#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include "pipe/p_context.h"
#include "pipe/p_state.h"
#include "util/format/u_format.h"
#include "util/os_file.h"
#include "util/simple_mtx.h"
#include "util/u_memory.h"
#include "util/u_inlines.h"
#include "util/u_hash_table.h"
#include "util/u_pointer.h"
#include "util/u_thread.h"

#include "nouveau_drm_public.h"

#include "nouveau/nouveau_winsys.h"
#include "nouveau/nouveau_screen.h"

#include "nvif/class.h"
#include "nvif/cl0080.h"

static struct hash_table *fd_tab = NULL;

static simple_mtx_t nouveau_screen_mutex = SIMPLE_MTX_INITIALIZER;

bool nouveau_drm_screen_unref(struct nouveau_screen *screen)
{
	int ret;
	if (screen->refcount == -1)
		return true;

	simple_mtx_lock(&nouveau_screen_mutex);
	ret = --screen->refcount;
	assert(ret >= 0);
	if (ret == 0)
		_mesa_hash_table_remove_key(fd_tab, intptr_to_pointer(screen->drm->fd));
	simple_mtx_unlock(&nouveau_screen_mutex);
	return ret == 0;
}

PUBLIC struct pipe_screen *
nouveau_drm_screen_create(int fd)
{
	struct nouveau_drm *drm = NULL;
	struct nouveau_device *dev = NULL;
	struct nouveau_screen *(*init)(struct nouveau_device *);
	struct nouveau_screen *screen = NULL;
	int ret, dupfd;

	simple_mtx_lock(&nouveau_screen_mutex);
	if (!fd_tab) {
		fd_tab = util_hash_table_create_fd_keys();
		if (!fd_tab) {
			simple_mtx_unlock(&nouveau_screen_mutex);
			return NULL;
		}
	}

	screen = util_hash_table_get(fd_tab, intptr_to_pointer(fd));
	if (screen) {
		screen->refcount++;
		simple_mtx_unlock(&nouveau_screen_mutex);
		return &screen->base;
	}

	/* Since the screen re-use is based on the device node and not the fd,
	 * create a copy of the fd to be owned by the device. Otherwise a
	 * scenario could occur where two screens are created, and the first
	 * one is shut down, along with the fd being closed. The second
	 * (identical) screen would now have a reference to the closed fd. We
	 * avoid this by duplicating the original fd. Note that
	 * nouveau_device_wrap does not close the fd in case of a device
	 * creation error.
	 */
	dupfd = os_dupfd_cloexec(fd);

	ret = nouveau_drm_new(dupfd, &drm);
	if (ret)
		goto err;

	ret = nouveau_device_new(&drm->client, &dev);
	if (ret)
		goto err;

	switch (dev->chipset & ~0xf) {
	case 0x30:
	case 0x40:
	case 0x60:
		init = nv30_screen_create;
		break;
	case 0x50:
	case 0x80:
	case 0x90:
	case 0xa0:
		init = nv50_screen_create;
		break;
	case 0xc0:
	case 0xd0:
	case 0xe0:
	case 0xf0:
	case 0x100:
	case 0x110:
	case 0x120:
	case 0x130:
	case 0x140:
	case 0x160:
	case 0x170:
	case 0x190:
		init = nvc0_screen_create;
		break;
	default:
		debug_printf("%s: unknown chipset nv%02x\n", __func__,
			     dev->chipset);
		goto err;
	}

	screen = init(dev);
	if (!screen || !screen->base.context_create)
		goto err;

	/* Use dupfd in hash table, to avoid errors if the original fd gets
	 * closed by its owner. The hash key needs to live at least as long as
	 * the screen.
	 */
	_mesa_hash_table_insert(fd_tab, intptr_to_pointer(dupfd), screen);
	screen->refcount = 1;
	simple_mtx_unlock(&nouveau_screen_mutex);
	return &screen->base;

err:
	if (screen) {
		screen->base.destroy(&screen->base);
	} else {
		nouveau_device_del(&dev);
		nouveau_drm_del(&drm);
		close(dupfd);
	}
	simple_mtx_unlock(&nouveau_screen_mutex);
	return NULL;
}