xref: /linux/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021-2023 Intel Corporation
4  * Copyright (C) 2021-2002 Red Hat
5  */
6 
7 #include <drm/drm_managed.h>
8 
9 #include <drm/ttm/ttm_device.h>
10 #include <drm/ttm/ttm_placement.h>
11 #include <drm/ttm/ttm_range_manager.h>
12 
13 #include <generated/xe_wa_oob.h>
14 
15 #include "regs/xe_bars.h"
16 #include "regs/xe_gt_regs.h"
17 #include "regs/xe_regs.h"
18 #include "xe_bo.h"
19 #include "xe_device.h"
20 #include "xe_gt.h"
21 #include "xe_gt_printk.h"
22 #include "xe_mmio.h"
23 #include "xe_res_cursor.h"
24 #include "xe_sriov.h"
25 #include "xe_ttm_stolen_mgr.h"
26 #include "xe_ttm_vram_mgr.h"
27 #include "xe_wa.h"
28 
29 struct xe_ttm_stolen_mgr {
30 	struct xe_ttm_vram_mgr base;
31 
32 	/* PCI base offset */
33 	resource_size_t io_base;
34 	/* GPU base offset */
35 	resource_size_t stolen_base;
36 
37 	void __iomem *mapping;
38 };
39 
40 static inline struct xe_ttm_stolen_mgr *
41 to_stolen_mgr(struct ttm_resource_manager *man)
42 {
43 	return container_of(man, struct xe_ttm_stolen_mgr, base.manager);
44 }
45 
46 /**
47  * xe_ttm_stolen_cpu_access_needs_ggtt() - If we can't directly CPU access
48  * stolen, can we then fallback to mapping through the GGTT.
49  * @xe: xe device
50  *
51  * Some older integrated platforms don't support reliable CPU access for stolen,
52  * however on such hardware we can always use the mappable part of the GGTT for
53  * CPU access. Check if that's the case for this device.
54  */
55 bool xe_ttm_stolen_cpu_access_needs_ggtt(struct xe_device *xe)
56 {
57 	return GRAPHICS_VERx100(xe) < 1270 && !IS_DGFX(xe);
58 }
59 
60 static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
61 {
62 	struct xe_tile *tile = xe_device_get_root_tile(xe);
63 	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
64 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
65 	u64 stolen_size;
66 	u64 tile_offset;
67 	u64 tile_size;
68 
69 	tile_offset = tile->mem.vram.io_start - xe->mem.vram.io_start;
70 	tile_size = tile->mem.vram.actual_physical_size;
71 
72 	/* Use DSM base address instead for stolen memory */
73 	mgr->stolen_base = (xe_mmio_read64_2x32(mmio, DSMBASE) & BDSM_MASK) - tile_offset;
74 	if (drm_WARN_ON(&xe->drm, tile_size < mgr->stolen_base))
75 		return 0;
76 
77 	stolen_size = tile_size - mgr->stolen_base;
78 
79 	/* Verify usage fits in the actual resource available */
80 	if (mgr->stolen_base + stolen_size <= pci_resource_len(pdev, LMEM_BAR))
81 		mgr->io_base = tile->mem.vram.io_start + mgr->stolen_base;
82 
83 	/*
84 	 * There may be few KB of platform dependent reserved memory at the end
85 	 * of vram which is not part of the DSM. Such reserved memory portion is
86 	 * always less then DSM granularity so align down the stolen_size to DSM
87 	 * granularity to accommodate such reserve vram portion.
88 	 */
89 	return ALIGN_DOWN(stolen_size, SZ_1M);
90 }
91 
92 static u32 get_wopcm_size(struct xe_device *xe)
93 {
94 	u32 wopcm_size;
95 	u64 val;
96 
97 	val = xe_mmio_read64_2x32(xe_root_tile_mmio(xe), STOLEN_RESERVED);
98 	val = REG_FIELD_GET64(WOPCM_SIZE_MASK, val);
99 
100 	switch (val) {
101 	case 0x5 ... 0x6:
102 		val--;
103 		fallthrough;
104 	case 0x0 ... 0x3:
105 		wopcm_size = (1U << val) * SZ_1M;
106 		break;
107 	default:
108 		WARN(1, "Missing case wopcm_size=%llx\n", val);
109 		wopcm_size = 0;
110 	}
111 
112 	return wopcm_size;
113 }
114 
115 static u32 detect_bar2_integrated(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
116 {
117 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
118 	struct xe_gt *media_gt = xe_device_get_root_tile(xe)->media_gt;
119 	u32 stolen_size, wopcm_size;
120 	u32 ggc, gms;
121 
122 	ggc = xe_mmio_read32(xe_root_tile_mmio(xe), GGC);
123 
124 	/*
125 	 * Check GGMS: it should be fixed 0x3 (8MB), which corresponds to the
126 	 * GTT size
127 	 */
128 	if (drm_WARN_ON(&xe->drm, (ggc & GGMS_MASK) != GGMS_MASK))
129 		return 0;
130 
131 	/*
132 	 * Graphics >= 1270 uses the offset to the GSMBASE as address in the
133 	 * PTEs, together with the DM flag being set. Previously there was no
134 	 * such flag so the address was the io_base.
