/*
 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 list of buffers that will be used in relocations, and receive the
 * corresponding state buffer object of state (plus associated auxiliary
 * data) in return.
 *
 * The inner workings are a simple hash table based on a CRC of the key data.
 * The cache_id and relocation target buffers associated with the state
 * buffer are included as auxiliary key data, but are not part of the hash
 * value (this should be fixed, but will likely be fixed instead by making
 * consumers use structured keys).
 *
 * Replacement is not implemented.  Instead, when the cache gets too big, at
 * a safe point (unlock) we throw out all of the cache data and let it
 * regenerate for the next rendering operation.
 *
 * The reloc structs need to be included as key data, otherwise the
 * non-unique values stuffed in the offset in key data through
 * brw_cache_data() may result in successful probe for state buffers
 * even when the buffer being referenced doesn't match.  The result would be
 * that the same state cache entry is used twice for different buffers,
 * only one of the two buffers referenced gets put into the offset, and the
 * incorrect program is run for the other instance.
 */
#include "util/u_memory.h"

#include "brw_debug.h"
#include "brw_state.h"

/* XXX: Fixme - have to include these to get the sizes of the prog_key
 * structs:
 */
#include "brw_wm.h"
#include "brw_vs.h"
#include "brw_clip.h"
#include "brw_sf.h"
#include "brw_gs.h"


static GLuint
hash_key(const void *key, GLuint key_size,
         struct brw_winsys_reloc *relocs, GLuint nr_relocs)
{
   GLuint *ikey = (GLuint *)key;
   GLuint hash = 0, i;

   assert(key_size % 4 == 0);

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

   /* Include the BO pointers as key data as well */
   ikey = (GLuint *)relocs;
   key_size = nr_relocs * sizeof(struct brw_winsys_reloc);
   for (i = 0; i < 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,
		  struct brw_winsys_buffer *bo)
{
   if (bo == cache->last_bo[cache_id])
      return; /* no change */

   bo_reference( &cache->last_bo[cache_id],  bo );

   cache->brw->state.dirty.cache |= 1 << cache_id;
}


static struct brw_cache_item *
search_cache(struct brw_cache *cache, enum brw_cache_id cache_id,
	     GLuint hash, const void *key, GLuint key_size,
	     struct brw_winsys_reloc *relocs, GLuint nr_relocs)
{
   struct brw_cache_item *c;

#if 0
   int bucketcount = 0;

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

   debug_printf("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 (c->cache_id == cache_id &&
	  c->hash == hash &&
	  c->key_size == key_size &&
	  memcmp(c->key, key, key_size) == 0 &&
	  c->nr_relocs == nr_relocs &&
	  memcmp(c->relocs, relocs, nr_relocs * sizeof *relocs) == 0)
	 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(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.
 */
boolean
brw_search_cache(struct brw_cache *cache,
                 enum brw_cache_id cache_id,
                 const void *key,
                 GLuint key_size,
                 struct brw_winsys_reloc *relocs, 
		 GLuint nr_relocs,
                 void *aux_return,
                 struct brw_winsys_buffer **bo_out)
{
   struct brw_cache_item *item;
   GLuint hash = hash_key(key, key_size, relocs, nr_relocs);

   item = search_cache(cache, cache_id, hash, key, key_size,
		       relocs, nr_relocs);

   if (item) {
      if (aux_return)
         *(void **)aux_return = (void *)((char *)item->key + item->key_size);
      
      update_cache_last(cache, cache_id, item->bo);
      bo_reference(bo_out, item->bo);
      return TRUE;
   }
   
   return FALSE;      
}


enum pipe_error
brw_upload_cache( struct brw_cache *cache,
		  enum brw_cache_id cache_id,
		  const void *key,
		  GLuint key_size,
		  struct brw_winsys_reloc *relocs,
		  GLuint nr_relocs,
		  const void *data,
		  GLuint data_size,
		  const void *aux,
		  void *aux_return,
                  struct brw_winsys_buffer **bo_out)
{
   struct brw_cache_item *item;
   GLuint hash = hash_key(key, key_size, relocs, nr_relocs);
   GLuint relocs_size = nr_relocs * sizeof relocs[0];
   GLuint aux_size = cache->aux_size[cache_id];
   enum pipe_error ret;
   void *tmp;
   int i;

   /* Create the buffer object to contain the data.  For now, use a
    * single buffer type to describe all cached state atoms.  Later,
    * may want to take advantage of hardware distinctions between
    * these various entities.
    */
   ret = cache->sws->bo_alloc(cache->sws,
                              cache->buffer_type,
                              data_size, 1 << 6, 
                              bo_out);
   if (ret)
      return ret;

   item = CALLOC_STRUCT(brw_cache_item);

