xref: /openbmc/linux/drivers/gpu/drm/i915/intel_pcode.c (revision 65844828)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2013-2021 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_reg.h"
8 #include "intel_pcode.h"
9 
10 static int gen6_check_mailbox_status(u32 mbox)
11 {
12 	switch (mbox & GEN6_PCODE_ERROR_MASK) {
13 	case GEN6_PCODE_SUCCESS:
14 		return 0;
15 	case GEN6_PCODE_UNIMPLEMENTED_CMD:
16 		return -ENODEV;
17 	case GEN6_PCODE_ILLEGAL_CMD:
18 		return -ENXIO;
19 	case GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
20 	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
21 		return -EOVERFLOW;
22 	case GEN6_PCODE_TIMEOUT:
23 		return -ETIMEDOUT;
24 	default:
25 		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
26 		return 0;
27 	}
28 }
29 
30 static int gen7_check_mailbox_status(u32 mbox)
31 {
32 	switch (mbox & GEN6_PCODE_ERROR_MASK) {
33 	case GEN6_PCODE_SUCCESS:
34 		return 0;
35 	case GEN6_PCODE_ILLEGAL_CMD:
36 		return -ENXIO;
37 	case GEN7_PCODE_TIMEOUT:
38 		return -ETIMEDOUT;
39 	case GEN7_PCODE_ILLEGAL_DATA:
40 		return -EINVAL;
41 	case GEN11_PCODE_ILLEGAL_SUBCOMMAND:
42 		return -ENXIO;
43 	case GEN11_PCODE_LOCKED:
44 		return -EBUSY;
45 	case GEN11_PCODE_REJECTED:
46 		return -EACCES;
47 	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
48 		return -EOVERFLOW;
49 	default:
50 		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
51 		return 0;
52 	}
53 }
54 
55 static int __snb_pcode_rw(struct intel_uncore *uncore, u32 mbox,
56 			  u32 *val, u32 *val1,
57 			  int fast_timeout_us, int slow_timeout_ms,
58 			  bool is_read)
59 {
60 	lockdep_assert_held(&uncore->i915->sb_lock);
61 
62 	/*
63 	 * GEN6_PCODE_* are outside of the forcewake domain, we can use
64 	 * intel_uncore_read/write_fw variants to reduce the amount of work
65 	 * required when reading/writing.
66 	 */
67 
68 	if (intel_uncore_read_fw(uncore, GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY)
69 		return -EAGAIN;
70 
71 	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA, *val);
72 	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA1, val1 ? *val1 : 0);
73 	intel_uncore_write_fw(uncore,
74 			      GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | mbox);
75 
76 	if (__intel_wait_for_register_fw(uncore,
77 					 GEN6_PCODE_MAILBOX,
78 					 GEN6_PCODE_READY, 0,
79 					 fast_timeout_us,
80 					 slow_timeout_ms,
81 					 &mbox))
82 		return -ETIMEDOUT;
83 
84 	if (is_read)
85 		*val = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA);
86 	if (is_read && val1)
87 		*val1 = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA1);
88 
89 	if (GRAPHICS_VER(uncore->i915) > 6)
90 		return gen7_check_mailbox_status(mbox);
91 	else
92 		return gen6_check_mailbox_status(mbox);
93 }
94 
95 int snb_pcode_read(struct intel_uncore *uncore, u32 mbox, u32 *val, u32 *val1)
96 {
97 	int err;
98 
99 	mutex_lock(&uncore->i915->sb_lock);
100 	err = __snb_pcode_rw(uncore, mbox, val, val1, 500, 20, true);
101 	mutex_unlock(&uncore->i915->sb_lock);
102 
103 	if (err) {
104 		drm_dbg(&uncore->i915->drm,
105 			"warning: pcode (read from mbox %x) mailbox access failed for %ps: %d\n",
106 			mbox, __builtin_return_address(0), err);
107 	}
108 
109 	return err;
110 }
111 
112 int snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val,
113 			    int fast_timeout_us, int slow_timeout_ms)
114 {
115 	int err;
116 
117 	mutex_lock(&uncore->i915->sb_lock);
118 	err = __snb_pcode_rw(uncore, mbox, &val, NULL,
119 			     fast_timeout_us, slow_timeout_ms, false);
120 	mutex_unlock(&uncore->i915->sb_lock);
121 
122 	if (err) {
123 		drm_dbg(&uncore->i915->drm,
124 			"warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps: %d\n",
125 			val, mbox, __builtin_return_address(0), err);
126 	}
127 
128 	return err;
129 }
130 
131 static bool skl_pcode_try_request(struct intel_uncore *uncore, u32 mbox,
132 				  u32 request, u32 reply_mask, u32 reply,
133 				  u32 *status)
134 {
135 	*status = __snb_pcode_rw(uncore, mbox, &request, NULL, 500, 0, true);
136 
137 	return (*status == 0) && ((request & reply_mask) == reply);
138 }
139 
140 /**
141  * skl_pcode_request - send PCODE request until acknowledgment
142  * @uncore: uncore
143  * @mbox: PCODE mailbox ID the request is targeted for
144  * @request: request ID
145  * @reply_mask: mask used to check for request acknowledgment
146  * @reply: value used to check for request acknowledgment
147  * @timeout_base_ms: timeout for polling with preemption enabled
148  *
149  * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
150  * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
151  * The request is acknowledged once the PCODE reply dword equals @reply after
152  * applying @reply_mask. Polling is first attempted with preemption enabled
153  * for @timeout_base_ms and if this times out for another 50 ms with
154  * preemption disabled.
