/*
 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
 Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
 develop this 3D driver.
 
 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 COPYRIGHT OWNER(S) 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.
 
 **********************************************************************/
 /*
  * Authors:
  *   Keith Whitwell <keith@tungstengraphics.com>
  */

/** @file brw_state_cache.c
 *
 * This file implements a simple static state cache for 965.  The
 * consumers can query the hash table of state using a cache_id,
 * opaque key data, and receive the corresponding state buffer object
 * of state (plus associated auxiliary data) in return.  Objects in
 * the cache may not have relocations (pointers to other BOs) in them.
 *
 * The inner workings are a simple hash table based on a CRC of the
 * key data.
 *
 * Replacement is not implemented.  Instead, when the cache gets too
 * big we throw out all of the cache data and let it get regenerated.
 */

#include "main/imports.h"
#include "brw_state.h"

#define FILE_DEBUG_FLAG DEBUG_STATE

static GLuint
hash_key(struct brw_cache_item *item)
{
   GLuint *ikey = (GLuint *)item->key;
   GLuint hash = item->cache_id, i;

   assert(item->key_size % 4 == 0);

   /* I'm sure this can be improved on:
    */
   for (i = 0; i < item->key_size/4; i++) {
      hash ^= ikey[i];
      hash = (hash << 5) | (hash >> 27);
   }

   return hash;
}


/**
 * Marks a new buffer as being chosen for the given cache id.
 */
static void
update_cache_last(struct brw_cache *cache, enum brw_cache_id cache_id,
		  drm_intel_bo *bo)
{
   if (bo == cache->last_bo[cache_id])
      return; /* no change */

   drm_intel_bo_unreference(cache->last_bo[cache_id]);
   cache->last_bo[cache_id] = bo;
   drm_intel_bo_reference(cache->last_bo[cache_id]);
   cache->brw->state.dirty.cache |= 1 << cache_id;
}

static int
brw_cache_item_equals(const struct brw_cache_item *a,
		      const struct brw_cache_item *b)
{
   return a->cache_id == b->cache_id &&
      a->hash == b->hash &&
      a->key_size == b->key_size &&
      (memcmp(a->key, b->key, a->key_size) == 0);
}

static struct brw_cache_item *
search_cache(struct brw_cache *cache, GLuint hash,
	     struct brw_cache_item *lookup)
{
   struct brw_cache_item *c;

#if 0
   int bucketcount = 0;

   for (c = cache->items[hash % cache->size]; c; c = c->next)
      bucketcount++;

   fprintf(stderr, "bucket %d/%d = %d/%d items\n", hash % cache->size,
	   cache->size, bucketcount, cache->n_items);
#endif

   for (c = cache->items[hash % cache->size]; c; c = c->next) {
      if (brw_cache_item_equals(lookup, c))
	 return c;
   }

   return NULL;
}


static void
rehash(struct brw_cache *cache)
{
   struct brw_cache_item **items;
   struct brw_cache_item *c, *next;
   GLuint size, i;

   size = cache->size * 3;
   items = (struct brw_cache_item**) calloc(1, size * sizeof(*items));

   for (i = 0; i < cache->size; i++)
      for (c = cache->items[i]; c; c = next) {
	 next = c->next;
	 c->next = items[c->hash % size];
	 items[c->hash % size] = c;
      }

   FREE(cache->items);
   cache->items = items;
   cache->size = size;
}


/**
 * Returns the buffer object matching cache_id and key, or NULL.
 */
drm_intel_bo *
brw_search_cache(struct brw_cache *cache,
                 enum brw_cache_id cache_id,
                 const void *key, GLuint key_size,
                 void *aux_return)
{
   struct brw_cache_item *item;
   struct brw_cache_item lookup;
   GLuint hash;

   lookup.cache_id = cache_id;
   lookup.key = key;
   lookup.key_size = key_size;
   hash = hash_key(&lookup);
   lookup.hash = hash;

   item = search_cache(cache, hash, &lookup);

   if (item == NULL)
      return NULL;

   if (aux_return)
      *(void **)aux_return = (void *)((char *)item->key + item->key_size);

   update_cache_last(cache, cache_id, item->bo);

   drm_intel_bo_reference(item->bo);
   return item->bo;
}


drm_intel_bo *
brw_upload_cache(struct brw_cache *cache,
		 enum brw_cache_id cache_id,
		 const void *key,
		 GLuint key_size,
		 const void *data,
		 GLuint data_size,
		 const void *aux,
		 GLuint aux_size,
		 void *aux_return)
{
   struct brw_cache_item *item = CALLOC_STRUCT(brw_cache_item);
   GLuint hash;
   void *tmp;
   drm_intel_bo *bo;

   item->cache_id = cache_id;
   item->key = key;
   item->key_size = key_size;
   hash = hash_key(item);
   item->hash = hash;

