xref: /openbmc/linux/drivers/gpu/drm/i915/intel_pcode.c (revision bacf743e)
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 drm_i915_private *i915, u32 mbox,
56 			  u32 *val, u32 *val1,
57 			  int fast_timeout_us, 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 snb_pcode_read(struct drm_i915_private *i915, u32 mbox, u32 *val, u32 *val1)
98 {
99 	int err;
100 
101 	mutex_lock(&i915->sb_lock);
102 	err = __snb_pcode_rw(i915, mbox, val, val1, 500, 20, true);
103 	mutex_unlock(&i915->sb_lock);
104 
105 	if (err) {
106 		drm_dbg(&i915->drm,
107 			"warning: pcode (read from mbox %x) mailbox access failed for %ps: %d\n",
108 			mbox, __builtin_return_address(0), err);
109 	}
110 
111 	return err;
112 }
113 
114 int snb_pcode_write_timeout(struct drm_i915_private *i915, u32 mbox, u32 val,
115 			    int fast_timeout_us, int slow_timeout_ms)
116 {
117 	int err;
118 
119 	mutex_lock(&i915->sb_lock);
120 	err = __snb_pcode_rw(i915, mbox, &val, NULL,
121 			     fast_timeout_us, slow_timeout_ms, false);
122 	mutex_unlock(&i915->sb_lock);
123 
124 	if (err) {
125 		drm_dbg(&i915->drm,
126 			"warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps: %d\n",
127 			val, mbox, __builtin_return_address(0), err);
128 	}
129 
130 	return err;
131 }
132 
133 static bool skl_pcode_try_request(struct drm_i915_private *i915, u32 mbox,
134 				  u32 request, u32 reply_mask, u32 reply,
135 				  u32 *status)
136 {
137 	*status = __snb_pcode_rw(i915, mbox, &request, NULL, 500, 0, true);
138 
139 	return *status || ((request & reply_mask) == reply);
140 }
141 
142 /**
143  * skl_pcode_request - send PCODE request until acknowledgment
144  * @i915: device private
145  * @mbox: PCODE mailbox ID the request is targeted for
146  * @request: request ID
147  * @reply_mask: mask used to check for request acknowledgment
148  * @reply: value used to check for request acknowledgment
149  * @timeout_base_ms: timeout for polling with preemption enabled
150  *
151  * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
152  * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
153  * The request is acknowledged once the PCODE reply dword equals @reply after
154  * applying @reply_mask. Polling is first attempted with preemption enabled
155  * for @timeout_base_ms and if this times out for another 50 ms with
156  * preemption disabled.
157  *
158  * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
159  * other error as reported by PCODE.
160  */
161 int skl_pcode_request(struct drm_i915_private *i915, u32 mbox, u32 request,
162 		      u32 reply_mask, u32 reply, int timeout_base_ms)
163 {
164 	u32 status;
165 	int ret;
166 
167 	mutex_lock(&i915->sb_lock);
168 
169 #define COND \
170 	skl_pcode_try_request(i915, mbox, request, reply_mask, reply, &status)
171 
172 	/*
173 	 * Prime the PCODE by doing a request first. Normally it guarantees
174 	 * that a subsequent request, at most @timeout_base_ms later, succeeds.
175 	 * _wait_for() doesn't guarantee when its passed condition is evaluated
176 	 * first, so send the first request explicitly.
177 	 */
178 	if (COND) {
179 		ret = 0;
180 		goto out;
181 	}
182 	ret = _wait_for(COND, timeout_base_ms * 1000, 10, 10);
183 	if (!ret)
184 		goto out;
185 
186 	/*
187 	 * The above can time out if the number of requests was low (2 in the
188 	 * worst case) _and_ PCODE was busy for some reason even after a
189 	 * (queued) request and @timeout_base_ms delay. As a workaround retry
190 	 * the poll with preemption disabled to maximize the number of
191 	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
192 	 * account for interrupts that could reduce the number of these
193 	 * requests, and for any quirks of the PCODE firmware that delays
194 	 * the request completion.
195 	 */
196 	drm_dbg_kms(&i915->drm,
197 		    "PCODE timeout, retrying with preemption disabled\n");
198 	drm_WARN_ON_ONCE(&i915->drm, timeout_base_ms > 3);
199 	preempt_disable();
200 	ret = wait_for_atomic(COND, 50);
201 	preempt_enable();
202 
203 out:
204 	mutex_unlock(&i915->sb_lock);
205 	return ret ? ret : status;
206 #undef COND
207 }
208 
209 int intel_pcode_init(struct drm_i915_private *i915)
210 {
211 	int ret = 0;
212 
213 	if (!IS_DGFX(i915))
214 		return ret;
215 
216 	ret = skl_pcode_request(i915, DG1_PCODE_STATUS,
217 				DG1_UNCORE_GET_INIT_STATUS,
218 				DG1_UNCORE_INIT_STATUS_COMPLETE,
219 				DG1_UNCORE_INIT_STATUS_COMPLETE, 180000);
220 
221 	drm_dbg(&i915->drm, "PCODE init status %d\n", ret);
222 
223 	if (ret)
224 		drm_err(&i915->drm, "Pcode did not report uncore initialization completion!\n");
225 
226 	return ret;
227 }
228