1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_vma.h"
8 #include "intel_context.h"
9 #include "intel_engine_pm.h"
10 #include "intel_gpu_commands.h"
11 #include "intel_lrc.h"
12 #include "intel_lrc_reg.h"
13 #include "intel_ring.h"
14 #include "intel_sseu.h"
15 
16 static int gen8_emit_rpcs_config(struct i915_request *rq,
17 				 const struct intel_context *ce,
18 				 const struct intel_sseu sseu)
19 {
20 	u64 offset;
21 	u32 *cs;
22 
23 	cs = intel_ring_begin(rq, 4);
24 	if (IS_ERR(cs))
25 		return PTR_ERR(cs);
26 
27 	offset = i915_ggtt_offset(ce->state) +
28 		 LRC_STATE_OFFSET + CTX_R_PWR_CLK_STATE * 4;
29 
30 	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
31 	*cs++ = lower_32_bits(offset);
32 	*cs++ = upper_32_bits(offset);
33 	*cs++ = intel_sseu_make_rpcs(rq->engine->gt, &sseu);
34 
35 	intel_ring_advance(rq, cs);
36 
37 	return 0;
38 }
39 
40 static int
41 gen8_modify_rpcs(struct intel_context *ce, const struct intel_sseu sseu)
42 {
43 	struct i915_request *rq;
44 	int ret;
45 
46 	lockdep_assert_held(&ce->pin_mutex);
47 
48 	/*
49 	 * If the context is not idle, we have to submit an ordered request to
50 	 * modify its context image via the kernel context (writing to our own
51 	 * image, or into the registers directory, does not stick). Pristine
52 	 * and idle contexts will be configured on pinning.
53 	 */
54 	if (!intel_context_pin_if_active(ce))
55 		return 0;
56 
57 	rq = intel_engine_create_kernel_request(ce->engine);
58 	if (IS_ERR(rq)) {
59 		ret = PTR_ERR(rq);
60 		goto out_unpin;
61 	}
62 
63 	/* Serialise with the remote context */
64 	ret = intel_context_prepare_remote_request(ce, rq);
65 	if (ret == 0)
66 		ret = gen8_emit_rpcs_config(rq, ce, sseu);
67 
68 	i915_request_add(rq);
69 out_unpin:
70 	intel_context_unpin(ce);
71 	return ret;
72 }
73 
74 int
75 intel_context_reconfigure_sseu(struct intel_context *ce,
76 			       const struct intel_sseu sseu)
77 {
78 	int ret;
79 
80 	GEM_BUG_ON(INTEL_GEN(ce->engine->i915) < 8);
81 
82 	ret = intel_context_lock_pinned(ce);
83 	if (ret)
84 		return ret;
85 
86 	/* Nothing to do if unmodified. */
87 	if (!memcmp(&ce->sseu, &sseu, sizeof(sseu)))
88 		goto unlock;
89 
90 	ret = gen8_modify_rpcs(ce, sseu);
91 	if (!ret)
92 		ce->sseu = sseu;
93 
94 unlock:
95 	intel_context_unlock_pinned(ce);
96 	return ret;
97 }
98