xref: /linux/drivers/gpu/drm/i915/gt/intel_region_lmem.c (revision 815e260a18a3af4dab59025ee99a7156c0e8b5e0)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <drm/drm_print.h>
7 
8 #include "i915_drv.h"
9 #include "i915_pci.h"
10 #include "i915_reg.h"
11 #include "intel_memory_region.h"
12 #include "intel_pci_config.h"
13 #include "intel_region_lmem.h"
14 #include "intel_region_ttm.h"
15 #include "gem/i915_gem_lmem.h"
16 #include "gem/i915_gem_region.h"
17 #include "gem/i915_gem_ttm.h"
18 #include "gt/intel_gt.h"
19 #include "gt/intel_gt_mcr.h"
20 #include "gt/intel_gt_regs.h"
21 
22 #ifdef CONFIG_64BIT
23 static void _release_bars(struct pci_dev *pdev)
24 {
25 	int resno;
26 
27 	for (resno = PCI_STD_RESOURCES; resno < PCI_STD_RESOURCE_END; resno++) {
28 		if (pci_resource_len(pdev, resno))
29 			pci_release_resource(pdev, resno);
30 	}
31 }
32 
33 static void
34 _resize_bar(struct drm_i915_private *i915, int resno, resource_size_t size)
35 {
36 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
37 	int bar_size = pci_rebar_bytes_to_size(size);
38 	int ret;
39 
40 	_release_bars(pdev);
41 
42 	ret = pci_resize_resource(pdev, resno, bar_size);
43 	if (ret) {
44 		drm_info(&i915->drm, "Failed to resize BAR%d to %dM (%pe)\n",
45 			 resno, 1 << bar_size, ERR_PTR(ret));
46 		return;
47 	}
48 
49 	drm_info(&i915->drm, "BAR%d resized to %dM\n", resno, 1 << bar_size);
50 }
51 
52 static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t lmem_size)
53 {
54 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
55 	struct pci_bus *root = pdev->bus;
56 	struct resource *root_res;
57 	resource_size_t rebar_size;
58 	resource_size_t current_size;
59 	intel_wakeref_t wakeref;
60 	u32 pci_cmd;
61 	int i;
62 
63 	current_size = roundup_pow_of_two(pci_resource_len(pdev, GEN12_LMEM_BAR));
64 
65 	if (i915->params.lmem_bar_size) {
66 		u32 bar_sizes;
67 
68 		rebar_size = i915->params.lmem_bar_size *
69 			(resource_size_t)SZ_1M;
70 		bar_sizes = pci_rebar_get_possible_sizes(pdev, GEN12_LMEM_BAR);
71 
72 		if (rebar_size == current_size)
73 			return;
74 
75 		if (!(bar_sizes & BIT(pci_rebar_bytes_to_size(rebar_size))) ||
76 		    rebar_size >= roundup_pow_of_two(lmem_size)) {
77 			rebar_size = lmem_size;
78 
79 			drm_info(&i915->drm,
80 				 "Given bar size is not within supported size, setting it to default: %llu\n",
81 				 (u64)lmem_size >> 20);
82 		}
83 	} else {
84 		rebar_size = current_size;
85 
86 		if (rebar_size != roundup_pow_of_two(lmem_size))
87 			rebar_size = lmem_size;
88 		else
89 			return;
90 	}
91 
92 	/* Find out if root bus contains 64bit memory addressing */
93 	while (root->parent)
94 		root = root->parent;
95 
96 	pci_bus_for_each_resource(root, root_res, i) {
97 		if (root_res && root_res->flags & (IORESOURCE_MEM | IORESOURCE_MEM_64) &&
98 		    root_res->start > 0x100000000ull)
99 			break;
100 	}
101 
102 	/* pci_resize_resource will fail anyways */
103 	if (!root_res) {
104 		drm_info(&i915->drm, "Can't resize LMEM BAR - platform support is missing\n");
105 		return;
106 	}
107 
108 	/*
109 	 * Releasing forcewake during BAR resizing results in later forcewake
110 	 * ack timeouts and former can happen any time - it is asynchronous.
111 	 * Grabbing all forcewakes prevents it.
