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authorWaldemar Brodkorb <wbx@uclibc-ng.org>2018-02-04 15:34:18 +0000
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2018-03-12 20:11:14 +0100
commit490e84f5e146485a26dea2f41279a4ff13aaca05 (patch)
tree03b9eab7297c5ad571b548b5ed916f17be78bf48 /libc/sysdeps/linux/tile/clone.S
parent6e627523ee4b3fc00c30dcff74c2adf93e2b6840 (diff)
tile: add basic support for tilegx
This adds basic support for tile architecture. Only static binaries, no ld.so or threading support. Tested with qemu-tilegx only.
Diffstat (limited to 'libc/sysdeps/linux/tile/clone.S')
-rw-r--r--libc/sysdeps/linux/tile/clone.S173
1 files changed, 173 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/tile/clone.S b/libc/sysdeps/linux/tile/clone.S
new file mode 100644
index 000000000..17b9ab1cd
--- /dev/null
+++ b/libc/sysdeps/linux/tile/clone.S
@@ -0,0 +1,173 @@
+/* Copyright (C) 2011-2018 Free Software Foundation, Inc.
+
+ 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/>. */
+
+/* clone() is even more special than fork() as it mucks with stacks
+ and invokes a function in the right context after it's all over. */
+
+#include <sysdep.h>
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+#include <asm/unistd.h>
+#include <arch/abi.h>
+#include <linux/sched.h>
+
+/* What we save where in the stack frame; must include all callee-saves. */
+#define FRAME_NEXT_LR (0 * REGSIZE) /* reserved by ABI; not used here */
+#define FRAME_SP (1 * REGSIZE)
+#define FRAME_R30 (2 * REGSIZE)
+#define FRAME_R31 (3 * REGSIZE)
+#define FRAME_R32 (4 * REGSIZE)
+#define FRAME_SIZE (5 * REGSIZE)
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+ pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
+
+ .text
+ENTRY (__clone)
+ /* Create a stack frame so we can pass callee-saves to new task. */
+ {
+ move r10, sp
+ st sp, lr
+ ADDI_PTR sp, sp, -FRAME_SIZE
+ }
+ cfi_offset (lr, 0)
+ cfi_def_cfa_offset (FRAME_SIZE)
+ ADDI_PTR r11, sp, FRAME_SP
+ {
+ st r11, r10
+ ADDI_PTR r11, sp, FRAME_R30
+ }
+ {
+ st r11, r30
+ ADDI_PTR r11, sp, FRAME_R31
+ }
+ cfi_offset (r30, FRAME_R30 - FRAME_SIZE)
+ {
+ st r11, r31
+ ADDI_PTR r11, sp, FRAME_R32
+ }
+ cfi_offset (r31, FRAME_R31 - FRAME_SIZE)
+ st r11, r32
+ cfi_offset (r32, FRAME_R32 - FRAME_SIZE)
+
+ /* sanity check arguments */
+ beqz r0, .Linvalid
+ beqz r1, .Linvalid
+
+ /* Make sure child stack is properly aligned, and set up the
+ top frame so that we can call out of it immediately in the
+ child. Setting it up here means we fault in the parent if
+ it's bogus, which is probably cleaner than faulting first
+ thing in the child. */
+ ADDI_PTR r1, r1, -C_ABI_SAVE_AREA_SIZE
+ andi r1, r1, -C_ABI_SAVE_AREA_SIZE
+ ADDI_PTR r9, r1, REGSIZE /* sp of this frame on entry, i.e. zero */
+ st r9, zero
+
+ /* We need to switch the argument convention around from
+ libc to kernel:
+
+ libc:
+ r0 fn
+ r1 child_stack
+ r2 flags
+ r3 arg
+ r4 ptid
+ r5 tls
+ r6 ctid
+
+ kernel:
+ r0 flags
+ r1 child_stack [same as libc]
+ r2 ptid
+ r3 ctid
+ r4 tls
+
+ Plus the callee-saves as described at .Lthread_start, below. */
+ {
+ move r32, r0
+ move r0, r2
+ }
+ {
+ move r31, r3
+ move r3, r6
+ }
+ {
+ move r30, r2
+ move r2, r4
+ }
+ {
+ move r4, r5
+ moveli TREG_SYSCALL_NR_NAME, __NR_clone
+ }
+ swint1
+ beqz r0, .Lthread_start /* If in child task. */
+
+.Ldone:
+ /* Restore the callee-saved registers and return. */
+ ADDLI_PTR lr, sp, FRAME_SIZE
+ {
+ ld lr, lr
+ ADDLI_PTR r30, sp, FRAME_R30
+ }
+ {
+ ld r30, r30
+ ADDLI_PTR r31, sp, FRAME_R31
+ }
+ {
+ ld r31, r31
+ ADDLI_PTR r32, sp, FRAME_R32
+ }
+ {
+ ld r32, r32
+ ADDI_PTR sp, sp, FRAME_SIZE
+ }
+ cfi_def_cfa_offset (0)
+
+ bnez r1, .Lerror
+ jrp lr
+
+.Lerror:
+ j SYSCALL_ERROR_NAME
+
+.Linvalid:
+ {
+ movei r1, EINVAL
+ j .Ldone
+ }
+
+/* This function expects to receive:
+
+ sp: the top of a valid stack area
+ r30: clone() flags
+ r31: the argument to pass to the user function
+ r32: the user function pointer */
+
+.Lthread_start:
+ cfi_def_cfa_offset (FRAME_SIZE)
+ cfi_undefined (lr)
+ {
+ /* Invoke user function with specified argument. */
+ move r0, r31
+ jalr r32
+ }
+ moveli TREG_SYSCALL_NR_NAME, __NR_exit
+ swint1
+PSEUDO_END (__clone)
+
+libc_hidden_def (clone)
+weak_alias (__clone, clone)