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#include <xen/xen.h>
 41
 42#include <drm/drm_agpsupport.h>
 43#include <drm/drm_cache.h>
 44#include <drm/drm_device.h>
 45
 46#include "drm_legacy.h"
 47
 48#if IS_ENABLED(CONFIG_AGP)
 49
 50#ifdef HAVE_PAGE_AGP
 51# include <asm/agp.h>
 52#else
 53# ifdef __powerpc__
 54#  define PAGE_AGP	pgprot_noncached_wc(PAGE_KERNEL)
 55# else
 56#  define PAGE_AGP	PAGE_KERNEL
 57# endif
 58#endif
 59
 60static void *agp_remap(unsigned long offset, unsigned long size,
 61		       struct drm_device *dev)
 62{
 63	unsigned long i, num_pages =
 64	    PAGE_ALIGN(size) / PAGE_SIZE;
 65	struct drm_agp_mem *agpmem;
 66	struct page **page_map;
 67	struct page **phys_page_map;
 68	void *addr;
 69
 70	size = PAGE_ALIGN(size);
 71
 72#ifdef __alpha__
 73	offset -= dev->hose->mem_space->start;
 74#endif
 75
 76	list_for_each_entry(agpmem, &dev->agp->memory, head)
 77		if (agpmem->bound <= offset
 78		    && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
 79		    (offset + size))
 80			break;
 81	if (&agpmem->head == &dev->agp->memory)
 82		return NULL;
 83
 84	/*
 85	 * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
 86	 * the CPU do not get remapped by the GART.  We fix this by using the kernel's
 87	 * page-table instead (that's probably faster anyhow...).
 88	 */
 89	/* note: use vmalloc() because num_pages could be large... */
 90	page_map = vmalloc(array_size(num_pages, sizeof(struct page *)));
 91	if (!page_map)
 92		return NULL;
 93
 94	phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
 95	for (i = 0; i < num_pages; ++i)
 96		page_map[i] = phys_page_map[i];
 97	addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
 98	vfree(page_map);
 99
100	return addr;
101}
102
103/** Wrapper around agp_free_memory() */
104void drm_free_agp(struct agp_memory *handle, int pages)
105{
106	agp_free_memory(handle);
107}
108
109/** Wrapper around agp_bind_memory() */
110int drm_bind_agp(struct agp_memory *handle, unsigned int start)
111{
112	return agp_bind_memory(handle, start);
113}
114
115/** Wrapper around agp_unbind_memory() */
116int drm_unbind_agp(struct agp_memory *handle)
117{
118	return agp_unbind_memory(handle);
119}
120
121#else /*  CONFIG_AGP  */
122static inline void *agp_remap(unsigned long offset, unsigned long size,
123			      struct drm_device *dev)
124{
125	return NULL;
126}
127
128#endif /* CONFIG_AGP */
129
130void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
131{
132	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
133		map->handle = agp_remap(map->offset, map->size, dev);
134	else
135		map->handle = ioremap(map->offset, map->size);
136}
137EXPORT_SYMBOL(drm_legacy_ioremap);
138
139void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
140{
141	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
142		map->handle = agp_remap(map->offset, map->size, dev);
143	else
144		map->handle = ioremap_wc(map->offset, map->size);
145}
146EXPORT_SYMBOL(drm_legacy_ioremap_wc);
147
148void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
149{
150	if (!map->handle || !map->size)
151		return;
152
153	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
154		vunmap(map->handle);
155	else
156		iounmap(map->handle);
157}
158EXPORT_SYMBOL(drm_legacy_ioremapfree);
159
160bool drm_need_swiotlb(int dma_bits)
161{
162	struct resource *tmp;
163	resource_size_t max_iomem = 0;
164
165	/*
166	 * Xen paravirtual hosts require swiotlb regardless of requested dma
167	 * transfer size.
168	 *
169	 * NOTE: Really, what it requires is use of the dma_alloc_coherent
170	 *       allocator used in ttm_dma_populate() instead of
171	 *       ttm_populate_and_map_pages(), which bounce buffers so much in
172	 *       Xen it leads to swiotlb buffer exhaustion.
173	 */
174	if (xen_pv_domain())
175		return true;
176
177	/*
178	 * Enforce dma_alloc_coherent when memory encryption is active as well
179	 * for the same reasons as for Xen paravirtual hosts.
180	 */
181	if (mem_encrypt_active())
182		return true;
183
184	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
185		max_iomem = max(max_iomem,  tmp->end);
186	}
187
188	return max_iomem > ((u64)1 << dma_bits);
189}
190EXPORT_SYMBOL(drm_need_swiotlb);