/*
 * Copyright (C) 2012-2018 Rob Clark <robclark@freedesktop.org>
 *
 * 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, sublicense,
 * 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 above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *    Rob Clark <robclark@freedesktop.org>
 */

#include "util/os_mman.h"

#include "freedreno_drmif.h"
#include "freedreno_priv.h"

simple_mtx_t table_lock = SIMPLE_MTX_INITIALIZER;
simple_mtx_t fence_lock = SIMPLE_MTX_INITIALIZER;

/* set buffer name, and add to table, call w/ table_lock held: */
static void
set_name(struct fd_bo *bo, uint32_t name)
{
   bo->name = name;
   /* add ourself into the handle table: */
   _mesa_hash_table_insert(bo->dev->name_table, &bo->name, bo);
}

static struct fd_bo zombie;

/* lookup a buffer, call w/ table_lock held: */
static struct fd_bo *
lookup_bo(struct hash_table *tbl, uint32_t key)
{
   struct fd_bo *bo = NULL;
   struct hash_entry *entry;

   simple_mtx_assert_locked(&table_lock);

   entry = _mesa_hash_table_search(tbl, &key);
   if (entry) {
      bo = entry->data;

      /* We could be racing with final unref in another thread, and won
       * the table_lock preventing the other thread from being able to
       * remove an object it is about to free.  Fortunately since table
       * lookup and removal are protected by the same lock (and table
       * removal happens before obj free) we can easily detect this by
       * checking for refcnt==0 (ie. 1 after p_atomic_inc_return).
       */
      if (p_atomic_inc_return(&bo->refcnt) == 1) {
         /* Restore the zombified reference count, so if another thread
          * that ends up calling lookup_bo() gets the table_lock before
          * the thread deleting the bo does, it doesn't mistakenly see
          * that the BO is live.
          *
          * We are holding the table_lock here so we can't be racing
          * with another caller of lookup_bo()
          */
         p_atomic_dec(&bo->refcnt);
         return &zombie;
      }

      if (!list_is_empty(&bo->node)) {
         mesa_logw("bo was in cache, size=%u, alloc_flags=0x%x\n",
                   bo->size, bo->alloc_flags);
      }

      /* don't break the bucket if this bo was found in one */
      list_delinit(&bo->node);
   }
   return bo;
}

void
fd_bo_init_common(struct fd_bo *bo, struct fd_device *dev)
{
   /* Backend should have initialized these: */
   assert(bo->size);
   assert(bo->handle);
   assert(bo->funcs);

   bo->dev = dev;
   bo->iova = bo->funcs->iova(bo);
   bo->reloc_flags = FD_RELOC_FLAGS_INIT;

   p_atomic_set(&bo->refcnt, 1);
   list_inithead(&bo->node);

   bo->max_fences = 1;
   bo->fences = &bo->_inline_fence;

   VG_BO_ALLOC(bo);
}

/* allocate a new buffer object, call w/ table_lock held */
static struct fd_bo *
import_bo_from_handle(struct fd_device *dev, uint32_t size, uint32_t handle)
{
   struct fd_bo *bo;

   simple_mtx_assert_locked(&table_lock);

   bo = dev->funcs->bo_from_handle(dev, size, handle);
   if (!bo) {
      struct drm_gem_close req = {
         .handle = handle,
      };
      drmIoctl(dev->fd, DRM_IOCTL_GEM_CLOSE, &req);
      return NULL;
   }

   bo->alloc_flags |= FD_BO_SHARED;

   /* add ourself into the handle table: */
   _mesa_hash_table_insert(dev->handle_table, &bo->handle, bo);

   return bo;
}

static struct fd_bo *
bo_new(struct fd_device *dev, uint32_t size, uint32_t flags,
       struct fd_bo_cache *cache)
{
   struct fd_bo *bo = NULL;

   if (size < FD_BO_HEAP_BLOCK_SIZE) {
      if ((flags == 0) && dev->default_heap)
         return fd_bo_heap_alloc(dev->default_heap, size);
      if ((flags == RING_FLAGS) && dev->ring_heap)
         return fd_bo_heap_alloc(dev->ring_heap, size);
   }

