| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* rwsem.S: RW semaphore assembler. | 
 | 2 |  * | 
 | 3 |  * Written by David S. Miller (davem@redhat.com), 2001. | 
 | 4 |  * Derived from asm-i386/rwsem.h | 
 | 5 |  */ | 
 | 6 |  | 
 | 7 | #include <asm/rwsem-const.h> | 
 | 8 |  | 
| Sam Ravnborg | c6d64c1 | 2008-01-28 21:06:23 -0800 | [diff] [blame] | 9 | 	.section	.sched.text, "ax" | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 |  | 
 | 11 | 	.globl		__down_read | 
 | 12 | __down_read: | 
 | 13 | 1:	lduw		[%o0], %g1 | 
 | 14 | 	add		%g1, 1, %g7 | 
 | 15 | 	cas		[%o0], %g1, %g7 | 
 | 16 | 	cmp		%g1, %g7 | 
 | 17 | 	bne,pn		%icc, 1b | 
 | 18 | 	 add		%g7, 1, %g7 | 
 | 19 | 	cmp		%g7, 0 | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 20 | 	membar		#StoreLoad | #StoreStore | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | 	bl,pn		%icc, 3f | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 22 | 	 nop | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | 2: | 
 | 24 | 	retl | 
 | 25 | 	 nop | 
 | 26 | 3: | 
 | 27 | 	save		%sp, -192, %sp | 
 | 28 | 	call		rwsem_down_read_failed | 
 | 29 | 	 mov		%i0, %o0 | 
 | 30 | 	ret | 
 | 31 | 	 restore | 
 | 32 | 	.size		__down_read, .-__down_read | 
 | 33 |  | 
 | 34 | 	.globl		__down_read_trylock | 
 | 35 | __down_read_trylock: | 
 | 36 | 1:	lduw		[%o0], %g1 | 
 | 37 | 	add		%g1, 1, %g7 | 
 | 38 | 	cmp		%g7, 0 | 
 | 39 | 	bl,pn		%icc, 2f | 
 | 40 | 	 mov		0, %o1 | 
 | 41 | 	cas		[%o0], %g1, %g7 | 
 | 42 | 	cmp		%g1, %g7 | 
 | 43 | 	bne,pn		%icc, 1b | 
 | 44 | 	 mov		1, %o1 | 
 | 45 | 	membar		#StoreLoad | #StoreStore | 
 | 46 | 2:	retl | 
 | 47 | 	 mov		%o1, %o0 | 
 | 48 | 	.size		__down_read_trylock, .-__down_read_trylock | 
 | 49 |  | 
 | 50 | 	.globl		__down_write | 
 | 51 | __down_write: | 
 | 52 | 	sethi		%hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 53 | 	or		%g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 54 | 1: | 
 | 55 | 	lduw		[%o0], %g3 | 
 | 56 | 	add		%g3, %g1, %g7 | 
 | 57 | 	cas		[%o0], %g3, %g7 | 
 | 58 | 	cmp		%g3, %g7 | 
 | 59 | 	bne,pn		%icc, 1b | 
 | 60 | 	 cmp		%g7, 0 | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 61 | 	membar		#StoreLoad | #StoreStore | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | 	bne,pn		%icc, 3f | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 63 | 	 nop | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | 2:	retl | 
 | 65 | 	 nop | 
 | 66 | 3: | 
 | 67 | 	save		%sp, -192, %sp | 
 | 68 | 	call		rwsem_down_write_failed | 
 | 69 | 	 mov		%i0, %o0 | 
 | 70 | 	ret | 
 | 71 | 	 restore | 
 | 72 | 	.size		__down_write, .-__down_write | 
 | 73 |  | 
 | 74 | 	.globl		__down_write_trylock | 
 | 75 | __down_write_trylock: | 
 | 76 | 	sethi		%hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 77 | 	or		%g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 78 | 1: | 
 | 79 | 	lduw		[%o0], %g3 | 
 | 80 | 	cmp		%g3, 0 | 
 | 81 | 	bne,pn		%icc, 2f | 
 | 82 | 	 mov		0, %o1 | 
 | 83 | 	add		%g3, %g1, %g7 | 
 | 84 | 	cas		[%o0], %g3, %g7 | 
 | 85 | 	cmp		%g3, %g7 | 
 | 86 | 	bne,pn		%icc, 1b | 
