xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/mmio.c (revision 171fa692)
1 /*
2  * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Ke Yu
25  *    Kevin Tian <kevin.tian@intel.com>
26  *    Dexuan Cui
27  *
28  * Contributors:
29  *    Tina Zhang <tina.zhang@intel.com>
30  *    Min He <min.he@intel.com>
31  *    Niu Bing <bing.niu@intel.com>
32  *    Zhi Wang <zhi.a.wang@intel.com>
33  *
34  */
35 
36 #include "i915_drv.h"
37 #include "gvt.h"
38 
39 /**
40  * intel_vgpu_gpa_to_mmio_offset - translate a GPA to MMIO offset
41  * @vgpu: a vGPU
42  *
43  * Returns:
44  * Zero on success, negative error code if failed
45  */
46 int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa)
47 {
48 	u64 gttmmio_gpa = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0) &
49 			  ~GENMASK(3, 0);
50 	return gpa - gttmmio_gpa;
51 }
52 
53 #define reg_is_mmio(gvt, reg)  \
54 	(reg >= 0 && reg < gvt->device_info.mmio_size)
55 
56 #define reg_is_gtt(gvt, reg)   \
57 	(reg >= gvt->device_info.gtt_start_offset \
58 	 && reg < gvt->device_info.gtt_start_offset + gvt_ggtt_sz(gvt))
59 
60 static void failsafe_emulate_mmio_rw(struct intel_vgpu *vgpu, uint64_t pa,
61 		void *p_data, unsigned int bytes, bool read)
62 {
63 	struct intel_gvt *gvt = NULL;
64 	void *pt = NULL;
65 	unsigned int offset = 0;
66 
67 	if (!vgpu || !p_data)
68 		return;
69 
70 	gvt = vgpu->gvt;
71 	mutex_lock(&gvt->lock);
72 	offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa);
73 	if (reg_is_mmio(gvt, offset)) {
74 		if (read)
75 			intel_vgpu_default_mmio_read(vgpu, offset, p_data,
76 					bytes);
77 		else
78 			intel_vgpu_default_mmio_write(vgpu, offset, p_data,
79 					bytes);
80 	} else if (reg_is_gtt(gvt, offset) &&
81 			vgpu->gtt.ggtt_mm->virtual_page_table) {
82 		offset -= gvt->device_info.gtt_start_offset;
83 		pt = vgpu->gtt.ggtt_mm->virtual_page_table + offset;
84 		if (read)
85 			memcpy(p_data, pt, bytes);
86 		else
87 			memcpy(pt, p_data, bytes);
88 
89 	} else if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
90 		struct intel_vgpu_guest_page *gp;
91 
92 		/* Since we enter the failsafe mode early during guest boot,
93 		 * guest may not have chance to set up its ppgtt table, so
94 		 * there should not be any wp pages for guest. Keep the wp
95 		 * related code here in case we need to handle it in furture.
