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authorWaldemar Brodkorb <wbx@openadk.org>2024-03-29 07:49:31 +0100
committerWaldemar Brodkorb <wbx@openadk.org>2024-03-29 07:54:27 +0100
commit8f200b7fef0b9320b84e09b4c16df6c72daadd36 (patch)
tree282a7c497298a659455dd822cad690c824862979 /libpthread/linuxthreads
parent4ce2bd0e5788e53f0377da857b72b08c4222aaef (diff)
riscv32: implement linuxthreads, from sorear
Diffstat (limited to 'libpthread/linuxthreads')
-rw-r--r--libpthread/linuxthreads/sysdeps/riscv32/pt-machine.h61
1 files changed, 61 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/riscv32/pt-machine.h b/libpthread/linuxthreads/sysdeps/riscv32/pt-machine.h
new file mode 100644
index 000000000..38f0d8eff
--- /dev/null
+++ b/libpthread/linuxthreads/sysdeps/riscv32/pt-machine.h
@@ -0,0 +1,61 @@
+/*
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#ifndef _PT_MACHINE_H
+#define _PT_MACHINE_H 1
+#include <features.h>
+
+#ifndef PT_EI
+# define PT_EI __extern_always_inline
+#endif
+
+#define HAS_COMPARE_AND_SWAP
+PT_EI int
+__compare_and_swap (long int *p, long int oldval, long int newval)
+{
+ long int ret, temp;
+
+ __asm__ __volatile__
+ ("/* Inline compare & swap */\n"
+ "1:\n\t"
+ "lr.w %1,%2\n\t"
+ "li %0,0\n\t"
+ "bne %1,%3,2f\n\t"
+ "li %0,1\n\t"
+ "sc.w %1,%4,%2\n\t"
+ "bnez %1,1b\n"
+ "2:\n\t"
+ "/* End compare & swap */"
+ : "=&r" (ret), "=&r" (temp), "+A" (*p)
+ : "r" (oldval), "r" (newval)
+ : "memory");
+
+ return ret;
+}
+
+extern long int testandset (int *spinlock);
+
+PT_EI long int
+testandset (int *spinlock)
+{
+ unsigned int old = 1;
+ int tmp = 1;
+
+ __asm__ __volatile__ (
+ "amoswap.w %0, %2, %1"
+ : "=r" (old), "+A" (*spinlock)
+ : "r" (tmp)
+ : "memory");
+
+ return old;
+}
+
+/* Get some notion of the current stack. Need not be exactly the top
+ of the stack, just something somewhere in the current frame. */
+#define CURRENT_STACK_FRAME stack_pointer
+register char * stack_pointer __asm__ ("sp");
+
+#else
+#error PT_MACHINE already defined
+#endif /* pt-machine.h */