summaryrefslogtreecommitdiff
path: root/arch/xtensa/include/asm/system.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/xtensa/include/asm/system.h')
-rw-r--r--arch/xtensa/include/asm/system.h215
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/system.h b/arch/xtensa/include/asm/system.h
new file mode 100644
index 000000000000..62b1e8f3c13c
--- /dev/null
+++ b/arch/xtensa/include/asm/system.h
@@ -0,0 +1,215 @@
+/*
+ * include/asm-xtensa/system.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_SYSTEM_H
+#define _XTENSA_SYSTEM_H
+
+#include <linux/stringify.h>
+
+#include <asm/processor.h>
+
+/* interrupt control */
+
+#define local_save_flags(x) \
+ __asm__ __volatile__ ("rsr %0,"__stringify(PS) : "=a" (x));
+#define local_irq_restore(x) do { \
+ __asm__ __volatile__ ("wsr %0, "__stringify(PS)" ; rsync" \
+ :: "a" (x) : "memory"); } while(0);
+#define local_irq_save(x) do { \
+ __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) \
+ : "=a" (x) :: "memory");} while(0);
+
+static inline void local_irq_disable(void)
+{
+ unsigned long flags;
+ __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL)
+ : "=a" (flags) :: "memory");
+}
+static inline void local_irq_enable(void)
+{
+ unsigned long flags;
+ __asm__ __volatile__ ("rsil %0, 0" : "=a" (flags) :: "memory");
+
+}
+
+static inline int irqs_disabled(void)
+{
+ unsigned long flags;
+ local_save_flags(flags);
+ return flags & 0xf;
+}
+
+
+#define smp_read_barrier_depends() do { } while(0)
+#define read_barrier_depends() do { } while(0)
+
+#define mb() barrier()
+#define rmb() mb()
+#define wmb() mb()
+
+#ifdef CONFIG_SMP
+#error smp_* not defined
+#else
+#define smp_mb() barrier()
+#define smp_rmb() barrier()
+#define smp_wmb() barrier()
+#endif
+
+#define set_mb(var, value) do { var = value; mb(); } while (0)
+
+#if !defined (__ASSEMBLY__)
+
+/* * switch_to(n) should switch tasks to task nr n, first
+ * checking that n isn't the current task, in which case it does nothing.
+ */
+extern void *_switch_to(void *last, void *next);
+
+#endif /* __ASSEMBLY__ */
+
+#define switch_to(prev,next,last) \
+do { \
+ (last) = _switch_to(prev, next); \
+} while(0)
+
+/*
+ * cmpxchg
+ */
+
+static inline unsigned long
+__cmpxchg_u32(volatile int *p, int old, int new)
+{
+ __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %1, 0 \n\t"
+ "bne %0, %2, 1f \n\t"
+ "s32i %3, %1, 0 \n\t"
+ "1: \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n\t"
+ : "=&a" (old)
+ : "a" (p), "a" (old), "r" (new)
+ : "a15", "memory");
+ return old;
+}
+/* This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid cmpxchg(). */
+
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+static __inline__ unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
+{
+ switch (size) {
+ case 4: return __cmpxchg_u32(ptr, old, new);
+ default: __cmpxchg_called_with_bad_pointer();
+ return old;
+ }
+}
+
+#define cmpxchg(ptr,o,n) \
+ ({ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
+ (unsigned long)_n_, sizeof (*(ptr))); \
+ })
+
+#include <asm-generic/cmpxchg-local.h>
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+ unsigned long old,
+ unsigned long new, int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32(ptr, old, new);
+ default:
+ return __cmpxchg_local_generic(ptr, old, new, size);
+ }
+
+ return old;
+}
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
+ (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+/*
+ * xchg_u32
+ *
+ * Note that a15 is used here because the register allocation
+ * done by the compiler is not guaranteed and a window overflow
+ * may not occur between the rsil and wsr instructions. By using
+ * a15 in the rsil, the machine is guaranteed to be in a state
+ * where no register reference will cause an overflow.
+ */
+
+static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
+{
+ unsigned long tmp;
+ __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %1, 0 \n\t"
+ "s32i %2, %1, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n\t"
+ : "=&a" (tmp)
+ : "a" (m), "a" (val)
+ : "a15", "memory");
+ return tmp;
+}
+
+#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+/*
+ * This only works if the compiler isn't horribly bad at optimizing.
+ * gcc-2.5.8 reportedly can't handle this, but I define that one to
+ * be dead anyway.
+ */
+
+extern void __xchg_called_with_bad_pointer(void);
+
+static __inline__ unsigned long
+__xchg(unsigned long x, volatile void * ptr, int size)
+{
+ switch (size) {
+ case 4:
+ return xchg_u32(ptr, x);
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
+
+extern void set_except_vector(int n, void *addr);
+
+static inline void spill_registers(void)
+{
+ unsigned int a0, ps;
+
+ __asm__ __volatile__ (
+ "movi a14," __stringify (PS_EXCM_BIT) " | 1\n\t"
+ "mov a12, a0\n\t"
+ "rsr a13," __stringify(SAR) "\n\t"
+ "xsr a14," __stringify(PS) "\n\t"
+ "movi a0, _spill_registers\n\t"
+ "rsync\n\t"
+ "callx0 a0\n\t"
+ "mov a0, a12\n\t"
+ "wsr a13," __stringify(SAR) "\n\t"
+ "wsr a14," __stringify(PS) "\n\t"
+ :: "a" (&a0), "a" (&ps)
+ : "a2", "a3", "a4", "a7", "a11", "a12", "a13", "a14", "a15", "memory");
+}
+
+#define arch_align_stack(x) (x)
+
+#endif /* _XTENSA_SYSTEM_H */