96 		 */
97 		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
98 		if (gp) {
99 			/* remove write protection to prevent furture traps */
100 			intel_vgpu_clean_guest_page(vgpu, gp);
101 			if (read)
102 				intel_gvt_hypervisor_read_gpa(vgpu, pa,
103 						p_data, bytes);
104 			else
105 				intel_gvt_hypervisor_write_gpa(vgpu, pa,
106 						p_data, bytes);
107 		}
108 	}
109 	mutex_unlock(&gvt->lock);
110 }
111 
112 /**
113  * intel_vgpu_emulate_mmio_read - emulate MMIO read
114  * @vgpu: a vGPU
115  * @pa: guest physical address
116  * @p_data: data return buffer
117  * @bytes: access data length
118  *
119  * Returns:
120  * Zero on success, negative error code if failed
121  */
122 int intel_vgpu_emulate_mmio_read(struct intel_vgpu *vgpu, uint64_t pa,
123 		void *p_data, unsigned int bytes)
124 {
125 	struct intel_gvt *gvt = vgpu->gvt;
126 	struct intel_gvt_mmio_info *mmio;
127 	unsigned int offset = 0;
128 	int ret = -EINVAL;
129 
130 
131 	if (vgpu->failsafe) {
132 		failsafe_emulate_mmio_rw(vgpu, pa, p_data, bytes, true);
133 		return 0;
134 	}
135 	mutex_lock(&gvt->lock);
136 
137 	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
138 		struct intel_vgpu_guest_page *gp;
139 
140 		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
141 		if (gp) {
142 			ret = intel_gvt_hypervisor_read_gpa(vgpu, pa,
143 					p_data, bytes);
144 			if (ret) {
145 				gvt_vgpu_err("guest page read error %d, "
146 					"gfn 0x%lx, pa 0x%llx, var 0x%x, len %d\n",
147 					ret, gp->gfn, pa, *(u32 *)p_data,
148 					bytes);
149 			}
150 			mutex_unlock(&gvt->lock);
151 			return ret;
152 		}
153 	}
154 
155 	offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa);
156 
157 	if (WARN_ON(bytes > 8))
158 		goto err;
159 
160 	if (reg_is_gtt(gvt, offset)) {
161 		if (WARN_ON(!IS_ALIGNED(offset, 4) && !IS_ALIGNED(offset, 8)))
162 			goto err;
163 		if (WARN_ON(bytes != 4 && bytes != 8))
164 			goto err;
165 		if (WARN_ON(!reg_is_gtt(gvt, offset + bytes - 1)))
166 			goto err;
167 
168 		ret = intel_vgpu_emulate_gtt_mmio_read(vgpu, offset,
169 				p_data, bytes);
170 		if (ret)
171 			goto err;
172 		mutex_unlock(&gvt->lock);
173 		return ret;
174 	}
175 
176 	if (WARN_ON_ONCE(!reg_is_mmio(gvt, offset))) {
177 		ret = intel_gvt_hypervisor_read_gpa(vgpu, pa, p_data, bytes);
178 		mutex_unlock(&gvt->lock);
179 		return ret;
180 	}
181 
182 	if (WARN_ON(!reg_is_mmio(gvt, offset + bytes - 1)))
183 		goto err;
184 
185 	if (!intel_gvt_mmio_is_unalign(gvt, offset)) {
186 		if (WARN_ON(!IS_ALIGNED(offset, bytes)))
187 			goto err;
188 	}
189 
190 	mmio = intel_gvt_find_mmio_info(gvt, rounddown(offset, 4));
191 	if (mmio) {
192 		if (!intel_gvt_mmio_is_unalign(gvt, mmio->offset)) {
193 			if (WARN_ON(offset + bytes > mmio->offset + mmio->size))
194 				goto err;
195 			if (WARN_ON(mmio->offset != offset))
196 				goto err;
197 		}
198 		ret = mmio->read(vgpu, offset, p_data, bytes);
199 	} else {
200 		ret = intel_vgpu_default_mmio_read(vgpu, offset, p_data, bytes);
201 
202 		if (!vgpu->mmio.disable_warn_untrack) {
203 			gvt_vgpu_err("read untracked MMIO %x(%dB) val %x\n",
