Add ARM 64bit sync helpers for use on older ARMs. Based on 32bit
versions but with check for sufficiently new kernel version.
gcc/
* config/arm/linux-atomic-64bit.c: New (based on linux-atomic.c)
* config/arm/linux-atomic.c: Change comment to point to 64bit version
(SYNC_LOCK_RELEASE): Instantiate 64bit version.
* config/arm/t-linux-eabi: Pull in linux-atomic-64bit.c
diff --git a/gcc/config/arm/linux-atomic-64bit.c
b/gcc/config/arm/linux-atomic-64bit.c
new file mode 100644
index 0000000..8b65de8
--- /dev/null
+++ b/gcc/config/arm/linux-atomic-64bit.c
@@ -0,0 +1,162 @@
+/* 64bit Linux-specific atomic operations for ARM EABI.
+ Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+ Based on linux-atomic.c
+
+ 64 bit additions david.gilb...@linaro.org
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+/* 64bit helper functions for atomic operations; the compiler will
+ call these when the code is compiled for a CPU without ldrexd/strexd.
+ (If the CPU had those then the compiler inlines the operation).
+
+ These helpers require a kernel helper that's only present on newer
+ kernels; we check for that in an init section and bail out rather
+ unceremoneously. */
+
+extern unsigned int __write(int fd, const void *buf, unsigned int count);
+extern void abort(void);
+
+/* Kernel helper for compare-and-exchange. */
+typedef int (__kernel_cmpxchg64_t) (const long long* oldval,
+ const long long* newval,
+ long long *ptr);
+#define __kernel_cmpxchg64 (*(__kernel_cmpxchg64_t *) 0xffff0f60)
+
+/* Kernel helper page version number */
+#define __kernel_helper_version (*(unsigned int *)0xffff0ffc)
+
+/* Check that the kernel has a new enough version at load */
+static void __check_for_sync8_kernelhelper (void)
+{
+ if (__kernel_helper_version < 5)
+ {
+ const char err[] = "A newer kernel is required to run this binary.
(__kernel_cmpxchg64 helper)\n";
+ /* At this point we need a way to crash with some information
+ for the user - I'm not sure I can rely on much else being
+ available at this point, so do the same as generic-morestack.c
+ write() and abort(). */
+ __write (2 /* stderr */, err, sizeof(err));
+ abort ();
+ }
+};
+
+static void (*__sync8_kernelhelper_inithook[]) (void) __attribute__ ((used,
section (".init_array"))) = {
+ &__check_for_sync8_kernelhelper
+};
+
+#define HIDDEN __attribute__ ((visibility ("hidden")))
+
+#define FETCH_AND_OP_WORD64(OP, PFX_OP, INF_OP) \
+ long long HIDDEN \
+ __sync_fetch_and_##OP##_8 (long long *ptr, long long val) \
+ { \
+ int failure; \
+ long long tmp,tmp2; \
+ \
+ do { \
+ tmp = *ptr; \
+ tmp2 = PFX_OP (tmp INF_OP val); \
+ failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \
+ } while (failure != 0); \
+ \
+ return tmp; \
+ }
+
+FETCH_AND_OP_WORD64 (add, , +)
+FETCH_AND_OP_WORD64 (sub, , -)
+FETCH_AND_OP_WORD64 (or, , |)
+FETCH_AND_OP_WORD64 (and, , &)
+FETCH_AND_OP_WORD64 (xor, , ^)
+FETCH_AND_OP_WORD64 (nand, ~, &)
+
+#define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH
+#define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH
+
+/* Implement both __sync_<op>_and_fetch and __sync_fetch_and_<op> for
+ subword-sized quantities. */
+
+#define OP_AND_FETCH_WORD64(OP, PFX_OP, INF_OP) \
+ long long HIDDEN \
+ __sync_##OP##_and_fetch_8 (long long *ptr, long long val) \
+ { \
+ int failure; \
+ long long tmp,tmp2; \
+ \
+ do { \
+ tmp = *ptr; \
+ tmp2 = PFX_OP (tmp INF_OP val); \
+ failure = __kernel_cmpxchg64 (&tmp, &tmp2, ptr); \
+ } while (failure != 0); \
+ \
+ return tmp2; \
+ }
+
+OP_AND_FETCH_WORD64 (add, , +)
+OP_AND_FETCH_WORD64 (sub, , -)
+OP_AND_FETCH_WORD64 (or, , |)
+OP_AND_FETCH_WORD64 (and, , &)
+OP_AND_FETCH_WORD64 (xor, , ^)
+OP_AND_FETCH_WORD64 (nand, ~, &)
+
+long long HIDDEN
+__sync_val_compare_and_swap_8 (long long *ptr, long long oldval, long long
newval)
+{
+ int failure;
+ long long actual_oldval;
+
+ while (1)
+ {
+ actual_oldval = *ptr;
+
+ if (__builtin_expect (oldval != actual_oldval, 0))
+ return actual_oldval;
+
+ failure = __kernel_cmpxchg64 (&actual_oldval, &newval, ptr);
+
+ if (__builtin_expect (!failure, 1))
+ return oldval;
+ }
+}
+
+typedef unsigned char bool;
+
+bool HIDDEN
+__sync_bool_compare_and_swap_8 (long long *ptr, long long oldval, long long
newval)
+{
+ int failure = __kernel_cmpxchg64 (&oldval, &newval, ptr);
+ return (failure == 0);
+}
+
+long long HIDDEN
+__sync_lock_test_and_set_8 (long long *ptr, long long val)
+{
+ int failure;
+ long long oldval;
+
+ do {
+ oldval = *ptr;
+ failure = __kernel_cmpxchg64 (&oldval, &val, ptr);
+ } while (failure != 0);
+
+ return oldval;
+}
diff --git a/gcc/config/arm/linux-atomic.c b/gcc/config/arm/linux-atomic.c
index 57065a6..80f161d 100644
--- a/gcc/config/arm/linux-atomic.c
+++ b/gcc/config/arm/linux-atomic.c
@@ -32,8 +32,8 @@ typedef void (__kernel_dmb_t) (void);
#define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0)
/* Note: we implement byte, short and int versions of atomic operations using
- the above kernel helpers, but there is no support for "long long" (64-bit)
- operations as yet. */
+ the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit)
+ operations. */
#define HIDDEN __attribute__ ((visibility ("hidden")))
@@ -273,6 +273,7 @@ SUBWORD_TEST_AND_SET (unsigned char, 1)
*ptr = 0; \
}
+SYNC_LOCK_RELEASE (long long, 8)
SYNC_LOCK_RELEASE (int, 4)
SYNC_LOCK_RELEASE (short, 2)
SYNC_LOCK_RELEASE (char, 1)
diff --git a/gcc/config/arm/t-linux-eabi b/gcc/config/arm/t-linux-eabi
index a328a00..3814cc0 100644
--- a/gcc/config/arm/t-linux-eabi
+++ b/gcc/config/arm/t-linux-eabi
@@ -36,3 +36,4 @@ LIB1ASMFUNCS := $(filter-out _dvmd_tls,$(LIB1ASMFUNCS))
_dvmd_lnx _clear_cache
EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o crtbeginS.o crtendS.o crtbeginT.o
LIB2FUNCS_STATIC_EXTRA += $(srcdir)/config/arm/linux-atomic.c
+LIB2FUNCS_STATIC_EXTRA += $(srcdir)/config/arm/linux-atomic-64bit.c
