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_PN * PAGE_SIZE +
29 		 CTX_R_PWR_CLK_STATE * 4;
30 
31 	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
32 	*cs++ = lower_32_bits(offset);
33 	*cs++ = upper_32_bits(offset);
34 	*cs++ = intel_sseu_make_rpcs(rq->i915, &sseu);
35 
36 	intel_ring_advance(rq, cs);
37 
38 	return 0;
39 }
40 
41 static int
42 gen8_modify_rpcs(struct intel_context *ce, const struct intel_sseu sseu)
43 {
44 	struct i915_request *rq;
45 	int ret;
46 
47 	lockdep_assert_held(&ce->pin_mutex);
48 
49 	/*
50 	 * If the context is not idle, we have to submit an ordered request to
51 	 * modify its context image via the kernel context (writing to our own
52 	 * image, or into the registers directory, does not stick). Pristine
53 	 * and idle contexts will be configured on pinning.
54 	 */
55 	if (!intel_context_pin_if_active(ce))
56 		return 0;
57 
58 	rq = intel_engine_create_kernel_request(ce->engine);
59 	if (IS_ERR(rq)) {
60 		ret = PTR_ERR(rq);
61 		goto out_unpin;
62 	}
63 
64 	/* Serialise with the remote context */
65 	ret = intel_context_prepare_remote_request(ce, rq);
66 	if (ret == 0)
67 		ret = gen8_emit_rpcs_config(rq, ce, sseu);
68 
69 	i915_request_add(rq);
70 out_unpin:
71 	intel_context_unpin(ce);
72 	return ret;
73 }
74 
75 int
76 intel_context_reconfigure_sseu(struct intel_context *ce,
77 			       const struct intel_sseu sseu)
78 {
79 	int ret;
80 
81 	GEM_BUG_ON(INTEL_GEN(ce->engine->i915) < 8);
82 
83 	ret = intel_context_lock_pinned(ce);
84 	if (ret)
85 		return ret;
86 
87 	/* Nothing to do if unmodified. */
88 	if (!memcmp(&ce->sseu, &sseu, sizeof(sseu)))
89 		goto unlock;
90 
91 	ret = gen8_modify_rpcs(ce, sseu);
92 	if (!ret)
93 		ce->sseu = sseu;
94 
95 unlock:
96 	intel_context_unlock_pinned(ce);
97 	return ret;
98 }
99