_scratch_get(rdev, &rdev->fence_drv.scratch_reg);
        if (r) {
                DRM_ERROR("Fence failed to get a scratch register.");
                write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
                return r;
        }
        WREG32(rdev->fence_drv.scratch_reg, 0);
        atomic_set(&rdev->fence_drv.seq, 0);
        INIT_LIST_HEAD(&rdev->fence_drv.created);
        INIT_LIST_HEAD(&rdev->fence_drv.emited);
        INIT_LIST_HEAD(&rdev->fence_drv.signaled);
        rdev->fence_drv.count_timeout = 0;
        init_waitqueue_head(&rdev->fence_drv.queue);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        if (radeon_debugfs_fence_init(rdev)) {
                DRM_ERROR("Failed to register debugfs file for fence !\n");
        }
        return 0;
}

void radeon_fence_driver_fini(struct radeon_device *rdev)
{
        unsigned long irq_flags;

        wake_up_all(&rdev->fence_drv.queue);
        write_lock_irqsave(&rdev->fence_drv.lock, irq_flags);
        radeon_scratch_free(rdev, rdev->fence_drv.scratch_reg);
        write_unlock_irqrestore(&rdev->fence_drv.lock, irq_flags);
        DRM_INFO("radeon: fence finalized\n");
}


/*
 * Fence debugfs
 */
#if defined(CONFIG_DEBUG_FS)
static int radeon_debugfs_fence_info(struct seq_file *m, void *data)
{
        struct drm_info_node *node = (struct drm_info_node *)m->private;
        struct drm_device *dev = node->minor->dev;
        struct radeon_device *rdev = dev->dev_private;
        struct radeon_fence *fence;

        seq_printf(m, "Last signaled fence 0x%08X\n",
                   RREG32(rdev->fence_drv.scratch_reg));
        if (!list_empty(&rdev->fence_drv.emited)) {
                   fence = list_entry(rdev->fence_drv.emited.prev,
                                      struct radeon_fence, list);
                   seq_printf(m, "Last emited fence %p with 0x%08X\n",
                              fence,  fence->seq);
        }
        return 0;
}

static struct drm_info_list radeon_debugfs_fence_list[] = {
        {"radeon_fence_info", &radeon_debugfs_fence_info, 0, NULL},
};
#endif

int radeon_debugfs_fence_init(struct radeon_device *rdev)
{
#if defined(CONFIG_DEBUG_FS)
        return radeon_debugfs_add_files(rdev, radeon_debugfs_fence_list, 1);
#else
        return 0;
#endif
}