/**************************************************************************
 *
 * Copyright 2009, VMware, Inc.
 * All Rights Reserved.
 * Copyright 2010 George Sapountzis <gsapountzis@gmail.com>
 *           2013 Red Hat, Inc.
 *
 * 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 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE 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.
 *
 **************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <limits.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <xf86drm.h>

#include "pipe/p_compiler.h"
#include "util/format/u_formats.h"
#include "pipe/p_state.h"
#include "util/u_inlines.h"
#include "util/format/u_format.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#include "util/list.h"

#include "frontend/sw_winsys.h"
#include "frontend/drm_driver.h"
#include "kms_dri_sw_winsys.h"

#include "util/simple_mtx.h"

#ifdef DEBUG
#define DEBUG_PRINT(msg, ...) fprintf(stderr, msg, __VA_ARGS__)
#else
#define DEBUG_PRINT(msg, ...)
#endif

struct kms_sw_displaytarget;

struct kms_sw_plane
{
   unsigned width;
   unsigned height;
   unsigned stride;
   unsigned offset;
   struct kms_sw_displaytarget *dt;
   struct list_head link;
};

struct kms_sw_displaytarget
{
   enum pipe_format format;
   unsigned size;

   uint32_t handle;
   void *mapped;
   void *ro_mapped;

   int ref_count;
   int map_count;
   struct list_head link;
   struct list_head planes;
   mtx_t map_lock;
};

struct kms_sw_winsys
{
   struct sw_winsys base;

   int fd;
   struct list_head bo_list;
};

static inline struct kms_sw_plane *
kms_sw_plane( struct sw_displaytarget *dt )
{
   return (struct kms_sw_plane *)dt;
}

static inline struct sw_displaytarget *
sw_displaytarget( struct kms_sw_plane *pl)
{
   return (struct sw_displaytarget *)pl;
}

static inline struct kms_sw_winsys *
kms_sw_winsys( struct sw_winsys *ws )
{
   return (struct kms_sw_winsys *)ws;
}


static bool
kms_sw_is_displaytarget_format_supported( struct sw_winsys *ws,
                                          unsigned tex_usage,
                                          enum pipe_format format )
{
   /* TODO: check visuals or other sensible thing here */
   return true;
}

static struct kms_sw_plane *get_plane(struct kms_sw_displaytarget *kms_sw_dt,
                                      enum pipe_format format,
                                      unsigned width, unsigned height,
                                      unsigned stride, unsigned offset)
{
   struct kms_sw_plane *plane = NULL;

   if (offset + util_format_get_2d_size(format, stride, height) >
       kms_sw_dt->size) {
      DEBUG_PRINT("KMS-DEBUG: plane too big. format: %d stride: %d height: %d "
                  "offset: %d size:%d\n", format, stride, height, offset,
                  kms_sw_dt->size);
      return NULL;
   }

   LIST_FOR_EACH_ENTRY(plane, &kms_sw_dt->planes, link) {
      if (plane->offset == offset)
         return plane;
   }

   plane = CALLOC_STRUCT(kms_sw_plane);
   if (!plane)
      return NULL;

   plane->width = width;
   plane->height = height;
   plane->stride = stride;
   plane->offset = offset;
   plane->dt = kms_sw_dt;
   list_add(&plane->link, &kms_sw_dt->planes);
   return plane;
}

static struct sw_displaytarget *
kms_sw_displaytarget_create(struct sw_winsys *ws,
                            unsigned tex_usage,
                            enum pipe_format format,
                            unsigned width, unsigned height,
                            unsigned alignment,
                            const void *front_private,
                            unsigned *stride)
{
   struct kms_sw_winsys *kms_sw = kms_sw_winsys(ws);
   struct kms_sw_displaytarget *kms_sw_dt;
   struct drm_mode_create_dumb create_req;
   struct drm_mode_destroy_dumb destroy_req;
   int ret;

   kms_sw_dt = CALLOC_STRUCT(kms_sw_displaytarget);
   if (!kms_sw_dt)
      goto no_dt;

   list_inithead(&kms_sw_dt->planes);
   kms_sw_dt->ref_count = 1;
   kms_sw_dt->mapped = MAP_FAILED;
   kms_sw_dt->ro_mapped = MAP_FAILED;

