ARC: [plat-eznps] Use dedicated atomic/bitops/cmpxchg
authorNoam Camus <noamc@ezchip.com>
Sat, 16 May 2015 14:49:35 +0000 (17:49 +0300)
committerVineet Gupta <vgupta@synopsys.com>
Mon, 9 May 2016 04:02:33 +0000 (09:32 +0530)
We need our own implementaions since we lack LLSC support.
Our extended ISA provided with optimized solution for all 32bit
operations we see in these three headers.
Signed-off-by: Noam Camus <noamc@ezchip.com>
arch/arc/include/asm/atomic.h
arch/arc/include/asm/bitops.h
arch/arc/include/asm/cmpxchg.h

index 7730d302cadb5620feff02b2fbe5ebebf1f3e53d..5f3dcbbc0cc9c14df199c55ff9e916b64be3be0d 100644 (file)
@@ -17,6 +17,8 @@
 #include <asm/barrier.h>
 #include <asm/smp.h>
 
+#ifndef CONFIG_ARC_PLAT_EZNPS
+
 #define atomic_read(v)  READ_ONCE((v)->counter)
 
 #ifdef CONFIG_ARC_HAS_LLSC
@@ -180,13 +182,88 @@ ATOMIC_OP(andnot, &= ~, bic)
 ATOMIC_OP(or, |=, or)
 ATOMIC_OP(xor, ^=, xor)
 
-#undef ATOMIC_OPS
-#undef ATOMIC_OP_RETURN
-#undef ATOMIC_OP
 #undef SCOND_FAIL_RETRY_VAR_DEF
 #undef SCOND_FAIL_RETRY_ASM
 #undef SCOND_FAIL_RETRY_VARS
 
+#else /* CONFIG_ARC_PLAT_EZNPS */
+
+static inline int atomic_read(const atomic_t *v)
+{
+       int temp;
+
+       __asm__ __volatile__(
+       "       ld.di %0, [%1]"
+       : "=r"(temp)
+       : "r"(&v->counter)
+       : "memory");
+       return temp;
+}
+
+static inline void atomic_set(atomic_t *v, int i)
+{
+       __asm__ __volatile__(
+       "       st.di %0,[%1]"
+       :
+       : "r"(i), "r"(&v->counter)
+       : "memory");
+}
+
+#define ATOMIC_OP(op, c_op, asm_op)                                    \
+static inline void atomic_##op(int i, atomic_t *v)                     \
+{                                                                      \
+       __asm__ __volatile__(                                           \
+       "       mov r2, %0\n"                                           \
+       "       mov r3, %1\n"                                           \
+       "       .word %2\n"                                             \
+       :                                                               \
+       : "r"(i), "r"(&v->counter), "i"(asm_op)                         \
+       : "r2", "r3", "memory");                                        \
+}                                                                      \
+
+#define ATOMIC_OP_RETURN(op, c_op, asm_op)                             \
+static inline int atomic_##op##_return(int i, atomic_t *v)             \
+{                                                                      \
+       unsigned int temp = i;                                          \
+                                                                       \
+       /* Explicit full memory barrier needed before/after */          \
+       smp_mb();                                                       \
+                                                                       \
+       __asm__ __volatile__(                                           \
+       "       mov r2, %0\n"                                           \
+       "       mov r3, %1\n"                                           \
+       "       .word %2\n"                                             \
+       "       mov %0, r2"                                             \
+       : "+r"(temp)                                                    \
+       : "r"(&v->counter), "i"(asm_op)                                 \
+       : "r2", "r3", "memory");                                        \
+                                                                       \
+       smp_mb();                                                       \
+                                                                       \
+       temp c_op i;                                                    \
+                                                                       \
+       return temp;                                                    \
+}
+
+#define ATOMIC_OPS(op, c_op, asm_op)                                   \
+       ATOMIC_OP(op, c_op, asm_op)                                     \
+       ATOMIC_OP_RETURN(op, c_op, asm_op)
+
+ATOMIC_OPS(add, +=, CTOP_INST_AADD_DI_R2_R2_R3)
+#define atomic_sub(i, v) atomic_add(-(i), (v))
+#define atomic_sub_return(i, v) atomic_add_return(-(i), (v))
+
+ATOMIC_OP(and, &=, CTOP_INST_AAND_DI_R2_R2_R3)
+#define atomic_andnot(mask, v) atomic_and(~(mask), (v))
+ATOMIC_OP(or, |=, CTOP_INST_AOR_DI_R2_R2_R3)
+ATOMIC_OP(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3)
+
+#endif /* CONFIG_ARC_PLAT_EZNPS */
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
 /**
  * __atomic_add_unless - add unless the number is a given value
  * @v: pointer of type atomic_t
index 0352fb8d21b998223b03e2bc327c3f4554df6ec5..8da87feec59aab58a1309fbd5f92fb12b72d8799 100644 (file)
@@ -22,7 +22,7 @@
 #include <asm/smp.h>
 #endif
 
