xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/cfg_space.c (revision 48c926cd)
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  *
60  * Use this function to write virtual cfg space memory.
61  * For standard cfg space, only RW bits can be changed,
62  * and we emulates the RW1C behavior of PCI_STATUS register.
63  */
64 static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
65 				   u8 *src, unsigned int bytes)
66 {
67 	u8 *cfg_base = vgpu_cfg_space(vgpu);
68 	u8 mask, new, old;
69 	int i = 0;
70 
71 	for (; i < bytes && (off + i < sizeof(pci_cfg_space_rw_bmp)); i++) {
72 		mask = pci_cfg_space_rw_bmp[off + i];
73 		old = cfg_base[off + i];
74 		new = src[i] & mask;
75 
76 		/**
77 		 * The PCI_STATUS high byte has RW1C bits, here
78 		 * emulates clear by writing 1 for these bits.
79 		 * Writing a 0b to RW1C bits has no effect.
80 		 */
81 		if (off + i == PCI_STATUS + 1)
82 			new = (~new & old) & mask;
83 
84 		cfg_base[off + i] = (old & ~mask) | new;
85 	}
86 
87 	/* For other configuration space directly copy as it is. */
88 	if (i < bytes)
89 		memcpy(cfg_base + off + i, src + i, bytes - i);
90 }
91 
92 /**
93  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space read
94  *
95  * Returns:
96  * Zero on success, negative error code if failed.
97  */
98 int intel_vgpu_emulate_cfg_read(struct intel_vgpu *vgpu, unsigned int offset,
99 	void *p_data, unsigned int bytes)
100 {
101 	if (WARN_ON(bytes > 4))
102 		return -EINVAL;
103 
104 	if (WARN_ON(offset + bytes > INTEL_GVT_MAX_CFG_SPACE_SZ))
105 		return -EINVAL;
106 
107 	memcpy(p_data, vgpu_cfg_space(vgpu) + offset, bytes);
108 	return 0;
109 }
110 
111 static int map_aperture(struct intel_vgpu *vgpu, bool map)
112 {
113 	u64 first_gfn, first_mfn;
114 	u64 val;
115 	int ret;
116 
117 	if (map == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked)
118 		return 0;
119 
120 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_2];
121 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
122 		val = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
123 	else
124 		val = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
125 
126 	first_gfn = (val + vgpu_aperture_offset(vgpu)) >> PAGE_SHIFT;
127 	first_mfn = vgpu_aperture_pa_base(vgpu) >> PAGE_SHIFT;
128 
129 	ret = intel_gvt_hypervisor_map_gfn_to_mfn(vgpu, first_gfn,
130 						  first_mfn,
131 						  vgpu_aperture_sz(vgpu) >>
132 						  PAGE_SHIFT, map);
133 	if (ret)
134 		return ret;
135 
136 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked = map;
137 	return 0;
138 }
139 
140 static int trap_gttmmio(struct intel_vgpu *vgpu, bool trap)
141 {
142 	u64 start, end;
143 	u64 val;
144 	int ret;
145 
146 	if (trap == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked)
147 		return 0;
148 
149 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_0];
150 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
151 		start = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
152 	else
153 		start = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
154 
155 	start &= ~GENMASK(3, 0);
156 	end = start + vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size - 1;
157 
158 	ret = intel_gvt_hypervisor_set_trap_area(vgpu, start, end, trap);
159 	if (ret)
160 		return ret;
161 
162 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked = trap;