135 	 *
136 	 * DSMBASE = GSMBASE + 8MB
137 	 */
138 	mgr->stolen_base = SZ_8M;
139 	mgr->io_base = pci_resource_start(pdev, 2) + mgr->stolen_base;
140 
141 	/* return valid GMS value, -EIO if invalid */
142 	gms = REG_FIELD_GET(GMS_MASK, ggc);
143 	switch (gms) {
144 	case 0x0 ... 0x04:
145 		stolen_size = gms * 32 * SZ_1M;
146 		break;
147 	case 0xf0 ... 0xfe:
148 		stolen_size = (gms - 0xf0 + 1) * 4 * SZ_1M;
149 		break;
150 	default:
151 		return 0;
152 	}
153 
154 	/* Carve out the top of DSM as it contains the reserved WOPCM region */
155 	wopcm_size = get_wopcm_size(xe);
156 	if (drm_WARN_ON(&xe->drm, !wopcm_size))
157 		return 0;
158 
159 	stolen_size -= wopcm_size;
160 
161 	if (media_gt && XE_WA(media_gt, 14019821291)) {
162 		u64 gscpsmi_base = xe_mmio_read64_2x32(&media_gt->mmio, GSCPSMI_BASE)
163 			& ~GENMASK_ULL(5, 0);
164 
165 		/*
166 		 * This workaround is primarily implemented by the BIOS.  We
167 		 * just need to figure out whether the BIOS has applied the
168 		 * workaround (meaning the programmed address falls within
169 		 * the DSM) and, if so, reserve that part of the DSM to
170 		 * prevent accidental reuse.  The DSM location should be just
171 		 * below the WOPCM.
172 		 */
173 		if (gscpsmi_base >= mgr->io_base &&
174 		    gscpsmi_base < mgr->io_base + stolen_size) {
175 			xe_gt_dbg(media_gt,
176 				  "Reserving %llu bytes of DSM for Wa_14019821291\n",
177 				  mgr->io_base + stolen_size - gscpsmi_base);
178 			stolen_size = gscpsmi_base - mgr->io_base;
179 		}
180 	}
181 
182 	if (drm_WARN_ON(&xe->drm, stolen_size + SZ_8M > pci_resource_len(pdev, 2)))
183 		return 0;
184 
185 	return stolen_size;
186 }
187 
188 extern struct resource intel_graphics_stolen_res;
189 
190 static u64 detect_stolen(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
191 {
192 #ifdef CONFIG_X86
193 	/* Map into GGTT */
194 	mgr->io_base = pci_resource_start(to_pci_dev(xe->drm.dev), 2);
195 
196 	/* Stolen memory is x86 only */
197 	mgr->stolen_base = intel_graphics_stolen_res.start;
198 	return resource_size(&intel_graphics_stolen_res);
199 #else
200 	return 0;
201 #endif
202 }
203 
204 void xe_ttm_stolen_mgr_init(struct xe_device *xe)
205 {
206 	struct xe_ttm_stolen_mgr *mgr = drmm_kzalloc(&xe->drm, sizeof(*mgr), GFP_KERNEL);
207 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
208 	u64 stolen_size, io_size;
209 	int err;
210 
211 	if (!mgr) {
212 		drm_dbg_kms(&xe->drm, "Stolen mgr init failed\n");
213 		return;
214 	}
215 
216 	if (IS_SRIOV_VF(xe))
217 		stolen_size = 0;
218 	else if (IS_DGFX(xe))
219 		stolen_size = detect_bar2_dgfx(xe, mgr);
220 	else if (GRAPHICS_VERx100(xe) >= 1270)
221 		stolen_size = detect_bar2_integrated(xe, mgr);
222 	else
223 		stolen_size = detect_stolen(xe, mgr);
224 
225 	if (!stolen_size) {
226 		drm_dbg_kms(&xe->drm, "No stolen memory support\n");
227 		return;
228 	}
229 
230 	/*
231 	 * We don't try to attempt partial visible support for stolen vram,
232 	 * since stolen is always at the end of vram, and the BAR size is pretty
233 	 * much always 256M, with small-bar.
