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authorPalmer Dabbelt <palmer@dabbelt.com>2018-01-29 10:27:17 -0800
committerPalmer Dabbelt <palmer@dabbelt.com>2018-01-29 10:27:17 -0800
commitd1c09b247130c1aedd11b913f579c7764b1b5ae1 (patch)
treef7b2eb5361ae69af3490074320178fb04f7e3fd7
parentb2cb5e0298e08b486190610a9e82356ccb6f564b (diff)
downloadglibc-d1c09b247130c1aedd11b913f579c7764b1b5ae1.tar.gz
RISC-V: Atomic and Locking Routines
This patch implements various atomic and locking routines on RISC-V. We mandate the A extension on Linux-capable RISC-V systems, so this can rely on always having the various atomic instructions availiable. 2018-01-29 Palmer Dabbelt <palmer@sifive.com> * sysdeps/riscv/nptl/bits/pthreadtypes-arch.h: New file. * sysdeps/riscv/nptl/bits/semaphore.h: Likewise. * sysdeps/riscv/nptl/libc-lowlevellock.c: Likewise. * sysdeps/unix/sysv/linux/riscv/atomic-machine.h: Likewise.
-rw-r--r--ChangeLog4
-rw-r--r--sysdeps/riscv/nptl/bits/pthreadtypes-arch.h68
-rw-r--r--sysdeps/riscv/nptl/bits/semaphore.h33
-rw-r--r--sysdeps/riscv/nptl/libc-lowlevellock.c8
-rw-r--r--sysdeps/unix/sysv/linux/riscv/atomic-machine.h194
5 files changed, 307 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 17edd31c9d..6df255ba3a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -92,6 +92,10 @@
* sysdeps/riscv/rvf/s_roundevenf.c: Likewise.
* sysdeps/riscv/rvf/s_roundf.c: Likewise.
* sysdeps/riscv/rvf/s_truncf.c: Likewise.
+ * sysdeps/riscv/nptl/bits/pthreadtypes-arch.h: New file.
+ * sysdeps/riscv/nptl/bits/semaphore.h: Likewise.
+ * sysdeps/riscv/nptl/libc-lowlevellock.c: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/atomic-machine.h: Likewise.
2018-01-29 Florian Weimer <fweimer@redhat.com>
diff --git a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
new file mode 100644
index 0000000000..f6a55b6233
--- /dev/null
+++ b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
@@ -0,0 +1,68 @@
+/* Machine-specific pthread type layouts. RISC-V version.
+ Copyright (C) 2011-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _BITS_PTHREADTYPES_ARCH_H
+#define _BITS_PTHREADTYPES_ARCH_H 1
+
+#include <endian.h>
+
+#if __riscv_xlen == 64
+# define __SIZEOF_PTHREAD_ATTR_T 56
+# define __SIZEOF_PTHREAD_MUTEX_T 40
+# define __SIZEOF_PTHREAD_MUTEXATTR_T 4
+# define __SIZEOF_PTHREAD_COND_T 48
+# define __SIZEOF_PTHREAD_CONDATTR_T 4
+# define __SIZEOF_PTHREAD_RWLOCK_T 56
+# define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
+# define __SIZEOF_PTHREAD_BARRIER_T 32
+# define __SIZEOF_PTHREAD_BARRIERATTR_T 4
+#else
+# error "rv32i-based systems are not supported"
+#endif
+
+#define __PTHREAD_COMPAT_PADDING_MID
+#define __PTHREAD_COMPAT_PADDING_END
+#define __PTHREAD_MUTEX_LOCK_ELISION 0
+#define __PTHREAD_MUTEX_USE_UNION 0
+#define __PTHREAD_MUTEX_NUSERS_AFTER_KIND 0
+
+#define __LOCK_ALIGNMENT
+#define __ONCE_ALIGNMENT
+
+/* There is a lot of padding in this structure. While it's not strictly
+ necessary on RISC-V, we're going to leave it in to be on the safe side in
+ case it's needed in the future. Most other architectures have the padding,
+ so this gives us the same extensibility as everyone else has. */
+struct __pthread_rwlock_arch_t
+{
+ unsigned int __readers;
+ unsigned int __writers;
+ unsigned int __wrphase_futex;
+ unsigned int __writers_futex;
+ unsigned int __pad3;
+ unsigned int __pad4;
+ int __cur_writer;
+ int __shared;
+ unsigned long int __pad1;
+ unsigned long int __pad2;
+ unsigned int __flags;
+};
+
+#define __PTHREAD_RWLOCK_ELISION_EXTRA 0
+
+#endif /* bits/pthreadtypes.h */
diff --git a/sysdeps/riscv/nptl/bits/semaphore.h b/sysdeps/riscv/nptl/bits/semaphore.h
new file mode 100644
index 0000000000..2fed17d0e5
--- /dev/null
+++ b/sysdeps/riscv/nptl/bits/semaphore.h
@@ -0,0 +1,33 @@
+/* Machine-specific POSIX semaphore type layouts. RISC-V version.
