riscv32: add arch headers

These are mostly copied from riscv64. _Addr and _Reg had to become int
to match compiler-controlled parts of the ABI (result type of sizeof,
etc.). There is no kernel stat struct; the userspace stat matches
glibc in the sizes and offsets of all fields (including glibc's
__dev_t __pad1). The jump buffer is 12 words larger to account for 12
saved double-precision floats; additionally it should be 64-bit
aligned to save doubles.

The syscall list was significantly revised by deleting all time32 and
pre-statx syscalls, and renaming several syscalls that have different
names depending on __BITS_PER_LONG, notably mmap2 and _llseek.

futex was added as an alias to futex_time64 since it is widely used by
software which does not pass time arguments.

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/riscv32/atomic_arch.h b/arch/riscv32/atomic_arch.h
new file mode 100644
index 00000000..4d418f63
--- /dev/null
+++ b/arch/riscv32/atomic_arch.h
@@ -0,0 +1,21 @@
+#define a_barrier a_barrier
+static inline void a_barrier()
+{
+	__asm__ __volatile__ ("fence rw,rw" : : : "memory");
+}
+
+#define a_cas a_cas
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	int old, tmp;
+	__asm__ __volatile__ (
+		"\n1:	lr.w.aqrl %0, (%2)\n"
+		"	bne %0, %3, 1f\n"
+		"	sc.w.aqrl %1, %4, (%2)\n"
+		"	bnez %1, 1b\n"
+		"1:"
+		: "=&r"(old), "=&r"(tmp)
+		: "r"(p), "r"((long)t), "r"((long)s)
+		: "memory");
+	return old;
+}