163 	return 0;
164 }
165 
166 static int emulate_pci_command_write(struct intel_vgpu *vgpu,
167 	unsigned int offset, void *p_data, unsigned int bytes)
168 {
169 	u8 old = vgpu_cfg_space(vgpu)[offset];
170 	u8 new = *(u8 *)p_data;
171 	u8 changed = old ^ new;
172 	int ret;
173 
174 	vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
175 	if (!(changed & PCI_COMMAND_MEMORY))
176 		return 0;
177 
178 	if (old & PCI_COMMAND_MEMORY) {
179 		ret = trap_gttmmio(vgpu, false);
180 		if (ret)
181 			return ret;
182 		ret = map_aperture(vgpu, false);
183 		if (ret)
184 			return ret;
185 	} else {
186 		ret = trap_gttmmio(vgpu, true);
187 		if (ret)
188 			return ret;
189 		ret = map_aperture(vgpu, true);
190 		if (ret)
191 			return ret;
192 	}
193 
194 	return 0;
195 }
196 
197 static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
198 	void *p_data, unsigned int bytes)
199 {
200 	unsigned int bar_index =
201 		(rounddown(offset, 8) % PCI_BASE_ADDRESS_0) / 8;
202 	u32 new = *(u32 *)(p_data);
203 	bool lo = IS_ALIGNED(offset, 8);
204 	u64 size;
205 	int ret = 0;
206 	bool mmio_enabled =
207 		vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
208 
209 	if (WARN_ON(bar_index >= INTEL_GVT_PCI_BAR_MAX))
210 		return -EINVAL;
211 
212 	if (new == 0xffffffff) {
213 		/*
214 		 * Power-up software can determine how much address
215 		 * space the device requires by writing a value of
216 		 * all 1's to the register and then reading the value
217 		 * back. The device will return 0's in all don't-care
218 		 * address bits.
219 		 */
220 		size = vgpu->cfg_space.bar[bar_index].size;
221 		if (lo) {
222 			new = rounddown(new, size);
223 		} else {
224 			u32 val = vgpu_cfg_space(vgpu)[rounddown(offset, 8)];
225 			/* for 32bit mode bar it returns all-0 in upper 32
226 			 * bit, for 64bit mode bar it will calculate the
227 			 * size with lower 32bit and return the corresponding
228 			 * value
229 			 */
230 			if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
231 				new &= (~(size-1)) >> 32;
232 			else
233 				new = 0;
234 		}
235 		/*
236 		 * Unmapp & untrap the BAR, since guest hasn't configured a
237 		 * valid GPA
238 		 */
239 		switch (bar_index) {
240 		case INTEL_GVT_PCI_BAR_GTTMMIO:
241 			ret = trap_gttmmio(vgpu, false);
242 			break;
243 		case INTEL_GVT_PCI_BAR_APERTURE:
244 			ret = map_aperture(vgpu, false);
245 			break;
246 		}
247 		intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
248 	} else {
249 		/*
250 		 * Unmapp & untrap the old BAR first, since guest has
251 		 * re-configured the BAR
252 		 */
253 		switch (bar_index) {
254 		case INTEL_GVT_PCI_BAR_GTTMMIO:
255 			ret = trap_gttmmio(vgpu, false);
256 			break;
257 		case INTEL_GVT_PCI_BAR_APERTURE:
258 			ret = map_aperture(vgpu, false);
259 			break;
260 		}
261 		intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
262 		/* Track the new BAR */
263 		if (mmio_enabled) {
264 			switch (bar_index) {
265 			case INTEL_GVT_PCI_BAR_GTTMMIO:
266 				ret = trap_gttmmio(vgpu, true);
267 				break;
268 			case INTEL_GVT_PCI_BAR_APERTURE:
269 				ret = map_aperture(vgpu, true);
270 				break;
271 			}
272 		}
273 	}
274 	return ret;
275 }
276 
277 /**
278  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
279  *
280  * Returns:
281  * Zero on success, negative error code if failed.
