1/*
  2 * SPDX-License-Identifier: MIT
  3 *
  4 * Copyright © 2014-2016 Intel Corporation
  5 */
  6
  7#include <linux/highmem.h>
  8#include <linux/shmem_fs.h>
  9#include <linux/swap.h>
 10
 11#include <drm/drm_cache.h>
 12
 13#include "gt/intel_gt.h"
 14#include "i915_drv.h"
 15#include "i915_gem_object.h"
 16#include "i915_gem_region.h"
 17#include "i915_gem_tiling.h"
 18#include "i915_scatterlist.h"
 19
 20static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
 21{
 22	struct address_space *mapping = obj->base.filp->f_mapping;
 23	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 24	struct scatterlist *sg;
 25	struct sg_table *st;
 26	dma_addr_t dma;
 27	void *vaddr;
 28	void *dst;
 29	int i;
 30
 31	if (GEM_WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
 32		return -EINVAL;
 33
 34	/*
 35	 * Always aligning to the object size, allows a single allocation
 36	 * to handle all possible callers, and given typical object sizes,
 37	 * the alignment of the buddy allocation will naturally match.
 38	 */
 39	vaddr = dma_alloc_coherent(obj->base.dev->dev,
 40				   roundup_pow_of_two(obj->base.size),
 41				   &dma, GFP_KERNEL);
 42	if (!vaddr)
 43		return -ENOMEM;
 44
 45	st = kmalloc(sizeof(*st), GFP_KERNEL);
 46	if (!st)
 47		goto err_pci;
 48
 49	if (sg_alloc_table(st, 1, GFP_KERNEL))
 50		goto err_st;
 51
 52	sg = st->sgl;
 53	sg->offset = 0;
 54	sg->length = obj->base.size;
 55
 56	sg_assign_page(sg, (struct page *)vaddr);
 57	sg_dma_address(sg) = dma;
 58	sg_dma_len(sg) = obj->base.size;
 59
 60	dst = vaddr;
 61	for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
 62		struct page *page;
 63		void *src;
 64
 65		page = shmem_read_mapping_page(mapping, i);
 66		if (IS_ERR(page))
 67			goto err_st;
 68
 69		src = kmap_atomic(page);
 70		memcpy(dst, src, PAGE_SIZE);
 71		drm_clflush_virt_range(dst, PAGE_SIZE);
 72		kunmap_atomic(src);
 73
 74		put_page(page);
 75		dst += PAGE_SIZE;
 76	}
 77
 78	intel_gt_chipset_flush(to_gt(i915));
 79
 80	/* We're no longer struct page backed */
 81	obj->mem_flags &= ~I915_BO_FLAG_STRUCT_PAGE;
 82	__i915_gem_object_set_pages(obj, st);
 83
 84	return 0;
 85
 86err_st:
 87	kfree(st);
 88err_pci:
 89	dma_free_coherent(obj->base.dev->dev,
 90			  roundup_pow_of_two(obj->base.size),
 91			  vaddr, dma);
 92	return -ENOMEM;
 93}
 94
 95void
 96i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
 97			       struct sg_table *pages)
 98{
 99	dma_addr_t dma = sg_dma_address(pages->sgl);
100	void *vaddr = sg_page(pages->sgl);
101
102	__i915_gem_object_release_shmem(obj, pages, false);
103
104	if (obj->mm.dirty) {
105		struct address_space *mapping = obj->base.filp->f_mapping;
106		void *src = vaddr;
107		int i;
108
109		for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
110			struct page *page;
111			char *dst;
112
113			page = shmem_read_mapping_page(mapping, i);
114			if (IS_ERR(page))
115				continue;
116
117			dst = kmap_atomic(page);
118			drm_clflush_virt_range(src, PAGE_SIZE);
119			memcpy(dst, src, PAGE_SIZE);
120			kunmap_atomic(dst);
121
122			set_page_dirty(page);
123			if (obj->mm.madv == I915_MADV_WILLNEED)
124				mark_page_accessed(page);
125			put_page(page);
126
127			src += PAGE_SIZE;
128		}
129		obj->mm.dirty = false;
130	}
131
132	sg_free_table(pages);
133	kfree(pages);
134
135	dma_free_coherent(obj->base.dev->dev,
136			  roundup_pow_of_two(obj->base.size),
137			  vaddr, dma);
138}
139
140int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
141				const struct drm_i915_gem_pwrite *args)
142{
143	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
144	char __user *user_data = u64_to_user_ptr(args->data_ptr);
145	struct drm_i915_private *i915 = to_i915(obj->base.dev);
146	int err;
147
148	err = i915_gem_object_wait(obj,
149				   I915_WAIT_INTERRUPTIBLE |
150				   I915_WAIT_ALL,
151				   MAX_SCHEDULE_TIMEOUT);
152	if (err)
153		return err;
154
155	/*
156	 * We manually control the domain here and pretend that it
157	 * remains coherent i.e. in the GTT domain, like shmem_pwrite.
158	 */
159	i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
160
161	if (copy_from_user(vaddr, user_data, args->size))
162		return -EFAULT;
163
164	drm_clflush_virt_range(vaddr, args->size);
165	intel_gt_chipset_flush(to_gt(i915));
166
167	i915_gem_object_flush_frontbuffer(obj, ORIGIN_CPU);
168	return 0;
169}
170
171int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
172			       const struct drm_i915_gem_pread *args)
173{
174	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
175	char __user *user_data = u64_to_user_ptr(args->data_ptr);
176	int err;
177
178	err = i915_gem_object_wait(obj,
179				   I915_WAIT_INTERRUPTIBLE,
180				   MAX_SCHEDULE_TIMEOUT);
181	if (err)
182		return err;
183
184	drm_clflush_virt_range(vaddr, args->size);
185	if (copy_to_user(user_data, vaddr, args->size))
186		return -EFAULT;
187
188	return 0;
189}
190
191static int i915_gem_object_shmem_to_phys(struct drm_i915_gem_object *obj)
192{
193	struct sg_table *pages;
194	int err;
195
196	pages = __i915_gem_object_unset_pages(obj);
197
198	err = i915_gem_object_get_pages_phys(obj);
199	if (err)
200		goto err_xfer;
201
202	/* Perma-pin (until release) the physical set of pages */
203	__i915_gem_object_pin_pages(obj);
204
205	if (!IS_ERR_OR_NULL(pages))
206		i915_gem_object_put_pages_shmem(obj, pages);
207
208	i915_gem_object_release_memory_region(obj);
209	return 0;
210
211err_xfer:
212	if (!IS_ERR_OR_NULL(pages))
213		__i915_gem_object_set_pages(obj, pages);
214	return err;
215}
216
217int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align)
218{
219	int err;
220
221	assert_object_held(obj);
222
223	if (align > obj->base.size)
224		return -EINVAL;
225
226	if (!i915_gem_object_is_shmem(obj))
227		return -EINVAL;
228
229	if (!i915_gem_object_has_struct_page(obj))
230		return 0;
231
232	err = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
233	if (err)
234		return err;
235
236	if (obj->mm.madv != I915_MADV_WILLNEED)
237		return -EFAULT;
238
239	if (i915_gem_object_has_tiling_quirk(obj))
240		return -EFAULT;
241
242	if (obj->mm.mapping || i915_gem_object_has_pinned_pages(obj))
243		return -EBUSY;
244
245	if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
246		drm_dbg(obj->base.dev,
247			"Attempting to obtain a purgeable object\n");
248		return -EFAULT;
249	}
250
251	return i915_gem_object_shmem_to_phys(obj);
252}
253
254#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
255#include "selftests/i915_gem_phys.c"
256#endif