   kms_sw_dt->format = format;

   mtx_init(&kms_sw_dt->map_lock, mtx_plain);

   memset(&create_req, 0, sizeof(create_req));
   create_req.bpp = util_format_get_blocksizebits(format);
   create_req.width = width;
   create_req.height = height;
   ret = drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_req);
   if (ret) {
      fprintf(stderr, "KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: %s\n", strerror(errno));
      goto free_bo;
   }

   kms_sw_dt->size = create_req.size;
   kms_sw_dt->handle = create_req.handle;
   struct kms_sw_plane *plane = get_plane(kms_sw_dt, format, width, height,
                                          create_req.pitch, 0);
   if (!plane)
      goto free_bo;

   list_add(&kms_sw_dt->link, &kms_sw->bo_list);

   DEBUG_PRINT("KMS-DEBUG: created buffer %u (size %u)\n", kms_sw_dt->handle, kms_sw_dt->size);

   *stride = create_req.pitch;
   return sw_displaytarget(plane);

 free_bo:
   memset(&destroy_req, 0, sizeof destroy_req);
   destroy_req.handle = create_req.handle;
   drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_req);
   FREE(kms_sw_dt);
 no_dt:
   return NULL;
}

static void
kms_sw_displaytarget_destroy(struct sw_winsys *ws,
                             struct sw_displaytarget *dt)
{
   struct kms_sw_winsys *kms_sw = kms_sw_winsys(ws);
   struct kms_sw_plane *plane = kms_sw_plane(dt);
   struct kms_sw_displaytarget *kms_sw_dt = plane->dt;
   struct drm_mode_destroy_dumb destroy_req;

   kms_sw_dt->ref_count --;
   if (kms_sw_dt->ref_count > 0)
      return;

   if (kms_sw_dt->map_count > 0) {
      DEBUG_PRINT("KMS-DEBUG: leaked map buffer %u\n", kms_sw_dt->handle);
   }

   memset(&destroy_req, 0, sizeof destroy_req);
   destroy_req.handle = kms_sw_dt->handle;
   drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_req);

   list_del(&kms_sw_dt->link);

   mtx_destroy(&kms_sw_dt->map_lock);
   DEBUG_PRINT("KMS-DEBUG: destroyed buffer %u\n", kms_sw_dt->handle);

   struct kms_sw_plane *tmp;
   LIST_FOR_EACH_ENTRY_SAFE(plane, tmp, &kms_sw_dt->planes, link) {
      FREE(plane);
   }

   FREE(kms_sw_dt);
}

static void *
kms_sw_displaytarget_map(struct sw_winsys *ws,
                         struct sw_displaytarget *dt,
                         unsigned flags)
{
   struct kms_sw_winsys *kms_sw = kms_sw_winsys(ws);
   struct kms_sw_plane *plane = kms_sw_plane(dt);
   struct kms_sw_displaytarget *kms_sw_dt = plane->dt;
   struct drm_mode_map_dumb map_req;
   int prot, ret;

   mtx_lock(&kms_sw_dt->map_lock);
   memset(&map_req, 0, sizeof map_req);
   map_req.handle = kms_sw_dt->handle;
   ret = drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_MAP_DUMB, &map_req);
   if (ret)
      goto fail_locked;

   prot = (flags == PIPE_MAP_READ) ? PROT_READ : (PROT_READ | PROT_WRITE);
   void **ptr = (flags == PIPE_MAP_READ) ? &kms_sw_dt->ro_mapped : &kms_sw_dt->mapped;
   if (*ptr == MAP_FAILED) {
      void *tmp = mmap(NULL, kms_sw_dt->size, prot, MAP_SHARED,
                       kms_sw->fd, map_req.offset);
      if (tmp == MAP_FAILED)
         goto fail_locked;
      *ptr = tmp;
   }

   DEBUG_PRINT("KMS-DEBUG: mapped buffer %u (size %u) at %p\n",
         kms_sw_dt->handle, kms_sw_dt->size, *ptr);

   kms_sw_dt->map_count++;

   mtx_unlock(&kms_sw_dt->map_lock);

   return *ptr + plane->offset;
fail_locked:
   mtx_unlock(&kms_sw_dt->map_lock);
   return NULL;
}

static struct kms_sw_displaytarget *
kms_sw_displaytarget_find_and_ref(struct kms_sw_winsys *kms_sw,
                                  unsigned int kms_handle)
{
   struct kms_sw_displaytarget *kms_sw_dt;