+ Copyright (C) 2002-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _SEMAPHORE_H
+# error "Never use <bits/semaphore.h> directly; include <semaphore.h> instead."
+#endif
+
+#define __SIZEOF_SEM_T (4 * __SIZEOF_POINTER__)
+
+/* Value returned if `sem_open' failed. */
+#define SEM_FAILED ((sem_t *) 0)
+
+
+typedef union
+{
+ char __size[__SIZEOF_SEM_T];
+ long int __align;
+} sem_t;
diff --git a/sysdeps/riscv/nptl/libc-lowlevellock.c b/sysdeps/riscv/nptl/libc-lowlevellock.c
new file mode 100644
index 0000000000..9523fb46a5
--- /dev/null
+++ b/sysdeps/riscv/nptl/libc-lowlevellock.c
@@ -0,0 +1,8 @@
+/* This kludge works around a libpthread static linking problem:
+ https://sourceware.org/bugzilla/show_bug.cgi?id=15648. */
+
+#ifndef SHARED
+# define __lll_lock_wait_private weak_function __lll_lock_wait_private
+#endif
+
+#include <lowlevellock.c>
diff --git a/sysdeps/unix/sysv/linux/riscv/atomic-machine.h b/sysdeps/unix/sysv/linux/riscv/atomic-machine.h
new file mode 100644
index 0000000000..3d967d3b08
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/atomic-machine.h
@@ -0,0 +1,194 @@
+/* Low-level functions for atomic operations. RISC-V version.
+ Copyright (C) 2014-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _LINUX_RISCV_BITS_ATOMIC_H
+#define _LINUX_RISCV_BITS_ATOMIC_H 1
+
+#include <stdint.h>
+
+typedef int32_t atomic32_t;
+typedef uint32_t uatomic32_t;
+
+typedef int64_t atomic64_t;
+typedef uint64_t uatomic64_t;
+
+typedef intptr_t atomicptr_t;
+typedef uintptr_t uatomicptr_t;
+typedef intmax_t atomic_max_t;
+typedef uintmax_t uatomic_max_t;
+
+#define atomic_full_barrier() __sync_synchronize ()
+
+#ifdef __riscv_atomic
+
+# define __HAVE_64B_ATOMICS (__riscv_xlen >= 64)
+# define USE_ATOMIC_COMPILER_BUILTINS 1
+# define ATOMIC_EXCHANGE_USES_CAS 0
+
+/* Compare and exchange.
