xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/cfg_space.c (revision 8c609698)
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 > vgpu->gvt->device_info.cfg_space_size))
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 	phys_addr_t aperture_pa = vgpu_aperture_pa_base(vgpu);
114 	unsigned long aperture_sz = vgpu_aperture_sz(vgpu);
115 	u64 first_gfn;
116 	u64 val;
117 	int ret;
118 
119 	if (map == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked)
120 		return 0;
121 
122 	if (map) {
123 		vgpu->gm.aperture_va = memremap(aperture_pa, aperture_sz,
124 						MEMREMAP_WC);
125 		if (!vgpu->gm.aperture_va)
126 			return -ENOMEM;
127 	} else {
128 		memunmap(vgpu->gm.aperture_va);
129 		vgpu->gm.aperture_va = NULL;
130 	}
131 
132 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_2];
133 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
134 		val = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
135 	else
136 		val = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
137 
138 	first_gfn = (val + vgpu_aperture_offset(vgpu)) >> PAGE_SHIFT;
139 
140 	ret = intel_gvt_hypervisor_map_gfn_to_mfn(vgpu, first_gfn,
141 						  aperture_pa >> PAGE_SHIFT,
142 						  aperture_sz >> PAGE_SHIFT,
143 						  map);
144 	if (ret) {
145 		memunmap(vgpu->gm.aperture_va);
146 		vgpu->gm.aperture_va = NULL;
147 		return ret;
148 	}
149 
150 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked = map;
151 	return 0;
152 }
153 
154 static int trap_gttmmio(struct intel_vgpu *vgpu, bool trap)
155 {
156 	u64 start, end;
157 	u64 val;
158 	int ret;
159 
160 	if (trap == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked)
161 		return 0;
162 
163 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_0];
164 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
165 		start = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
166 	else
167 		start = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
168 
169 	start &= ~GENMASK(3, 0);
170 	end = start + vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size - 1;
171 
172 	ret = intel_gvt_hypervisor_set_trap_area(vgpu, start, end, trap);
173 	if (ret)
174 		return ret;
175 
176 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked = trap;
177 	return 0;
178 }
179 
180 static int emulate_pci_command_write(struct intel_vgpu *vgpu,
181 	unsigned int offset, void *p_data, unsigned int bytes)
182 {
183 	u8 old = vgpu_cfg_space(vgpu)[offset];
184 	u8 new = *(u8 *)p_data;
185 	u8 changed = old ^ new;
186 	int ret;
187 
188 	vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
189 	if (!(changed & PCI_COMMAND_MEMORY))
190 		return 0;
191 
192 	if (old & PCI_COMMAND_MEMORY) {
193 		ret = trap_gttmmio(vgpu, false);
194 		if (ret)
195 			return ret;
196 		ret = map_aperture(vgpu, false);
197 		if (ret)
198 			return ret;
199 	} else {
200 		ret = trap_gttmmio(vgpu, true);
201 		if (ret)
202 			return ret;
203 		ret = map_aperture(vgpu, true);
204 		if (ret)
205 			return ret;
206 	}
207 
208 	return 0;
209 }
210 
211 static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
212 	void *p_data, unsigned int bytes)
213 {
214 	u32 new = *(u32 *)(p_data);
215 	bool lo = IS_ALIGNED(offset, 8);
216 	u64 size;
217 	int ret = 0;
218 	bool mmio_enabled =
219 		vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
220 	struct intel_vgpu_pci_bar *bars = vgpu->cfg_space.bar;
221 
222 	/*
223 	 * Power-up software can determine how much address
224 	 * space the device requires by writing a value of
225 	 * all 1's to the register and then reading the value
226 	 * back. The device will return 0's in all don't-care
227 	 * address bits.
228 	 */
229 	if (new == 0xffffffff) {
230 		switch (offset) {
231 		case PCI_BASE_ADDRESS_0:
232 		case PCI_BASE_ADDRESS_1:
233 			size = ~(bars[INTEL_GVT_PCI_BAR_GTTMMIO].size -1);
234 			intel_vgpu_write_pci_bar(vgpu, offset,
235 						size >> (lo ? 0 : 32), lo);
236 			/*
237 			 * Untrap the BAR, since guest hasn't configured a
238 			 * valid GPA
239 			 */
240 			ret = trap_gttmmio(vgpu, false);
241 			break;
242 		case PCI_BASE_ADDRESS_2:
243 		case PCI_BASE_ADDRESS_3:
244 			size = ~(bars[INTEL_GVT_PCI_BAR_APERTURE].size -1);
245 			intel_vgpu_write_pci_bar(vgpu, offset,
246 						size >> (lo ? 0 : 32), lo);
247 			ret = map_aperture(vgpu, false);
248 			break;
249 		default:
250 			/* Unimplemented BARs */
251 			intel_vgpu_write_pci_bar(vgpu, offset, 0x0, false);
252 		}
253 	} else {
254 		switch (offset) {
255 		case PCI_BASE_ADDRESS_0:
256 		case PCI_BASE_ADDRESS_1:
257 			/*
258 			 * Untrap the old BAR first, since guest has
259 			 * re-configured the BAR
260 			 */
261 			trap_gttmmio(vgpu, false);
262 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
263 			ret = trap_gttmmio(vgpu, mmio_enabled);
264 			break;
265 		case PCI_BASE_ADDRESS_2:
266 		case PCI_BASE_ADDRESS_3:
267 			map_aperture(vgpu, false);
268 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
269 			ret = map_aperture(vgpu, mmio_enabled);
270 			break;
271 		default:
272 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
273 		}
274 	}
275 	return ret;
276 }
277 
278 /**
279  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
280  *
281  * Returns:
282  * Zero on success, negative error code if failed.
283  */
284 int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset,
285 	void *p_data, unsigned int bytes)
286 {
287 	int ret;
288 
289 	if (WARN_ON(bytes > 4))
290 		return -EINVAL;
291 
292 	if (WARN_ON(offset + bytes > vgpu->gvt->device_info.cfg_space_size))
293 		return -EINVAL;
294 
295 	/* First check if it's PCI_COMMAND */
296 	if (IS_ALIGNED(offset, 2) && offset == PCI_COMMAND) {
297 		if (WARN_ON(bytes > 2))
298 			return -EINVAL;
299 		return emulate_pci_command_write(vgpu, offset, p_data, bytes);
300 	}
301 
302 	switch (rounddown(offset, 4)) {
303 	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5:
304 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
305 			return -EINVAL;
306 		return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
307 
308 	case INTEL_GVT_PCI_SWSCI:
309 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
310 			return -EINVAL;
311 		ret = intel_vgpu_emulate_opregion_request(vgpu, *(u32 *)p_data);
312 		if (ret)
313 			return ret;
314 		break;
315 
316 	case INTEL_GVT_PCI_OPREGION:
317 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
318 			return -EINVAL;
319 		ret = intel_vgpu_init_opregion(vgpu, *(u32 *)p_data);
320 		if (ret)
321 			return ret;
322 
323 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
324 		break;
325 	default:
326 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
327 		break;
328 	}
329 	return 0;
330 }
331 
332 /**
333  * intel_vgpu_init_cfg_space - init vGPU configuration space when create vGPU
334  *
335  * @vgpu: a vGPU
336  * @primary: is the vGPU presented as primary
337  *
338  */
339 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
340 			       bool primary)
341 {
342 	struct intel_gvt *gvt = vgpu->gvt;
343 	const struct intel_gvt_device_info *info = &gvt->device_info;
344 	u16 *gmch_ctl;
345 
346 	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
347 	       info->cfg_space_size);
348 
349 	if (!primary) {
350 		vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] =
351 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
352 		vgpu_cfg_space(vgpu)[PCI_CLASS_PROG] =
353 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
354 	}
355 
356 	/* Show guest that there isn't any stolen memory.*/
357 	gmch_ctl = (u16 *)(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_GMCH_CONTROL);
358 	*gmch_ctl &= ~(BDW_GMCH_GMS_MASK << BDW_GMCH_GMS_SHIFT);
359 
360 	intel_vgpu_write_pci_bar(vgpu, PCI_BASE_ADDRESS_2,
361 				 gvt_aperture_pa_base(gvt), true);
362 
363 	vgpu_cfg_space(vgpu)[PCI_COMMAND] &= ~(PCI_COMMAND_IO
364 					     | PCI_COMMAND_MEMORY
365 					     | PCI_COMMAND_MASTER);
366 	/*
367 	 * Clear the bar upper 32bit and let guest to assign the new value
368 	 */
369 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
370 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
371 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_4, 0, 8);
372 	memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);
373 
374 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size =
375 				pci_resource_len(gvt->dev_priv->drm.pdev, 0);
376 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].size =
377 				pci_resource_len(gvt->dev_priv->drm.pdev, 2);
378 }
379 
380 /**
381  * intel_vgpu_reset_cfg_space - reset vGPU configuration space
382  *
383  * @vgpu: a vGPU
384  *
385  */
386 void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
387 {
388 	u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
389 	bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
390 				INTEL_GVT_PCI_CLASS_VGA_OTHER;
391 
392 	if (cmd & PCI_COMMAND_MEMORY) {
393 		trap_gttmmio(vgpu, false);
394 		map_aperture(vgpu, false);
395 	}
396 
397 	/**
398 	 * Currently we only do such reset when vGPU is not
399 	 * owned by any VM, so we simply restore entire cfg
400 	 * space to default value.
401 	 */
402 	intel_vgpu_init_cfg_space(vgpu, primary);
403 }
404