xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/cfg_space.c (revision 15e3ae36)
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  *    Eddie Dong <eddie.dong@intel.com>
25  *    Jike Song <jike.song@intel.com>
26  *
27  * Contributors:
28  *    Zhi Wang <zhi.a.wang@intel.com>
29  *    Min He <min.he@intel.com>
30  *    Bing Niu <bing.niu@intel.com>
31  *
32  */
33 
34 #include "i915_drv.h"
35 #include "gvt.h"
36 
37 enum {
38 	INTEL_GVT_PCI_BAR_GTTMMIO = 0,
39 	INTEL_GVT_PCI_BAR_APERTURE,
40 	INTEL_GVT_PCI_BAR_PIO,
41 	INTEL_GVT_PCI_BAR_MAX,
42 };
43 
44 /* bitmap for writable bits (RW or RW1C bits, but cannot co-exist in one
45  * byte) byte by byte in standard pci configuration space. (not the full
46  * 256 bytes.)
47  */
48 static const u8 pci_cfg_space_rw_bmp[PCI_INTERRUPT_LINE + 4] = {
49 	[PCI_COMMAND]		= 0xff, 0x07,
50 	[PCI_STATUS]		= 0x00, 0xf9, /* the only one RW1C byte */
51 	[PCI_CACHE_LINE_SIZE]	= 0xff,
52 	[PCI_BASE_ADDRESS_0 ... PCI_CARDBUS_CIS - 1] = 0xff,
53 	[PCI_ROM_ADDRESS]	= 0x01, 0xf8, 0xff, 0xff,
54 	[PCI_INTERRUPT_LINE]	= 0xff,
55 };
56 
57 /**
58  * vgpu_pci_cfg_mem_write - write virtual cfg space memory
59  * @vgpu: target vgpu
60  * @off: offset
61  * @src: src ptr to write
62  * @bytes: number of bytes
63  *
64  * Use this function to write virtual cfg space memory.
65  * For standard cfg space, only RW bits can be changed,
66  * and we emulates the RW1C behavior of PCI_STATUS register.
67  */
68 static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
69 				   u8 *src, unsigned int bytes)
70 {
71 	u8 *cfg_base = vgpu_cfg_space(vgpu);
72 	u8 mask, new, old;
73 	int i = 0;
74 
75 	for (; i < bytes && (off + i < sizeof(pci_cfg_space_rw_bmp)); i++) {
76 		mask = pci_cfg_space_rw_bmp[off + i];
77 		old = cfg_base[off + i];
78 		new = src[i] & mask;
79 
80 		/**
81 		 * The PCI_STATUS high byte has RW1C bits, here
82 		 * emulates clear by writing 1 for these bits.
83 		 * Writing a 0b to RW1C bits has no effect.
84 		 */
85 		if (off + i == PCI_STATUS + 1)
86 			new = (~new & old) & mask;
87 
88 		cfg_base[off + i] = (old & ~mask) | new;
89 	}
90 
91 	/* For other configuration space directly copy as it is. */
92 	if (i < bytes)
93 		memcpy(cfg_base + off + i, src + i, bytes - i);
94 }
95 
96 /**
97  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space read
98  * @vgpu: target vgpu
99  * @offset: offset
100  * @p_data: return data ptr
101  * @bytes: number of bytes to read
102  *
103  * Returns:
104  * Zero on success, negative error code if failed.
105  */
106 int intel_vgpu_emulate_cfg_read(struct intel_vgpu *vgpu, unsigned int offset,
107 	void *p_data, unsigned int bytes)
108 {
109 	struct drm_i915_private *i915 = vgpu->gvt->gt->i915;
110 
111 	if (drm_WARN_ON(&i915->drm, bytes > 4))
112 		return -EINVAL;
113 
114 	if (drm_WARN_ON(&i915->drm,
115 			offset + bytes > vgpu->gvt->device_info.cfg_space_size))
116 		return -EINVAL;
117 
118 	memcpy(p_data, vgpu_cfg_space(vgpu) + offset, bytes);
119 	return 0;
120 }
121 
122 static int map_aperture(struct intel_vgpu *vgpu, bool map)
123 {
124 	phys_addr_t aperture_pa = vgpu_aperture_pa_base(vgpu);
125 	unsigned long aperture_sz = vgpu_aperture_sz(vgpu);
126 	u64 first_gfn;
127 	u64 val;
128 	int ret;
129 
130 	if (map == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked)
131 		return 0;
132 
133 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_2];
134 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
135 		val = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
136 	else
137 		val = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
138 
139 	first_gfn = (val + vgpu_aperture_offset(vgpu)) >> PAGE_SHIFT;
140 
141 	ret = intel_gvt_hypervisor_map_gfn_to_mfn(vgpu, first_gfn,
142 						  aperture_pa >> PAGE_SHIFT,
143 						  aperture_sz >> PAGE_SHIFT,
144 						  map);
145 	if (ret)
146 		return ret;
147 
148 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked = map;
149 	return 0;
150 }
151 
152 static int trap_gttmmio(struct intel_vgpu *vgpu, bool trap)
153 {
154 	u64 start, end;
155 	u64 val;
156 	int ret;
157 
158 	if (trap == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked)