   /* demote cached-coherent to WC if not supported: */
   if ((flags & FD_BO_CACHED_COHERENT) && !dev->has_cached_coherent)
      flags &= ~FD_BO_CACHED_COHERENT;

   bo = fd_bo_cache_alloc(cache, &size, flags);
   if (bo)
      return bo;

   bo = dev->funcs->bo_new(dev, size, flags);
   if (!bo)
      return NULL;

   simple_mtx_lock(&table_lock);
   /* add ourself into the handle table: */
   _mesa_hash_table_insert(dev->handle_table, &bo->handle, bo);
   simple_mtx_unlock(&table_lock);

   bo->alloc_flags = flags;

   return bo;
}

struct fd_bo *
_fd_bo_new(struct fd_device *dev, uint32_t size, uint32_t flags)
{
   struct fd_bo *bo = bo_new(dev, size, flags, &dev->bo_cache);
   if (bo)
      bo->bo_reuse = BO_CACHE;
   return bo;
}

void
_fd_bo_set_name(struct fd_bo *bo, const char *fmt, va_list ap)
{
   bo->funcs->set_name(bo, fmt, ap);
}

/* internal function to allocate bo's that use the ringbuffer cache
 * instead of the normal bo_cache.  The purpose is, because cmdstream
 * bo's get vmap'd on the kernel side, and that is expensive, we want
 * to re-use cmdstream bo's for cmdstream and not unrelated purposes.
 */
struct fd_bo *
fd_bo_new_ring(struct fd_device *dev, uint32_t size)
{
   struct fd_bo *bo = bo_new(dev, size, RING_FLAGS, &dev->ring_cache);
   if (bo) {
      bo->bo_reuse = RING_CACHE;
      bo->reloc_flags |= FD_RELOC_DUMP;
      fd_bo_set_name(bo, "cmdstream");
   }
   return bo;
}

struct fd_bo *
fd_bo_from_handle(struct fd_device *dev, uint32_t handle, uint32_t size)
{
   struct fd_bo *bo = NULL;

   simple_mtx_lock(&table_lock);

   bo = lookup_bo(dev->handle_table, handle);
   if (bo)
      goto out_unlock;

   bo = import_bo_from_handle(dev, size, handle);

   VG_BO_ALLOC(bo);

out_unlock:
   simple_mtx_unlock(&table_lock);

   /* We've raced with the handle being closed, so the handle is no longer
    * valid.  Friends don't let friends share handles.
    */
   if (bo == &zombie)
      return NULL;

   return bo;
}

struct fd_bo *
fd_bo_from_dmabuf(struct fd_device *dev, int fd)
{
   int ret, size;
   uint32_t handle;
   struct fd_bo *bo;

restart:
   simple_mtx_lock(&table_lock);
   ret = drmPrimeFDToHandle(dev->fd, fd, &handle);
   if (ret) {
      simple_mtx_unlock(&table_lock);
      return NULL;
   }

   bo = lookup_bo(dev->handle_table, handle);
   if (bo)
      goto out_unlock;

   /* lseek() to get bo size */
   size = lseek(fd, 0, SEEK_END);
   lseek(fd, 0, SEEK_CUR);

   bo = import_bo_from_handle(dev, size, handle);

   VG_BO_ALLOC(bo);

out_unlock:
   simple_mtx_unlock(&table_lock);

   if (bo == &zombie)
      goto restart;

   return bo;
}

struct fd_bo *
fd_bo_from_name(struct fd_device *dev, uint32_t name)
{
   struct drm_gem_open req = {
      .name = name,
   };
   struct fd_bo *bo;

   simple_mtx_lock(&table_lock);

   /* check name table first, to see if bo is already open: */
   bo = lookup_bo(dev->name_table, name);
   if (bo)
      goto out_unlock;

restart:
   if (drmIoctl(dev->fd, DRM_IOCTL_GEM_OPEN, &req)) {
      ERROR_MSG("gem-open failed: %s", strerror(errno));
      goto out_unlock;
   }

   bo = lookup_bo(dev->handle_table, req.handle);
   if (bo)
      goto out_unlock;

   bo = import_bo_from_handle(dev, req.size, req.handle);
   if (bo) {
      set_name(bo, name);
      VG_BO_ALLOC(bo);
   }

out_unlock:
   simple_mtx_unlock(&table_lock);

   if (bo == &zombie)
      goto restart;

   return bo;
}

void
fd_bo_mark_for_dump(struct fd_bo *bo)
{
   bo->reloc_flags |= FD_RELOC_DUMP;
}

struct fd_bo *
fd_bo_ref(struct fd_bo *bo)
{
   ref(&bo->refcnt);
   return bo;
}

static void
bo_finalize(struct fd_bo *bo)
{
   if (bo->funcs->finalize)
      bo->funcs->finalize(bo);
}

static void
dev_flush(struct fd_device *dev)
{
   if (dev->funcs->flush)
      dev->funcs->flush(dev);
}

static void
bo_del(struct fd_bo *bo)
{
   bo->funcs->destroy(bo);
}

static bool
try_recycle(struct fd_bo *bo)
{
   struct fd_device *dev = bo->dev;