   LIST_FOR_EACH_ENTRY(kms_sw_dt, &kms_sw->bo_list, link) {
      if (kms_sw_dt->handle == kms_handle) {
         kms_sw_dt->ref_count++;

         DEBUG_PRINT("KMS-DEBUG: imported buffer %u (size %u)\n",
                     kms_sw_dt->handle, kms_sw_dt->size);

         return kms_sw_dt;
      }
   }

   return NULL;
}

static struct kms_sw_plane *
kms_sw_displaytarget_add_from_prime(struct kms_sw_winsys *kms_sw, int fd,
                                    enum pipe_format format,
                                    unsigned width, unsigned height,
                                    unsigned stride, unsigned offset)
{
   uint32_t handle = -1;
   struct kms_sw_displaytarget * kms_sw_dt;
   int ret;

   ret = drmPrimeFDToHandle(kms_sw->fd, fd, &handle);

   if (ret)
      return NULL;

   kms_sw_dt = kms_sw_displaytarget_find_and_ref(kms_sw, handle);
   struct kms_sw_plane *plane = NULL;
   if (kms_sw_dt) {
      plane = get_plane(kms_sw_dt, format, width, height, stride, offset);
      if (!plane)
        kms_sw_dt->ref_count --;
      return plane;
   }

   kms_sw_dt = CALLOC_STRUCT(kms_sw_displaytarget);
   if (!kms_sw_dt)
      return NULL;

   list_inithead(&kms_sw_dt->planes);
   off_t lseek_ret = lseek(fd, 0, SEEK_END);
   if (lseek_ret == -1) {
      FREE(kms_sw_dt);
      return NULL;
   }
   kms_sw_dt->mapped = MAP_FAILED;
   kms_sw_dt->ro_mapped = MAP_FAILED;
   kms_sw_dt->size = lseek_ret;
   kms_sw_dt->ref_count = 1;
   kms_sw_dt->handle = handle;

   lseek(fd, 0, SEEK_SET);
   plane = get_plane(kms_sw_dt, format, width, height, stride, offset);
   if (!plane) {
      FREE(kms_sw_dt);
      return NULL;
   }

   list_add(&kms_sw_dt->link, &kms_sw->bo_list);

   return plane;
}

static void
kms_sw_displaytarget_unmap(struct sw_winsys *ws,
                           struct sw_displaytarget *dt)
{
   struct kms_sw_plane *plane = kms_sw_plane(dt);
   struct kms_sw_displaytarget *kms_sw_dt = plane->dt;

   mtx_lock(&kms_sw_dt->map_lock);
   if (!kms_sw_dt->map_count)  {
      DEBUG_PRINT("KMS-DEBUG: ignore duplicated unmap %u", kms_sw_dt->handle);
      mtx_unlock(&kms_sw_dt->map_lock);
      return;
   }
   kms_sw_dt->map_count--;
   if (kms_sw_dt->map_count) {
      DEBUG_PRINT("KMS-DEBUG: ignore unmap for busy buffer %u", kms_sw_dt->handle);
      mtx_unlock(&kms_sw_dt->map_lock);
      return;
   }

   DEBUG_PRINT("KMS-DEBUG: unmapped buffer %u (was %p)\n", kms_sw_dt->handle, kms_sw_dt->mapped);
   DEBUG_PRINT("KMS-DEBUG: unmapped buffer %u (was %p)\n", kms_sw_dt->handle, kms_sw_dt->ro_mapped);

   if (kms_sw_dt->mapped != MAP_FAILED) {
      munmap(kms_sw_dt->mapped, kms_sw_dt->size);
      kms_sw_dt->mapped = MAP_FAILED;
   }
   if (kms_sw_dt->ro_mapped != MAP_FAILED) {
      munmap(kms_sw_dt->ro_mapped, kms_sw_dt->size);
      kms_sw_dt->ro_mapped = MAP_FAILED;
   }
   mtx_unlock(&kms_sw_dt->map_lock);
}