-#if defined(CONFIG_ARC_HAS_LLSC)
+#ifdef CONFIG_ARC_HAS_LLSC
 
 /*
  * Hardware assisted Atomic-R-M-W
@@ -88,7 +88,7 @@ static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *
        return (old & (1 << nr)) != 0;                                  \
 }
 
-#else  /* !CONFIG_ARC_HAS_LLSC */
+#elif !defined(CONFIG_ARC_PLAT_EZNPS)
 
 /*
  * Non hardware assisted Atomic-R-M-W
@@ -139,7 +139,55 @@ static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *
        return (old & (1UL << (nr & 0x1f))) != 0;                       \
 }
 
-#endif /* CONFIG_ARC_HAS_LLSC */
+#else /* CONFIG_ARC_PLAT_EZNPS */
+
+#define BIT_OP(op, c_op, asm_op)                                       \
+static inline void op##_bit(unsigned long nr, volatile unsigned long *m)\
+{                                                                      \
+       m += nr >> 5;                                                   \
+                                                                       \
+       nr = (1UL << (nr & 0x1f));                                      \
+       if (asm_op == CTOP_INST_AAND_DI_R2_R2_R3)                       \
+               nr = ~nr;                                               \
+                                                                       \
+       __asm__ __volatile__(                                           \
+       "       mov r2, %0\n"                                           \
+       "       mov r3, %1\n"                                           \
+       "       .word %2\n"                                             \
+       :                                                               \
+       : "r"(nr), "r"(m), "i"(asm_op)                                  \
+       : "r2", "r3", "memory");                                        \
+}
+
+#define TEST_N_BIT_OP(op, c_op, asm_op)                                        \
+static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
+{                                                                      \
+       unsigned long old;                                              \
+                                                                       \
+       m += nr >> 5;                                                   \
+                                                                       \
+       nr = old = (1UL << (nr & 0x1f));                                \
+       if (asm_op == CTOP_INST_AAND_DI_R2_R2_R3)                       \
+               old = ~old;                                             \
+                                                                       \
+       /* Explicit full memory barrier needed before/after */          \
+       smp_mb();                                                       \
+                                                                       \
+       __asm__ __volatile__(                                           \
+       "       mov r2, %0\n"                                           \
+       "       mov r3, %1\n"                                           \
+       "       .word %2\n"                                             \
+       "       mov %0, r2"                                             \
+       : "+r"(old)                                                     \
+       : "r"(m), "i"(asm_op)                                           \
+       : "r2", "r3", "memory");                                        \
+                                                                       \
+       smp_mb();                                                       \
+                                                                       \
+       return (old & nr) != 0;                                 \
+}
+
+#endif /* CONFIG_ARC_PLAT_EZNPS */
 
 /***************************************
  * Non atomic variants
@@ -181,9 +229,15 @@ static inline int __test_and_##op##_bit(unsigned long nr, volatile unsigned long
        /* __test_and_set_bit(), __test_and_clear_bit(), __test_and_change_bit() */\
        __TEST_N_BIT_OP(op, c_op, asm_op)
 
