frv: Rewrite atomic implementation
Mostly complete rewrite of the FRV atomic implementation, instead of
using assembly files, use inline assembler.
The out-of-line CONFIG option makes a bit of a mess of things, but a
little CPP trickery gets that done too.
FRV already had the atomic logic ops but under a non standard name,
the reimplementation provides the generic names and provides the
intermediate form required for the bitops implementation.
The slightly inconsistent __atomic32_fetch_##op naming is because
__atomic_fetch_##op conlicts with GCC builtin functions.
The 64bit atomic ops use the inline assembly %Ln construct to access
the low word register (r+1), afaik this construct was not previously
used in the kernel and is completely undocumented, but I found it in
the FRV GCC code and it seems to work.
FRV had a non-standard definition of atomic_{clear,set}_mask() which
would work types other than atomic_t, the one user relying on that
(arch/frv/kernel/dma.c) got converted to use the new intermediate
form.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/frv/include/asm/atomic_defs.h b/arch/frv/include/asm/atomic_defs.h
new file mode 100644
index 0000000..36e126d
--- /dev/null
+++ b/arch/frv/include/asm/atomic_defs.h
@@ -0,0 +1,172 @@
+
+#include <asm/spr-regs.h>
+
+#ifdef __ATOMIC_LIB__
+
+#ifdef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
+
+#define ATOMIC_QUALS
+#define ATOMIC_EXPORT(x) EXPORT_SYMBOL(x)
+
+#else /* !OUTOFLINE && LIB */
+
+#define ATOMIC_OP_RETURN(op)
+#define ATOMIC_FETCH_OP(op)
+
+#endif /* OUTOFLINE */
+
+#else /* !__ATOMIC_LIB__ */
+
+#define ATOMIC_EXPORT(x)
+
+#ifdef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
+
+#define ATOMIC_OP_RETURN(op) \
+extern int __atomic_##op##_return(int i, int *v); \
+extern long long __atomic64_##op##_return(long long i, long long *v);
+
+#define ATOMIC_FETCH_OP(op) \
+extern int __atomic32_fetch_##op(int i, int *v); \
+extern long long __atomic64_fetch_##op(long long i, long long *v);
+
+#else /* !OUTOFLINE && !LIB */
+
+#define ATOMIC_QUALS static inline
+
+#endif /* OUTOFLINE */
+#endif /* __ATOMIC_LIB__ */
+
+
+/*
+ * Note on the 64 bit inline asm variants...
+ *
+ * CSTD is a conditional instruction and needs a constrained memory reference.
+ * Normally 'U' provides the correct constraints for conditional instructions
+ * and this is used for the 32 bit version, however 'U' does not appear to work
+ * for 64 bit values (gcc-4.9)
+ *
+ * The exact constraint is that conditional instructions cannot deal with an
+ * immediate displacement in the memory reference, so what we do is we read the
+ * address through a volatile cast into a local variable in order to insure we
+ * _have_ to compute the correct address without displacement. This allows us
+ * to use the regular 'm' for the memory address.
+ *
+ * Furthermore, the %Ln operand, which prints the low word register (r+1),
+ * really only works for registers, this means we cannot allow immediate values
+ * for the 64 bit versions -- like we do for the 32 bit ones.
+ *
+ */
+
+#ifndef ATOMIC_OP_RETURN
+#define ATOMIC_OP_RETURN(op) \
+ATOMIC_QUALS int __atomic_##op##_return(int i, int *v) \
+{ \
+ int val; \
+ \
+ asm volatile( \
+ "0: \n" \
+ " orcc gr0,gr0,gr0,icc3 \n" \
+ " ckeq icc3,cc7 \n" \
+ " ld.p %M0,%1 \n" \
+ " orcr cc7,cc7,cc3 \n" \
+ " "#op"%I2 %1,%2,%1 \n" \
+ " cst.p %1,%M0 ,cc3,#1 \n" \
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
+ " beq icc3,#0,0b \n" \
+ : "+U"(*v), "=&r"(val) \
+ : "NPr"(i) \
+ : "memory", "cc7", "cc3", "icc3" \
+ ); \
+ \
+ return val; \
+} \
+ATOMIC_EXPORT(__atomic_##op##_return); \
+ \
+ATOMIC_QUALS long long __atomic64_##op##_return(long long i, long long *v) \
+{ \
+ long long *__v = READ_ONCE(v); \
+ long long val; \
+ \
+ asm volatile( \
+ "0: \n" \
+ " orcc gr0,gr0,gr0,icc3 \n" \
+ " ckeq icc3,cc7 \n" \
+ " ldd.p %M0,%1 \n" \
+ " orcr cc7,cc7,cc3 \n" \
+ " "#op"cc %L1,%L2,%L1,icc0 \n" \
+ " "#op"x %1,%2,%1,icc0 \n" \
+ " cstd.p %1,%M0 ,cc3,#1 \n" \
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
+ " beq icc3,#0,0b \n" \
+ : "+m"(*__v), "=&e"(val) \
+ : "e"(i) \
+ : "memory", "cc7", "cc3", "icc0", "icc3" \
+ ); \
+ \
+ return val; \
+} \
+ATOMIC_EXPORT(__atomic64_##op##_return);
+#endif
+
+#ifndef ATOMIC_FETCH_OP
+#define ATOMIC_FETCH_OP(op) \
+ATOMIC_QUALS int __atomic32_fetch_##op(int i, int *v) \
+{ \
+ int old, tmp; \
+ \
+ asm volatile( \
+ "0: \n" \
+ " orcc gr0,gr0,gr0,icc3 \n" \
+ " ckeq icc3,cc7 \n" \
+ " ld.p %M0,%1 \n" \
+ " orcr cc7,cc7,cc3 \n" \
+ " "#op"%I3 %1,%3,%2 \n" \
+ " cst.p %2,%M0 ,cc3,#1 \n" \
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
+ " beq icc3,#0,0b \n" \
+ : "+U"(*v), "=&r"(old), "=r"(tmp) \
+ : "NPr"(i) \
+ : "memory", "cc7", "cc3", "icc3" \
+ ); \
+ \
+ return old; \
+} \
+ATOMIC_EXPORT(__atomic32_fetch_##op); \
+ \
+ATOMIC_QUALS long long __atomic64_fetch_##op(long long i, long long *v) \
+{ \
+ long long *__v = READ_ONCE(v); \
+ long long old, tmp; \
+ \
+ asm volatile( \
+ "0: \n" \
+ " orcc gr0,gr0,gr0,icc3 \n" \
+ " ckeq icc3,cc7 \n" \
+ " ldd.p %M0,%1 \n" \
+ " orcr cc7,cc7,cc3 \n" \
+ " "#op" %L1,%L3,%L2 \n" \
+ " "#op" %1,%3,%2 \n" \
+ " cstd.p %2,%M0 ,cc3,#1 \n" \
+ " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
+ " beq icc3,#0,0b \n" \
+ : "+m"(*__v), "=&e"(old), "=e"(tmp) \
+ : "e"(i) \
+ : "memory", "cc7", "cc3", "icc3" \
+ ); \
+ \
+ return old; \
+} \
+ATOMIC_EXPORT(__atomic64_fetch_##op);
+#endif
+
+ATOMIC_FETCH_OP(or)
+ATOMIC_FETCH_OP(and)
+ATOMIC_FETCH_OP(xor)
+
+ATOMIC_OP_RETURN(add)
+ATOMIC_OP_RETURN(sub)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_QUALS
+#undef ATOMIC_EXPORT