   /* No point in BO cache for suballocated buffers: */
   if (suballoc_bo(bo))
      return false;

   if (bo->bo_reuse == BO_CACHE)
      return fd_bo_cache_free(&dev->bo_cache, bo) == 0;

   if (bo->bo_reuse == RING_CACHE)
      return fd_bo_cache_free(&dev->ring_cache, bo) == 0;

   return false;
}

void
fd_bo_del(struct fd_bo *bo)
{
   if (!unref(&bo->refcnt))
      return;

   if (try_recycle(bo))
      return;

   struct fd_device *dev = bo->dev;

   bo_finalize(bo);
   dev_flush(dev);
   bo_del(bo);
}

void
fd_bo_del_array(struct fd_bo **bos, int count)
{
   if (!count)
      return;

   struct fd_device *dev = bos[0]->dev;

   /*
    * First pass, remove objects from the table that either (a) still have
    * a live reference, or (b) no longer have a reference but are released
    * to the BO cache:
    */

   for (int i = 0; i < count; i++) {
      if (!unref(&bos[i]->refcnt) || try_recycle(bos[i])) {
         bos[i--] = bos[--count];
      } else {
         /* We are going to delete this one, so finalize it first: */
         bo_finalize(bos[i]);
      }
   }

   dev_flush(dev);

   /*
    * Second pass, delete all of the objects remaining after first pass.
    */

   for (int i = 0; i < count; i++) {
      bo_del(bos[i]);
   }
}

/**
 * Special interface for fd_bo_cache to batch delete a list of handles.
 * Similar to fd_bo_del_array() but bypasses the BO cache (since it is
 * called from the BO cache to expire a list of BOs).
 */
void
fd_bo_del_list_nocache(struct list_head *list)
{
   if (list_is_empty(list))
      return;

   struct fd_device *dev = first_bo(list)->dev;

   foreach_bo (bo, list) {
      bo_finalize(bo);
   }

   dev_flush(dev);

   foreach_bo_safe (bo, list) {
      assert(bo->refcnt == 0);
      bo_del(bo);
   }
}

void
fd_bo_fini_fences(struct fd_bo *bo)
{
   for (int i = 0; i < bo->nr_fences; i++)
      fd_fence_del(bo->fences[i]);

   if (bo->fences != &bo->_inline_fence)
      free(bo->fences);
}

/**
 * Helper called by backends bo->funcs->destroy()
 *
 * Called under table_lock, bo_del_flush() *must* be called before
 * table_lock is released (but bo->funcs->destroy() can be called
 * multiple times before bo_del_flush(), as long as table_lock is
 * held the entire time)
 */
void
fd_bo_fini_common(struct fd_bo *bo)
{
   struct fd_device *dev = bo->dev;
   uint32_t handle = bo->handle;

   VG_BO_FREE(bo);

   fd_bo_fini_fences(bo);

   if (bo->map)
      os_munmap(bo->map, bo->size);

   if (handle) {
      simple_mtx_lock(&table_lock);
      struct drm_gem_close req = {
         .handle = handle,
      };
      drmIoctl(dev->fd, DRM_IOCTL_GEM_CLOSE, &req);
      _mesa_hash_table_remove_key(dev->handle_table, &handle);
      if (bo->name)
         _mesa_hash_table_remove_key(dev->name_table, &bo->name);
      simple_mtx_unlock(&table_lock);
   }

   free(bo);
}

static void
bo_flush(struct fd_bo *bo)
{
   MESA_TRACE_FUNC();

   simple_mtx_lock(&fence_lock);
   unsigned nr = bo->nr_fences;
   struct fd_fence *fences[nr];
   for (unsigned i = 0; i < nr; i++)
      fences[i] = fd_fence_ref_locked(bo->fences[i]);
   simple_mtx_unlock(&fence_lock);

