RISC-V: Linux ABI

Linux-specific code that is required for maintaining ABI compatibility.
This doesn't contain the actual system call interface, that is split out
in order to avoid having a patch that's too big.

2018-01-29  Palmer Dabbelt  <palmer@sifive.com>

        * sysdeps/riscv/nptl/pthread-offsets.h: New file.
        * sysdeps/riscv/nptl/pthreaddef.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/fcntl.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/mman.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/sigcontext.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/dl-cache.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/flush-icache.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/getcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/init-first.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/libc-vdso.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/makecontext.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/readelflib.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/register-dump.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/setcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sigcontextinfo.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/swapcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/cachectl.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/procfs.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/ucontext.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/user.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/ucontext-macros.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/ucontext_i.sym: Likewise.

1 files changed, 77 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/riscv/getcontext.S b/sysdeps/unix/sysv/linux/riscv/getcontext.S
new file mode 100644
index 0000000000..bde350f721
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/getcontext.S
@@ -0,0 +1,77 @@
+/* Save current context.
+   Copyright (C) 2009-2018 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/>.  */
+
+#include "ucontext-macros.h"
+
+/* int getcontext (ucontext_t *ucp) */
+
+	.text
+LEAF (__getcontext)
+	SAVE_INT_REG (ra,   0, a0)
+	SAVE_INT_REG (ra,   1, a0)
+	SAVE_INT_REG (sp,   2, a0)
+	SAVE_INT_REG (s0,   8, a0)
+	SAVE_INT_REG (s1,   9, a0)
+	SAVE_INT_REG (x0,  10, a0)	/* return 0 by overwriting a0.  */
+	SAVE_INT_REG (s2,  18, a0)
+	SAVE_INT_REG (s3,  19, a0)
+	SAVE_INT_REG (s4,  20, a0)
+	SAVE_INT_REG (s5,  21, a0)
+	SAVE_INT_REG (s6,  22, a0)
+	SAVE_INT_REG (s7,  23, a0)
+	SAVE_INT_REG (s8,  24, a0)
+	SAVE_INT_REG (s9,  25, a0)
+	SAVE_INT_REG (s10, 26, a0)
+	SAVE_INT_REG (s11, 27, a0)
+
+#ifndef __riscv_float_abi_soft
+	frsr	a1
+
+	SAVE_FP_REG (fs0,   8, a0)
+	SAVE_FP_REG (fs1,   9, a0)
+	SAVE_FP_REG (fs2,  18, a0)
+	SAVE_FP_REG (fs3,  19, a0)
+	SAVE_FP_REG (fs4,  20, a0)
+	SAVE_FP_REG (fs5,  21, a0)
+	SAVE_FP_REG (fs6,  22, a0)
+	SAVE_FP_REG (fs7,  23, a0)
+	SAVE_FP_REG (fs8,  24, a0)
+	SAVE_FP_REG (fs9,  25, a0)
+	SAVE_FP_REG (fs10, 26, a0)
+	SAVE_FP_REG (fs11, 27, a0)
+
+	sw	a1, MCONTEXT_FSR(a0)
+#endif /* __riscv_float_abi_soft */
+
+/* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
+	li	a3, _NSIG8
+	add     a2, a0, UCONTEXT_SIGMASK
+	mv	a1, zero
+	li	a0, SIG_BLOCK
+
+	li	a7, SYS_ify (rt_sigprocmask)
+	scall
+	bltz	a0, 99f
+
+	ret
+
+99:	j	__syscall_error
+
+PSEUDO_END (__getcontext)
+
+weak_alias (__getcontext, getcontext)