204 				offset, bytes, *(u32 *)p_data);
205 
206 			if (offset == 0x206c) {
207 				gvt_vgpu_err("------------------------------------------\n");
208 				gvt_vgpu_err("likely triggers a gfx reset\n");
209 				gvt_vgpu_err("------------------------------------------\n");
210 				vgpu->mmio.disable_warn_untrack = true;
211 			}
212 		}
213 	}
214 
215 	if (ret)
216 		goto err;
217 
218 	intel_gvt_mmio_set_accessed(gvt, offset);
219 	mutex_unlock(&gvt->lock);
220 	return 0;
221 err:
222 	gvt_vgpu_err("fail to emulate MMIO read %08x len %d\n",
223 			offset, bytes);
224 	mutex_unlock(&gvt->lock);
225 	return ret;
226 }
227 
228 /**
229  * intel_vgpu_emulate_mmio_write - emulate MMIO write
230  * @vgpu: a vGPU
231  * @pa: guest physical address
232  * @p_data: write data buffer
233  * @bytes: access data length
234  *
235  * Returns:
236  * Zero on success, negative error code if failed
237  */
238 int intel_vgpu_emulate_mmio_write(struct intel_vgpu *vgpu, uint64_t pa,
239 		void *p_data, unsigned int bytes)
240 {
241 	struct intel_gvt *gvt = vgpu->gvt;
242 	struct intel_gvt_mmio_info *mmio;
243 	unsigned int offset = 0;
244 	u32 old_vreg = 0, old_sreg = 0;
245 	int ret = -EINVAL;
246 
247 	if (vgpu->failsafe) {
248 		failsafe_emulate_mmio_rw(vgpu, pa, p_data, bytes, false);
249 		return 0;
250 	}
251 
252 	mutex_lock(&gvt->lock);
253 
254 	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
255 		struct intel_vgpu_guest_page *gp;
256 
257 		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
258 		if (gp) {
259 			ret = gp->handler(gp, pa, p_data, bytes);
260 			if (ret) {
261 				gvt_err("guest page write error %d, "
262 					"gfn 0x%lx, pa 0x%llx, "
263 					"var 0x%x, len %d\n",
264 					ret, gp->gfn, pa,
265 					*(u32 *)p_data, bytes);
266 			}
267 			mutex_unlock(&gvt->lock);
268 			return ret;
269 		}
270 	}
271 
272 	offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa);
273 
274 	if (WARN_ON(bytes > 8))
275 		goto err;
276 
277 	if (reg_is_gtt(gvt, offset)) {
278 		if (WARN_ON(!IS_ALIGNED(offset, 4) && !IS_ALIGNED(offset, 8)))
279 			goto err;
280 		if (WARN_ON(bytes != 4 && bytes != 8))
281 			goto err;
282 		if (WARN_ON(!reg_is_gtt(gvt, offset + bytes - 1)))
283 			goto err;
284 
285 		ret = intel_vgpu_emulate_gtt_mmio_write(vgpu, offset,
286 				p_data, bytes);
287 		if (ret)
288 			goto err;
289 		mutex_unlock(&gvt->lock);
290 		return ret;
291 	}
292 
293 	if (WARN_ON_ONCE(!reg_is_mmio(gvt, offset))) {
294 		ret = intel_gvt_hypervisor_write_gpa(vgpu, pa, p_data, bytes);
295 		mutex_unlock(&gvt->lock);
296 		return ret;
297 	}
298 
299 	mmio = intel_gvt_find_mmio_info(gvt, rounddown(offset, 4));
300 	if (!mmio && !vgpu->mmio.disable_warn_untrack)
301 		gvt_dbg_mmio("vgpu%d: write untracked MMIO %x len %d val %x\n",
302 				vgpu->id, offset, bytes, *(u32 *)p_data);
303 
304 	if (!intel_gvt_mmio_is_unalign(gvt, offset)) {
305 		if (WARN_ON(!IS_ALIGNED(offset, bytes)))
306 			goto err;
307 	}
308 
309 	if (mmio) {
310 		u64 ro_mask = mmio->ro_mask;
311 
312 		if (!intel_gvt_mmio_is_unalign(gvt, mmio->offset)) {
