1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * locks.S: SMP low-level lock primitives on S 3 * locks.S: SMP low-level lock primitives on Sparc.
4 * 4 *
5 * Copyright (C) 1996 David S. Miller (davem@c 5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1998 Anton Blanchard (anton@p 6 * Copyright (C) 1998 Anton Blanchard (anton@progsoc.uts.edu.au)
7 * Copyright (C) 1998 Jakub Jelinek (jj@ultr 7 * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
8 */ 8 */
9 9
10 #include <linux/export.h> 10 #include <linux/export.h>
11 #include <asm/ptrace.h> 11 #include <asm/ptrace.h>
12 #include <asm/psr.h> 12 #include <asm/psr.h>
13 #include <asm/smp.h> 13 #include <asm/smp.h>
14 #include <asm/spinlock.h> 14 #include <asm/spinlock.h>
15 15
16 .text 16 .text
17 .align 4 17 .align 4
18 18
19 /* Read/writer locks, as usual this is 19 /* Read/writer locks, as usual this is overly clever to make it
20 * as fast as possible. 20 * as fast as possible.
21 */ 21 */
22 22
23 /* caches... */ 23 /* caches... */
24 ___rw_read_enter_spin_on_wlock: 24 ___rw_read_enter_spin_on_wlock:
25 orcc %g2, 0x0, %g0 25 orcc %g2, 0x0, %g0
26 be,a ___rw_read_enter 26 be,a ___rw_read_enter
27 ldstub [%g1 + 3], %g2 27 ldstub [%g1 + 3], %g2
28 b ___rw_read_enter_spin_on_wlock 28 b ___rw_read_enter_spin_on_wlock
29 ldub [%g1 + 3], %g2 29 ldub [%g1 + 3], %g2
30 ___rw_read_try_spin_on_wlock: 30 ___rw_read_try_spin_on_wlock:
31 andcc %g2, 0xff, %g0 31 andcc %g2, 0xff, %g0
32 be,a ___rw_read_try 32 be,a ___rw_read_try
33 ldstub [%g1 + 3], %g2 33 ldstub [%g1 + 3], %g2
34 xnorcc %g2, 0x0, %o0 /* if g2 is ~0 34 xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */
35 bne,a ___rw_read_enter_spin_on_wlock 35 bne,a ___rw_read_enter_spin_on_wlock
36 ld [%g1], %g2 36 ld [%g1], %g2
37 retl 37 retl
38 mov %g4, %o7 38 mov %g4, %o7
39 ___rw_read_exit_spin_on_wlock: 39 ___rw_read_exit_spin_on_wlock:
40 orcc %g2, 0x0, %g0 40 orcc %g2, 0x0, %g0
41 be,a ___rw_read_exit 41 be,a ___rw_read_exit
42 ldstub [%g1 + 3], %g2 42 ldstub [%g1 + 3], %g2
43 b ___rw_read_exit_spin_on_wlock 43 b ___rw_read_exit_spin_on_wlock
44 ldub [%g1 + 3], %g2 44 ldub [%g1 + 3], %g2
45 ___rw_write_enter_spin_on_wlock: 45 ___rw_write_enter_spin_on_wlock:
46 orcc %g2, 0x0, %g0 46 orcc %g2, 0x0, %g0
47 be,a ___rw_write_enter 47 be,a ___rw_write_enter
48 ldstub [%g1 + 3], %g2 48 ldstub [%g1 + 3], %g2
49 b ___rw_write_enter_spin_on_wloc 49 b ___rw_write_enter_spin_on_wlock
50 ld [%g1], %g2 50 ld [%g1], %g2
51 51
52 .globl ___rw_read_enter 52 .globl ___rw_read_enter
53 EXPORT_SYMBOL(___rw_read_enter) 53 EXPORT_SYMBOL(___rw_read_enter)
54 ___rw_read_enter: 54 ___rw_read_enter:
55 orcc %g2, 0x0, %g0 55 orcc %g2, 0x0, %g0
56 bne,a ___rw_read_enter_spin_on_wlock 56 bne,a ___rw_read_enter_spin_on_wlock
57 ldub [%g1 + 3], %g2 57 ldub [%g1 + 3], %g2
58 ld [%g1], %g2 58 ld [%g1], %g2
59 add %g2, 1, %g2 59 add %g2, 1, %g2
60 st %g2, [%g1] 60 st %g2, [%g1]
61 retl 61 retl
62 mov %g4, %o7 62 mov %g4, %o7
63 63
64 .globl ___rw_read_exit 64 .globl ___rw_read_exit
65 EXPORT_SYMBOL(___rw_read_exit) 65 EXPORT_SYMBOL(___rw_read_exit)
66 ___rw_read_exit: 66 ___rw_read_exit:
67 orcc %g2, 0x0, %g0 67 orcc %g2, 0x0, %g0
68 bne,a ___rw_read_exit_spin_on_wlock 68 bne,a ___rw_read_exit_spin_on_wlock
69 ldub [%g1 + 3], %g2 69 ldub [%g1 + 3], %g2
70 ld [%g1], %g2 70 ld [%g1], %g2
71 sub %g2, 0x1ff, %g2 71 sub %g2, 0x1ff, %g2
72 st %g2, [%g1] 72 st %g2, [%g1]
73 retl 73 retl
74 mov %g4, %o7 74 mov %g4, %o7
75 75
76 .globl ___rw_read_try 76 .globl ___rw_read_try
77 EXPORT_SYMBOL(___rw_read_try) 77 EXPORT_SYMBOL(___rw_read_try)
78 ___rw_read_try: 78 ___rw_read_try:
79 orcc %g2, 0x0, %g0 79 orcc %g2, 0x0, %g0
80 bne ___rw_read_try_spin_on_wlock 80 bne ___rw_read_try_spin_on_wlock
81 ld [%g1], %g2 81 ld [%g1], %g2
82 add %g2, 1, %g2 82 add %g2, 1, %g2
83 st %g2, [%g1] 83 st %g2, [%g1]
84 set 1, %o1 84 set 1, %o1
85 retl 85 retl
86 mov %g4, %o7 86 mov %g4, %o7
87 87
88 .globl ___rw_write_enter 88 .globl ___rw_write_enter
89 EXPORT_SYMBOL(___rw_write_enter) 89 EXPORT_SYMBOL(___rw_write_enter)
90 ___rw_write_enter: 90 ___rw_write_enter:
91 orcc %g2, 0x0, %g0 91 orcc %g2, 0x0, %g0
92 bne ___rw_write_enter_spin_on_wloc 92 bne ___rw_write_enter_spin_on_wlock
93 ld [%g1], %g2 93 ld [%g1], %g2
94 andncc %g2, 0xff, %g0 94 andncc %g2, 0xff, %g0
95 bne,a ___rw_write_enter_spin_on_wloc 95 bne,a ___rw_write_enter_spin_on_wlock
96 stb %g0, [%g1 + 3] 96 stb %g0, [%g1 + 3]
97 retl 97 retl
98 mov %g4, %o7 98 mov %g4, %o7
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