NPTL: ARC support

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

5 files changed, 120 insertions, 7 deletions

diff --git a/libc/sysdeps/linux/arc/bits/atomic.h b/libc/sysdeps/linux/arc/bits/atomic.h
new file mode 100644
index 000000000..d4abf4eb7
--- /dev/null
+++ b/libc/sysdeps/linux/arc/bits/atomic.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#include <stdint.h>
+#include <sysdep.h>
+
+typedef int8_t atomic8_t;
+typedef uint8_t uatomic8_t;
+typedef int_fast8_t atomic_fast8_t;
+typedef uint_fast8_t uatomic_fast8_t;
+
+typedef int32_t atomic32_t;
+typedef uint32_t uatomic32_t;
+typedef int_fast32_t atomic_fast32_t;
+typedef uint_fast32_t uatomic_fast32_t;
+
+typedef intptr_t atomicptr_t;
+typedef uintptr_t uatomicptr_t;
+typedef intmax_t atomic_max_t;
+typedef uintmax_t uatomic_max_t;
+
+void __arc_link_error (void);
+
+#define atomic_full_barrier() \
+     __asm__ __volatile__("": : :"memory")
+
+/* Atomic compare and exchange. */
+
+#define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
+  ({ __arc_link_error (); oldval; })
+
+#define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
+  ({ __arc_link_error (); oldval; })
+
+#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval)     \
+  ({									\
+	__typeof(oldval) prev;						\
+									\
+	__asm__ __volatile__(						\
+	"1:	llock   %0, [%1]	\n"				\
+	"	brne    %0, %2, 2f	\n"				\
+	"	scond   %3, [%1]	\n"				\
+	"	bnz     1b		\n"				\
+	"2:				\n"				\
+	: "=&r"(prev)							\
+	: "r"(mem), "ir"(oldval),					\
+	  "r"(newval) /* can't be "ir". scond can't take limm for "b" */\
+	: "cc", "memory");						\
+									\
+	prev;								\
+  })
+
+#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
+  ({ __arc_link_error (); oldval; })
diff --git a/libc/sysdeps/linux/arc/clone.S b/libc/sysdeps/linux/arc/clone.S
index 9aa8d92cd..db5000caf 100644
--- a/libc/sysdeps/linux/arc/clone.S
+++ b/libc/sysdeps/linux/arc/clone.S
@@ -19,25 +19,32 @@
 ;       Current (Jul 2012) upstream powerpc/clone.S assumes similarly.
 ;	Our LTP (from 2007) doesn't seem to have tests to prove otherwise
 
-; clone syscall in kernel
+; clone syscall in kernel (ABI: CONFIG_CLONE_BACKWARDS)
 ;
-; int sys_clone(unsigned long clone_flags, unsigned long newsp,
-;		int __user *parent_tidptr, void *tls,
+; int sys_clone(unsigned long clone_flags,
+;		unsigned long newsp,
+;		int __user *parent_tidptr,
+;		void *tls,
 ;		int __user *child_tidptr)
 
+#define CLONE_VM		0x00000100
+#define CLONE_THREAD		0x00010000
+#define CLONE_THREAD_N_VM	(CLONE_THREAD | CLONE_VM)
 
 ENTRY(clone)
 	cmp	r0, 0		; @fn can't be NULL
 	cmp.ne	r1, 0		; @child_stack can't be NULL
 	bz	.L__sys_err
 
-	; @fn and @args needed after the syscall for child
-	; However r3 containing @arg will be clobbered BEFORE syscall
+	; save some of the orig args
 	; r0 containg @fn will be clobbered AFTER syscall (with ret val)
-	mov	r10, r0
-	mov	r11, r3
+	; rest are clobbered BEFORE syscall due to different arg ordering
+	mov	r10, r0		; @fn
+	mov	r11, r3		; @args
+	mov	r12, r2		; @clone_flags
 
