v4.19.13 snapshot.
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
new file mode 100644
index 0000000..158af07
--- /dev/null
+++ b/arch/arc/include/asm/atomic.h
@@ -0,0 +1,562 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_ATOMIC_H
+#define _ASM_ARC_ATOMIC_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+#include <asm/smp.h>
+
+#define ATOMIC_INIT(i) { (i) }
+
+#ifndef CONFIG_ARC_PLAT_EZNPS
+
+#define atomic_read(v) READ_ONCE((v)->counter)
+
+#ifdef CONFIG_ARC_HAS_LLSC
+
+#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
+
+#define ATOMIC_OP(op, c_op, asm_op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned int val; \
+ \
+ __asm__ __volatile__( \
+ "1: llock %[val], [%[ctr]] \n" \
+ " " #asm_op " %[val], %[val], %[i] \n" \
+ " scond %[val], [%[ctr]] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r" (val) /* Early clobber to prevent reg reuse */ \
+ : [ctr] "r" (&v->counter), /* Not "m": llock only supports reg direct addr mode */ \
+ [i] "ir" (i) \
+ : "cc"); \
+} \
+
+#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
+static inline int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned int val; \
+ \
+ /* \
+ * Explicit full memory barrier needed before/after as \
+ * LLOCK/SCOND thmeselves don't provide any such semantics \
+ */ \
+ smp_mb(); \
+ \
+ __asm__ __volatile__( \
+ "1: llock %[val], [%[ctr]] \n" \
+ " " #asm_op " %[val], %[val], %[i] \n" \
+ " scond %[val], [%[ctr]] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r" (val) \
+ : [ctr] "r" (&v->counter), \
+ [i] "ir" (i) \
+ : "cc"); \
+ \
+ smp_mb(); \
+ \
+ return val; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
+static inline int atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned int val, orig; \
+ \
+ /* \
+ * Explicit full memory barrier needed before/after as \
+ * LLOCK/SCOND thmeselves don't provide any such semantics \
+ */ \
+ smp_mb(); \
+ \
+ __asm__ __volatile__( \
+ "1: llock %[orig], [%[ctr]] \n" \
+ " " #asm_op " %[val], %[orig], %[i] \n" \
+ " scond %[val], [%[ctr]] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r" (val), \
+ [orig] "=&r" (orig) \
+ : [ctr] "r" (&v->counter), \
+ [i] "ir" (i) \
+ : "cc"); \
+ \
+ smp_mb(); \
+ \
+ return orig; \
+}
+
+#else /* !CONFIG_ARC_HAS_LLSC */
+
+#ifndef CONFIG_SMP
+
+ /* violating atomic_xxx API locking protocol in UP for optimization sake */
+#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
+
+#else
+
+static inline void atomic_set(atomic_t *v, int i)
+{
+ /*
+ * Independent of hardware support, all of the atomic_xxx() APIs need
+ * to follow the same locking rules to make sure that a "hardware"
+ * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn
+ * sequence
+ *
+ * Thus atomic_set() despite being 1 insn (and seemingly atomic)
+ * requires the locking.
+ */
+ unsigned long flags;
+
+ atomic_ops_lock(flags);
+ WRITE_ONCE(v->counter, i);
+ atomic_ops_unlock(flags);
+}
+
+#define atomic_set_release(v, i) atomic_set((v), (i))
+
+#endif
+
+/*
+ * Non hardware assisted Atomic-R-M-W
+ * Locking would change to irq-disabling only (UP) and spinlocks (SMP)
+ */
+
+#define ATOMIC_OP(op, c_op, asm_op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ \
+ atomic_ops_lock(flags); \
+ v->counter c_op i; \
+ atomic_ops_unlock(flags); \
+}
+
+#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
+static inline int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ unsigned long temp; \
+ \
+ /* \
+ * spin lock/unlock provides the needed smp_mb() before/after \
+ */ \
+ atomic_ops_lock(flags); \
+ temp = v->counter; \
+ temp c_op i; \
+ v->counter = temp; \
+ atomic_ops_unlock(flags); \
+ \
