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_guc_reg.h"
10 #include "intel_huc.h"
11 #include "i915_drv.h"
12 
13 /**
14  * DOC: HuC
15  *
16  * The HuC is a dedicated microcontroller for usage in media HEVC (High
17  * Efficiency Video Coding) operations. Userspace can directly use the firmware
18  * capabilities by adding HuC specific commands to batch buffers.
19  *
20  * The kernel driver is only responsible for loading the HuC firmware and
21  * triggering its security authentication, which is performed by the GuC on
22  * older platforms and by the GSC on newer ones. For the GuC to correctly
23  * perform the authentication, the HuC binary must be loaded before the GuC one.
24  * Loading the HuC is optional; however, not using the HuC might negatively
25  * impact power usage and/or performance of media workloads, depending on the
26  * use-cases.
27  * HuC must be reloaded on events that cause the WOPCM to lose its contents
28  * (S3/S4, FLR); GuC-authenticated HuC must also be reloaded on GuC/GT reset,
29  * while GSC-managed HuC will survive that.
30  *
31  * See https://github.com/intel/media-driver for the latest details on HuC
32  * functionality.
33  */
34 
35 /**
36  * DOC: HuC Memory Management
37  *
38  * Similarly to the GuC, the HuC can't do any memory allocations on its own,
39  * with the difference being that the allocations for HuC usage are handled by
40  * the userspace driver instead of the kernel one. The HuC accesses the memory
41  * via the PPGTT belonging to the context loaded on the VCS executing the
42  * HuC-specific commands.
43  */
44 
intel_huc_init_early(struct intel_huc * huc)45 void intel_huc_init_early(struct intel_huc *huc)
46 {
47 	struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
48 
49 	intel_uc_fw_init_early(&huc->fw, INTEL_UC_FW_TYPE_HUC);
50 
51 	if (GRAPHICS_VER(i915) >= 11) {
52 		huc->status.reg = GEN11_HUC_KERNEL_LOAD_INFO;
53 		huc->status.mask = HUC_LOAD_SUCCESSFUL;
54 		huc->status.value = HUC_LOAD_SUCCESSFUL;
55 	} else {
56 		huc->status.reg = HUC_STATUS2;
57 		huc->status.mask = HUC_FW_VERIFIED;
58 		huc->status.value = HUC_FW_VERIFIED;
59 	}
60 }
61 
62 #define HUC_LOAD_MODE_STRING(x) (x ? "GSC" : "legacy")
check_huc_loading_mode(struct intel_huc * huc)63 static int check_huc_loading_mode(struct intel_huc *huc)
64 {
65 	struct intel_gt *gt = huc_to_gt(huc);
66 	bool fw_needs_gsc = intel_huc_is_loaded_by_gsc(huc);
67 	bool hw_uses_gsc = false;
68 
69 	/*
70 	 * The fuse for HuC load via GSC is only valid on platforms that have
71 	 * GuC deprivilege.
72 	 */
73 	if (HAS_GUC_DEPRIVILEGE(gt->i915))
74 		hw_uses_gsc = intel_uncore_read(gt->uncore, GUC_SHIM_CONTROL2) &
75 			      GSC_LOADS_HUC;
76 
77 	if (fw_needs_gsc != hw_uses_gsc) {
78 		drm_err(&gt->i915->drm,
79 			"mismatch between HuC FW (%s) and HW (%s) load modes\n",
80 			HUC_LOAD_MODE_STRING(fw_needs_gsc),
81 			HUC_LOAD_MODE_STRING(hw_uses_gsc));
82 		return -ENOEXEC;
83 	}
84 
85 	/* make sure we can access the GSC via the mei driver if we need it */
86 	if (!(IS_ENABLED(CONFIG_INTEL_MEI_PXP) && IS_ENABLED(CONFIG_INTEL_MEI_GSC)) &&
87 	    fw_needs_gsc) {
88 		drm_info(&gt->i915->drm,
89 			 "Can't load HuC due to missing MEI modules\n");
90 		return -EIO;
91 	}
92 
93 	drm_dbg(&gt->i915->drm, "GSC loads huc=%s\n", str_yes_no(fw_needs_gsc));
94 
95 	return 0;
96 }
97 
intel_huc_init(struct intel_huc * huc)98 int intel_huc_init(struct intel_huc *huc)
99 {
100 	struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
101 	int err;
102 
103 	err = check_huc_loading_mode(huc);
104 	if (err)
105 		goto out;
106 
107 	err = intel_uc_fw_init(&huc->fw);
108 	if (err)
109 		goto out;
110 
111 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_LOADABLE);
112 
113 	return 0;
114 
115 out:
116 	drm_info(&i915->drm, "HuC init failed with %d\n", err);
117 	return err;
118 }
119 
intel_huc_fini(struct intel_huc * huc)120 void intel_huc_fini(struct intel_huc *huc)
121 {
122 	if (!intel_uc_fw_is_loadable(&huc->fw))
123 		return;
124 
125 	intel_uc_fw_fini(&huc->fw);
126 }
127 
128 /**
129  * intel_huc_auth() - Authenticate HuC uCode
130  * @huc: intel_huc structure
131  *
132  * Called after HuC and GuC firmware loading during intel_uc_init_hw().
