xref: /openbmc/linux/drivers/gpu/drm/i915/intel_pcode.c (revision 405db98b)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2013-2021 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "intel_pcode.h"
8 
9 static int gen6_check_mailbox_status(u32 mbox)
10 {
11 	switch (mbox & GEN6_PCODE_ERROR_MASK) {
12 	case GEN6_PCODE_SUCCESS:
13 		return 0;
14 	case GEN6_PCODE_UNIMPLEMENTED_CMD:
15 		return -ENODEV;
16 	case GEN6_PCODE_ILLEGAL_CMD:
17 		return -ENXIO;
18 	case GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
19 	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
20 		return -EOVERFLOW;
21 	case GEN6_PCODE_TIMEOUT:
22 		return -ETIMEDOUT;
23 	default:
24 		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
25 		return 0;
26 	}
27 }
28 
29 static int gen7_check_mailbox_status(u32 mbox)
30 {
31 	switch (mbox & GEN6_PCODE_ERROR_MASK) {
32 	case GEN6_PCODE_SUCCESS:
33 		return 0;
34 	case GEN6_PCODE_ILLEGAL_CMD:
35 		return -ENXIO;
36 	case GEN7_PCODE_TIMEOUT:
37 		return -ETIMEDOUT;
38 	case GEN7_PCODE_ILLEGAL_DATA:
39 		return -EINVAL;
40 	case GEN11_PCODE_ILLEGAL_SUBCOMMAND:
41 		return -ENXIO;
42 	case GEN11_PCODE_LOCKED:
43 		return -EBUSY;
44 	case GEN11_PCODE_REJECTED:
45 		return -EACCES;
46 	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
47 		return -EOVERFLOW;
48 	default:
49 		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
50 		return 0;
51 	}
52 }
53 
54 static int __sandybridge_pcode_rw(struct drm_i915_private *i915,
55 				  u32 mbox, u32 *val, u32 *val1,
56 				  int fast_timeout_us,
57 				  int slow_timeout_ms,
58 				  bool is_read)
59 {
60 	struct intel_uncore *uncore = &i915->uncore;
61 
62 	lockdep_assert_held(&i915->sb_lock);
63 
64 	/*
65 	 * GEN6_PCODE_* are outside of the forcewake domain, we can use
66 	 * intel_uncore_read/write_fw variants to reduce the amount of work
67 	 * required when reading/writing.
68 	 */
69 
70 	if (intel_uncore_read_fw(uncore, GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY)
71 		return -EAGAIN;
72 
73 	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA, *val);
74 	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA1, val1 ? *val1 : 0);
75 	intel_uncore_write_fw(uncore,
76 			      GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | mbox);
77 
78 	if (__intel_wait_for_register_fw(uncore,
79 					 GEN6_PCODE_MAILBOX,
80 					 GEN6_PCODE_READY, 0,
81 					 fast_timeout_us,
82 					 slow_timeout_ms,
83 					 &mbox))
84 		return -ETIMEDOUT;
85 
86 	if (is_read)
87 		*val = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA);
88 	if (is_read && val1)
89 		*val1 = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA1);
90 
91 	if (GRAPHICS_VER(i915) > 6)
92 		return gen7_check_mailbox_status(mbox);
93 	else
94 		return gen6_check_mailbox_status(mbox);
95 }
96 
97 int sandybridge_pcode_read(struct drm_i915_private *i915, u32 mbox,
98 			   u32 *val, u32 *val1)
99 {
100 	int err;
101 
102 	mutex_lock(&i915->sb_lock);
103 	err = __sandybridge_pcode_rw(i915, mbox, val, val1,
104 				     500, 20,
105 				     true);
106 	mutex_unlock(&i915->sb_lock);
107 
108 	if (err) {
109 		drm_dbg(&i915->drm,
110 			"warning: pcode (read from mbox %x) mailbox access failed for %ps: %d\n",
111 			mbox, __builtin_return_address(0), err);
112 	}
113 
114 	return err;
115 }
116 
117 int sandybridge_pcode_write_timeout(struct drm_i915_private *i915,
118 				    u32 mbox, u32 val,
119 				    int fast_timeout_us,
120 				    int slow_timeout_ms)
121 {
122 	int err;
123 
124 	mutex_lock(&i915->sb_lock);
125 	err = __sandybridge_pcode_rw(i915, mbox, &val, NULL,
126 				     fast_timeout_us, slow_timeout_ms,
