xref: /linux/drivers/gpu/drm/i915/gt/intel_region_lmem.c (revision 6beeaf48db6c548fcfc2ad32739d33af2fef3a5b)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "intel_memory_region.h"
8 #include "intel_region_lmem.h"
9 #include "intel_region_ttm.h"
10 #include "gem/i915_gem_lmem.h"
11 #include "gem/i915_gem_region.h"
12 #include "gem/i915_gem_ttm.h"
13 #include "gt/intel_gt.h"
14 
15 static int init_fake_lmem_bar(struct intel_memory_region *mem)
16 {
17 	struct drm_i915_private *i915 = mem->i915;
18 	struct i915_ggtt *ggtt = &i915->ggtt;
19 	unsigned long n;
20 	int ret;
21 
22 	/* We want to 1:1 map the mappable aperture to our reserved region */
23 
24 	mem->fake_mappable.start = 0;
25 	mem->fake_mappable.size = resource_size(&mem->region);
26 	mem->fake_mappable.color = I915_COLOR_UNEVICTABLE;
27 
28 	ret = drm_mm_reserve_node(&ggtt->vm.mm, &mem->fake_mappable);
29 	if (ret)
30 		return ret;
31 
32 	mem->remap_addr = dma_map_resource(i915->drm.dev,
33 					   mem->region.start,
34 					   mem->fake_mappable.size,
35 					   PCI_DMA_BIDIRECTIONAL,
36 					   DMA_ATTR_FORCE_CONTIGUOUS);
37 	if (dma_mapping_error(i915->drm.dev, mem->remap_addr)) {
38 		drm_mm_remove_node(&mem->fake_mappable);
39 		return -EINVAL;
40 	}
41 
42 	for (n = 0; n < mem->fake_mappable.size >> PAGE_SHIFT; ++n) {
43 		ggtt->vm.insert_page(&ggtt->vm,
44 				     mem->remap_addr + (n << PAGE_SHIFT),
45 				     n << PAGE_SHIFT,
46 				     I915_CACHE_NONE, 0);
47 	}
48 
49 	mem->region = (struct resource)DEFINE_RES_MEM(mem->remap_addr,
50 						      mem->fake_mappable.size);
51 
52 	return 0;
53 }
54 
55 static void release_fake_lmem_bar(struct intel_memory_region *mem)
56 {
57 	if (!drm_mm_node_allocated(&mem->fake_mappable))
58 		return;
59 
60 	drm_mm_remove_node(&mem->fake_mappable);
61 
62 	dma_unmap_resource(mem->i915->drm.dev,
63 			   mem->remap_addr,
64 			   mem->fake_mappable.size,
65 			   PCI_DMA_BIDIRECTIONAL,
66 			   DMA_ATTR_FORCE_CONTIGUOUS);
67 }
68 
69 static void
70 region_lmem_release(struct intel_memory_region *mem)
71 {
72 	intel_region_ttm_fini(mem);
73 	io_mapping_fini(&mem->iomap);
74 	release_fake_lmem_bar(mem);
75 }
76 
77 static int
78 region_lmem_init(struct intel_memory_region *mem)
79 {
80 	int ret;
81 
82 	if (mem->i915->params.fake_lmem_start) {
83 		ret = init_fake_lmem_bar(mem);
84 		GEM_BUG_ON(ret);
85 	}
86 
87 	if (!io_mapping_init_wc(&mem->iomap,
88 				mem->io_start,
89 				resource_size(&mem->region))) {
90 		ret = -EIO;
91 		goto out_no_io;
92 	}
93 
94 	ret = intel_region_ttm_init(mem);
95 	if (ret)
96 		goto out_no_buddy;
97 
98 	return 0;
99 
100 out_no_buddy:
101 	io_mapping_fini(&mem->iomap);
102 out_no_io:
103 	release_fake_lmem_bar(mem);
104 
105 	return ret;
106 }
107 
108 static const struct intel_memory_region_ops intel_region_lmem_ops = {
109 	.init = region_lmem_init,
110 	.release = region_lmem_release,
111 	.init_object = __i915_gem_ttm_object_init,
112 };
113 
114 struct intel_memory_region *
115 intel_gt_setup_fake_lmem(struct intel_gt *gt)
116 {
117 	struct drm_i915_private *i915 = gt->i915;
118 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
119 	struct intel_memory_region *mem;
120 	resource_size_t mappable_end;
121 	resource_size_t io_start;
122 	resource_size_t start;
123 