+ return temp; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
+static inline int atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ unsigned long orig; \
+ \
+ /* \
+ * spin lock/unlock provides the needed smp_mb() before/after \
+ */ \
+ atomic_ops_lock(flags); \
+ orig = v->counter; \
+ v->counter c_op i; \
+ atomic_ops_unlock(flags); \
+ \
+ return orig; \
+}
+
+#endif /* !CONFIG_ARC_HAS_LLSC */
+
+#define ATOMIC_OPS(op, c_op, asm_op) \
+ ATOMIC_OP(op, c_op, asm_op) \
+ ATOMIC_OP_RETURN(op, c_op, asm_op) \
+ ATOMIC_FETCH_OP(op, c_op, asm_op)
+
+ATOMIC_OPS(add, +=, add)
+ATOMIC_OPS(sub, -=, sub)
+
+#define atomic_andnot atomic_andnot
+#define atomic_fetch_andnot atomic_fetch_andnot
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op, c_op, asm_op) \
+ ATOMIC_OP(op, c_op, asm_op) \
+ ATOMIC_FETCH_OP(op, c_op, asm_op)
+
+ATOMIC_OPS(and, &=, and)
+ATOMIC_OPS(andnot, &= ~, bic)
+ATOMIC_OPS(or, |=, or)
+ATOMIC_OPS(xor, ^=, xor)
+
+#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_FETCH_OP(op, c_op, asm_op) \
+static inline int atomic_fetch_##op(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(); \
+ \
+ 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_FETCH_OP(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))
+#define atomic_fetch_sub(i, v) atomic_fetch_add(-(i), (v))
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op, c_op, asm_op) \
+ ATOMIC_OP(op, c_op, asm_op) \
+ ATOMIC_FETCH_OP(op, c_op, asm_op)
+
+ATOMIC_OPS(and, &=, CTOP_INST_AAND_DI_R2_R2_R3)
+ATOMIC_OPS(or, |=, CTOP_INST_AOR_DI_R2_R2_R3)
+ATOMIC_OPS(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3)
+
+#endif /* CONFIG_ARC_PLAT_EZNPS */
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+
+#include <asm-generic/atomic64.h>
+
+#else /* Kconfig ensures this is only enabled with needed h/w assist */
+
+/*
+ * ARCv2 supports 64-bit exclusive load (LLOCKD) / store (SCONDD)
+ * - The address HAS to be 64-bit aligned
+ * - There are 2 semantics involved here:
+ * = exclusive implies no interim update between load/store to same addr
+ * = both words are observed/updated together: this is guaranteed even
+ * for regular 64-bit load (LDD) / store (STD). Thus atomic64_set()
+ * is NOT required to use LLOCKD+SCONDD, STD suffices
+ */
+
+typedef struct {
+ aligned_u64 counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(a) { (a) }
+
+static inline long long atomic64_read(const atomic64_t *v)
+{
+ unsigned long long val;
+
+ __asm__ __volatile__(
+ " ldd %0, [%1] \n"
+ : "=r"(val)
+ : "r"(&v->counter));
+
+ return val;
+}
+
+static inline void atomic64_set(atomic64_t *v, long long a)
+{
+ /*
+ * This could have been a simple assignment in "C" but would need
+ * explicit volatile. Otherwise gcc optimizers could elide the store
+ * which borked atomic64 self-test
+ * In the inline asm version, memory clobber needed for exact same
+ * reason, to tell gcc about the store.
+ *
+ * This however is not needed for sibling atomic64_add() etc since both
+ * load/store are explicitly done in inline asm. As long as API is used
+ * for each access, gcc has no way to optimize away any load/store
+ */
+ __asm__ __volatile__(
+ " std %0, [%1] \n"
+ :
+ : "r"(a), "r"(&v->counter)
+ : "memory");
+}
+
+#define ATOMIC64_OP(op, op1, op2) \
+static inline void atomic64_##op(long long a, atomic64_t *v) \
+{ \
+ unsigned long long val; \
+ \
+ __asm__ __volatile__( \
+ "1: \n" \
+ " llockd %0, [%1] \n" \
+ " " #op1 " %L0, %L0, %L2 \n" \
+ " " #op2 " %H0, %H0, %H2 \n" \
+ " scondd %0, [%1] \n" \
+ " bnz 1b \n" \
+ : "=&r"(val) \
+ : "r"(&v->counter), "ir"(a) \
+ : "cc"); \
+} \
+
+#define ATOMIC64_OP_RETURN(op, op1, op2) \
