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drm_gem_framebuffer_helper.c revision 1.1 
      1 /*	$NetBSD: drm_gem_framebuffer_helper.c,v 1.1 2021/12/19 00:25:53 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2018 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: drm_gem_framebuffer_helper.c,v 1.1 2021/12/19 00:25:53 riastradh Exp $");
     34 
     35 #include <linux/err.h>
     36 #include <linux/slab.h>
     37 
     38 #include <drm/drm_framebuffer.h>
     39 #include <drm/drm_gem.h>
     40 
     41 #include <uapi/drm/drm_mode.h>
     42 
     43 /*
     44  * drm_gem_fb_destroy(fb)
     45  *
     46  *	Release the objects in, clean up and, kfree a framebuffer
     47  *	allocated with drm_gem_fb_create_with_funcs.
     48  *
     49  *	Fit for use as struct drm_framebuffer_funcs::destroy.  Caller
     50  *	must guarantee that the struct drm_framebuffer is allocated
     51  *	with kmalloc.
     52  */
     53 void
     54 drm_gem_fb_destroy(struct drm_framebuffer *fb)
     55 {
     56 	unsigned plane;
     57 
     58 	for (plane = 0; plane < __arraycount(fb->obj); plane++)
     59 		drm_gem_object_put_unlocked(fb->obj[plane]);
     60 	drm_framebuffer_cleanup(fb);
     61 	kfree(fb);
     62 }
     63 
     64 /*
     65  * drm_gem_fb_create_handle(fb, file, handlep)
     66  *
     67  *	Create a GEM handle for the object of the first plane (plane=0)
     68  *	of fb in the specified drm file namespace, and store it in
     69  *	*handlep.
     70  *
     71  *	Returns 0 on success, negative error on failure.
     72  */
     73 int
     74 drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
     75     unsigned *handlep)
     76 {
     77 
     78 	return drm_gem_handle_create(file, fb->obj[0], handlep);
     79 }
     80 
     81 /*
     82  * drm_gem_fb_create_with_funcs(dev, file, mode_cmd, funcs)
     83  *
     84  *	Create a framebuffer in the specified drm device from the given
     85  *	mode command, resolving mode_cmd's handles in the specified drm
     86  *	file.
     87  *
     88  *	Returns pointer on success, ERR_PTR on failure.
     89  *
     90  *	ENOENT	missing handle
     91  *	EINVAL	wrong size object, invalid mode format
     92  */
     93 struct drm_framebuffer *
     94 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
     95     const struct drm_mode_fb_cmd2 *mode_cmd,
     96     const struct drm_framebuffer_funcs *funcs)
     97 {
     98 	struct drm_framebuffer *fb;
     99 	unsigned plane;
    100 	int ret;
    101 
    102 	/* Allocate a framebuffer object with kmalloc.  */
    103 	fb = kmalloc(sizeof(*fb), GFP_KERNEL);
    104 	if (fb == NULL) {
    105 		ret = -ENOMEM;
    106 		goto fail0;
    107 	}
    108 
    109 	/*
    110 	 * Fill framebuffer parameters from mode_cmd.  If they're not
    111 	 * valid, fail with EINVAL.
    112 	 */
    113 	drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
    114 	if (fb->format == NULL) {
    115 		ret = -EINVAL;
    116 		goto fail1;
    117 	}
    118 
    119 	/* Get the object for each plane.  */
    120 	for (plane = 0; plane < fb->format->num_planes; plane++) {
    121 		unsigned vsub = (plane > 0 ? info->vsub : 1); /* XXX ? */
    122 		unsigned hsub = (plane > 0 ? info->hsub : 1); /* XXX ? */
    123 		unsigned handle = mode_cmd->handles[plane];
    124 		unsigned size;
    125 
    126 		/* Look up the object for this plane.  */
    127 		fb->obj[plane] = drm_gem_object_lookup(file, handle);
    128 		if (fb->obj[plane] == NULL) {
    129 			ret = -ENOENT;
    130 			goto fail2;
    131 		}
    132 
    133 		/* Confirm the object is large enough to handle it.  */
    134 		size = (mode_cmd->height/vsub - 1)*mode_cmd->pitches[plane]
    135 		    + (mode_cmd->width/hsub)*fb->format->cpp[plane]
    136 		    + mode_cmd->offsets[plane];
    137 		if (fb->obj[plane]->size < size) {
    138 			ret = -EINVAL;
    139 			plane++; /* free this one too */
    140 			goto fail2;
    141 		}
    142 	}
    143 
    144 	/* Initialize the framebuffer.  */
    145 	ret = drm_framebuffer_init(dev, fb, funcs);
    146 	if (ret)
    147 		goto fail2;
    148 
    149 	/* Success!  */
    150 	return fb;
    151 
    152 fail2:	while (plane --> 0)
    153 		drm_gem_object_put_unlocked(fb->obj[plane]);
    154 fail1:	kmem_free(fb, sizeof(*fb));
    155 fail0:	KASSERT(ret);
    156 	return ERR_PTR(ret);
    157 }
    158