+ For all "bool" routines, we return FALSE if exchange succesful. */
+
+# define __arch_compare_and_exchange_bool_8_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ })
+
+# define __arch_compare_and_exchange_bool_16_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ })
+
+# define __arch_compare_and_exchange_bool_32_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ })
+
+# define __arch_compare_and_exchange_bool_64_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ !__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ })
+
+# define __arch_compare_and_exchange_val_8_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ __oldval; \
+ })
+
+# define __arch_compare_and_exchange_val_16_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ __oldval; \
+ })
+
+# define __arch_compare_and_exchange_val_32_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ __oldval; \
+ })
+
+# define __arch_compare_and_exchange_val_64_int(mem, newval, oldval, model) \
+ ({ \
+ typeof (*mem) __oldval = (oldval); \
+ __atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
+ model, __ATOMIC_RELAXED); \
+ __oldval; \
+ })
+
+/* Atomic compare and exchange. */
+
+# define atomic_compare_and_exchange_bool_acq(mem, new, old) \
+ __atomic_bool_bysize (__arch_compare_and_exchange_bool, int, \
+ mem, new, old, __ATOMIC_ACQUIRE)
+
+# define atomic_compare_and_exchange_val_acq(mem, new, old) \
+ __atomic_val_bysize (__arch_compare_and_exchange_val, int, \
+ mem, new, old, __ATOMIC_ACQUIRE)
+
+# define atomic_compare_and_exchange_val_rel(mem, new, old) \
+ __atomic_val_bysize (__arch_compare_and_exchange_val, int, \
+ mem, new, old, __ATOMIC_RELEASE)
+
+/* Atomic exchange (without compare). */
+
+# define __arch_exchange_8_int(mem, newval, model) \
+ __atomic_exchange_n (mem, newval, model)
+
+# define __arch_exchange_16_int(mem, newval, model) \
+ __atomic_exchange_n (mem, newval, model)
+
+# define __arch_exchange_32_int(mem, newval, model) \
+ __atomic_exchange_n (mem, newval, model)
+
+# define __arch_exchange_64_int(mem, newval, model) \
+ __atomic_exchange_n (mem, newval, model)
+
+# define atomic_exchange_acq(mem, value) \
+ __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_ACQUIRE)
+
+# define atomic_exchange_rel(mem, value) \
+ __atomic_val_bysize (__arch_exchange, int, mem, value, __ATOMIC_RELEASE)
+
+/* Atomically add value and return the previous (unincremented) value. */
+
+# define __arch_exchange_and_add_8_int(mem, value, model) \
+ __atomic_fetch_add (mem, value, model)
+
+# define __arch_exchange_and_add_16_int(mem, value, model) \
+ __atomic_fetch_add (mem, value, model)
+
+# define __arch_exchange_and_add_32_int(mem, value, model) \
+ __atomic_fetch_add (mem, value, model)
+
+# define __arch_exchange_and_add_64_int(mem, value, model) \
+ __atomic_fetch_add (mem, value, model)
+
+# define atomic_exchange_and_add_acq(mem, value) \
+ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \
+ __ATOMIC_ACQUIRE)
+
+# define atomic_exchange_and_add_rel(mem, value) \
+ __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, \
+ __ATOMIC_RELEASE)
+
+/* Miscellaneous. */
+
+# define asm_amo(which, ordering, mem, value) ({ \
+ __atomic_check_size (mem); \
+ typeof (*mem) __tmp; \
+ if (sizeof (__tmp) == 4) \
+ asm volatile (which ".w" ordering "\t%0, %z2, %1" \
+ : "=r" (__tmp), "+A" (* (mem)) \
+ : "rJ" (value)); \
+ else if (sizeof (__tmp) == 8) \
+ asm volatile (which ".d" ordering "\t%0, %z2, %1" \
+ : "=r" (__tmp), "+A" (* (mem)) \
+ : "rJ" (value)); \
+ else \
+ abort (); \
+ __tmp; })
+
+# define atomic_max(mem, value) asm_amo ("amomaxu", ".aq", mem, value)
+# define atomic_min(mem, value) asm_amo ("amominu", ".aq", mem, value)
+
+# define atomic_bit_test_set(mem, bit) \
+ ({ typeof (*mem) __mask = (typeof (*mem))1 << (bit); \
+ asm_amo ("amoor", ".aq", mem, __mask) & __mask; })
+
+# define catomic_exchange_and_add(mem, value) \
+ atomic_exchange_and_add (mem, value)
+# define catomic_max(mem, value) atomic_max (mem, value)
+
+#else /* __riscv_atomic */
+# error "ISAs that do not subsume the A extension are not supported"
+#endif /* !__riscv_atomic */
+
+#endif /* bits/atomic.h */