124 	if (!HAS_LMEM(i915))
125 		return ERR_PTR(-ENODEV);
126 
127 	if (!i915->params.fake_lmem_start)
128 		return ERR_PTR(-ENODEV);
129 
130 	GEM_BUG_ON(i915_ggtt_has_aperture(&i915->ggtt));
131 
132 	/* Your mappable aperture belongs to me now! */
133 	mappable_end = pci_resource_len(pdev, 2);
134 	io_start = pci_resource_start(pdev, 2);
135 	start = i915->params.fake_lmem_start;
136 
137 	mem = intel_memory_region_create(i915,
138 					 start,
139 					 mappable_end,
140 					 PAGE_SIZE,
141 					 io_start,
142 					 INTEL_MEMORY_LOCAL,
143 					 0,
144 					 &intel_region_lmem_ops);
145 	if (!IS_ERR(mem)) {
146 		drm_info(&i915->drm, "Intel graphics fake LMEM: %pR\n",
147 			 &mem->region);
148 		drm_info(&i915->drm,
149 			 "Intel graphics fake LMEM IO start: %llx\n",
150 			(u64)mem->io_start);
151 		drm_info(&i915->drm, "Intel graphics fake LMEM size: %llx\n",
152 			 (u64)resource_size(&mem->region));
153 	}
154 
155 	return mem;
156 }
157 
158 static bool get_legacy_lowmem_region(struct intel_uncore *uncore,
159 				     u64 *start, u32 *size)
160 {
161 	if (!IS_DG1_GT_STEP(uncore->i915, STEP_A0, STEP_C0))
162 		return false;
163 
164 	*start = 0;
165 	*size = SZ_1M;
166 
167 	drm_dbg(&uncore->i915->drm, "LMEM: reserved legacy low-memory [0x%llx-0x%llx]\n",
168 		*start, *start + *size);
169 
170 	return true;
171 }
172 
173 static int reserve_lowmem_region(struct intel_uncore *uncore,
174 				 struct intel_memory_region *mem)
175 {
176 	u64 reserve_start;
177 	u32 reserve_size;
178 	int ret;
179 
180 	if (!get_legacy_lowmem_region(uncore, &reserve_start, &reserve_size))
181 		return 0;
182 
183 	ret = intel_memory_region_reserve(mem, reserve_start, reserve_size);
184 	if (ret)
185 		drm_err(&uncore->i915->drm, "LMEM: reserving low memory region failed\n");
186 
187 	return ret;
188 }
189 
190 static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
191 {
192 	struct drm_i915_private *i915 = gt->i915;
193 	struct intel_uncore *uncore = gt->uncore;
194 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
195 	struct intel_memory_region *mem;
196 	resource_size_t io_start;
197 	resource_size_t lmem_size;
198 	int err;
199 
200 	if (!IS_DGFX(i915))
201 		return ERR_PTR(-ENODEV);
202 
203 	/* Stolen starts from GSMBASE on DG1 */
204 	lmem_size = intel_uncore_read64(uncore, GEN12_GSMBASE);
205 
206 	io_start = pci_resource_start(pdev, 2);
207 	if (GEM_WARN_ON(lmem_size > pci_resource_len(pdev, 2)))
208 		return ERR_PTR(-ENODEV);
209 
210 	mem = intel_memory_region_create(i915,
211 					 0,
212 					 lmem_size,
213 					 I915_GTT_PAGE_SIZE_4K,
214 					 io_start,
215 					 INTEL_MEMORY_LOCAL,
216 					 0,
217 					 &intel_region_lmem_ops);
218 	if (IS_ERR(mem))
219 		return mem;
220 
221 	err = reserve_lowmem_region(uncore, mem);
222 	if (err)
223 		goto err_region_put;
224 
225 	drm_dbg(&i915->drm, "Local memory: %pR\n", &mem->region);
226 	drm_dbg(&i915->drm, "Local memory IO start: %pa\n",
227 		&mem->io_start);
228 	drm_info(&i915->drm, "Local memory available: %pa\n",
229 		 &lmem_size);
230 
231 	return mem;
232 
233 err_region_put:
234 	intel_memory_region_put(mem);
235 	return ERR_PTR(err);
236 }
237 
238 struct intel_memory_region *intel_gt_setup_lmem(struct intel_gt *gt)
239 {
240 	return setup_lmem(gt);
241 }
242