diff options
Diffstat (limited to 'include/asm-arm26/locks.h')
| -rw-r--r-- | include/asm-arm26/locks.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/include/asm-arm26/locks.h b/include/asm-arm26/locks.h new file mode 100644 index 00000000000..81b3bda2ed0 --- /dev/null +++ b/include/asm-arm26/locks.h @@ -0,0 +1,161 @@ +/* + * linux/include/asm-arm/proc-armo/locks.h + * + * Copyright (C) 2000 Russell King + * Fixes for 26 bit machines, (C) 2000 Dave Gilbert + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Interrupt safe locking assembler. + */ +#ifndef __ASM_PROC_LOCKS_H +#define __ASM_PROC_LOCKS_H + +/* Decrements by 1, fails if value < 0 */ +#define __down_op(ptr,fail) \ + ({ \ + __asm__ __volatile__ ( \ + "@ atomic down operation\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +" ldr lr, [%0]\n" \ +" and ip, ip, #0x0c000003\n" \ +" subs lr, lr, #1\n" \ +" str lr, [%0]\n" \ +" orrmi ip, ip, #0x80000000 @ set N\n" \ +" teqp ip, #0\n" \ +" movmi ip, %0\n" \ +" blmi " #fail \ + : \ + : "r" (ptr) \ + : "ip", "lr", "cc"); \ + }) + +#define __down_op_ret(ptr,fail) \ + ({ \ + unsigned int result; \ + __asm__ __volatile__ ( \ +" @ down_op_ret\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +" ldr lr, [%1]\n" \ +" and ip, ip, #0x0c000003\n" \ +" subs lr, lr, #1\n" \ +" str lr, [%1]\n" \ +" orrmi ip, ip, #0x80000000 @ set N\n" \ +" teqp ip, #0\n" \ +" movmi ip, %1\n" \ +" movpl ip, #0\n" \ +" blmi " #fail "\n" \ +" mov %0, ip" \ + : "=&r" (result) \ + : "r" (ptr) \ + : "ip", "lr", "cc"); \ + result; \ + }) + +#define __up_op(ptr,wake) \ + ({ \ + __asm__ __volatile__ ( \ + "@ up_op\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +" ldr lr, [%0]\n" \ +" and ip, ip, #0x0c000003\n" \ +" adds lr, lr, #1\n" \ +" str lr, [%0]\n" \ +" orrle ip, ip, #0x80000000 @ set N - should this be mi ??? DAG ! \n" \ +" teqp ip, #0\n" \ +" movmi ip, %0\n" \ +" blmi " #wake \ + : \ + : "r" (ptr) \ + : "ip", "lr", "cc"); \ + }) + +/* + * The value 0x01000000 supports up to 128 processors and + * lots of processes. BIAS must be chosen such that sub'ing + * BIAS once per CPU will result in the long remaining + * negative. + */ +#define RW_LOCK_BIAS 0x01000000 +#define RW_LOCK_BIAS_STR "0x01000000" + +/* Decrements by RW_LOCK_BIAS rather than 1, fails if value != 0 */ +#define __down_op_write(ptr,fail) \ + ({ \ + __asm__ __volatile__( \ + "@ down_op_write\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +" and ip, ip, #0x0c000003\n" \ +\ +" ldr lr, [%0]\n" \ +" subs lr, lr, %1\n" \ +" str lr, [%0]\n" \ +\ +" orreq ip, ip, #0x40000000 @ set Z \n"\ +" teqp ip, #0\n" \ +" movne ip, %0\n" \ +" blne " #fail \ + : \ + : "r" (ptr), "I" (RW_LOCK_BIAS) \ + : "ip", "lr", "cc"); \ + }) + +/* Increments by RW_LOCK_BIAS, wakes if value >= 0 */ +#define __up_op_write(ptr,wake) \ + ({ \ + __asm__ __volatile__( \ + "@ up_op_read\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +\ +" ldr lr, [%0]\n" \ +" and ip, ip, #0x0c000003\n" \ +" adds lr, lr, %1\n" \ +" str lr, [%0]\n" \ +\ +" orrcs ip, ip, #0x20000000 @ set C\n" \ +" teqp ip, #0\n" \ +" movcs ip, %0\n" \ +" blcs " #wake \ + : \ + : "r" (ptr), "I" (RW_LOCK_BIAS) \ + : "ip", "lr", "cc"); \ + }) + +#define __down_op_read(ptr,fail) \ + __down_op(ptr, fail) + +#define __up_op_read(ptr,wake) \ + ({ \ + __asm__ __volatile__( \ + "@ up_op_read\n" \ +" mov ip, pc\n" \ +" orr lr, ip, #0x08000000\n" \ +" teqp lr, #0\n" \ +\ +" ldr lr, [%0]\n" \ +" and ip, ip, #0x0c000003\n" \ +" adds lr, lr, %1\n" \ +" str lr, [%0]\n" \ +\ +" orreq ip, ip, #0x40000000 @ Set Z \n" \ +" teqp ip, #0\n" \ +" moveq ip, %0\n" \ +" bleq " #wake \ + : \ + : "r" (ptr), "I" (1) \ + : "ip", "lr", "cc"); \ + }) + +#endif |