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-rw-r--r--arch/arm/include/asm/locks.h274
1 files changed, 274 insertions, 0 deletions
diff --git a/arch/arm/include/asm/locks.h b/arch/arm/include/asm/locks.h
new file mode 100644
index 0000000..ef4c897
--- /dev/null
+++ b/arch/arm/include/asm/locks.h
@@ -0,0 +1,274 @@
+/*
+ * arch/arm/include/asm/locks.h
+ *
+ * Copyright (C) 2000 Russell King
+ *
+ * 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
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+#define __down_op(ptr,fail) \
+ ({ \
+ __asm__ __volatile__( \
+ "@ down_op\n" \
+"1: ldrex lr, [%0]\n" \
+" sub lr, lr, %1\n" \
+" strex ip, lr, [%0]\n" \
+" teq ip, #0\n" \
+" bne 1b\n" \
+" teq lr, #0\n" \
+" movmi ip, %0\n" \
+" blmi " #fail \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ })
+
+#define __down_op_ret(ptr,fail) \
+ ({ \
+ unsigned int ret; \
+ __asm__ __volatile__( \
+ "@ down_op_ret\n" \
+"1: ldrex lr, [%1]\n" \
+" sub lr, lr, %2\n" \
+" strex ip, lr, [%1]\n" \
+" teq ip, #0\n" \
+" bne 1b\n" \
+" teq lr, #0\n" \
+" movmi ip, %1\n" \
+" movpl ip, #0\n" \
+" blmi " #fail "\n" \
+" mov %0, ip" \
+ : "=&r" (ret) \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ ret; \
+ })
+
+#define __up_op(ptr,wake) \
+ ({ \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "@ up_op\n" \
+"1: ldrex lr, [%0]\n" \
+" add lr, lr, %1\n" \
+" strex ip, lr, [%0]\n" \
+" teq ip, #0\n" \
+" bne 1b\n" \
+" cmp lr, #0\n" \
+" movle ip, %0\n" \
+" blle " #wake \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "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"
+
+#define __down_op_write(ptr,fail) \
+ ({ \
+ __asm__ __volatile__( \
+ "@ down_op_write\n" \
+"1: ldrex lr, [%0]\n" \
+" sub lr, lr, %1\n" \
+" strex ip, lr, [%0]\n" \
+" teq ip, #0\n" \
+" bne 1b\n" \
+" teq lr, #0\n" \
+" movne ip, %0\n" \
+" blne " #fail \
+ : \
+ : "r" (ptr), "I" (RW_LOCK_BIAS) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ })
+
+#define __up_op_write(ptr,wake) \
+ ({ \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "@ up_op_write\n" \
+"1: ldrex lr, [%0]\n" \
+" adds lr, lr, %1\n" \
+" strex ip, lr, [%0]\n" \
+" teq ip, #0\n" \
+" bne 1b\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) \
+ ({ \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "@ up_op_read\n" \
+"1: ldrex lr, [%0]\n" \
+" add lr, lr, %1\n" \
+" strex ip, lr, [%0]\n" \
+" teq ip, #0\n" \
+" bne 1b\n" \
+" teq lr, #0\n" \
+" moveq ip, %0\n" \
+" bleq " #wake \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ })
+
+#else
+
+#define __down_op(ptr,fail) \
+ ({ \
+ __asm__ __volatile__( \
+ "@ down_op\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%0]\n" \
+" subs lr, lr, %1\n" \
+" str lr, [%0]\n" \
+" msr cpsr_c, ip\n" \
+" movmi ip, %0\n" \
+" blmi " #fail \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ })
+
+#define __down_op_ret(ptr,fail) \
+ ({ \
+ unsigned int ret; \
+ __asm__ __volatile__( \
+ "@ down_op_ret\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%1]\n" \
+" subs lr, lr, %2\n" \
+" str lr, [%1]\n" \
+" msr cpsr_c, ip\n" \
+" movmi ip, %1\n" \
+" movpl ip, #0\n" \
+" blmi " #fail "\n" \
+" mov %0, ip" \
+ : "=&r" (ret) \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ ret; \
+ })
+
+#define __up_op(ptr,wake) \
+ ({ \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "@ up_op\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%0]\n" \
+" adds lr, lr, %1\n" \
+" str lr, [%0]\n" \
+" msr cpsr_c, ip\n" \
+" movle ip, %0\n" \
+" blle " #wake \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "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"
+
+#define __down_op_write(ptr,fail) \
+ ({ \
+ __asm__ __volatile__( \
+ "@ down_op_write\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%0]\n" \
+" subs lr, lr, %1\n" \
+" str lr, [%0]\n" \
+" msr cpsr_c, ip\n" \
+" movne ip, %0\n" \
+" blne " #fail \
+ : \
+ : "r" (ptr), "I" (RW_LOCK_BIAS) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ })
+
+#define __up_op_write(ptr,wake) \
+ ({ \
+ __asm__ __volatile__( \
+ "@ up_op_write\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%0]\n" \
+" adds lr, lr, %1\n" \
+" str lr, [%0]\n" \
+" msr cpsr_c, ip\n" \
+" movcs ip, %0\n" \
+" blcs " #wake \
+ : \
+ : "r" (ptr), "I" (RW_LOCK_BIAS) \
+ : "ip", "lr", "cc"); \
+ smp_mb(); \
+ })
+
+#define __down_op_read(ptr,fail) \
+ __down_op(ptr, fail)
+
+#define __up_op_read(ptr,wake) \
+ ({ \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "@ up_op_read\n" \
+" mrs ip, cpsr\n" \
+" orr lr, ip, #128\n" \
+" msr cpsr_c, lr\n" \
+" ldr lr, [%0]\n" \
+" adds lr, lr, %1\n" \
+" str lr, [%0]\n" \
+" msr cpsr_c, ip\n" \
+" moveq ip, %0\n" \
+" bleq " #wake \
+ : \
+ : "r" (ptr), "I" (1) \
+ : "ip", "lr", "cc"); \
+ })
+
+#endif
+
+#endif
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