127 				     false);
128 	mutex_unlock(&i915->sb_lock);
129 
130 	if (err) {
131 		drm_dbg(&i915->drm,
132 			"warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps: %d\n",
133 			val, mbox, __builtin_return_address(0), err);
134 	}
135 
136 	return err;
137 }
138 
139 static bool skl_pcode_try_request(struct drm_i915_private *i915, u32 mbox,
140 				  u32 request, u32 reply_mask, u32 reply,
141 				  u32 *status)
142 {
143 	*status = __sandybridge_pcode_rw(i915, mbox, &request, NULL,
144 					 500, 0,
145 					 true);
146 
147 	return *status || ((request & reply_mask) == reply);
148 }
149 
150 /**
151  * skl_pcode_request - send PCODE request until acknowledgment
152  * @i915: device private
153  * @mbox: PCODE mailbox ID the request is targeted for
154  * @request: request ID
155  * @reply_mask: mask used to check for request acknowledgment
156  * @reply: value used to check for request acknowledgment
157  * @timeout_base_ms: timeout for polling with preemption enabled
158  *
159  * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
160  * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
161  * The request is acknowledged once the PCODE reply dword equals @reply after
162  * applying @reply_mask. Polling is first attempted with preemption enabled
163  * for @timeout_base_ms and if this times out for another 50 ms with
164  * preemption disabled.
165  *
166  * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
167  * other error as reported by PCODE.
168  */
169 int skl_pcode_request(struct drm_i915_private *i915, u32 mbox, u32 request,
170 		      u32 reply_mask, u32 reply, int timeout_base_ms)
171 {
172 	u32 status;
173 	int ret;
174 
175 	mutex_lock(&i915->sb_lock);
176 
177 #define COND \
178 	skl_pcode_try_request(i915, mbox, request, reply_mask, reply, &status)
179 
180 	/*
181 	 * Prime the PCODE by doing a request first. Normally it guarantees
182 	 * that a subsequent request, at most @timeout_base_ms later, succeeds.
183 	 * _wait_for() doesn't guarantee when its passed condition is evaluated
184 	 * first, so send the first request explicitly.
185 	 */
186 	if (COND) {
187 		ret = 0;
188 		goto out;
189 	}
190 	ret = _wait_for(COND, timeout_base_ms * 1000, 10, 10);
191 	if (!ret)
192 		goto out;
193 
194 	/*
195 	 * The above can time out if the number of requests was low (2 in the
196 	 * worst case) _and_ PCODE was busy for some reason even after a
197 	 * (queued) request and @timeout_base_ms delay. As a workaround retry
198 	 * the poll with preemption disabled to maximize the number of
199 	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
200 	 * account for interrupts that could reduce the number of these
201 	 * requests, and for any quirks of the PCODE firmware that delays
202 	 * the request completion.
203 	 */
204 	drm_dbg_kms(&i915->drm,
205 		    "PCODE timeout, retrying with preemption disabled\n");
206 	drm_WARN_ON_ONCE(&i915->drm, timeout_base_ms > 3);
207 	preempt_disable();
208 	ret = wait_for_atomic(COND, 50);
209 	preempt_enable();
210 
211 out:
212 	mutex_unlock(&i915->sb_lock);
213 	return ret ? ret : status;
214 #undef COND
215 }
216 
217 int intel_pcode_init(struct drm_i915_private *i915)
218 {
219 	int ret = 0;
220 
221 	if (!IS_DGFX(i915))
222 		return ret;
223 
224 	ret = skl_pcode_request(i915, DG1_PCODE_STATUS,
225 				DG1_UNCORE_GET_INIT_STATUS,
226 				DG1_UNCORE_INIT_STATUS_COMPLETE,
227 				DG1_UNCORE_INIT_STATUS_COMPLETE, 180000);
228 
229 	drm_dbg(&i915->drm, "PCODE init status %d\n", ret);
230 
231 	if (ret)
232 		drm_err(&i915->drm, "Pcode did not report uncore initialization completion!\n");
233 
234 	return ret;
235 }
236