   /* Set up the memory containing the key, aux_data, and relocs */
   tmp = MALLOC(key_size + aux_size + relocs_size);

   memcpy(tmp, key, key_size);
   memcpy((char *)tmp + key_size, aux, cache->aux_size[cache_id]);
   memcpy((char *)tmp + key_size + aux_size, relocs, relocs_size);
   for (i = 0; i < nr_relocs; i++) {
      p_atomic_inc(&relocs[i].bo->reference.count);
   }

   item->cache_id = cache_id;
   item->key = tmp;
   item->hash = hash;
   item->key_size = key_size;
   item->relocs = (struct brw_winsys_reloc *)((char *)tmp + key_size + aux_size);
   item->nr_relocs = nr_relocs;
   bo_reference( &item->bo, *bo_out );
   item->data_size = data_size;

   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) {
      assert(cache->aux_size[cache_id]);
      *(void **)aux_return = (void *)((char *)item->key + item->key_size);
   }

   if (BRW_DEBUG & DEBUG_STATE)
      debug_printf("upload %s: %d bytes to cache id %d\n",
		   cache->name[cache_id],
		   data_size, cache_id);

   /* Copy data to the buffer */
   ret = cache->sws->bo_subdata(item->bo, 
                                cache_id,
                                0, data_size, data,
                                relocs, nr_relocs);
   if (ret)
      return ret;

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

   return PIPE_OK;
}


/**
 * This doesn't really work with aux data.  Use search/upload instead
 */
enum pipe_error
brw_cache_data_sz(struct brw_cache *cache,
		  enum brw_cache_id cache_id,
		  const void *data,
		  GLuint data_size,
		  struct brw_winsys_reloc *relocs,
		  GLuint nr_relocs,
                  struct brw_winsys_buffer **bo_out)
{
   struct brw_cache_item *item;
   GLuint hash = hash_key(data, data_size, relocs, nr_relocs);

   item = search_cache(cache, cache_id, hash, data, data_size,
		       relocs, nr_relocs);
   if (item) {
      update_cache_last(cache, cache_id, item->bo);

      bo_reference(bo_out, item->bo);
      return PIPE_OK;
   }

   return brw_upload_cache(cache, cache_id,
                           data, data_size,
                           relocs, nr_relocs,
                           data, data_size,
                           NULL, NULL,
                           bo_out);
}


/**
 * Wrapper around brw_cache_data_sz using the cache_id's canonical key size.
 *
 * If nr_relocs is nonzero, brw_search_cache()/brw_upload_cache() would be
 * better to use, as the potentially changing offsets in the data-used-as-key
 * will result in excessive cache misses.
 * 
 * XXX: above is no longer true -- can we remove some code?
 */
enum pipe_error
brw_cache_data(struct brw_cache *cache,
	       enum brw_cache_id cache_id,
	       const void *data,
	       struct brw_winsys_reloc *relocs,
	       GLuint nr_relocs,
               struct brw_winsys_buffer **bo_out)
{
   return brw_cache_data_sz(cache, cache_id, data, cache->key_size[cache_id],
			    relocs, nr_relocs, bo_out);
}


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


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

   cache->brw = brw;
   cache->sws = brw->sws;

   cache->buffer_type = BRW_BUFFER_TYPE_GENERAL_STATE;

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

   brw_init_cache_id(cache,
		     "CC_VP",
		     BRW_CC_VP,
		     sizeof(struct brw_cc_viewport),
		     0);

   brw_init_cache_id(cache,
		     "CC_UNIT",
		     BRW_CC_UNIT,
		     sizeof(struct brw_cc_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "WM_PROG",
		     BRW_WM_PROG,
		     sizeof(struct brw_wm_prog_key),
		     sizeof(struct brw_wm_prog_data));

   brw_init_cache_id(cache,
		     "SAMPLER_DEFAULT_COLOR",
		     BRW_SAMPLER_DEFAULT_COLOR,
		     sizeof(struct brw_sampler_default_color),
		     0);

   brw_init_cache_id(cache,
		     "SAMPLER",
		     BRW_SAMPLER,
		     0,		/* variable key/data size */
		     0);

   brw_init_cache_id(cache,
		     "WM_UNIT",
		     BRW_WM_UNIT,
		     sizeof(struct brw_wm_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "SF_PROG",
		     BRW_SF_PROG,
		     sizeof(struct brw_sf_prog_key),
		     sizeof(struct brw_sf_prog_data));

   brw_init_cache_id(cache,
		     "SF_VP",
		     BRW_SF_VP,
		     sizeof(struct brw_sf_viewport),
		     0);