   /* Create the buffer object to contain the data */
   bo = drm_intel_bo_alloc(cache->brw->intel.bufmgr,
			   cache->name[cache_id], data_size, 1 << 6);


   /* Set up the memory containing the key and aux_data */
   tmp = malloc(key_size + aux_size);

   memcpy(tmp, key, key_size);
   memcpy(tmp + key_size, aux, aux_size);

   item->key = tmp;

   item->bo = bo;
   drm_intel_bo_reference(bo);

   if (cache->n_items > cache->size * 1.5)
      rehash(cache);

   hash %= cache->size;
   item->next = cache->items[hash];
   cache->items[hash] = item;
   cache->n_items++;

   if (aux_return) {
      *(void **)aux_return = (void *)((char *)item->key + item->key_size);
   }

   DBG("upload %s: %d bytes to cache id %d\n",
       cache->name[cache_id],
       data_size, cache_id);

   /* Copy data to the buffer */
   drm_intel_bo_subdata(bo, 0, data_size, data);

   update_cache_last(cache, cache_id, bo);

   return bo;
}

static void
brw_init_cache_id(struct brw_cache *cache,
                  const char *name,
                  enum brw_cache_id id)
{
   cache->name[id] = strdup(name);
}


void
brw_init_caches(struct brw_context *brw)
{
   struct brw_cache *cache = &brw->cache;

   cache->brw = brw;

   cache->size = 7;
   cache->n_items = 0;
   cache->items = (struct brw_cache_item **)
      calloc(1, cache->size * sizeof(struct brw_cache_item));

   brw_init_cache_id(cache, "CC_VP", BRW_CC_VP);
   brw_init_cache_id(cache, "CC_UNIT", BRW_CC_UNIT);
   brw_init_cache_id(cache, "WM_PROG", BRW_WM_PROG);
   brw_init_cache_id(cache, "SAMPLER", BRW_SAMPLER);
   brw_init_cache_id(cache, "WM_UNIT", BRW_WM_UNIT);
   brw_init_cache_id(cache, "SF_PROG", BRW_SF_PROG);
   brw_init_cache_id(cache, "SF_VP", BRW_SF_VP);

   brw_init_cache_id(cache, "SF_UNIT", BRW_SF_UNIT);

   brw_init_cache_id(cache, "VS_UNIT", BRW_VS_UNIT);

   brw_init_cache_id(cache, "VS_PROG", BRW_VS_PROG);

   brw_init_cache_id(cache, "CLIP_UNIT", BRW_CLIP_UNIT);

   brw_init_cache_id(cache, "CLIP_PROG", BRW_CLIP_PROG);
   brw_init_cache_id(cache, "CLIP_VP", BRW_CLIP_VP);

   brw_init_cache_id(cache, "GS_UNIT", BRW_GS_UNIT);

   brw_init_cache_id(cache, "GS_PROG", BRW_GS_PROG);
   brw_init_cache_id(cache, "BLEND_STATE", BRW_BLEND_STATE);
   brw_init_cache_id(cache, "COLOR_CALC_STATE", BRW_COLOR_CALC_STATE);
   brw_init_cache_id(cache, "DEPTH_STENCIL_STATE", BRW_DEPTH_STENCIL_STATE);
}

static void
brw_clear_cache(struct brw_context *brw, struct brw_cache *cache)
{
   struct brw_cache_item *c, *next;
   GLuint i;

   DBG("%s\n", __FUNCTION__);

   for (i = 0; i < cache->size; i++) {
      for (c = cache->items[i]; c; c = next) {
	 next = c->next;
	 drm_intel_bo_unreference(c->bo);
	 free((void *)c->key);
	 free(c);
      }
      cache->items[i] = NULL;
   }

   cache->n_items = 0;

   brw->state.dirty.mesa |= ~0;
   brw->state.dirty.brw |= ~0;
   brw->state.dirty.cache |= ~0;
}

void
brw_state_cache_check_size(struct brw_context *brw)
{
   /* un-tuned guess.  Each object is generally a page, so 1000 of them is 4 MB of
    * state cache.
    */
   if (brw->cache.n_items > 1000)
      brw_clear_cache(brw, &brw->cache);
}


static void
brw_destroy_cache(struct brw_context *brw, struct brw_cache *cache)
{
   GLuint i;

   DBG("%s\n", __FUNCTION__);

   brw_clear_cache(brw, cache);
   for (i = 0; i < BRW_MAX_CACHE; i++) {
      drm_intel_bo_unreference(cache->last_bo[i]);
      free(cache->name[i]);
   }
   free(cache->items);
   cache->items = NULL;
   cache->size = 0;
}


void
brw_destroy_caches(struct brw_context *brw)
{
   brw_destroy_cache(brw, &brw->cache);
}