282  */
283 int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset,
284 	void *p_data, unsigned int bytes)
285 {
286 	int ret;
287 
288 	if (WARN_ON(bytes > 4))
289 		return -EINVAL;
290 
291 	if (WARN_ON(offset + bytes > INTEL_GVT_MAX_CFG_SPACE_SZ))
292 		return -EINVAL;
293 
294 	/* First check if it's PCI_COMMAND */
295 	if (IS_ALIGNED(offset, 2) && offset == PCI_COMMAND) {
296 		if (WARN_ON(bytes > 2))
297 			return -EINVAL;
298 		return emulate_pci_command_write(vgpu, offset, p_data, bytes);
299 	}
300 
301 	switch (rounddown(offset, 4)) {
302 	case PCI_BASE_ADDRESS_0:
303 	case PCI_BASE_ADDRESS_1:
304 	case PCI_BASE_ADDRESS_2:
305 	case PCI_BASE_ADDRESS_3:
306 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
307 			return -EINVAL;
308 		return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
309 
310 	case INTEL_GVT_PCI_SWSCI:
311 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
312 			return -EINVAL;
313 		ret = intel_vgpu_emulate_opregion_request(vgpu, *(u32 *)p_data);
314 		if (ret)
315 			return ret;
316 		break;
317 
318 	case INTEL_GVT_PCI_OPREGION:
319 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
320 			return -EINVAL;
321 		ret = intel_vgpu_init_opregion(vgpu, *(u32 *)p_data);
322 		if (ret)
323 			return ret;
324 
325 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
326 		break;
327 	default:
328 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
329 		break;
330 	}
331 	return 0;
332 }
333 
334 /**
335  * intel_vgpu_init_cfg_space - init vGPU configuration space when create vGPU
336  *
337  * @vgpu: a vGPU
338  * @primary: is the vGPU presented as primary
339  *
340  */
341 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
342 			       bool primary)
343 {
344 	struct intel_gvt *gvt = vgpu->gvt;
345 	const struct intel_gvt_device_info *info = &gvt->device_info;
346 	u16 *gmch_ctl;
347 	int i;
348 
349 	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
350 	       info->cfg_space_size);
351 
352 	if (!primary) {
353 		vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] =
354 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
355 		vgpu_cfg_space(vgpu)[PCI_CLASS_PROG] =
356 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
357 	}
358 
359 	/* Show guest that there isn't any stolen memory.*/
360 	gmch_ctl = (u16 *)(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_GMCH_CONTROL);
361 	*gmch_ctl &= ~(BDW_GMCH_GMS_MASK << BDW_GMCH_GMS_SHIFT);
362 
363 	intel_vgpu_write_pci_bar(vgpu, PCI_BASE_ADDRESS_2,
364 				 gvt_aperture_pa_base(gvt), true);
365 
366 	vgpu_cfg_space(vgpu)[PCI_COMMAND] &= ~(PCI_COMMAND_IO
367 					     | PCI_COMMAND_MEMORY
368 					     | PCI_COMMAND_MASTER);
369 	/*
370 	 * Clear the bar upper 32bit and let guest to assign the new value
371 	 */
372 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
373 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
374 	memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);
375 
376 	for (i = 0; i < INTEL_GVT_MAX_BAR_NUM; i++) {
377 		vgpu->cfg_space.bar[i].size = pci_resource_len(
378 					      gvt->dev_priv->drm.pdev, i * 2);
379 		vgpu->cfg_space.bar[i].tracked = false;
380 	}
381 }
382 
383 /**
384  * intel_vgpu_reset_cfg_space - reset vGPU configuration space
385  *
386  * @vgpu: a vGPU
387  *
388  */
389 void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
390 {
391 	u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
392 	bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
393 				INTEL_GVT_PCI_CLASS_VGA_OTHER;
394 
395 	if (cmd & PCI_COMMAND_MEMORY) {
396 		trap_gttmmio(vgpu, false);
397 		map_aperture(vgpu, false);
398 	}
399 
400 	/**
401 	 * Currently we only do such reset when vGPU is not
402 	 * owned by any VM, so we simply restore entire cfg
403 	 * space to default value.
404 	 */
405 	intel_vgpu_init_cfg_space(vgpu, primary);
406 }
407