xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/cfg_space.c (revision 727dede0)
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 	u32 new = *(u32 *)(p_data);
201 	bool lo = IS_ALIGNED(offset, 8);
202 	u64 size;
203 	int ret = 0;
204 	bool mmio_enabled =
205 		vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
206 	struct intel_vgpu_pci_bar *bars = vgpu->cfg_space.bar;
207 
208 	/*
209 	 * Power-up software can determine how much address
210 	 * space the device requires by writing a value of
211 	 * all 1's to the register and then reading the value
212 	 * back. The device will return 0's in all don't-care
213 	 * address bits.
214 	 */
215 	if (new == 0xffffffff) {
216 		switch (offset) {
217 		case PCI_BASE_ADDRESS_0:
218 		case PCI_BASE_ADDRESS_1:
219 			size = ~(bars[INTEL_GVT_PCI_BAR_GTTMMIO].size -1);
220 			intel_vgpu_write_pci_bar(vgpu, offset,
221 						size >> (lo ? 0 : 32), lo);
222 			/*
223 			 * Untrap the BAR, since guest hasn't configured a
224 			 * valid GPA
225 			 */
226 			ret = trap_gttmmio(vgpu, false);
227 			break;
228 		case PCI_BASE_ADDRESS_2:
229 		case PCI_BASE_ADDRESS_3:
230 			size = ~(bars[INTEL_GVT_PCI_BAR_APERTURE].size -1);
231 			intel_vgpu_write_pci_bar(vgpu, offset,
232 						size >> (lo ? 0 : 32), lo);
233 			ret = map_aperture(vgpu, false);
234 			break;
235 		default:
236 			/* Unimplemented BARs */
237 			intel_vgpu_write_pci_bar(vgpu, offset, 0x0, false);
238 		}
239 	} else {
240 		switch (offset) {
241 		case PCI_BASE_ADDRESS_0:
242 		case PCI_BASE_ADDRESS_1:
243 			/*
244 			 * Untrap the old BAR first, since guest has
245 			 * re-configured the BAR
246 			 */
247 			trap_gttmmio(vgpu, false);
248 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
249 			ret = trap_gttmmio(vgpu, mmio_enabled);
250 			break;
251 		case PCI_BASE_ADDRESS_2:
252 		case PCI_BASE_ADDRESS_3:
253 			map_aperture(vgpu, false);
254 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
255 			ret = map_aperture(vgpu, mmio_enabled);
256 			break;
257 		default:
258 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
259 		}
260 	}
261 	return ret;
262 }
263 
264 /**
265  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
266  *
267  * Returns:
268  * Zero on success, negative error code if failed.
269  */
270 int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset,
271 	void *p_data, unsigned int bytes)
272 {
273 	int ret;
274 
275 	if (WARN_ON(bytes > 4))
276 		return -EINVAL;
277 
278 	if (WARN_ON(offset + bytes > INTEL_GVT_MAX_CFG_SPACE_SZ))
279 		return -EINVAL;
280 
281 	/* First check if it's PCI_COMMAND */
282 	if (IS_ALIGNED(offset, 2) && offset == PCI_COMMAND) {
283 		if (WARN_ON(bytes > 2))
284 			return -EINVAL;
285 		return emulate_pci_command_write(vgpu, offset, p_data, bytes);
286 	}
287 
288 	switch (rounddown(offset, 4)) {
289 	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5:
290 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
291 			return -EINVAL;
292 		return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
293 
294 	case INTEL_GVT_PCI_SWSCI:
295 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
296 			return -EINVAL;
297 		ret = intel_vgpu_emulate_opregion_request(vgpu, *(u32 *)p_data);
298 		if (ret)
299 			return ret;
300 		break;
301 
302 	case INTEL_GVT_PCI_OPREGION:
303 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
304 			return -EINVAL;
305 		ret = intel_vgpu_init_opregion(vgpu, *(u32 *)p_data);
306 		if (ret)
307 			return ret;
308 
309 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
310 		break;
311 	default:
312 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
313 		break;
314 	}
315 	return 0;
316 }
317 
318 /**
319  * intel_vgpu_init_cfg_space - init vGPU configuration space when create vGPU
320  *
321  * @vgpu: a vGPU
322  * @primary: is the vGPU presented as primary
323  *
324  */
325 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
326 			       bool primary)
327 {
328 	struct intel_gvt *gvt = vgpu->gvt;
329 	const struct intel_gvt_device_info *info = &gvt->device_info;
330 	u16 *gmch_ctl;
331 
332 	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
333 	       info->cfg_space_size);
334 
335 	if (!primary) {
336 		vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] =
337 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
338 		vgpu_cfg_space(vgpu)[PCI_CLASS_PROG] =
339 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
340 	}
341 
342 	/* Show guest that there isn't any stolen memory.*/
343 	gmch_ctl = (u16 *)(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_GMCH_CONTROL);
344 	*gmch_ctl &= ~(BDW_GMCH_GMS_MASK << BDW_GMCH_GMS_SHIFT);
345 
346 	intel_vgpu_write_pci_bar(vgpu, PCI_BASE_ADDRESS_2,
347 				 gvt_aperture_pa_base(gvt), true);
348 
349 	vgpu_cfg_space(vgpu)[PCI_COMMAND] &= ~(PCI_COMMAND_IO
350 					     | PCI_COMMAND_MEMORY
351 					     | PCI_COMMAND_MASTER);
352 	/*
353 	 * Clear the bar upper 32bit and let guest to assign the new value
354 	 */
355 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
356 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
357 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_4, 0, 8);
358 	memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);
359 
360 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size =
361 				pci_resource_len(gvt->dev_priv->drm.pdev, 0);
362 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].size =
363 				pci_resource_len(gvt->dev_priv->drm.pdev, 2);
364 }
365 
366 /**
367  * intel_vgpu_reset_cfg_space - reset vGPU configuration space
368  *
369  * @vgpu: a vGPU
370  *
371  */
372 void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
373 {
374 	u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
375 	bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
376 				INTEL_GVT_PCI_CLASS_VGA_OTHER;
377 
378 	if (cmd & PCI_COMMAND_MEMORY) {
379 		trap_gttmmio(vgpu, false);
380 		map_aperture(vgpu, false);
381 	}
382 
383 	/**
384 	 * Currently we only do such reset when vGPU is not
385 	 * owned by any VM, so we simply restore entire cfg
386 	 * space to default value.
387 	 */
388 	intel_vgpu_init_cfg_space(vgpu, primary);
389 }
390