drm_memory.c revision 1.30 
1/*
2 * \file drm_memory.c
3 * Memory management wrappers for DRM
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
7 */
8
9/*
10 * Created: Thu Feb  4 14:00:34 1999 by faith@valinux.com
11 *
12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
22 *
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
25 * Software.
26 *
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
34 */
35
36#include <linux/export.h>
37#include <linux/highmem.h>
38#include <linux/pci.h>
39#include <linux/vmalloc.h>
40#ifdef __linux__
41#include <xen/xen.h>
42#endif
43
44#include <drm/drm_agpsupport.h>
45#include <drm/drm_cache.h>
46#include <drm/drm_device.h>
47
48#include "drm_legacy.h"
49
50#if IS_ENABLED(CONFIG_AGP) && defined(__linux__)
51
52#ifdef HAVE_PAGE_AGP
53# include <asm/agp.h>
54#else
55# ifdef __powerpc__
56#  define PAGE_AGP	pgprot_noncached_wc(PAGE_KERNEL)
57# else
58#  define PAGE_AGP	PAGE_KERNEL
59# endif
60#endif
61
62static void *agp_remap(unsigned long offset, unsigned long size,
63		       struct drm_device *dev)
64{
65	unsigned long i, num_pages =
66	    PAGE_ALIGN(size) / PAGE_SIZE;
67	struct drm_agp_mem *agpmem;
68	struct vm_page **page_map;
69	struct vm_page **phys_page_map;
70	void *addr;
71
72	size = PAGE_ALIGN(size);
73
74#ifdef __alpha__
75	offset -= dev->hose->mem_space->start;
76#endif
77
78	list_for_each_entry(agpmem, &dev->agp->memory, head)
79		if (agpmem->bound <= offset
80		    && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
81		    (offset + size))
82			break;
83	if (&agpmem->head == &dev->agp->memory)
84		return NULL;
85
86	/*
87	 * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
88	 * the CPU do not get remapped by the GART.  We fix this by using the kernel's
89	 * page-table instead (that's probably faster anyhow...).
90	 */
91	/* note: use vmalloc() because num_pages could be large... */
92	page_map = vmalloc(array_size(num_pages, sizeof(struct vm_page *)));
93	if (!page_map)
94		return NULL;
95
96	phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
97	for (i = 0; i < num_pages; ++i)
98		page_map[i] = phys_page_map[i];
99	addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
100	vfree(page_map);
101
102	return addr;
103}
104
105/** Wrapper around agp_free_memory() */
106void drm_free_agp(struct agp_memory *handle, int pages)
107{
108	agp_free_memory(handle);
109}
110
111/** Wrapper around agp_bind_memory() */
112int drm_bind_agp(struct agp_memory *handle, unsigned int start)
113{
114	return agp_bind_memory(handle, start);
115}
116
117/** Wrapper around agp_unbind_memory() */
118int drm_unbind_agp(struct agp_memory *handle)
119{
120	return agp_unbind_memory(handle);
121}
122
123#else /*  CONFIG_AGP  */
124static inline void *agp_remap(unsigned long offset, unsigned long size,
125			      struct drm_device *dev)
126{
127	return NULL;
128}
129
130#endif /* CONFIG_AGP */
131
132#ifdef __linux__
133
134void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
135{
136	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
137		map->handle = agp_remap(map->offset, map->size, dev);
138	else
139		map->handle = ioremap(map->offset, map->size);
140}
141EXPORT_SYMBOL(drm_legacy_ioremap);
142
143void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
144{
145	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
146		map->handle = agp_remap(map->offset, map->size, dev);
147	else
148		map->handle = ioremap_wc(map->offset, map->size);
149}
150EXPORT_SYMBOL(drm_legacy_ioremap_wc);
151
152void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
153{
154	if (!map->handle || !map->size)
155		return;
156
157	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
158		vunmap(map->handle);
159	else
160		iounmap(map->handle);
161}
162EXPORT_SYMBOL(drm_legacy_ioremapfree);
163
164#endif /* __linux__ */
165
166bool drm_need_swiotlb(int dma_bits)
167{
168	return false;
169#ifdef notyet
170	struct resource *tmp;
171	resource_size_t max_iomem = 0;
172
173	/*
174	 * Xen paravirtual hosts require swiotlb regardless of requested dma
175	 * transfer size.
176	 *
177	 * NOTE: Really, what it requires is use of the dma_alloc_coherent
178	 *       allocator used in ttm_dma_populate() instead of
179	 *       ttm_populate_and_map_pages(), which bounce buffers so much in
180	 *       Xen it leads to swiotlb buffer exhaustion.
181	 */
182	if (xen_pv_domain())
183		return true;
184
185	/*
186	 * Enforce dma_alloc_coherent when memory encryption is active as well
187	 * for the same reasons as for Xen paravirtual hosts.
188	 */
189	if (mem_encrypt_active())
190		return true;
191
192	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
193		max_iomem = max(max_iomem,  tmp->end);
194	}
195
196	return max_iomem > ((u64)1 << dma_bits);
197#endif
198}
199EXPORT_SYMBOL(drm_need_swiotlb);
200