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 "gem/i915_gem_lmem.h"
9 #include "gem/i915_gem_region.h"
10 #include "intel_region_lmem.h"
11 
12 static int init_fake_lmem_bar(struct intel_memory_region *mem)
13 {
14 	struct drm_i915_private *i915 = mem->i915;
15 	struct i915_ggtt *ggtt = &i915->ggtt;
16 	unsigned long n;
17 	int ret;
18 
19 	/* We want to 1:1 map the mappable aperture to our reserved region */
20 
21 	mem->fake_mappable.start = 0;
22 	mem->fake_mappable.size = resource_size(&mem->region);
23 	mem->fake_mappable.color = I915_COLOR_UNEVICTABLE;
24 
25 	ret = drm_mm_reserve_node(&ggtt->vm.mm, &mem->fake_mappable);
26 	if (ret)
27 		return ret;
28 
29 	mem->remap_addr = dma_map_resource(&i915->drm.pdev->dev,
30 					   mem->region.start,
31 					   mem->fake_mappable.size,
32 					   PCI_DMA_BIDIRECTIONAL,
33 					   DMA_ATTR_FORCE_CONTIGUOUS);
34 	if (dma_mapping_error(&i915->drm.pdev->dev, mem->remap_addr)) {
35 		drm_mm_remove_node(&mem->fake_mappable);
36 		return -EINVAL;
37 	}
38 
39 	for (n = 0; n < mem->fake_mappable.size >> PAGE_SHIFT; ++n) {
40 		ggtt->vm.insert_page(&ggtt->vm,
41 				     mem->remap_addr + (n << PAGE_SHIFT),
42 				     n << PAGE_SHIFT,
43 				     I915_CACHE_NONE, 0);
44 	}
45 
46 	mem->region = (struct resource)DEFINE_RES_MEM(mem->remap_addr,
47 						      mem->fake_mappable.size);
48 
49 	return 0;
50 }
51 
52 static void release_fake_lmem_bar(struct intel_memory_region *mem)
53 {
54 	if (!drm_mm_node_allocated(&mem->fake_mappable))
55 		return;
56 
57 	drm_mm_remove_node(&mem->fake_mappable);
58 
59 	dma_unmap_resource(&mem->i915->drm.pdev->dev,
60 			   mem->remap_addr,
61 			   mem->fake_mappable.size,
62 			   PCI_DMA_BIDIRECTIONAL,
63 			   DMA_ATTR_FORCE_CONTIGUOUS);
64 }
65 
66 static void
67 region_lmem_release(struct intel_memory_region *mem)
68 {
69 	release_fake_lmem_bar(mem);
70 	io_mapping_fini(&mem->iomap);
71 	intel_memory_region_release_buddy(mem);
72 }
73 
74 static int
75 region_lmem_init(struct intel_memory_region *mem)
76 {
77 	int ret;
78 
79 	if (mem->i915->params.fake_lmem_start) {
80 		ret = init_fake_lmem_bar(mem);
81 		GEM_BUG_ON(ret);
82 	}
83 
84 	if (!io_mapping_init_wc(&mem->iomap,
85 				mem->io_start,
86 				resource_size(&mem->region)))
87 		return -EIO;
88 
89 	ret = intel_memory_region_init_buddy(mem);
90 	if (ret)
91 		io_mapping_fini(&mem->iomap);
92 
93 	intel_memory_region_set_name(mem, "local");
94 
95 	return ret;
96 }
97 
98 static const struct intel_memory_region_ops intel_region_lmem_ops = {
99 	.init = region_lmem_init,
100 	.release = region_lmem_release,
101 	.init_object = __i915_gem_lmem_object_init,
102 };
103 
104 struct intel_memory_region *
105 intel_setup_fake_lmem(struct drm_i915_private *i915)
106 {
107 	struct pci_dev *pdev = i915->drm.pdev;
108 	struct intel_memory_region *mem;
109 	resource_size_t mappable_end;
110 	resource_size_t io_start;
111 	resource_size_t start;
112 
113 	GEM_BUG_ON(i915_ggtt_has_aperture(&i915->ggtt));
114 	GEM_BUG_ON(!i915->params.fake_lmem_start);
115 
116 	/* Your mappable aperture belongs to me now! */
117 	mappable_end = pci_resource_len(pdev, 2);
118 	io_start = pci_resource_start(pdev, 2),
119 	start = i915->params.fake_lmem_start;
120 
121 	mem = intel_memory_region_create(i915,
122 					 start,
123 					 mappable_end,
124 					 PAGE_SIZE,
125 					 io_start,
126 					 &intel_region_lmem_ops);
127 	if (!IS_ERR(mem)) {
128 		drm_info(&i915->drm, "Intel graphics fake LMEM: %pR\n",
129 			 &mem->region);
130 		drm_info(&i915->drm,
131 			 "Intel graphics fake LMEM IO start: %llx\n",
132 			(u64)mem->io_start);
133 		drm_info(&i915->drm, "Intel graphics fake LMEM size: %llx\n",
134 			 (u64)resource_size(&mem->region));
135 	}
136 
137 	return mem;
138 }
139