arm64: lse: fix LSE atomics with LLVM's integrated assembler

commit e0d5896bd3 upstream.

Unlike gcc, clang considers each inline assembly block to be independent
and therefore, when using the integrated assembler for inline assembly,
any preambles that enable features must be repeated in each block.

This change defines __LSE_PREAMBLE and adds it to each inline assembly
block that has LSE instructions, which allows them to be compiled also
with clang's assembler.

Link: https://github.com/ClangBuiltLinux/linux/issues/671
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Andrew Murray <andrew.murray@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
[nd: backport adjusted due to missing:
  commit addfc38672 ("arm64: atomics: avoid out-of-line ll/sc atomics")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sami Tolvanen
2019-10-31 12:57:05 -07:00
committed by Greg Kroah-Hartman
parent 88ee1af064
commit 5681cce44c
2 changed files with 60 additions and 22 deletions

View File

@@ -32,7 +32,9 @@ static inline void atomic_##op(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(op), \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC(op), \
" " #asm_op " %w[i], %[v]\n") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
@@ -52,7 +54,9 @@ static inline int atomic_fetch_##op##name(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_##op##name), \
/* LSE atomics */ \
@@ -84,7 +88,9 @@ static inline int atomic_add_return##name(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(add_return##name) \
__nops(1), \
@@ -110,7 +116,9 @@ static inline void atomic_and(int i, atomic_t *v)
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
asm volatile(
__LSE_PREAMBLE
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC(and)
__nops(1),
@@ -128,7 +136,9 @@ static inline int atomic_fetch_and##name(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_and##name) \
__nops(1), \
@@ -154,7 +164,9 @@ static inline void atomic_sub(int i, atomic_t *v)
register int w0 asm ("w0") = i;
register atomic_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
asm volatile(
__LSE_PREAMBLE
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC(sub)
__nops(1),
@@ -172,7 +184,9 @@ static inline int atomic_sub_return##name(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(sub_return##name) \
__nops(2), \
@@ -200,7 +214,9 @@ static inline int atomic_fetch_sub##name(int i, atomic_t *v) \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_sub##name) \
__nops(1), \
@@ -229,7 +245,9 @@ static inline void atomic64_##op(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(op), \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN(__LL_SC_ATOMIC64(op), \
" " #asm_op " %[i], %[v]\n") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
@@ -249,7 +267,9 @@ static inline long atomic64_fetch_##op##name(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_##op##name), \
/* LSE atomics */ \
@@ -281,7 +301,9 @@ static inline long atomic64_add_return##name(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(add_return##name) \
__nops(1), \
@@ -307,7 +329,9 @@ static inline void atomic64_and(long i, atomic64_t *v)
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
asm volatile(
__LSE_PREAMBLE
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(and)
__nops(1),
@@ -325,7 +349,9 @@ static inline long atomic64_fetch_and##name(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_and##name) \
__nops(1), \
@@ -351,7 +377,9 @@ static inline void atomic64_sub(long i, atomic64_t *v)
register long x0 asm ("x0") = i;
register atomic64_t *x1 asm ("x1") = v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
asm volatile(
__LSE_PREAMBLE
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(sub)
__nops(1),
@@ -369,7 +397,9 @@ static inline long atomic64_sub_return##name(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(sub_return##name) \
__nops(2), \
@@ -397,7 +427,9 @@ static inline long atomic64_fetch_sub##name(long i, atomic64_t *v) \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_sub##name) \
__nops(1), \
@@ -422,7 +454,9 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
{
register long x0 asm ("x0") = (long)v;
asm volatile(ARM64_LSE_ATOMIC_INSN(
asm volatile(
__LSE_PREAMBLE
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
__LL_SC_ATOMIC64(dec_if_positive)
__nops(6),
@@ -455,7 +489,9 @@ static inline unsigned long __cmpxchg_case_##name(volatile void *ptr, \
register unsigned long x1 asm ("x1") = old; \
register unsigned long x2 asm ("x2") = new; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_CMPXCHG(name) \
__nops(2), \
@@ -507,7 +543,9 @@ static inline long __cmpxchg_double##name(unsigned long old1, \
register unsigned long x3 asm ("x3") = new2; \
register unsigned long x4 asm ("x4") = (unsigned long)ptr; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
asm volatile( \
__LSE_PREAMBLE \
ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_CMPXCHG_DBL(name) \
__nops(3), \

View File

@@ -4,6 +4,8 @@
#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
#define __LSE_PREAMBLE ".arch armv8-a+lse\n"
#include <linux/compiler_types.h>
#include <linux/export.h>
#include <linux/stringify.h>
@@ -20,8 +22,6 @@
#else /* __ASSEMBLER__ */
__asm__(".arch_extension lse");
/* Move the ll/sc atomics out-of-line */
#define __LL_SC_INLINE notrace
#define __LL_SC_PREFIX(x) __ll_sc_##x
@@ -33,7 +33,7 @@ __asm__(".arch_extension lse");
/* In-line patching at runtime */
#define ARM64_LSE_ATOMIC_INSN(llsc, lse) \
ALTERNATIVE(llsc, lse, ARM64_HAS_LSE_ATOMICS)
ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
#endif /* __ASSEMBLER__ */
#else /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */