xref: /openbmc/linux/drivers/gpu/drm/i915/gt/uc/intel_huc.c (revision 3d37ef41)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2016-2019 Intel Corporation
4  */
5 
6 #include <linux/types.h>
7 
8 #include "gt/intel_gt.h"
9 #include "intel_huc.h"
10 #include "i915_drv.h"
11 
12 /**
13  * DOC: HuC
14  *
15  * The HuC is a dedicated microcontroller for usage in media HEVC (High
16  * Efficiency Video Coding) operations. Userspace can directly use the firmware
17  * capabilities by adding HuC specific commands to batch buffers.
18  *
19  * The kernel driver is only responsible for loading the HuC firmware and
20  * triggering its security authentication, which is performed by the GuC. For
21  * The GuC to correctly perform the authentication, the HuC binary must be
22  * loaded before the GuC one. Loading the HuC is optional; however, not using
23  * the HuC might negatively impact power usage and/or performance of media
24  * workloads, depending on the use-cases.
25  *
26  * See https://github.com/intel/media-driver for the latest details on HuC
27  * functionality.
28  */
29 
30 /**
31  * DOC: HuC Memory Management
32  *
33  * Similarly to the GuC, the HuC can't do any memory allocations on its own,
34  * with the difference being that the allocations for HuC usage are handled by
35  * the userspace driver instead of the kernel one. The HuC accesses the memory
36  * via the PPGTT belonging to the context loaded on the VCS executing the
37  * HuC-specific commands.
38  */
39 
40 void intel_huc_init_early(struct intel_huc *huc)
41 {
42 	struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
43 
44 	intel_uc_fw_init_early(&huc->fw, INTEL_UC_FW_TYPE_HUC);
45 
46 	if (INTEL_GEN(i915) >= 11) {
47 		huc->status.reg = GEN11_HUC_KERNEL_LOAD_INFO;
48 		huc->status.mask = HUC_LOAD_SUCCESSFUL;
49 		huc->status.value = HUC_LOAD_SUCCESSFUL;
50 	} else {
51 		huc->status.reg = HUC_STATUS2;
52 		huc->status.mask = HUC_FW_VERIFIED;
53 		huc->status.value = HUC_FW_VERIFIED;
54 	}
55 }
56 
57 static int intel_huc_rsa_data_create(struct intel_huc *huc)
58 {
59 	struct intel_gt *gt = huc_to_gt(huc);
60 	struct intel_guc *guc = &gt->uc.guc;
61 	struct i915_vma *vma;
62 	size_t copied;
63 	void *vaddr;
64 	int err;
65 
66 	err = i915_inject_probe_error(gt->i915, -ENXIO);
67 	if (err)
68 		return err;
69 
70 	/*
71 	 * HuC firmware will sit above GUC_GGTT_TOP and will not map
72 	 * through GTT. Unfortunately, this means GuC cannot perform
73 	 * the HuC auth. as the rsa offset now falls within the GuC
74 	 * inaccessible range. We resort to perma-pinning an additional
75 	 * vma within the accessible range that only contains the rsa
76 	 * signature. The GuC can use this extra pinning to perform
77 	 * the authentication since its GGTT offset will be GuC
78 	 * accessible.
79 	 */
80 	GEM_BUG_ON(huc->fw.rsa_size > PAGE_SIZE);
81 	vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
82 	if (IS_ERR(vma))
83 		return PTR_ERR(vma);
84 
85 	vaddr = i915_gem_object_pin_map_unlocked(vma->obj, I915_MAP_WB);
86 	if (IS_ERR(vaddr)) {
87 		i915_vma_unpin_and_release(&vma, 0);
88 		return PTR_ERR(vaddr);
89 	}
90 
91 	copied = intel_uc_fw_copy_rsa(&huc->fw, vaddr, vma->size);
92 	GEM_BUG_ON(copied < huc->fw.rsa_size);
93 
94 	i915_gem_object_unpin_map(vma->obj);
95 
96 	huc->rsa_data = vma;
97 
98 	return 0;
99 }
100 
101 static void intel_huc_rsa_data_destroy(struct intel_huc *huc)
102 {
103 	i915_vma_unpin_and_release(&huc->rsa_data, 0);
104 }
105 
106 int intel_huc_init(struct intel_huc *huc)
107 {
108 	struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
109 	int err;
110 
111 	err = intel_uc_fw_init(&huc->fw);
112 	if (err)
113 		goto out;
114 
115 	/*
116 	 * HuC firmware image is outside GuC accessible range.
117 	 * Copy the RSA signature out of the image into
118 	 * a perma-pinned region set aside for it
119 	 */
120 	err = intel_huc_rsa_data_create(huc);
121 	if (err)
122 		goto out_fini;
123 
124 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_LOADABLE);
125 
126 	return 0;
127 
128 out_fini:
129 	intel_uc_fw_fini(&huc->fw);
130 out:
131 	i915_probe_error(i915, "failed with %d\n", err);
132 	return err;
133 }
134 
135 void intel_huc_fini(struct intel_huc *huc)
136 {
137 	if (!intel_uc_fw_is_loadable(&huc->fw))
138 		return;
139 
140 	intel_huc_rsa_data_destroy(huc);
141 	intel_uc_fw_fini(&huc->fw);
142 }
143 
144 /**
145  * intel_huc_auth() - Authenticate HuC uCode
146  * @huc: intel_huc structure
147  *
148  * Called after HuC and GuC firmware loading during intel_uc_init_hw().
149  *
150  * This function invokes the GuC action to authenticate the HuC firmware,
151  * passing the offset of the RSA signature to intel_guc_auth_huc(). It then
152  * waits for up to 50ms for firmware verification ACK.
153  */
154 int intel_huc_auth(struct intel_huc *huc)
155 {
156 	struct intel_gt *gt = huc_to_gt(huc);
157 	struct intel_guc *guc = &gt->uc.guc;
158 	int ret;
159 
160 	GEM_BUG_ON(intel_huc_is_authenticated(huc));
161 
162 	if (!intel_uc_fw_is_loaded(&huc->fw))
163 		return -ENOEXEC;
164 
165 	ret = i915_inject_probe_error(gt->i915, -ENXIO);
166 	if (ret)
167 		goto fail;
168 
169 	ret = intel_guc_auth_huc(guc,
170 				 intel_guc_ggtt_offset(guc, huc->rsa_data));
171 	if (ret) {
172 		DRM_ERROR("HuC: GuC did not ack Auth request %d\n", ret);
173 		goto fail;
174 	}
175 
176 	/* Check authentication status, it should be done by now */
177 	ret = __intel_wait_for_register(gt->uncore,
178 					huc->status.reg,
179 					huc->status.mask,
180 					huc->status.value,
181 					2, 50, NULL);
182 	if (ret) {
183 		DRM_ERROR("HuC: Firmware not verified %d\n", ret);
184 		goto fail;
185 	}
186 
187 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_RUNNING);
188 	return 0;
189 
190 fail:
191 	i915_probe_error(gt->i915, "HuC: Authentication failed %d\n", ret);
192 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_FAIL);
193 	return ret;
194 }
195 
196 /**
197  * intel_huc_check_status() - check HuC status
198  * @huc: intel_huc structure
199  *
200  * This function reads status register to verify if HuC
201  * firmware was successfully loaded.
202  *
203  * Returns:
204  *  * -ENODEV if HuC is not present on this platform,
205  *  * -EOPNOTSUPP if HuC firmware is disabled,
206  *  * -ENOPKG if HuC firmware was not installed,
207  *  * -ENOEXEC if HuC firmware is invalid or mismatched,
208  *  * 0 if HuC firmware is not running,
209  *  * 1 if HuC firmware is authenticated and running.
210  */
211 int intel_huc_check_status(struct intel_huc *huc)
212 {
213 	struct intel_gt *gt = huc_to_gt(huc);
214 	intel_wakeref_t wakeref;
215 	u32 status = 0;
216 
217 	switch (__intel_uc_fw_status(&huc->fw)) {
218 	case INTEL_UC_FIRMWARE_NOT_SUPPORTED:
219 		return -ENODEV;
220 	case INTEL_UC_FIRMWARE_DISABLED:
221 		return -EOPNOTSUPP;
222 	case INTEL_UC_FIRMWARE_MISSING:
223 		return -ENOPKG;
224 	case INTEL_UC_FIRMWARE_ERROR:
225 		return -ENOEXEC;
226 	default:
227 		break;
228 	}
229 
230 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
231 		status = intel_uncore_read(gt->uncore, huc->status.reg);
232 
233 	return (status & huc->status.mask) == huc->status.value;
234 }
235 
236 /**
237  * intel_huc_load_status - dump information about HuC load status
238  * @huc: the HuC
239  * @p: the &drm_printer
240  *
241  * Pretty printer for HuC load status.
242  */
243 void intel_huc_load_status(struct intel_huc *huc, struct drm_printer *p)
244 {
245 	struct intel_gt *gt = huc_to_gt(huc);
246 	intel_wakeref_t wakeref;
247 
248 	if (!intel_huc_is_supported(huc)) {
249 		drm_printf(p, "HuC not supported\n");
250 		return;
251 	}
252 
253 	if (!intel_huc_is_wanted(huc)) {
254 		drm_printf(p, "HuC disabled\n");
255 		return;
256 	}
257 
258 	intel_uc_fw_dump(&huc->fw, p);
259 
260 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
261 		drm_printf(p, "HuC status: 0x%08x\n",
262 			   intel_uncore_read(gt->uncore, huc->status.reg));
263 }
264