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      1 /*	$NetBSD: drm_dma.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $	*/
      2 
      3 /*
      4  * \file drm_dma.c
      5  * DMA IOCTL and function support
      6  *
      7  * \author Rickard E. (Rik) Faith <faith (at) valinux.com>
      8  * \author Gareth Hughes <gareth (at) valinux.com>
      9  */
     10 
     11 /*
     12  * Created: Fri Mar 19 14:30:16 1999 by faith (at) valinux.com
     13  *
     14  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
     15  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
     16  * All Rights Reserved.
     17  *
     18  * Permission is hereby granted, free of charge, to any person obtaining a
     19  * copy of this software and associated documentation files (the "Software"),
     20  * to deal in the Software without restriction, including without limitation
     21  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     22  * and/or sell copies of the Software, and to permit persons to whom the
     23  * Software is furnished to do so, subject to the following conditions:
     24  *
     25  * The above copyright notice and this permission notice (including the next
     26  * paragraph) shall be included in all copies or substantial portions of the
     27  * Software.
     28  *
     29  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     30  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     31  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     32  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
     33  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     34  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     35  * OTHER DEALINGS IN THE SOFTWARE.
     36  */
     37 
     38 #include <sys/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: drm_dma.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $");
     40 
     41 #include <linux/export.h>
     42 
     43 #include <drm/drm_drv.h>
     44 #include <drm/drm_pci.h>
     45 #include <drm/drm_print.h>
     46 
     47 #include "drm_legacy.h"
     48 
     49 /**
     50  * Initialize the DMA data.
     51  *
     52  * \param dev DRM device.
     53  * \return zero on success or a negative value on failure.
     54  *
     55  * Allocate and initialize a drm_device_dma structure.
     56  */
     57 int drm_legacy_dma_setup(struct drm_device *dev)
     58 {
     59 	int i;
     60 
     61 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA) ||
     62 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
     63 		return 0;
     64 
     65 	dev->buf_use = 0;
     66 	atomic_set(&dev->buf_alloc, 0);
     67 
     68 	dev->dma = kzalloc(sizeof(*dev->dma), GFP_KERNEL);
     69 	if (!dev->dma)
     70 		return -ENOMEM;
     71 
     72 	for (i = 0; i <= DRM_MAX_ORDER; i++)
     73 		memset(&dev->dma->bufs[i], 0, sizeof(dev->dma->bufs[0]));
     74 
     75 	return 0;
     76 }
     77 
     78 /**
     79  * Cleanup the DMA resources.
     80  *
     81  * \param dev DRM device.
     82  *
     83  * Free all pages associated with DMA buffers, the buffers and pages lists, and
     84  * finally the drm_device::dma structure itself.
     85  */
     86 void drm_legacy_dma_takedown(struct drm_device *dev)
     87 {
     88 	struct drm_device_dma *dma = dev->dma;
     89 	int i, j;
     90 
     91 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA) ||
     92 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
     93 		return;
     94 
     95 	if (!dma)
     96 		return;
     97 
     98 	/* Clear dma buffers */
     99 	for (i = 0; i <= DRM_MAX_ORDER; i++) {
    100 		if (dma->bufs[i].seg_count) {
    101 			DRM_DEBUG("order %d: buf_count = %d,"
    102 				  " seg_count = %d\n",
    103 				  i,
    104 				  dma->bufs[i].buf_count,
    105 				  dma->bufs[i].seg_count);
    106 			for (j = 0; j < dma->bufs[i].seg_count; j++) {
    107 				if (dma->bufs[i].seglist[j]) {
    108 					drm_pci_free(dev, dma->bufs[i].seglist[j]);
    109 				}
    110 			}
    111 			kfree(dma->bufs[i].seglist);
    112 		}
    113 		if (dma->bufs[i].buf_count) {
    114 			for (j = 0; j < dma->bufs[i].buf_count; j++) {
    115 				kfree(dma->bufs[i].buflist[j].dev_private);
    116 			}
    117 			kfree(dma->bufs[i].buflist);
    118 		}
    119 	}
    120 
    121 	kfree(dma->buflist);
    122 	kfree(dma->pagelist);
    123 	kfree(dev->dma);
    124 	dev->dma = NULL;
    125 }
    126 
    127 /**
    128  * Free a buffer.
    129  *
    130  * \param dev DRM device.
    131  * \param buf buffer to free.
    132  *
    133  * Resets the fields of \p buf.
    134  */
    135 void drm_legacy_free_buffer(struct drm_device *dev, struct drm_buf * buf)
    136 {
    137 	if (!buf)
    138 		return;
    139 
    140 	buf->waiting = 0;
    141 	buf->pending = 0;
    142 	buf->file_priv = NULL;
    143 	buf->used = 0;
    144 }
    145 
    146 /**
    147  * Reclaim the buffers.
    148  *
    149  * \param file_priv DRM file private.
    150  *
    151  * Frees each buffer associated with \p file_priv not already on the hardware.
    152  */
    153 void drm_legacy_reclaim_buffers(struct drm_device *dev,
    154 				struct drm_file *file_priv)
    155 {
    156 	struct drm_device_dma *dma = dev->dma;
    157 	int i;
    158 
    159 	if (!dma)
    160 		return;
    161 	for (i = 0; i < dma->buf_count; i++) {
    162 		if (dma->buflist[i]->file_priv == file_priv) {
    163 			switch (dma->buflist[i]->list) {
    164 			case DRM_LIST_NONE:
    165 				drm_legacy_free_buffer(dev, dma->buflist[i]);
    166 				break;
    167 			case DRM_LIST_WAIT:
    168 				dma->buflist[i]->list = DRM_LIST_RECLAIM;
    169 				break;
    170 			default:
    171 				/* Buffer already on hardware. */
    172 				break;
    173 			}
    174 		}
    175 	}
    176 }
    177