   for (unsigned i = 0; i < nr; i++) {
      fd_fence_flush(bo->fences[i]);
      fd_fence_del(fences[i]);
   }
}

int
fd_bo_get_name(struct fd_bo *bo, uint32_t *name)
{
   if (suballoc_bo(bo))
      return -1;

   if (!bo->name) {
      struct drm_gem_flink req = {
         .handle = bo->handle,
      };
      int ret;

      ret = drmIoctl(bo->dev->fd, DRM_IOCTL_GEM_FLINK, &req);
      if (ret) {
         return ret;
      }

      simple_mtx_lock(&table_lock);
      set_name(bo, req.name);
      simple_mtx_unlock(&table_lock);
      bo->bo_reuse = NO_CACHE;
      bo->alloc_flags |= FD_BO_SHARED;
      bo_flush(bo);
   }

   *name = bo->name;

   return 0;
}

uint32_t
fd_bo_handle(struct fd_bo *bo)
{
   if (suballoc_bo(bo))
      return 0;
   bo->bo_reuse = NO_CACHE;
   bo->alloc_flags |= FD_BO_SHARED;
   bo_flush(bo);
   return bo->handle;
}

int
fd_bo_dmabuf(struct fd_bo *bo)
{
   int ret, prime_fd;

   if (suballoc_bo(bo))
      return -1;

   ret = drmPrimeHandleToFD(bo->dev->fd, bo->handle, DRM_CLOEXEC | DRM_RDWR,
                            &prime_fd);
   if (ret) {
      ERROR_MSG("failed to get dmabuf fd: %d", ret);
      return ret;
   }

   bo->bo_reuse = NO_CACHE;
   bo->alloc_flags |= FD_BO_SHARED;
   bo_flush(bo);

   return prime_fd;
}

uint32_t
fd_bo_size(struct fd_bo *bo)
{
   return bo->size;
}

bool
fd_bo_is_cached(struct fd_bo *bo)
{
   return !!(bo->alloc_flags & FD_BO_CACHED_COHERENT);
}

static void *
bo_map(struct fd_bo *bo)
{
   if (!bo->map) {
      uint64_t offset;
      int ret;

      ret = bo->funcs->offset(bo, &offset);
      if (ret) {
         return NULL;
      }

      bo->map = os_mmap(0, bo->size, PROT_READ | PROT_WRITE, MAP_SHARED,
                        bo->dev->fd, offset);
      if (bo->map == MAP_FAILED) {
         ERROR_MSG("mmap failed: %s", strerror(errno));
         bo->map = NULL;
      }
   }
   return bo->map;
}

void *
fd_bo_map(struct fd_bo *bo)
{
   /* don't allow mmap'ing something allocated with FD_BO_NOMAP
    * for sanity
    */
   if (bo->alloc_flags & FD_BO_NOMAP)
      return NULL;

   return bo_map(bo);
}

void
fd_bo_upload(struct fd_bo *bo, void *src, unsigned off, unsigned len)
{
   if (bo->funcs->upload) {
      bo->funcs->upload(bo, src, off, len);
      return;
   }

   memcpy((uint8_t *)bo_map(bo) + off, src, len);
}

bool
fd_bo_prefer_upload(struct fd_bo *bo, unsigned len)
{
   if (bo->funcs->prefer_upload)
      return bo->funcs->prefer_upload(bo, len);

   return false;
}

/* a bit odd to take the pipe as an arg, but it's a, umm, quirk of kgsl.. */
int
fd_bo_cpu_prep(struct fd_bo *bo, struct fd_pipe *pipe, uint32_t op)
{
   enum fd_bo_state state = fd_bo_state(bo);

   if (state == FD_BO_STATE_IDLE)
      return 0;

   MESA_TRACE_FUNC();

   if (op & (FD_BO_PREP_NOSYNC | FD_BO_PREP_FLUSH)) {
      if (op & FD_BO_PREP_FLUSH)
         bo_flush(bo);

      /* If we have *only* been asked to flush, then we aren't really
       * interested about whether shared buffers are busy, so avoid
       * the kernel ioctl.
       */
      if ((state == FD_BO_STATE_BUSY) ||
          (op == FD_BO_PREP_FLUSH))
         return -EBUSY;
   }

