1/*
  2 * \file drm_scatter.c
  3 * IOCTLs to manage scatter/gather memory
  4 *
  5 * \author Gareth Hughes <gareth@valinux.com>
  6 */
  7
  8/*
  9 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
 10 *
 11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 12 * All Rights Reserved.
 13 *
 14 * Permission is hereby granted, free of charge, to any person obtaining a
 15 * copy of this software and associated documentation files (the "Software"),
 16 * to deal in the Software without restriction, including without limitation
 17 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 18 * and/or sell copies of the Software, and to permit persons to whom the
 19 * Software is furnished to do so, subject to the following conditions:
 20 *
 21 * The above copyright notice and this permission notice (including the next
 22 * paragraph) shall be included in all copies or substantial portions of the
 23 * Software.
 24 *
 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 28 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 31 * DEALINGS IN THE SOFTWARE.
 32 */
 33
 34#include <linux/mm.h>
 35#include <linux/slab.h>
 36#include <linux/vmalloc.h>
 37
 38#include <drm/drm.h>
 39#include <drm/drm_drv.h>
 40#include <drm/drm_print.h>
 41
 42#include "drm_legacy.h"
 43
 44#define DEBUG_SCATTER 0
 45
 46static inline void *drm_vmalloc_dma(unsigned long size)
 47{
 48#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
 49	return __vmalloc(size, GFP_KERNEL, pgprot_noncached_wc(PAGE_KERNEL));
 50#else
 51	return vmalloc_32(size);
 52#endif
 53}
 54
 55static void drm_sg_cleanup(struct drm_sg_mem * entry)
 56{
 57	struct page *page;
 58	int i;
 59
 60	for (i = 0; i < entry->pages; i++) {
 61		page = entry->pagelist[i];
 62		if (page)
 63			ClearPageReserved(page);
 64	}
 65
 66	vfree(entry->virtual);
 67
 68	kfree(entry->busaddr);
 69	kfree(entry->pagelist);
 70	kfree(entry);
 71}
 72
 73void drm_legacy_sg_cleanup(struct drm_device *dev)
 74{
 75	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
 76	    drm_core_check_feature(dev, DRIVER_LEGACY)) {
 77		drm_sg_cleanup(dev->sg);
 78		dev->sg = NULL;
 79	}
 80}
 81#ifdef _LP64
 82# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
 83#else
 84# define ScatterHandle(x) (unsigned int)(x)
 85#endif
 86
 87int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
 88			struct drm_file *file_priv)
 89{
 90	struct drm_scatter_gather *request = data;
 91	struct drm_sg_mem *entry;
 92	unsigned long pages, i, j;
 93
 94	DRM_DEBUG("\n");
 95
 96	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 97		return -EOPNOTSUPP;
 98
 99	if (!drm_core_check_feature(dev, DRIVER_SG))
100		return -EOPNOTSUPP;
101
102	if (dev->sg)
103		return -EINVAL;
104
105	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
106	if (!entry)
107		return -ENOMEM;
108
109	pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
110	DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
111
112	entry->pages = pages;
113	entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
114	if (!entry->pagelist) {
115		kfree(entry);
116		return -ENOMEM;
117	}
118
119	entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
120	if (!entry->busaddr) {
121		kfree(entry->pagelist);
122		kfree(entry);
123		return -ENOMEM;
124	}
125
126	entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
127	if (!entry->virtual) {
128		kfree(entry->busaddr);
129		kfree(entry->pagelist);
130		kfree(entry);
131		return -ENOMEM;
132	}
133
134	/* This also forces the mapping of COW pages, so our page list
135	 * will be valid.  Please don't remove it...
136	 */
137	memset(entry->virtual, 0, pages << PAGE_SHIFT);
138
139	entry->handle = ScatterHandle((unsigned long)entry->virtual);
140
141	DRM_DEBUG("handle  = %08lx\n", entry->handle);
142	DRM_DEBUG("virtual = %p\n", entry->virtual);
143
144	for (i = (unsigned long)entry->virtual, j = 0; j < pages;
145	     i += PAGE_SIZE, j++) {
146		entry->pagelist[j] = vmalloc_to_page((void *)i);
147		if (!entry->pagelist[j])
148			goto failed;
149		SetPageReserved(entry->pagelist[j]);
150	}
151
152	request->handle = entry->handle;
153
154	dev->sg = entry;
155
156#if DEBUG_SCATTER
157	/* Verify that each page points to its virtual address, and vice
158	 * versa.
159	 */
160	{
161		int error = 0;
162
163		for (i = 0; i < pages; i++) {
164			unsigned long *tmp;
165
166			tmp = page_address(entry->pagelist[i]);
167			for (j = 0;
168			     j < PAGE_SIZE / sizeof(unsigned long);
169			     j++, tmp++) {
170				*tmp = 0xcafebabe;
171			}
172			tmp = (unsigned long *)((u8 *) entry->virtual +
173						(PAGE_SIZE * i));
174			for (j = 0;
175			     j < PAGE_SIZE / sizeof(unsigned long);
176			     j++, tmp++) {
177				if (*tmp != 0xcafebabe && error == 0) {
178					error = 1;
179					DRM_ERROR("Scatter allocation error, "
180						  "pagelist does not match "
181						  "virtual mapping\n");
182				}
183			}
184			tmp = page_address(entry->pagelist[i]);
185			for (j = 0;
186			     j < PAGE_SIZE / sizeof(unsigned long);
187			     j++, tmp++) {
188				*tmp = 0;
189			}
190		}
191		if (error == 0)
192			DRM_ERROR("Scatter allocation matches pagelist\n");
193	}
194#endif
195
196	return 0;
197
198      failed:
199	drm_sg_cleanup(entry);
200	return -ENOMEM;
201}
202
203int drm_legacy_sg_free(struct drm_device *dev, void *data,
204		       struct drm_file *file_priv)
205{
206	struct drm_scatter_gather *request = data;
207	struct drm_sg_mem *entry;
208
209	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
210		return -EOPNOTSUPP;
211
212	if (!drm_core_check_feature(dev, DRIVER_SG))
213		return -EOPNOTSUPP;
214
215	entry = dev->sg;
216	dev->sg = NULL;
217
218	if (!entry || entry->handle != request->handle)
219		return -EINVAL;
220
221	DRM_DEBUG("virtual  = %p\n", entry->virtual);
222
223	drm_sg_cleanup(entry);
224
225	return 0;
226}