155  *
156  * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
157  * other error as reported by PCODE.
158  */
159 int skl_pcode_request(struct intel_uncore *uncore, u32 mbox, u32 request,
160 		      u32 reply_mask, u32 reply, int timeout_base_ms)
161 {
162 	u32 status;
163 	int ret;
164 
165 	mutex_lock(&uncore->i915->sb_lock);
166 
167 #define COND \
168 	skl_pcode_try_request(uncore, mbox, request, reply_mask, reply, &status)
169 
170 	/*
171 	 * Prime the PCODE by doing a request first. Normally it guarantees
172 	 * that a subsequent request, at most @timeout_base_ms later, succeeds.
173 	 * _wait_for() doesn't guarantee when its passed condition is evaluated
174 	 * first, so send the first request explicitly.
175 	 */
176 	if (COND) {
177 		ret = 0;
178 		goto out;
179 	}
180 	ret = _wait_for(COND, timeout_base_ms * 1000, 10, 10);
181 	if (!ret)
182 		goto out;
183 
184 	/*
185 	 * The above can time out if the number of requests was low (2 in the
186 	 * worst case) _and_ PCODE was busy for some reason even after a
187 	 * (queued) request and @timeout_base_ms delay. As a workaround retry
188 	 * the poll with preemption disabled to maximize the number of
189 	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
190 	 * account for interrupts that could reduce the number of these
191 	 * requests, and for any quirks of the PCODE firmware that delays
192 	 * the request completion.
193 	 */
194 	drm_dbg_kms(&uncore->i915->drm,
195 		    "PCODE timeout, retrying with preemption disabled\n");
196 	drm_WARN_ON_ONCE(&uncore->i915->drm, timeout_base_ms > 3);
197 	preempt_disable();
198 	ret = wait_for_atomic(COND, 50);
199 	preempt_enable();
200 
201 out:
202 	mutex_unlock(&uncore->i915->sb_lock);
203 	return status ? status : ret;
204 #undef COND
205 }
206 
207 int intel_pcode_init(struct intel_uncore *uncore)
208 {
209 	if (!IS_DGFX(uncore->i915))
210 		return 0;
211 
212 	return skl_pcode_request(uncore, DG1_PCODE_STATUS,
213 				 DG1_UNCORE_GET_INIT_STATUS,
214 				 DG1_UNCORE_INIT_STATUS_COMPLETE,
215 				 DG1_UNCORE_INIT_STATUS_COMPLETE, 180000);
216 }
217 
218 int snb_pcode_read_p(struct intel_uncore *uncore, u32 mbcmd, u32 p1, u32 p2, u32 *val)
219 {
220 	intel_wakeref_t wakeref;
221 	u32 mbox;
222 	int err;
223 
224 	mbox = REG_FIELD_PREP(GEN6_PCODE_MB_COMMAND, mbcmd)
225 		| REG_FIELD_PREP(GEN6_PCODE_MB_PARAM1, p1)
226 		| REG_FIELD_PREP(GEN6_PCODE_MB_PARAM2, p2);
227 
228 	with_intel_runtime_pm(uncore->rpm, wakeref)
229 		err = snb_pcode_read(uncore, mbox, val, NULL);
230 
231 	return err;
232 }
233 
234 int snb_pcode_write_p(struct intel_uncore *uncore, u32 mbcmd, u32 p1, u32 p2, u32 val)
235 {
236 	intel_wakeref_t wakeref;
237 	u32 mbox;
238 	int err;
239 
240 	mbox = REG_FIELD_PREP(GEN6_PCODE_MB_COMMAND, mbcmd)
241 		| REG_FIELD_PREP(GEN6_PCODE_MB_PARAM1, p1)
242 		| REG_FIELD_PREP(GEN6_PCODE_MB_PARAM2, p2);
243 
244 	with_intel_runtime_pm(uncore->rpm, wakeref)
245 		err = snb_pcode_write(uncore, mbox, val);
246 
247 	return err;
248 }
249