static struct sw_displaytarget *
kms_sw_displaytarget_from_handle(struct sw_winsys *ws,
                                 const struct pipe_resource *templ,
                                 struct winsys_handle *whandle,
                                 unsigned *stride)
{
   struct kms_sw_winsys *kms_sw = kms_sw_winsys(ws);
   struct kms_sw_displaytarget *kms_sw_dt;
   struct kms_sw_plane *kms_sw_pl;


   assert(whandle->type == WINSYS_HANDLE_TYPE_KMS ||
          whandle->type == WINSYS_HANDLE_TYPE_FD);

   switch(whandle->type) {
   case WINSYS_HANDLE_TYPE_FD:
      kms_sw_pl = kms_sw_displaytarget_add_from_prime(kms_sw, whandle->handle,
                                                      templ->format,
                                                      templ->width0,
                                                      templ->height0,
                                                      whandle->stride,
                                                      whandle->offset);
      if (kms_sw_pl)
         *stride = kms_sw_pl->stride;
      return sw_displaytarget(kms_sw_pl);
   case WINSYS_HANDLE_TYPE_KMS:
      kms_sw_dt = kms_sw_displaytarget_find_and_ref(kms_sw, whandle->handle);
      if (kms_sw_dt) {
         struct kms_sw_plane *plane;
         LIST_FOR_EACH_ENTRY(plane, &kms_sw_dt->planes, link) {
            if (whandle->offset == plane->offset) {
               *stride = plane->stride;
               return sw_displaytarget(plane);
            }
         }
         kms_sw_dt->ref_count --;
      }
      FALLTHROUGH;
   default:
      break;
   }

   assert(0);
   return NULL;
}

static bool
kms_sw_displaytarget_get_handle(struct sw_winsys *winsys,
                                struct sw_displaytarget *dt,
                                struct winsys_handle *whandle)
{
   struct kms_sw_winsys *kms_sw = kms_sw_winsys(winsys);
   struct kms_sw_plane *plane = kms_sw_plane(dt);
   struct kms_sw_displaytarget *kms_sw_dt = plane->dt;

   switch(whandle->type) {
   case WINSYS_HANDLE_TYPE_KMS:
      whandle->handle = kms_sw_dt->handle;
      whandle->stride = plane->stride;
      whandle->offset = plane->offset;
      return true;
   case WINSYS_HANDLE_TYPE_FD:
      if (!drmPrimeHandleToFD(kms_sw->fd, kms_sw_dt->handle,
                             DRM_CLOEXEC, (int*)&whandle->handle)) {
         whandle->stride = plane->stride;
         whandle->offset = plane->offset;
         return true;
      }
      FALLTHROUGH;
   default:
      whandle->handle = 0;
      whandle->stride = 0;
      whandle->offset = 0;
      return false;
   }
}

static void
kms_sw_displaytarget_display(struct sw_winsys *ws,
                             struct sw_displaytarget *dt,
                             void *context_private,
                             struct pipe_box *box)
{
   /* This function should not be called, instead the dri2 loader should
      handle swap buffers internally.
   */
   assert(0);
}


static void
kms_destroy_sw_winsys(struct sw_winsys *winsys)
{
   FREE(winsys);
}

struct sw_winsys *
kms_dri_create_winsys(int fd)
{
   struct kms_sw_winsys *ws;

   ws = CALLOC_STRUCT(kms_sw_winsys);
   if (!ws)
      return NULL;

   ws->fd = fd;
   list_inithead(&ws->bo_list);

   ws->base.destroy = kms_destroy_sw_winsys;

   ws->base.is_displaytarget_format_supported = kms_sw_is_displaytarget_format_supported;

   /* screen texture functions */
   ws->base.displaytarget_create = kms_sw_displaytarget_create;
   ws->base.displaytarget_destroy = kms_sw_displaytarget_destroy;
   ws->base.displaytarget_from_handle = kms_sw_displaytarget_from_handle;
   ws->base.displaytarget_get_handle = kms_sw_displaytarget_get_handle;

   /* texture functions */
   ws->base.displaytarget_map = kms_sw_displaytarget_map;
   ws->base.displaytarget_unmap = kms_sw_displaytarget_unmap;

   ws->base.displaytarget_display = kms_sw_displaytarget_display;

   return &ws->base;
}

/* vim: set sw=3 ts=8 sts=3 expandtab: */