   /* In case the bo is referenced by a deferred submit, flush up to the
    * required fence now:
    */
   bo_flush(bo);

   /* FD_BO_PREP_FLUSH is purely a frontend flag, and is not seen/handled
    * by backend or kernel:
    */
   op &= ~FD_BO_PREP_FLUSH;

   if (!op)
      return 0;

   /* Wait on fences.. first grab a reference under the fence lock, and then
    * wait and drop ref.
    */
   simple_mtx_lock(&fence_lock);
   unsigned nr = bo->nr_fences;
   struct fd_fence *fences[nr];
   for (unsigned i = 0; i < nr; i++)
      fences[i] = fd_fence_ref_locked(bo->fences[i]);
   simple_mtx_unlock(&fence_lock);

   for (unsigned i = 0; i < nr; i++) {
      fd_fence_wait(fences[i]);
      fd_fence_del(fences[i]);
   }

   /* expire completed fences */
   fd_bo_state(bo);

   /* None shared buffers will not have any external usage (ie. fences
    * that we are not aware of) so nothing more to do.
    */
   if (!(bo->alloc_flags & FD_BO_SHARED))
      return 0;

   /* If buffer is shared, but we are using explicit sync, no need to
    * fallback to implicit sync:
    */
   if (pipe && pipe->no_implicit_sync)
      return 0;

   return bo->funcs->cpu_prep(bo, pipe, op);
}

/**
 * Cleanup fences, dropping pipe references.  If 'expired' is true, only
 * cleanup expired fences.
 *
 * Normally we expect at most a single fence, the exception being bo's
 * shared between contexts
 */
static void
cleanup_fences(struct fd_bo *bo)
{
   simple_mtx_assert_locked(&fence_lock);

   for (int i = 0; i < bo->nr_fences; i++) {
      struct fd_fence *f = bo->fences[i];

      if (fd_fence_before(f->pipe->control->fence, f->ufence))
         continue;

      bo->nr_fences--;

      if (bo->nr_fences > 0) {
         /* Shuffle up the last entry to replace the current slot: */
         bo->fences[i] = bo->fences[bo->nr_fences];
         i--;
      }

      fd_fence_del_locked(f);
   }
}

void
fd_bo_add_fence(struct fd_bo *bo, struct fd_fence *fence)
{
   simple_mtx_assert_locked(&fence_lock);

   if (bo->alloc_flags & _FD_BO_NOSYNC)
      return;

   /* The common case is bo re-used on the same pipe it had previously
    * been used on, so just replace the previous fence.
    */
   for (int i = 0; i < bo->nr_fences; i++) {
      struct fd_fence *f = bo->fences[i];
      if (f == fence)
         return;
      if (f->pipe == fence->pipe) {
         assert(fd_fence_before(f->ufence, fence->ufence));
         fd_fence_del_locked(f);
         bo->fences[i] = fd_fence_ref_locked(fence);
         return;
      }
   }

   cleanup_fences(bo);

   /* The first time we grow past a single fence, we need some special
    * handling, as we've been using the embedded _inline_fence to avoid
    * a separate allocation:
    */
   if (unlikely((bo->nr_fences == 1) &&
                (bo->fences == &bo->_inline_fence))) {
      bo->nr_fences = bo->max_fences = 0;
      bo->fences = NULL;
      APPEND(bo, fences, bo->_inline_fence);
   }

   APPEND(bo, fences, fd_fence_ref_locked(fence));
}

enum fd_bo_state
fd_bo_state(struct fd_bo *bo)
{
   /* NOTE: check the nosync case before touching fence_lock in case we end
    * up here recursively from dropping pipe reference in cleanup_fences().
    * The pipe's control buffer is specifically nosync to avoid recursive
    * lock problems here.
    */
   if (bo->alloc_flags & (FD_BO_SHARED | _FD_BO_NOSYNC))
      return FD_BO_STATE_UNKNOWN;

   /* Speculatively check, if we already know we're idle, no need to acquire
    * lock and do the cleanup_fences() dance:
    */
   if (!bo->nr_fences)
      return FD_BO_STATE_IDLE;

   simple_mtx_lock(&fence_lock);
   cleanup_fences(bo);
   simple_mtx_unlock(&fence_lock);

   if (!bo->nr_fences)
      return FD_BO_STATE_IDLE;

   return FD_BO_STATE_BUSY;
}