313 			if (WARN_ON(offset + bytes > mmio->offset + mmio->size))
314 				goto err;
315 			if (WARN_ON(mmio->offset != offset))
316 				goto err;
317 		}
318 
319 		if (intel_gvt_mmio_has_mode_mask(gvt, mmio->offset)) {
320 			old_vreg = vgpu_vreg(vgpu, offset);
321 			old_sreg = vgpu_sreg(vgpu, offset);
322 		}
323 
324 		if (!ro_mask) {
325 			ret = mmio->write(vgpu, offset, p_data, bytes);
326 		} else {
327 			/* Protect RO bits like HW */
328 			u64 data = 0;
329 
330 			/* all register bits are RO. */
331 			if (ro_mask == ~(u64)0) {
332 				gvt_vgpu_err("try to write RO reg %x\n",
333 					offset);
334 				ret = 0;
335 				goto out;
336 			}
337 			/* keep the RO bits in the virtual register */
338 			memcpy(&data, p_data, bytes);
339 			data &= ~mmio->ro_mask;
340 			data |= vgpu_vreg(vgpu, offset) & mmio->ro_mask;
341 			ret = mmio->write(vgpu, offset, &data, bytes);
342 		}
343 
344 		/* higher 16bits of mode ctl regs are mask bits for change */
345 		if (intel_gvt_mmio_has_mode_mask(gvt, mmio->offset)) {
346 			u32 mask = vgpu_vreg(vgpu, offset) >> 16;
347 
348 			vgpu_vreg(vgpu, offset) = (old_vreg & ~mask)
349 				| (vgpu_vreg(vgpu, offset) & mask);
350 			vgpu_sreg(vgpu, offset) = (old_sreg & ~mask)
351 				| (vgpu_sreg(vgpu, offset) & mask);
352 		}
353 	} else
354 		ret = intel_vgpu_default_mmio_write(vgpu, offset, p_data,
355 				bytes);
356 	if (ret)
357 		goto err;
358 out:
359 	intel_gvt_mmio_set_accessed(gvt, offset);
360 	mutex_unlock(&gvt->lock);
361 	return 0;
362 err:
363 	gvt_vgpu_err("fail to emulate MMIO write %08x len %d\n", offset,
364 		     bytes);
365 	mutex_unlock(&gvt->lock);
366 	return ret;
367 }
368 
369 
370 /**
371  * intel_vgpu_reset_mmio - reset virtual MMIO space
372  * @vgpu: a vGPU
373  *
374  */
375 void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu)
376 {
377 	struct intel_gvt *gvt = vgpu->gvt;
378 	const struct intel_gvt_device_info *info = &gvt->device_info;
379 
380 	memcpy(vgpu->mmio.vreg, gvt->firmware.mmio, info->mmio_size);
381 	memcpy(vgpu->mmio.sreg, gvt->firmware.mmio, info->mmio_size);
382 
383 	vgpu_vreg(vgpu, GEN6_GT_THREAD_STATUS_REG) = 0;
384 
385 	/* set the bit 0:2(Core C-State ) to C0 */
386 	vgpu_vreg(vgpu, GEN6_GT_CORE_STATUS) = 0;
387 
388 	vgpu->mmio.disable_warn_untrack = false;
389 }
390 
391 /**
392  * intel_vgpu_init_mmio - init MMIO  space
393  * @vgpu: a vGPU
394  *
395  * Returns:
396  * Zero on success, negative error code if failed
397  */
398 int intel_vgpu_init_mmio(struct intel_vgpu *vgpu)
399 {
400 	const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
401 
402 	vgpu->mmio.vreg = vzalloc(info->mmio_size * 2);
403 	if (!vgpu->mmio.vreg)
404 		return -ENOMEM;
405 
406 	vgpu->mmio.sreg = vgpu->mmio.vreg + info->mmio_size;
407 
408 	intel_vgpu_reset_mmio(vgpu);
409 
410 	return 0;
411 }
412 
413 /**
414  * intel_vgpu_clean_mmio - clean MMIO space
415  * @vgpu: a vGPU
416  *
417  */
418 void intel_vgpu_clean_mmio(struct intel_vgpu *vgpu)
419 {
420 	vfree(vgpu->mmio.vreg);
421 	vgpu->mmio.vreg = vgpu->mmio.sreg = NULL;
422 }
423