   brw_init_cache_id(cache,
		     "SF_UNIT",
		     BRW_SF_UNIT,
		     sizeof(struct brw_sf_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "VS_UNIT",
		     BRW_VS_UNIT,
		     sizeof(struct brw_vs_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "VS_PROG",
		     BRW_VS_PROG,
		     sizeof(struct brw_vs_prog_key),
		     sizeof(struct brw_vs_prog_data));

   brw_init_cache_id(cache,
		     "CLIP_UNIT",
		     BRW_CLIP_UNIT,
		     sizeof(struct brw_clip_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "CLIP_PROG",
		     BRW_CLIP_PROG,
		     sizeof(struct brw_clip_prog_key),
		     sizeof(struct brw_clip_prog_data));

   brw_init_cache_id(cache,
		     "GS_UNIT",
		     BRW_GS_UNIT,
		     sizeof(struct brw_gs_unit_state),
		     0);

   brw_init_cache_id(cache,
		     "GS_PROG",
		     BRW_GS_PROG,
		     sizeof(struct brw_gs_prog_key),
		     sizeof(struct brw_gs_prog_data));
}


static void
brw_init_surface_state_cache(struct brw_context *brw)
{
   struct brw_cache *cache = &brw->surface_cache;

   cache->brw = brw;
   cache->sws = brw->sws;

   cache->buffer_type = BRW_BUFFER_TYPE_SURFACE_STATE;

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

   brw_init_cache_id(cache,
		     "SS_SURFACE",
		     BRW_SS_SURFACE,
		     sizeof(struct brw_surface_state),
		     0);

   brw_init_cache_id(cache,
		     "SS_SURF_BIND",
		     BRW_SS_SURF_BIND,
		     0,
		     0);
}


void
brw_init_caches(struct brw_context *brw)
{
   brw_init_general_state_cache(brw);
   brw_init_surface_state_cache(brw);
}


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

   if (BRW_DEBUG & DEBUG_STATE)
      debug_printf("%s\n", __FUNCTION__);

   for (i = 0; i < cache->size; i++) {
      for (c = cache->items[i]; c; c = next) {
	 int j;

	 next = c->next;

	 for (j = 0; j < c->nr_relocs; j++)
	    bo_reference(&c->relocs[j].bo, NULL);

	 bo_reference(&c->bo, NULL);
	 FREE((void *)c->key);
	 FREE(c);
      }
      cache->items[i] = NULL;
   }

   cache->n_items = 0;

   if (brw->curbe.last_buf) {
      FREE(brw->curbe.last_buf);
      brw->curbe.last_buf = NULL;
   }

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

/* Clear all entries from the cache that point to the given bo.
 *
 * This lets us release memory for reuse earlier for known-dead buffers,
 * at the cost of walking the entire hash table.
 */
void
brw_state_cache_bo_delete(struct brw_cache *cache, struct brw_winsys_buffer *bo)
{
   struct brw_cache_item **prev;
   GLuint i;

   if (BRW_DEBUG & DEBUG_STATE)
      debug_printf("%s\n", __FUNCTION__);

   for (i = 0; i < cache->size; i++) {
      for (prev = &cache->items[i]; *prev;) {
	 struct brw_cache_item *c = *prev;

	 if (cache->sws->bo_references(c->bo, bo)) {
	    int j;

	    *prev = c->next;

	    for (j = 0; j < c->nr_relocs; j++)
	       bo_reference(&c->relocs[j].bo, NULL);

	    bo_reference(&c->bo, NULL);

	    FREE((void *)c->key);
	    FREE(c);
	    cache->n_items--;
	 } else {
	    prev = &c->next;
	 }
      }
   }
}

void
brw_state_cache_check_size(struct brw_context *brw)
{
   if (BRW_DEBUG & DEBUG_STATE)
      debug_printf("%s (n_items=%d)\n", __FUNCTION__, brw->cache.n_items);

   /* un-tuned guess.  We've got around 20 state objects for a total of around
    * 32k, so 1000 of them is around 1.5MB.
    */
   if (brw->cache.n_items > 1000)
      brw_clear_cache(brw, &brw->cache);

   if (brw->surface_cache.n_items > 1000)
      brw_clear_cache(brw, &brw->surface_cache);
}


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

   if (BRW_DEBUG & DEBUG_STATE)
      debug_printf("%s\n", __FUNCTION__);

   brw_clear_cache(brw, cache);
   for (i = 0; i < BRW_MAX_CACHE; i++) {
      bo_reference(&cache->last_bo[i], NULL);
      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);
   brw_destroy_cache(brw, &brw->surface_cache);
}