+static inline long long atomic64_##op##_return(long long a, atomic64_t *v) \
+{ \
+ unsigned long long val; \
+ \
+ smp_mb(); \
+ \
+ __asm__ __volatile__( \
+ "1: \n" \
+ " llockd %0, [%1] \n" \
+ " " #op1 " %L0, %L0, %L2 \n" \
+ " " #op2 " %H0, %H0, %H2 \n" \
+ " scondd %0, [%1] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r"(val) \
+ : "r"(&v->counter), "ir"(a) \
+ : "cc"); /* memory clobber comes from smp_mb() */ \
+ \
+ smp_mb(); \
+ \
+ return val; \
+}
+
+#define ATOMIC64_FETCH_OP(op, op1, op2) \
+static inline long long atomic64_fetch_##op(long long a, atomic64_t *v) \
+{ \
+ unsigned long long val, orig; \
+ \
+ smp_mb(); \
+ \
+ __asm__ __volatile__( \
+ "1: \n" \
+ " llockd %0, [%2] \n" \
+ " " #op1 " %L1, %L0, %L3 \n" \
+ " " #op2 " %H1, %H0, %H3 \n" \
+ " scondd %1, [%2] \n" \
+ " bnz 1b \n" \
+ : "=&r"(orig), "=&r"(val) \
+ : "r"(&v->counter), "ir"(a) \
+ : "cc"); /* memory clobber comes from smp_mb() */ \
+ \
+ smp_mb(); \
+ \
+ return orig; \
+}
+
+#define ATOMIC64_OPS(op, op1, op2) \
+ ATOMIC64_OP(op, op1, op2) \
+ ATOMIC64_OP_RETURN(op, op1, op2) \
+ ATOMIC64_FETCH_OP(op, op1, op2)
+
+#define atomic64_andnot atomic64_andnot
+#define atomic64_fetch_andnot atomic64_fetch_andnot
+
+ATOMIC64_OPS(add, add.f, adc)
+ATOMIC64_OPS(sub, sub.f, sbc)
+ATOMIC64_OPS(and, and, and)
+ATOMIC64_OPS(andnot, bic, bic)
+ATOMIC64_OPS(or, or, or)
+ATOMIC64_OPS(xor, xor, xor)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_FETCH_OP
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+static inline long long
+atomic64_cmpxchg(atomic64_t *ptr, long long expected, long long new)
+{
+ long long prev;
+
+ smp_mb();
+
+ __asm__ __volatile__(
+ "1: llockd %0, [%1] \n"
+ " brne %L0, %L2, 2f \n"
+ " brne %H0, %H2, 2f \n"
+ " scondd %3, [%1] \n"
+ " bnz 1b \n"
+ "2: \n"
+ : "=&r"(prev)
+ : "r"(ptr), "ir"(expected), "r"(new)
+ : "cc"); /* memory clobber comes from smp_mb() */
+
+ smp_mb();
+
+ return prev;
+}
+
+static inline long long atomic64_xchg(atomic64_t *ptr, long long new)
+{
+ long long prev;
+
+ smp_mb();
+
+ __asm__ __volatile__(
+ "1: llockd %0, [%1] \n"
+ " scondd %2, [%1] \n"
+ " bnz 1b \n"
+ "2: \n"
+ : "=&r"(prev)
+ : "r"(ptr), "r"(new)
+ : "cc"); /* memory clobber comes from smp_mb() */
+
+ smp_mb();
+
+ return prev;
+}
+
+/**
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic64_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+
+static inline long long atomic64_dec_if_positive(atomic64_t *v)
+{
+ long long val;
+
+ smp_mb();
+
+ __asm__ __volatile__(
+ "1: llockd %0, [%1] \n"
+ " sub.f %L0, %L0, 1 # w0 - 1, set C on borrow\n"
+ " sub.c %H0, %H0, 1 # if C set, w1 - 1\n"
+ " brlt %H0, 0, 2f \n"
+ " scondd %0, [%1] \n"
+ " bnz 1b \n"
+ "2: \n"
+ : "=&r"(val)
+ : "r"(&v->counter)
+ : "cc"); /* memory clobber comes from smp_mb() */
+
+ smp_mb();
+
+ return val;
+}
+#define atomic64_dec_if_positive atomic64_dec_if_positive
+
+/**
+ * atomic64_fetch_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, if it was not @u.
+ * Returns the old value of @v
+ */
+static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a,
+ long long u)
+{
+ long long old, temp;
+
+ smp_mb();
+
+ __asm__ __volatile__(
+ "1: llockd %0, [%2] \n"
+ " brne %L0, %L4, 2f # continue to add since v != u \n"
+ " breq.d %H0, %H4, 3f # return since v == u \n"
+ "2: \n"
+ " add.f %L1, %L0, %L3 \n"
+ " adc %H1, %H0, %H3 \n"
+ " scondd %1, [%2] \n"
+ " bnz 1b \n"
+ "3: \n"
+ : "=&r"(old), "=&r" (temp)
+ : "r"(&v->counter), "r"(a), "r"(u)
+ : "cc"); /* memory clobber comes from smp_mb() */
+
+ smp_mb();
+
+ return old;
+}
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+
+#endif /* !CONFIG_GENERIC_ATOMIC64 */
+
+#endif /* !__ASSEMBLY__ */
+
+#endif