112 	 */
113 	with_intel_runtime_pm(i915->uncore.rpm, wakeref) {
114 		intel_uncore_forcewake_get(&i915->uncore, FORCEWAKE_ALL);
115 
116 		/* First disable PCI memory decoding references */
117 		pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);
118 		pci_write_config_dword(pdev, PCI_COMMAND,
119 				       pci_cmd & ~PCI_COMMAND_MEMORY);
120 
121 		_resize_bar(i915, GEN12_LMEM_BAR, rebar_size);
122 
123 		pci_assign_unassigned_bus_resources(pdev->bus);
124 		pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);
125 		intel_uncore_forcewake_put(&i915->uncore, FORCEWAKE_ALL);
126 	}
127 }
128 #else
129 static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t lmem_size) {}
130 #endif
131 
132 static int
133 region_lmem_release(struct intel_memory_region *mem)
134 {
135 	int ret;
136 
137 	ret = intel_region_ttm_fini(mem);
138 	io_mapping_fini(&mem->iomap);
139 
140 	return ret;
141 }
142 
143 static int
144 region_lmem_init(struct intel_memory_region *mem)
145 {
146 	int ret;
147 
148 	if (!io_mapping_init_wc(&mem->iomap,
149 				mem->io.start,
150 				resource_size(&mem->io)))
151 		return -EIO;
152 
153 	ret = intel_region_ttm_init(mem);
154 	if (ret)
155 		goto out_no_buddy;
156 
157 	return 0;
158 
159 out_no_buddy:
160 	io_mapping_fini(&mem->iomap);
161 
162 	return ret;
163 }
164 
165 static const struct intel_memory_region_ops intel_region_lmem_ops = {
166 	.init = region_lmem_init,
167 	.release = region_lmem_release,
168 	.init_object = __i915_gem_ttm_object_init,
169 };
170 
171 static bool get_legacy_lowmem_region(struct intel_uncore *uncore,
172 				     u64 *start, u32 *size)
173 {
174 	if (!IS_DG1(uncore->i915))
175 		return false;
176 
177 	*start = 0;
178 	*size = SZ_1M;
179 
180 	drm_dbg(&uncore->i915->drm, "LMEM: reserved legacy low-memory [0x%llx-0x%llx]\n",
181 		*start, *start + *size);
182 
183 	return true;
184 }
185 
186 static int reserve_lowmem_region(struct intel_uncore *uncore,
187 				 struct intel_memory_region *mem)
188 {
189 	u64 reserve_start;
190 	u32 reserve_size;
191 	int ret;
192 
193 	if (!get_legacy_lowmem_region(uncore, &reserve_start, &reserve_size))
194 		return 0;
195 
196 	ret = intel_memory_region_reserve(mem, reserve_start, reserve_size);
197 	if (ret)
198 		drm_err(&uncore->i915->drm, "LMEM: reserving low memory region failed\n");
199 
200 	return ret;
201 }
202 
203 static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
204 {
205 	struct drm_i915_private *i915 = gt->i915;
206 	struct intel_uncore *uncore = gt->uncore;
207 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
208 	struct intel_memory_region *mem;
209 	resource_size_t min_page_size;
210 	resource_size_t io_start;
211 	resource_size_t io_size;
212 	resource_size_t lmem_size;
213 	int err;
214 
215 	if (!IS_DGFX(i915))
216 		return ERR_PTR(-ENODEV);
217 
218 	if (!i915_pci_resource_valid(pdev, GEN12_LMEM_BAR))
219 		return ERR_PTR(-ENXIO);
220 
221 	if (HAS_FLAT_CCS(i915)) {
222 		resource_size_t lmem_range;
223 		u64 tile_stolen, flat_ccs_base;
224 
225 		lmem_range = intel_gt_mcr_read_any(to_gt(i915), XEHP_TILE0_ADDR_RANGE) & 0xFFFF;
226 		lmem_size = lmem_range >> XEHP_TILE_LMEM_RANGE_SHIFT;
227 		lmem_size *= SZ_1G;
228 
229 		flat_ccs_base = intel_gt_mcr_read_any(gt, XEHP_FLAT_CCS_BASE_ADDR);
230 		flat_ccs_base = (flat_ccs_base >> XEHP_CCS_BASE_SHIFT) * SZ_64K;
231 
232 		if (GEM_WARN_ON(lmem_size < flat_ccs_base))
233 			return ERR_PTR(-EIO);
234 
235 		tile_stolen = lmem_size - flat_ccs_base;
236 
237 		/* If the FLAT_CCS_BASE_ADDR register is not populated, flag an error */
238 		if (tile_stolen == lmem_size)
239 			drm_err(&i915->drm,
240 				"CCS_BASE_ADDR register did not have expected value\n");
241 
242 		lmem_size -= tile_stolen;
243 	} else {
244 		/* Stolen starts from GSMBASE without CCS */
245 		lmem_size = intel_uncore_read64(&i915->uncore, GEN6_GSMBASE);
246 	}
247 
248 	i915_resize_lmem_bar(i915, lmem_size);
249 
250 	if (i915->params.lmem_size > 0) {
251 		lmem_size = min_t(resource_size_t, lmem_size,
252 				  mul_u32_u32(i915->params.lmem_size, SZ_1M));
253 	}
254 
255 	io_start = pci_resource_start(pdev, GEN12_LMEM_BAR);
256 	io_size = min(pci_resource_len(pdev, GEN12_LMEM_BAR), lmem_size);
257 	if (!io_size)
258 		return ERR_PTR(-EIO);
259 
260 	min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K :
261 						I915_GTT_PAGE_SIZE_4K;
262 	mem = intel_memory_region_create(i915,
263 					 0,
264 					 lmem_size,
265 					 min_page_size,
266 					 io_start,
267 					 io_size,
268 					 INTEL_MEMORY_LOCAL,
269 					 0,
270 					 &intel_region_lmem_ops);
271 	if (IS_ERR(mem))
272 		return mem;
273 
274 	err = reserve_lowmem_region(uncore, mem);
275 	if (err)
276 		goto err_region_put;
277 
278 	if (io_size < lmem_size)
279 		drm_info(&i915->drm, "Using a reduced BAR size of %lluMiB. Consider enabling 'Resizable BAR' or similar, if available in the BIOS.\n",
280 			 (u64)io_size >> 20);
281 
282 	return mem;
283 
284 err_region_put:
285 	intel_memory_region_destroy(mem);
286 	return ERR_PTR(err);
287 }
288 
289 struct intel_memory_region *intel_gt_setup_lmem(struct intel_gt *gt)
290 {
291 	return setup_lmem(gt);
292 }
293