159 		return 0;
160 
161 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_0];
162 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
163 		start = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
164 	else
165 		start = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
166 
167 	start &= ~GENMASK(3, 0);
168 	end = start + vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size - 1;
169 
170 	ret = intel_gvt_hypervisor_set_trap_area(vgpu, start, end, trap);
171 	if (ret)
172 		return ret;
173 
174 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked = trap;
175 	return 0;
176 }
177 
178 static int emulate_pci_command_write(struct intel_vgpu *vgpu,
179 	unsigned int offset, void *p_data, unsigned int bytes)
180 {
181 	u8 old = vgpu_cfg_space(vgpu)[offset];
182 	u8 new = *(u8 *)p_data;
183 	u8 changed = old ^ new;
184 	int ret;
185 
186 	vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
187 	if (!(changed & PCI_COMMAND_MEMORY))
188 		return 0;
189 
190 	if (old & PCI_COMMAND_MEMORY) {
191 		ret = trap_gttmmio(vgpu, false);
192 		if (ret)
193 			return ret;
194 		ret = map_aperture(vgpu, false);
195 		if (ret)
196 			return ret;
197 	} else {
198 		ret = trap_gttmmio(vgpu, true);
199 		if (ret)
200 			return ret;
201 		ret = map_aperture(vgpu, true);
202 		if (ret)
203 			return ret;
204 	}
205 
206 	return 0;
207 }
208 
209 static int emulate_pci_rom_bar_write(struct intel_vgpu *vgpu,
210 	unsigned int offset, void *p_data, unsigned int bytes)
211 {
212 	u32 *pval = (u32 *)(vgpu_cfg_space(vgpu) + offset);
213 	u32 new = *(u32 *)(p_data);
214 
215 	if ((new & PCI_ROM_ADDRESS_MASK) == PCI_ROM_ADDRESS_MASK)
216 		/* We don't have rom, return size of 0. */
217 		*pval = 0;
218 	else
219 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
220 	return 0;
221 }
222 
223 static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
224 	void *p_data, unsigned int bytes)
225 {
226 	u32 new = *(u32 *)(p_data);
227 	bool lo = IS_ALIGNED(offset, 8);
228 	u64 size;
229 	int ret = 0;
230 	bool mmio_enabled =
231 		vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
232 	struct intel_vgpu_pci_bar *bars = vgpu->cfg_space.bar;
233 
234 	/*
235 	 * Power-up software can determine how much address
236 	 * space the device requires by writing a value of
237 	 * all 1's to the register and then reading the value
238 	 * back. The device will return 0's in all don't-care
239 	 * address bits.
240 	 */
241 	if (new == 0xffffffff) {
242 		switch (offset) {
243 		case PCI_BASE_ADDRESS_0:
244 		case PCI_BASE_ADDRESS_1:
245 			size = ~(bars[INTEL_GVT_PCI_BAR_GTTMMIO].size -1);
246 			intel_vgpu_write_pci_bar(vgpu, offset,
247 						size >> (lo ? 0 : 32), lo);
248 			/*
249 			 * Untrap the BAR, since guest hasn't configured a
250 			 * valid GPA
251 			 */
252 			ret = trap_gttmmio(vgpu, false);
253 			break;
254 		case PCI_BASE_ADDRESS_2:
255 		case PCI_BASE_ADDRESS_3:
256 			size = ~(bars[INTEL_GVT_PCI_BAR_APERTURE].size -1);
257 			intel_vgpu_write_pci_bar(vgpu, offset,
258 						size >> (lo ? 0 : 32), lo);
259 			ret = map_aperture(vgpu, false);
260 			break;
261 		default:
262 			/* Unimplemented BARs */
263 			intel_vgpu_write_pci_bar(vgpu, offset, 0x0, false);
264 		}
265 	} else {
266 		switch (offset) {
267 		case PCI_BASE_ADDRESS_0:
268 		case PCI_BASE_ADDRESS_1:
269 			/*
270 			 * Untrap the old BAR first, since guest has
271 			 * re-configured the BAR
272 			 */
273 			trap_gttmmio(vgpu, false);
274 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
275 			ret = trap_gttmmio(vgpu, mmio_enabled);
276 			break;
277 		case PCI_BASE_ADDRESS_2:
278 		case PCI_BASE_ADDRESS_3:
279 			map_aperture(vgpu, false);
280 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
281 			ret = map_aperture(vgpu, mmio_enabled);
282 			break;
283 		default:
284 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
285 		}
286 	}
287 	return ret;
288 }
289 
290 /**
291  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
292  * @vgpu: target vgpu
293  * @offset: offset
294  * @p_data: write data ptr
295  * @bytes: number of bytes to write
296  *
297  * Returns:
298  * Zero on success, negative error code if failed.