 | 87 | 	 mov		1, %o1 | 
 | 88 | 	membar		#StoreLoad | #StoreStore | 
 | 89 | 2:	retl | 
 | 90 | 	 mov		%o1, %o0 | 
 | 91 | 	.size		__down_write_trylock, .-__down_write_trylock | 
 | 92 |  | 
 | 93 | 	.globl		__up_read | 
 | 94 | __up_read: | 
 | 95 | 1: | 
 | 96 | 	lduw		[%o0], %g1 | 
 | 97 | 	sub		%g1, 1, %g7 | 
 | 98 | 	cas		[%o0], %g1, %g7 | 
 | 99 | 	cmp		%g1, %g7 | 
 | 100 | 	bne,pn		%icc, 1b | 
 | 101 | 	 cmp		%g7, 0 | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 102 | 	membar		#StoreLoad | #StoreStore | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | 	bl,pn		%icc, 3f | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 104 | 	 nop | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | 2:	retl | 
 | 106 | 	 nop | 
 | 107 | 3:	sethi		%hi(RWSEM_ACTIVE_MASK), %g1 | 
 | 108 | 	sub		%g7, 1, %g7 | 
 | 109 | 	or		%g1, %lo(RWSEM_ACTIVE_MASK), %g1 | 
 | 110 | 	andcc		%g7, %g1, %g0 | 
 | 111 | 	bne,pn		%icc, 2b | 
 | 112 | 	 nop | 
 | 113 | 	save		%sp, -192, %sp | 
 | 114 | 	call		rwsem_wake | 
 | 115 | 	 mov		%i0, %o0 | 
 | 116 | 	ret | 
 | 117 | 	 restore | 
 | 118 | 	.size		__up_read, .-__up_read | 
 | 119 |  | 
 | 120 | 	.globl		__up_write | 
 | 121 | __up_write: | 
 | 122 | 	sethi		%hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 123 | 	or		%g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 | 
 | 124 | 1: | 
 | 125 | 	lduw		[%o0], %g3 | 
 | 126 | 	sub		%g3, %g1, %g7 | 
 | 127 | 	cas		[%o0], %g3, %g7 | 
 | 128 | 	cmp		%g3, %g7 | 
 | 129 | 	bne,pn		%icc, 1b | 
 | 130 | 	 sub		%g7, %g1, %g7 | 
 | 131 | 	cmp		%g7, 0 | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 132 | 	membar		#StoreLoad | #StoreStore | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | 	bl,pn		%icc, 3f | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 134 | 	 nop | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | 2: | 
 | 136 | 	retl | 
 | 137 | 	 nop | 
 | 138 | 3: | 
 | 139 | 	save		%sp, -192, %sp | 
 | 140 | 	call		rwsem_wake | 
 | 141 | 	 mov		%i0, %o0 | 
 | 142 | 	ret | 
 | 143 | 	 restore | 
 | 144 | 	.size		__up_write, .-__up_write | 
 | 145 |  | 
 | 146 | 	.globl		__downgrade_write | 
 | 147 | __downgrade_write: | 
 | 148 | 	sethi		%hi(RWSEM_WAITING_BIAS), %g1 | 
 | 149 | 	or		%g1, %lo(RWSEM_WAITING_BIAS), %g1 | 
 | 150 | 1: | 
 | 151 | 	lduw		[%o0], %g3 | 
 | 152 | 	sub		%g3, %g1, %g7 | 
 | 153 | 	cas		[%o0], %g3, %g7 | 
 | 154 | 	cmp		%g3, %g7 | 
 | 155 | 	bne,pn		%icc, 1b | 
 | 156 | 	 sub		%g7, %g1, %g7 | 
 | 157 | 	cmp		%g7, 0 | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 158 | 	membar		#StoreLoad | #StoreStore | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | 	bl,pn		%icc, 3f | 
| David S. Miller | b445e26 | 2005-06-27 15:42:04 -0700 | [diff] [blame] | 160 | 	 nop | 
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | 2: | 
 | 162 | 	retl | 
 | 163 | 	 nop | 
 | 164 | 3: | 
 | 165 | 	save		%sp, -192, %sp | 
 | 166 | 	call		rwsem_downgrade_wake | 
 | 167 | 	 mov		%i0, %o0 | 
 | 168 | 	ret | 
 | 169 | 	 restore | 
 | 170 | 	.size		__downgrade_write, .-__downgrade_write |