1 /*
2 * Copyright 2019 The Hafnium Authors.
3 *
4 * Use of this source code is governed by a BSD-style
5 * license that can be found in the LICENSE file or at
6 * https://opensource.org/licenses/BSD-3-Clause.
7 */
8
9 #include "hf/arch/vm/power_mgmt.h"
10
11 #include "hf/arch/mm.h"
12 #include "hf/arch/types.h"
13
14 #include "hf/mm.h"
15 #include "hf/spinlock.h"
16
17 #include "test/hftest.h"
18
19 struct cpu_start_state {
20 cpu_entry_point *entry;
21 uintreg_t arg;
22 struct spinlock lock;
23 };
24
cpu_entry(uintptr_t arg)25 [[noreturn]] static void cpu_entry(uintptr_t arg)
26 {
27 /*
28 * The function prototype must match the entry function so we permit the
29 * int to pointer conversion.
30 */
31 // NOLINTNEXTLINE(performance-no-int-to-ptr)
32 struct cpu_start_state *s = (struct cpu_start_state *)arg;
33 struct cpu_start_state s_copy;
34
35 /*
36 * Initialize memory and enable caching. Must be the first thing we do.
37 */
38 hftest_mm_vcpu_init();
39
40 /* Make a copy of the cpu_start_state struct. */
41 s_copy = *s;
42
43 /* Inform cpu_start() that the state struct memory can now be freed. */
44 sl_unlock(&s->lock);
45
46 /* Call the given entry function with the given argument. */
47 s_copy.entry(s_copy.arg);
48
49 /* If the entry function returns, turn off the CPU. */
50 arch_cpu_stop();
51 }
52
hftest_cpu_start(cpu_id_t id,const uint8_t * secondary_ec_stack,cpu_entry_point * entry,uintptr_t arg)53 bool hftest_cpu_start(cpu_id_t id, const uint8_t *secondary_ec_stack,
54 cpu_entry_point *entry, uintptr_t arg)
55 {
56 struct cpu_start_state s;
57 struct arch_cpu_start_state s_arch;
58
59 /*
60 * Config for arch_cpu_start() which will start a new CPU and
61 * immediately jump to cpu_entry(). This function must guarantee that
62 * the state struct is not be freed until cpu_entry() is called.
63 */
64 s_arch.initial_sp = (uintptr_t)secondary_ec_stack;
65 s_arch.entry = cpu_entry;
66 s_arch.arg = (uintptr_t)&s;
67
68 /*
69 * Flush the `cpu_start_state` struct because the new CPU will be
70 * started without caching enabled and will need the data early on.
71 * Write back is all that is really needed so flushing will definitely
72 * get the job done.
73 */
74 arch_mm_flush_dcache(&s_arch, sizeof(s_arch));
75
76 if ((s_arch.initial_sp % STACK_ALIGN) != 0) {
77 HFTEST_FAIL(true,
78 "Stack pointer of new vCPU not properly aligned.");
79 }
80
81 /*
82 * Config for cpu_entry(). Its job is to initialize memory and call the
83 * provided entry point with the provided argument.
84 */
85 s.entry = entry;
86 s.arg = arg;
87 sl_init(&s.lock);
88
89 /*
90 * Lock the cpu_start_state struct which will be unlocked once
91 * cpu_entry() does not need its content anymore. This simultaneously
92 * protects the arch_cpu_start_state struct which must not be freed
93 * before cpu_entry() is called.
94 */
95 sl_lock(&s.lock);
96
97 /* Try to start the given CPU. */
98 if (!arch_cpu_start(id, &s_arch)) {
99 HFTEST_LOG("Couldn't start cpu %lu", id);
100 return false;
101 }
102
103 /*
104 * Wait until cpu_entry() unlocks the cpu_start_state lock before
105 * freeing stack memory.
106 */
107 sl_lock(&s.lock);
108 return true;
109 }
110