299  */
300 int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset,
301 	void *p_data, unsigned int bytes)
302 {
303 	struct drm_i915_private *i915 = vgpu->gvt->gt->i915;
304 	int ret;
305 
306 	if (drm_WARN_ON(&i915->drm, bytes > 4))
307 		return -EINVAL;
308 
309 	if (drm_WARN_ON(&i915->drm,
310 			offset + bytes > vgpu->gvt->device_info.cfg_space_size))
311 		return -EINVAL;
312 
313 	/* First check if it's PCI_COMMAND */
314 	if (IS_ALIGNED(offset, 2) && offset == PCI_COMMAND) {
315 		if (drm_WARN_ON(&i915->drm, bytes > 2))
316 			return -EINVAL;
317 		return emulate_pci_command_write(vgpu, offset, p_data, bytes);
318 	}
319 
320 	switch (rounddown(offset, 4)) {
321 	case PCI_ROM_ADDRESS:
322 		if (drm_WARN_ON(&i915->drm, !IS_ALIGNED(offset, 4)))
323 			return -EINVAL;
324 		return emulate_pci_rom_bar_write(vgpu, offset, p_data, bytes);
325 
326 	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5:
327 		if (drm_WARN_ON(&i915->drm, !IS_ALIGNED(offset, 4)))
328 			return -EINVAL;
329 		return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
330 
331 	case INTEL_GVT_PCI_SWSCI:
332 		if (drm_WARN_ON(&i915->drm, !IS_ALIGNED(offset, 4)))
333 			return -EINVAL;
334 		ret = intel_vgpu_emulate_opregion_request(vgpu, *(u32 *)p_data);
335 		if (ret)
336 			return ret;
337 		break;
338 
339 	case INTEL_GVT_PCI_OPREGION:
340 		if (drm_WARN_ON(&i915->drm, !IS_ALIGNED(offset, 4)))
341 			return -EINVAL;
342 		ret = intel_vgpu_opregion_base_write_handler(vgpu,
343 						   *(u32 *)p_data);
344 		if (ret)
345 			return ret;
346 
347 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
348 		break;
349 	default:
350 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
351 		break;
352 	}
353 	return 0;
354 }
355 
356 /**
357  * intel_vgpu_init_cfg_space - init vGPU configuration space when create vGPU
358  *
359  * @vgpu: a vGPU
360  * @primary: is the vGPU presented as primary
361  *
362  */
363 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
364 			       bool primary)
365 {
366 	struct intel_gvt *gvt = vgpu->gvt;
367 	const struct intel_gvt_device_info *info = &gvt->device_info;
368 	u16 *gmch_ctl;
369 
370 	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
371 	       info->cfg_space_size);
372 
373 	if (!primary) {
374 		vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] =
375 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
376 		vgpu_cfg_space(vgpu)[PCI_CLASS_PROG] =
377 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
378 	}
379 
380 	/* Show guest that there isn't any stolen memory.*/
381 	gmch_ctl = (u16 *)(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_GMCH_CONTROL);
382 	*gmch_ctl &= ~(BDW_GMCH_GMS_MASK << BDW_GMCH_GMS_SHIFT);
383 
384 	intel_vgpu_write_pci_bar(vgpu, PCI_BASE_ADDRESS_2,
385 				 gvt_aperture_pa_base(gvt), true);
386 
387 	vgpu_cfg_space(vgpu)[PCI_COMMAND] &= ~(PCI_COMMAND_IO
388 					     | PCI_COMMAND_MEMORY
389 					     | PCI_COMMAND_MASTER);
390 	/*
391 	 * Clear the bar upper 32bit and let guest to assign the new value
392 	 */
393 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
394 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
395 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_4, 0, 8);
396 	memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);
397 
398 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size =
399 		pci_resource_len(gvt->gt->i915->drm.pdev, 0);
400 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].size =
401 		pci_resource_len(gvt->gt->i915->drm.pdev, 2);
402 
403 	memset(vgpu_cfg_space(vgpu) + PCI_ROM_ADDRESS, 0, 4);
404 }
405 
406 /**
407  * intel_vgpu_reset_cfg_space - reset vGPU configuration space
408  *
409  * @vgpu: a vGPU
410  *
411  */
412 void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
413 {
414 	u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
415 	bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
416 				INTEL_GVT_PCI_CLASS_VGA_OTHER;
417 
418 	if (cmd & PCI_COMMAND_MEMORY) {
419 		trap_gttmmio(vgpu, false);
420 		map_aperture(vgpu, false);
421 	}
422 
423 	/**
424 	 * Currently we only do such reset when vGPU is not
425 	 * owned by any VM, so we simply restore entire cfg
426 	 * space to default value.
427 	 */
428 	intel_vgpu_init_cfg_space(vgpu, primary);
429 }
430