+#ifndef CONFIG_ARC_PLAT_EZNPS
 BIT_OPS(set, |, bset)
 BIT_OPS(clear, & ~, bclr)
 BIT_OPS(change, ^, bxor)
+#else
+BIT_OPS(set, |, CTOP_INST_AOR_DI_R2_R2_R3)
+BIT_OPS(clear, & ~, CTOP_INST_AAND_DI_R2_R2_R3)
+BIT_OPS(change, ^, CTOP_INST_AXOR_DI_R2_R2_R3)
+#endif
 
 /*
  * This routine doesn't need to be atomic.
index a444be67cd53e7906d2c2d808a08b75182463918..d819de1c5d10ed21d951a4cf18a7cef75370e1de 100644 (file)
@@ -44,7 +44,7 @@ __cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
        return prev;
 }
 
-#else
+#elif !defined(CONFIG_ARC_PLAT_EZNPS)
 
 static inline unsigned long
 __cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
@@ -64,23 +64,48 @@ __cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
        return prev;
 }
 
+#else /* CONFIG_ARC_PLAT_EZNPS */
+
+static inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long expected, unsigned long new)
+{
+       /*
+        * Explicit full memory barrier needed before/after
+        */
+       smp_mb();
+
+       write_aux_reg(CTOP_AUX_GPA1, expected);
+
+       __asm__ __volatile__(
+       "       mov r2, %0\n"
+       "       mov r3, %1\n"
+       "       .word %2\n"
+       "       mov %0, r2"
+       : "+r"(new)
+       : "r"(ptr), "i"(CTOP_INST_EXC_DI_R2_R2_R3)
+       : "r2", "r3", "memory");
+
+       smp_mb();
+
+       return new;
+}
+
 #endif /* CONFIG_ARC_HAS_LLSC */
 
 #define cmpxchg(ptr, o, n) ((typeof(*(ptr)))__cmpxchg((ptr), \
                                (unsigned long)(o), (unsigned long)(n)))
 
 /*
- * Since not supported natively, ARC cmpxchg() uses atomic_ops_lock (UP/SMP)
- * just to gaurantee semantics.
- * atomic_cmpxchg() needs to use the same locks as it's other atomic siblings
- * which also happens to be atomic_ops_lock.
- *
- * Thus despite semantically being different, implementation of atomic_cmpxchg()
- * is same as cmpxchg().
+ * atomic_cmpxchg is same as cmpxchg
+ *   LLSC: only different in data-type, semantics are exactly same
+ *  !LLSC: cmpxchg() has to use an external lock atomic_ops_lock to guarantee
+ *         semantics, and this lock also happens to be used by atomic_*()
  */
 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
 
 
+#ifndef CONFIG_ARC_PLAT_EZNPS
+
 /*
  * xchg (reg with memory) based on "Native atomic" EX insn
  */
@@ -143,6 +168,41 @@ static inline unsigned long __xchg(unsigned long val, volatile void *ptr,
 
 #endif
 
+#else /* CONFIG_ARC_PLAT_EZNPS */
+
+static inline unsigned long __xchg(unsigned long val, volatile void *ptr,
+                                  int size)
+{
+       extern unsigned long __xchg_bad_pointer(void);
+
+       switch (size) {
+       case 4:
+               /*
+                * Explicit full memory barrier needed before/after
+                */
+               smp_mb();
+
+               __asm__ __volatile__(
+               "       mov r2, %0\n"
+               "       mov r3, %1\n"
+               "       .word %2\n"
+               "       mov %0, r2\n"
+               : "+r"(val)
+               : "r"(ptr), "i"(CTOP_INST_XEX_DI_R2_R2_R3)
+               : "r2", "r3", "memory");
+
+               smp_mb();
+
+               return val;
+       }
+       return __xchg_bad_pointer();
+}
+
+#define xchg(ptr, with) ((typeof(*(ptr)))__xchg((unsigned long)(with), (ptr), \
+                                                sizeof(*(ptr))))
+
+#endif /* CONFIG_ARC_PLAT_EZNPS */
+
 /*
  * "atomic" variant of xchg()
  * REQ: It needs to follow the same serialization rules as other atomic_xxx()