 	; adjust libc args for syscall
+
 	mov 	r0, r2		; libc @flags is 1st syscall arg
 	mov	r2, r4		; libc @ptid
 	mov	r3, r5		; libc @tls
@@ -49,6 +56,21 @@ ENTRY(clone)
 	blt	.L__sys_err2	; < 0 (signed) error
 	jnz	[blink]		; Parent returns
 
+	; ----- child starts here ---------
+#ifdef RESET_PID
+	mov_s	r2, CLONE_THREAD_N_VM
+	and_s	r2, r2, r12
+	brne	r2, r12, .Lgo_thread
+
+	mov	r8, __NR_clone
+	ARC_TRAP_INSN		; r0 has PID
+	THREAD_SELF r1		; Get to struct pthread (just before TCB)
+	st	r0, [r1, PTHREAD_PID]
+	st	r0, [r1, PTHREAD_TID]
+
+.Lgo_thread:
+#endif
+
 	; child jumps off to @fn with @arg as argument, and returns here
 	jl.d	[r10]
 	mov	r0, r11
diff --git a/libc/sysdeps/linux/arc/jmpbuf-unwind.h b/libc/sysdeps/linux/arc/jmpbuf-unwind.h
index e4ed8fe75..8c41816c5 100644
--- a/libc/sysdeps/linux/arc/jmpbuf-unwind.h
+++ b/libc/sysdeps/linux/arc/jmpbuf-unwind.h
@@ -11,3 +11,20 @@
    containing a local variable at ADDRESS.  */
 #define _JMPBUF_UNWINDS(jmpbuf, address) \
   ((void *) (address) < (void *) (jmpbuf[__JMP_BUF_SP]))
+
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
+#include <stdint.h>
+#include <unwind.h>
+
+/* Test if longjmp to JMPBUF would unwind the frame
+   containing a local variable at ADDRESS.  */
+#undef _JMPBUF_UNWINDS
+#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
+  ((void *) (address) < (void *) demangle (jmpbuf[__JMP_BUF_SP]))
+
+#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
+  _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
+
+#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
+  ((uintptr_t) (_address) - (_adj) < (uintptr_t) (_jmpbuf)[__JMP_BUF_SP] - (_adj))
+#endif
diff --git a/libc/sysdeps/linux/arc/sysdep.h b/libc/sysdeps/linux/arc/sysdep.h
index 76d3788e5..d75d89100 100644
--- a/libc/sysdeps/linux/arc/sysdep.h
+++ b/libc/sysdeps/linux/arc/sysdep.h
@@ -19,4 +19,8 @@ nm:
 
 #include <common/sysdep.h>
 
+/* Pointer mangling is not yet supported  */
+#define PTR_MANGLE(var) (void) (var)
+#define PTR_DEMANGLE(var) (void) (var)
+
 #endif
diff --git a/libc/sysdeps/linux/arc/vfork.S b/libc/sysdeps/linux/arc/vfork.S
index 11959b66b..573a29f26 100644
--- a/libc/sysdeps/linux/arc/vfork.S
+++ b/libc/sysdeps/linux/arc/vfork.S
@@ -16,12 +16,25 @@
 #define CLONE_FLAGS_FOR_VFORK	(CLONE_VM|CLONE_VFORK|SIGCHLD)
 
 ENTRY(__vfork)
+#ifdef SAVE_PID
+	THREAD_SELF r1		; Get to struct pthread (just before TCB)
+	ld	r2, [r1, PTHREAD_PID]
+	neg.f	r3, r2
+	bset.z	r3, r3, 31
+	st	r3, [r1, PTHREAD_PID]
+#endif
 	mov	r0, CLONE_FLAGS_FOR_VFORK
 	mov_s	r1, sp
 	mov	r8, __NR_clone
 	ARC_TRAP_INSN
 
 	cmp	r0, 0
+#ifdef RESTORE_PID
+	bz	1f	; child continues
+	THREAD_SELF r1		; Get to struct pthread (just before TCB)
+	st	r2, [r1, PTHREAD_PID]
+1:
+#endif
 	jge	[blink]	; pid >=0 return, else detour via tailcall to errno
 
 	b   __syscall_error