234 	 */
235 	io_size = 0;
236 	if (mgr->io_base && !xe_ttm_stolen_cpu_access_needs_ggtt(xe))
237 		io_size = stolen_size;
238 
239 	err = __xe_ttm_vram_mgr_init(xe, &mgr->base, XE_PL_STOLEN, stolen_size,
240 				     io_size, PAGE_SIZE);
241 	if (err) {
242 		drm_dbg_kms(&xe->drm, "Stolen mgr init failed: %i\n", err);
243 		return;
244 	}
245 
246 	drm_dbg_kms(&xe->drm, "Initialized stolen memory support with %llu bytes\n",
247 		    stolen_size);
248 
249 	if (io_size)
250 		mgr->mapping = devm_ioremap_wc(&pdev->dev, mgr->io_base, io_size);
251 }
252 
253 u64 xe_ttm_stolen_io_offset(struct xe_bo *bo, u32 offset)
254 {
255 	struct xe_device *xe = xe_bo_device(bo);
256 	struct ttm_resource_manager *ttm_mgr = ttm_manager_type(&xe->ttm, XE_PL_STOLEN);
257 	struct xe_ttm_stolen_mgr *mgr = to_stolen_mgr(ttm_mgr);
258 	struct xe_res_cursor cur;
259 
260 	XE_WARN_ON(!mgr->io_base);
261 
262 	if (xe_ttm_stolen_cpu_access_needs_ggtt(xe))
263 		return mgr->io_base + xe_bo_ggtt_addr(bo) + offset;
264 
265 	xe_res_first(bo->ttm.resource, offset, 4096, &cur);
266 	return mgr->io_base + cur.start;
267 }
268 
269 static int __xe_ttm_stolen_io_mem_reserve_bar2(struct xe_device *xe,
270 					       struct xe_ttm_stolen_mgr *mgr,
271 					       struct ttm_resource *mem)
272 {
273 	struct xe_res_cursor cur;
274 
275 	if (!mgr->io_base)
276 		return -EIO;
277 
278 	xe_res_first(mem, 0, 4096, &cur);
279 	mem->bus.offset = cur.start;
280 
281 	drm_WARN_ON(&xe->drm, !(mem->placement & TTM_PL_FLAG_CONTIGUOUS));
282 
283 	if (mem->placement & TTM_PL_FLAG_CONTIGUOUS && mgr->mapping)
284 		mem->bus.addr = (u8 __force *)mgr->mapping + mem->bus.offset;
285 
286 	mem->bus.offset += mgr->io_base;
287 	mem->bus.is_iomem = true;
288 	mem->bus.caching = ttm_write_combined;
289 
290 	return 0;
291 }
292 
293 static int __xe_ttm_stolen_io_mem_reserve_stolen(struct xe_device *xe,
294 						 struct xe_ttm_stolen_mgr *mgr,
295 						 struct ttm_resource *mem)
296 {
297 #ifdef CONFIG_X86
298 	struct xe_bo *bo = ttm_to_xe_bo(mem->bo);
299 
300 	XE_WARN_ON(IS_DGFX(xe));
301 
302 	/* XXX: Require BO to be mapped to GGTT? */
303 	if (drm_WARN_ON(&xe->drm, !(bo->flags & XE_BO_FLAG_GGTT)))
304 		return -EIO;
305 
306 	/* GGTT is always contiguously mapped */
307 	mem->bus.offset = xe_bo_ggtt_addr(bo) + mgr->io_base;
308 
309 	mem->bus.is_iomem = true;
310 	mem->bus.caching = ttm_write_combined;
311 
312 	return 0;
313 #else
314 	/* How is it even possible to get here without gen12 stolen? */
315 	drm_WARN_ON(&xe->drm, 1);
316 	return -EIO;
317 #endif
318 }
319 
320 int xe_ttm_stolen_io_mem_reserve(struct xe_device *xe, struct ttm_resource *mem)
321 {
322 	struct ttm_resource_manager *ttm_mgr = ttm_manager_type(&xe->ttm, XE_PL_STOLEN);
323 	struct xe_ttm_stolen_mgr *mgr = ttm_mgr ? to_stolen_mgr(ttm_mgr) : NULL;
324 
325 	if (!mgr || !mgr->io_base)
326 		return -EIO;
327 
328 	if (xe_ttm_stolen_cpu_access_needs_ggtt(xe))
329 		return __xe_ttm_stolen_io_mem_reserve_stolen(xe, mgr, mem);
330 	else
331 		return __xe_ttm_stolen_io_mem_reserve_bar2(xe, mgr, mem);
332 }
333 
334 u64 xe_ttm_stolen_gpu_offset(struct xe_device *xe)
335 {
336 	struct xe_ttm_stolen_mgr *mgr =
337 		to_stolen_mgr(ttm_manager_type(&xe->ttm, XE_PL_STOLEN));
338 
339 	return mgr->stolen_base;
340 }
341