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authorNoam Camus <noamc@ezchip.com>2015-05-16 17:49:35 +0300
committerVineet Gupta <vgupta@synopsys.com>2016-05-09 07:02:33 +0300
commita5a10d99a946602cf4ae50eadc65c2480dbd2e56 (patch)
tree613088aec1988af74826a53277e0dde3812bccc2 /arch/arc
parent8bcf2c48f32e22f923b69f779c95b1348308d5b1 (diff)
downloadlinux-a5a10d99a946602cf4ae50eadc65c2480dbd2e56.tar.xz
ARC: [plat-eznps] Use dedicated atomic/bitops/cmpxchg
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>
Diffstat (limited to 'arch/arc')
-rw-r--r--arch/arc/include/asm/atomic.h83
-rw-r--r--arch/arc/include/asm/bitops.h60
-rw-r--r--arch/arc/include/asm/cmpxchg.h76
3 files changed, 205 insertions, 14 deletions
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 7730d302cadb..5f3dcbbc0cc9 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -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
diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h
index 0352fb8d21b9..8da87feec59a 100644
--- a/arch/arc/include/asm/bitops.h
+++ b/arch/arc/include/asm/bitops.h
@@ -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.
diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h
index a444be67cd53..d819de1c5d10 100644
--- a/arch/arc/include/asm/cmpxchg.h
+++ b/arch/arc/include/asm/cmpxchg.h
@@ -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()