133  *
134  * This function invokes the GuC action to authenticate the HuC firmware,
135  * passing the offset of the RSA signature to intel_guc_auth_huc(). It then
136  * waits for up to 50ms for firmware verification ACK.
137  */
intel_huc_auth(struct intel_huc * huc)138 int intel_huc_auth(struct intel_huc *huc)
139 {
140 	struct intel_gt *gt = huc_to_gt(huc);
141 	struct intel_guc *guc = &gt->uc.guc;
142 	int ret;
143 
144 	if (!intel_uc_fw_is_loaded(&huc->fw))
145 		return -ENOEXEC;
146 
147 	/* GSC will do the auth */
148 	if (intel_huc_is_loaded_by_gsc(huc))
149 		return -ENODEV;
150 
151 	ret = i915_inject_probe_error(gt->i915, -ENXIO);
152 	if (ret)
153 		goto fail;
154 
155 	GEM_BUG_ON(intel_uc_fw_is_running(&huc->fw));
156 
157 	ret = intel_guc_auth_huc(guc, intel_guc_ggtt_offset(guc, huc->fw.rsa_data));
158 	if (ret) {
159 		DRM_ERROR("HuC: GuC did not ack Auth request %d\n", ret);
160 		goto fail;
161 	}
162 
163 	/* Check authentication status, it should be done by now */
164 	ret = __intel_wait_for_register(gt->uncore,
165 					huc->status.reg,
166 					huc->status.mask,
167 					huc->status.value,
168 					2, 50, NULL);
169 	if (ret) {
170 		DRM_ERROR("HuC: Firmware not verified %d\n", ret);
171 		goto fail;
172 	}
173 
174 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_RUNNING);
175 	drm_info(&gt->i915->drm, "HuC authenticated\n");
176 	return 0;
177 
178 fail:
179 	i915_probe_error(gt->i915, "HuC: Authentication failed %d\n", ret);
180 	intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_LOAD_FAIL);
181 	return ret;
182 }
183 
huc_is_authenticated(struct intel_huc * huc)184 static bool huc_is_authenticated(struct intel_huc *huc)
185 {
186 	struct intel_gt *gt = huc_to_gt(huc);
187 	intel_wakeref_t wakeref;
188 	u32 status = 0;
189 
190 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
191 		status = intel_uncore_read(gt->uncore, huc->status.reg);
192 
193 	return (status & huc->status.mask) == huc->status.value;
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  */
intel_huc_check_status(struct intel_huc * huc)211 int intel_huc_check_status(struct intel_huc *huc)
212 {
213 	switch (__intel_uc_fw_status(&huc->fw)) {
214 	case INTEL_UC_FIRMWARE_NOT_SUPPORTED:
215 		return -ENODEV;
216 	case INTEL_UC_FIRMWARE_DISABLED:
217 		return -EOPNOTSUPP;
218 	case INTEL_UC_FIRMWARE_MISSING:
219 		return -ENOPKG;
220 	case INTEL_UC_FIRMWARE_ERROR:
221 		return -ENOEXEC;
222 	default:
223 		break;
224 	}
225 
226 	return huc_is_authenticated(huc);
227 }
228 
intel_huc_update_auth_status(struct intel_huc * huc)229 void intel_huc_update_auth_status(struct intel_huc *huc)
230 {
231 	if (!intel_uc_fw_is_loadable(&huc->fw))
232 		return;
233 
234 	if (huc_is_authenticated(huc))
235 		intel_uc_fw_change_status(&huc->fw,
236 					  INTEL_UC_FIRMWARE_RUNNING);
237 }
238 
239 /**
240  * intel_huc_load_status - dump information about HuC load status
241  * @huc: the HuC
242  * @p: the &drm_printer
243  *
244  * Pretty printer for HuC load status.
245  */
intel_huc_load_status(struct intel_huc * huc,struct drm_printer * p)246 void intel_huc_load_status(struct intel_huc *huc, struct drm_printer *p)
247 {
248 	struct intel_gt *gt = huc_to_gt(huc);
249 	intel_wakeref_t wakeref;
250 
251 	if (!intel_huc_is_supported(huc)) {
252 		drm_printf(p, "HuC not supported\n");
253 		return;
254 	}
255 
256 	if (!intel_huc_is_wanted(huc)) {
257 		drm_printf(p, "HuC disabled\n");
258 		return;
259 	}
260 
261 	intel_uc_fw_dump(&huc->fw, p);
262 
263 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
264 		drm_printf(p, "HuC status: 0x%08x\n",
265 			   intel_uncore_read(gt->uncore, huc->status.reg));
266 }
267