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_scatterlist.h"
 18
 19static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
 20{
 21	struct address_space *mapping = obj->base.filp->f_mapping;
 22	struct scatterlist *sg;
 23	struct sg_table *st;
 24	dma_addr_t dma;
 25	void *vaddr;
 26	void *dst;
 27	int i;
 28
 29	if (GEM_WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
 30		return -EINVAL;
 31
 32	/*
 33	 * Always aligning to the object size, allows a single allocation
 34	 * to handle all possible callers, and given typical object sizes,
 35	 * the alignment of the buddy allocation will naturally match.
 36	 */
 37	vaddr = dma_alloc_coherent(obj->base.dev->dev,
 38				   roundup_pow_of_two(obj->base.size),
 39				   &dma, GFP_KERNEL);
 40	if (!vaddr)
 41		return -ENOMEM;
 42
 43	st = kmalloc(sizeof(*st), GFP_KERNEL);
 44	if (!st)
 45		goto err_pci;
 46
 47	if (sg_alloc_table(st, 1, GFP_KERNEL))
 48		goto err_st;
 49
 50	sg = st->sgl;
 51	sg->offset = 0;
 52	sg->length = obj->base.size;
 53
 54	sg_assign_page(sg, (struct page *)vaddr);
 55	sg_dma_address(sg) = dma;
 56	sg_dma_len(sg) = obj->base.size;
 57
 58	dst = vaddr;
 59	for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
 60		struct page *page;
 61		void *src;
 62
 63		page = shmem_read_mapping_page(mapping, i);
 64		if (IS_ERR(page))
 65			goto err_st;
 66
 67		src = kmap_atomic(page);
 68		memcpy(dst, src, PAGE_SIZE);
 69		drm_clflush_virt_range(dst, PAGE_SIZE);
 70		kunmap_atomic(src);
 71
 72		put_page(page);
 73		dst += PAGE_SIZE;
 74	}
 75
 76	intel_gt_chipset_flush(&to_i915(obj->base.dev)->gt);
 77
 78	/* We're no longer struct page backed */
 79	obj->flags &= ~I915_BO_ALLOC_STRUCT_PAGE;
 80	__i915_gem_object_set_pages(obj, st, sg->length);
 81
 82	return 0;
 83
 84err_st:
 85	kfree(st);
 86err_pci:
 87	dma_free_coherent(obj->base.dev->dev,
 88			  roundup_pow_of_two(obj->base.size),
 89			  vaddr, dma);
 90	return -ENOMEM;
 91}
 92
 93void
 94i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
 95			       struct sg_table *pages)
 96{
 97	dma_addr_t dma = sg_dma_address(pages->sgl);
 98	void *vaddr = sg_page(pages->sgl);
 99
100	__i915_gem_object_release_shmem(obj, pages, false);
101
102	if (obj->mm.dirty) {
103		struct address_space *mapping = obj->base.filp->f_mapping;
104		void *src = vaddr;
105		int i;
106
107		for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
108			struct page *page;
109			char *dst;
110
111			page = shmem_read_mapping_page(mapping, i);
112			if (IS_ERR(page))
113				continue;
114
115			dst = kmap_atomic(page);
116			drm_clflush_virt_range(src, PAGE_SIZE);
117			memcpy(dst, src, PAGE_SIZE);
118			kunmap_atomic(dst);
119
120			set_page_dirty(page);
121			if (obj->mm.madv == I915_MADV_WILLNEED)
122				mark_page_accessed(page);
123			put_page(page);
124
125			src += PAGE_SIZE;
126		}
127		obj->mm.dirty = false;
128	}
129
130	sg_free_table(pages);
131	kfree(pages);
132
133	dma_free_coherent(obj->base.dev->dev,
134			  roundup_pow_of_two(obj->base.size),
135			  vaddr, dma);
136}
137
138int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
139				const struct drm_i915_gem_pwrite *args)
140{
141	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
142	char __user *user_data = u64_to_user_ptr(args->data_ptr);
143	int err;
144
145	err = i915_gem_object_wait(obj,
146				   I915_WAIT_INTERRUPTIBLE |
147				   I915_WAIT_ALL,
148				   MAX_SCHEDULE_TIMEOUT);
149	if (err)
150		return err;
151
152	/*
153	 * We manually control the domain here and pretend that it
154	 * remains coherent i.e. in the GTT domain, like shmem_pwrite.
155	 */
156	i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
157
158	if (copy_from_user(vaddr, user_data, args->size))
159		return -EFAULT;
160
161	drm_clflush_virt_range(vaddr, args->size);
162	intel_gt_chipset_flush(&to_i915(obj->base.dev)->gt);
163
164	i915_gem_object_flush_frontbuffer(obj, ORIGIN_CPU);
165	return 0;
166}
167
168int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
169			       const struct drm_i915_gem_pread *args)
170{
171	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
172	char __user *user_data = u64_to_user_ptr(args->data_ptr);
173	int err;
174
175	err = i915_gem_object_wait(obj,
176				   I915_WAIT_INTERRUPTIBLE,
177				   MAX_SCHEDULE_TIMEOUT);
178	if (err)
179		return err;
180
181	drm_clflush_virt_range(vaddr, args->size);
182	if (copy_to_user(user_data, vaddr, args->size))
183		return -EFAULT;
184
185	return 0;
186}
187
188static int i915_gem_object_shmem_to_phys(struct drm_i915_gem_object *obj)
189{
190	struct sg_table *pages;
191	int err;
192
193	pages = __i915_gem_object_unset_pages(obj);
194
195	err = i915_gem_object_get_pages_phys(obj);
196	if (err)
197		goto err_xfer;
198
199	/* Perma-pin (until release) the physical set of pages */
200	__i915_gem_object_pin_pages(obj);
201
202	if (!IS_ERR_OR_NULL(pages))
203		i915_gem_object_put_pages_shmem(obj, pages);
204
205	i915_gem_object_release_memory_region(obj);
206	return 0;
207
208err_xfer:
209	if (!IS_ERR_OR_NULL(pages)) {
210		unsigned int sg_page_sizes = i915_sg_dma_sizes(pages->sgl);
211
212		__i915_gem_object_set_pages(obj, pages, sg_page_sizes);
213	}
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