8322 nl: misleading-indentation
[unleashed/tickless.git] / usr / src / lib / commpage / i386 / cp_subr.s
blob990864d0ba14ed334cf0d782d385ef6691f95fce
1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
13 * Copyright 2016 Joyent, Inc.
16 #include <sys/asm_linkage.h>
17 #include <sys/segments.h>
18 #include <sys/time_impl.h>
19 #include <sys/tsc.h>
20 #include <cp_offsets.h>
22 #define GETCPU_GDT_OFFSET SEL_GDT(GDT_CPUID, SEL_UPL)
24 .file "cp_subr.s"
27 * hrtime_t
28 * __cp_tsc_read(uint_t cp_tsc_type)
30 * Stack usage: 0x18 bytes
32 ENTRY_NP(__cp_tsc_read)
33 pushl %ebp
34 movl %esp, %ebp
35 pushl %edi
36 pushl %esi
37 subl $0x4, %esp
39 movl 0x8(%ebp), %edi
40 movl CP_TSC_TYPE(%edi), %eax
41 movl CP_TSC_NCPU(%edi), %esi
42 cmpl $TSC_TSCP, %eax
43 jne 3f
44 rdtscp
45 cmpl $0, %esi
46 jne 2f
48 addl $0x4, %esp
49 popl %esi
50 popl %edi
51 leave
52 ret
55 * When cp_tsc_ncpu is non-zero, it indicates the length of the
56 * cp_tsc_sync_tick_delta array, which contains per-CPU offsets for the
57 * TSC. The CPU ID furnished by the IA32_TSC_AUX register via rdtscp
58 * is used to look up an offset value in that array and apply it to the
59 * TSC reading.
61 leal CP_TSC_SYNC_TICK_DELTA(%edi), %esi
62 leal (%esi, %ecx, 8), %ecx
63 addl (%ecx), %eax
64 adcl 0x4(%ecx), %edx
65 jmp 1b
68 cmpl $0, %esi
69 je 4f
70 mov $GETCPU_GDT_OFFSET, %eax
71 lsl %ax, %eax
72 movl %eax, (%esp)
73 movl CP_TSC_TYPE(%edi), %eax
76 cmpl $TSC_RDTSC_MFENCE, %eax
77 jne 5f
78 mfence
79 rdtsc
80 jmp 8f
83 cmpl $TSC_RDTSC_LFENCE, %eax
84 jne 6f
85 lfence
86 rdtsc
87 jmp 8f
90 cmpl $TSC_RDTSC_CPUID, %eax
91 jne 7f
92 pushl %ebx
93 xorl %eax, %eax
94 cpuid
95 rdtsc
96 popl %ebx
97 jmp 8f
101 * Other protections should have prevented this function from being
102 * called in the first place. The only sane action is to abort.
103 * The easiest means in this context is via SIGILL.
105 ud2a
109 cmpl $0, %esi
110 je 1b
112 * With a TSC reading in-hand, confirm that the thread has not migrated
113 * since the cpu_id was first checked.
115 movl $GETCPU_GDT_OFFSET, %ecx
116 lsl %cx, %ecx
117 movl (%esp), %esi
118 cmpl %ecx, %esi
119 je 9f
121 * There was a CPU migration, perform another reading.
123 movl %eax, (%esp)
124 movl CP_TSC_NCPU(%edi), %esi
125 movl CP_TSC_TYPE(%edi), %eax
126 jmp 4b
129 /* Grab the per-cpu offset and add it to the TSC result */
130 leal CP_TSC_SYNC_TICK_DELTA(%edi), %esi
131 leal (%esi, %ecx, 8), %ecx
132 addl (%ecx), %eax
133 adcl 0x4(%ecx), %edx
134 jmp 1b
135 SET_SIZE(__cp_tsc_read)
138 * uint_t
139 * __cp_getcpu(uint_t cp_tsc_type)
141 ENTRY_NP(__cp_getcpu)
143 * If RDTSCP is available, it is a quick way to grab the cpu_id which
144 * is stored in the TSC_AUX MSR by the kernel.
146 movl 4(%esp), %eax
147 movl CP_TSC_TYPE(%eax), %eax
148 cmpl $TSC_TSCP, %eax
149 jne 1f
150 rdtscp
151 movl %ecx, %eax
154 mov $GETCPU_GDT_OFFSET, %eax
155 lsl %ax, %eax
157 SET_SIZE(__cp_getcpu)