--- /dev/null
+/*
+ * linux/include/asm-arm/proc-armv/system.h
+ *
+ * Copyright (C) 1996 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.
+ */
+#ifndef __ASM_PROC_SYSTEM_H
+#define __ASM_PROC_SYSTEM_H
+
+/*
+ * Save the current interrupt enable state & disable IRQs
+ */
+#ifdef CONFIG_ARM64
+
+/*
+ * Save the current interrupt enable state
+ * and disable IRQs/FIQs
+ */
+#define local_irq_save(flags) \
+ ({ \
+ asm volatile( \
+ "mrs %0, daif" \
+ "msr daifset, #3" \
+ : "=r" (flags) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * restore saved IRQ & FIQ state
+ */
+#define local_irq_restore(flags) \
+ ({ \
+ asm volatile( \
+ "msr daif, %0" \
+ : \
+ : "r" (flags) \
+ : "memory"); \
+ })
+
+/*
+ * Enable IRQs/FIQs
+ */
+#define local_irq_enable() \
+ ({ \
+ asm volatile( \
+ "msr daifclr, #3" \
+ : \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Disable IRQs/FIQs
+ */
+#define local_irq_disable() \
+ ({ \
+ asm volatile( \
+ "msr daifset, #3" \
+ : \
+ : \
+ : "memory"); \
+ })
+
+#else /* CONFIG_ARM64 */
+
+#define local_irq_save(x) \
+ ({ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ local_irq_save\n" \
+" orr %1, %0, #128\n" \
+" msr cpsr_c, %1" \
+ : "=r" (x), "=r" (temp) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Enable IRQs
+ */
+#define local_irq_enable() \
+ ({ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ local_irq_enable\n" \
+" bic %0, %0, #128\n" \
+" msr cpsr_c, %0" \
+ : "=r" (temp) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Disable IRQs
+ */
+#define local_irq_disable() \
+ ({ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ local_irq_disable\n" \
+" orr %0, %0, #128\n" \
+" msr cpsr_c, %0" \
+ : "=r" (temp) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Enable FIQs
+ */
+#define __stf() \
+ ({ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ stf\n" \
+" bic %0, %0, #64\n" \
+" msr cpsr_c, %0" \
+ : "=r" (temp) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Disable FIQs
+ */
+#define __clf() \
+ ({ \
+ unsigned long temp; \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ clf\n" \
+" orr %0, %0, #64\n" \
+" msr cpsr_c, %0" \
+ : "=r" (temp) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * Save the current interrupt enable state.
+ */
+#define local_save_flags(x) \
+ ({ \
+ __asm__ __volatile__( \
+ "mrs %0, cpsr @ local_save_flags\n" \
+ : "=r" (x) \
+ : \
+ : "memory"); \
+ })
+
+/*
+ * restore saved IRQ & FIQ state
+ */
+#define local_irq_restore(x) \
+ __asm__ __volatile__( \
+ "msr cpsr_c, %0 @ local_irq_restore\n" \
+ : \
+ : "r" (x) \
+ : "memory")
+
+#endif /* CONFIG_ARM64 */
+
+#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110) || \
+ defined(CONFIG_ARM64)
+/*
+ * On the StrongARM, "swp" is terminally broken since it bypasses the
+ * cache totally. This means that the cache becomes inconsistent, and,
+ * since we use normal loads/stores as well, this is really bad.
+ * Typically, this causes oopsen in filp_close, but could have other,
+ * more disasterous effects. There are two work-arounds:
+ * 1. Disable interrupts and emulate the atomic swap
+ * 2. Clean the cache, perform atomic swap, flush the cache
+ *
+ * We choose (1) since its the "easiest" to achieve here and is not
+ * dependent on the processor type.
+ */
+#define swp_is_buggy
+#endif
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+{
+ extern void __bad_xchg(volatile void *, int);
+ unsigned long ret;
+#ifdef swp_is_buggy
+ unsigned long flags;
+#endif
+
+ switch (size) {
+#ifdef swp_is_buggy
+ case 1:
+ local_irq_save(flags);
+ ret = *(volatile unsigned char *)ptr;
+ *(volatile unsigned char *)ptr = x;
+ local_irq_restore(flags);
+ break;
+
+ case 4:
+ local_irq_save(flags);
+ ret = *(volatile unsigned long *)ptr;
+ *(volatile unsigned long *)ptr = x;
+ local_irq_restore(flags);
+ break;
+#else
+ case 1: __asm__ __volatile__ ("swpb %0, %1, [%2]"
+ : "=&r" (ret)
+ : "r" (x), "r" (ptr)
+ : "memory");
+ break;
+ case 4: __asm__ __volatile__ ("swp %0, %1, [%2]"
+ : "=&r" (ret)
+ : "r" (x), "r" (ptr)
+ : "memory");
+ break;
+#endif
+ default: __bad_xchg(ptr, size), ret = 0;
+ }
+
+ return ret;
+}
+
+#endif
Code Review / kvmfornfv.git / blobdiff