} \
} while (0)
-/*
- * Add return operation
- */
-#define percpu_add_return_op(var, val) \
-({ \
- typeof(var) paro_ret__ = val; \
- switch (sizeof(var)) { \
- case 1: \
- asm("xaddb %0, "__percpu_arg(1) \
- : "+q" (paro_ret__), "+m" (var) \
- : : "memory"); \
- break; \
- case 2: \
- asm("xaddw %0, "__percpu_arg(1) \
- : "+r" (paro_ret__), "+m" (var) \
- : : "memory"); \
- break; \
- case 4: \
- asm("xaddl %0, "__percpu_arg(1) \
- : "+r" (paro_ret__), "+m" (var) \
- : : "memory"); \
- break; \
- case 8: \
- asm("xaddq %0, "__percpu_arg(1) \
- : "+re" (paro_ret__), "+m" (var) \
- : : "memory"); \
- break; \
- default: __bad_percpu_size(); \
- } \
- paro_ret__ += val; \
- paro_ret__; \
-})
-
#define percpu_from_op(op, var, constraint) \
({ \
typeof(var) pfo_ret__; \
} \
})
+/*
+ * Add return operation
+ */
+#define percpu_add_return_op(var, val) \
+({ \
+ typeof(var) paro_ret__ = val; \
+ switch (sizeof(var)) { \
+ case 1: \
+ asm("xaddb %0, "__percpu_arg(1) \
+ : "+q" (paro_ret__), "+m" (var) \
+ : : "memory"); \
+ break; \
+ case 2: \
+ asm("xaddw %0, "__percpu_arg(1) \
+ : "+r" (paro_ret__), "+m" (var) \
+ : : "memory"); \
+ break; \
+ case 4: \
+ asm("xaddl %0, "__percpu_arg(1) \
+ : "+r" (paro_ret__), "+m" (var) \
+ : : "memory"); \
+ break; \
+ case 8: \
+ asm("xaddq %0, "__percpu_arg(1) \
+ : "+re" (paro_ret__), "+m" (var) \
+ : : "memory"); \
+ break; \
+ default: __bad_percpu_size(); \
+ } \
+ paro_ret__ += val; \
+ paro_ret__; \
+})
+
+/*
+ * Beware: xchg on x86 has an implied lock prefix. There will be the cost of
+ * full lock semantics even though they are not needed.
+ */
+#define percpu_xchg_op(var, nval) \
+({ \
+ typeof(var) pxo_ret__; \
+ typeof(var) pxo_new__ = (nval); \
+ switch (sizeof(var)) { \
+ case 1: \
+ asm("xchgb %2, "__percpu_arg(1) \
+ : "=a" (pxo_ret__), "+m" (var) \
+ : "q" (pxo_new__) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm("xchgw %2, "__percpu_arg(1) \
+ : "=a" (pxo_ret__), "+m" (var) \
+ : "r" (pxo_new__) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm("xchgl %2, "__percpu_arg(1) \
+ : "=a" (pxo_ret__), "+m" (var) \
+ : "r" (pxo_new__) \
+ : "memory"); \
+ break; \
+ case 8: \
+ asm("xchgq %2, "__percpu_arg(1) \
+ : "=a" (pxo_ret__), "+m" (var) \
+ : "r" (pxo_new__) \
+ : "memory"); \
+ break; \
+ default: __bad_percpu_size(); \
+ } \
+ pxo_ret__; \
+})
+
+/*
+ * cmpxchg has no such implied lock semantics as a result it is much
+ * more efficient for cpu local operations.
+ */
+#define percpu_cmpxchg_op(var, oval, nval) \
+({ \
+ typeof(var) pco_ret__; \
+ typeof(var) pco_old__ = (oval); \
+ typeof(var) pco_new__ = (nval); \
+ switch (sizeof(var)) { \
+ case 1: \
+ asm("cmpxchgb %2, "__percpu_arg(1) \
+ : "=a" (pco_ret__), "+m" (var) \
+ : "q" (pco_new__), "0" (pco_old__) \
+ : "memory"); \
+ break; \
+ case 2: \
+ asm("cmpxchgw %2, "__percpu_arg(1) \
+ : "=a" (pco_ret__), "+m" (var) \
+ : "r" (pco_new__), "0" (pco_old__) \
+ : "memory"); \
+ break; \
+ case 4: \
+ asm("cmpxchgl %2, "__percpu_arg(1) \
+ : "=a" (pco_ret__), "+m" (var) \
+ : "r" (pco_new__), "0" (pco_old__) \
+ : "memory"); \
+ break; \
+ case 8: \
+ asm("cmpxchgq %2, "__percpu_arg(1) \
+ : "=a" (pco_ret__), "+m" (var) \
+ : "r" (pco_new__), "0" (pco_old__) \
+ : "memory"); \
+ break; \
+ default: __bad_percpu_size(); \
+ } \
+ pco_ret__; \
+})
+
/*
* percpu_read() makes gcc load the percpu variable every time it is
* accessed while percpu_read_stable() allows the value to be cached.
#define __this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
#define __this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
#define __this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
+/*
+ * Generic fallback operations for __this_cpu_xchg_[1-4] are okay and much
+ * faster than an xchg with forced lock semantics.
+ */
+#define __this_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
+#define __this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
#define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
#define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
+#define this_cpu_xchg_1(pcp, nval) percpu_xchg_op(pcp, nval)
+#define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval)
+#define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval)
+#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
+#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define irqsafe_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
#define irqsafe_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
#define irqsafe_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
#define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
#define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
+#define irqsafe_cpu_xchg_1(pcp, nval) percpu_xchg_op(pcp, nval)
+#define irqsafe_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval)
+#define irqsafe_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval)
+#define irqsafe_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
+#define irqsafe_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#ifndef CONFIG_M386
#define __this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define __this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define __this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
+#define __this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define __this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define __this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+
#define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
-#endif
+#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+
+#define irqsafe_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define irqsafe_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#define irqsafe_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
+#endif /* !CONFIG_M386 */
+
/*
* Per cpu atomic 64 bit operations are only available under 64 bit.
* 32 bit must fall back to generic operations.
#define __this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define __this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define __this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
+#define __this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
+#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define irqsafe_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
#define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
-
-#define __this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
-#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#endif
/* This is not atomic against other CPUs -- CPU preemption needs to be off */
projects / firefly-linux-kernel-4.4.55.git / blobdiff