xtensa: support call0 ABI

Most changes are mechanical replacement of 'retw' instruction with
'abi_ret' macro, defined to 'retw' or 'ret' according to ABI.
Assembly code that makes calls is duplicated for call0 ABI with changed
register numbers for parameters/return value and call instruction.
'entry' instructions are replaced with 'abi_entry' macro.

More interesting changes:
- non-leaf assembly functions (e.g. _dl_tlsdesc_dynamic,
  _dl_linux_resolve, SYSCALL_ERROR_HANDLER, PSEUDO) now need to preserve
  registers around intermediate calls they make, use temporary stack
  frame for that;
- setjmp/longjmp only need to save and restore return address, stack
  pointer and callee-saved registers in the jmpbuf;
- __clone and syscall functions had hardcoded offsets to parameter
  passed on stack, on call0 ABI they don't need stack frame, so the
  offset is different. Replace these offsets with FRAMESIZE macro.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

3 files changed, 68 insertions, 23 deletions

diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/xtensa/sysdep-cancel.h b/libpthread/nptl/sysdeps/unix/sysv/linux/xtensa/sysdep-cancel.h
index f82957d15..02fe27869 100644
--- a/libpthread/nptl/sysdeps/unix/sysv/linux/xtensa/sysdep-cancel.h
+++ b/libpthread/nptl/sysdeps/unix/sysv/linux/xtensa/sysdep-cancel.h
@@ -25,6 +25,7 @@
 
 #if !defined NOT_IN_libc || defined IS_IN_libpthread || defined IS_IN_librt
 
+#if defined(__XTENSA_WINDOWED_ABI__)
 /* CENABLE/CDISABLE in PSEUDO below use call8, stack frame size must be
  * at least 32.
  */
@@ -58,6 +59,64 @@
     j        SYSCALL_ERROR_LABEL;					      \
   .Lpseudo_end:
 
+# define CENABLE	movi    a8, CENABLE_FUNC;		\
+			callx8  a8
+# define CDISABLE	movi    a8, CDISABLE_FUNC;		\
+			callx8  a8
+#elif defined(__XTENSA_CALL0_ABI__)
+
+# undef PSEUDO
+# define PSEUDO(name, syscall_name, args)				      \
+  .text;								      \
+  ENTRY (name)								      \
+    SINGLE_THREAD_P(a10);						      \
+    bnez     a10, .Lpseudo_cancel;					      \
+    DO_CALL (syscall_name, args);					      \
+    bgez     a2, .Lpseudo_done;						      \
+    movi     a4, -4095;							      \
+    blt      a2, a4, .Lpseudo_done;					      \
+    j        SYSCALL_ERROR_LABEL;					      \
+  .Lpseudo_done:							      \
+    ret;								      \
+  .Lpseudo_cancel:							      \
+    addi     a1, a1, -32;						      \
+    /* The syscall args are in a2...a7; save them */			      \
+    s32i     a0, a1, 0;							      \
+    s32i     a2, a1, 4;							      \
+    s32i     a3, a1, 8;							      \
+    s32i     a4, a1, 12;						      \
+    s32i     a5, a1, 16;						      \
+    s32i     a6, a1, 20;						      \
+    s32i     a7, a1, 24;						      \
+    CENABLE;								      \
+    /* Move return value to a10 preserved across the syscall */		      \
+    mov      a10, a2;							      \
+    l32i     a2, a1, 4;							      \
+    l32i     a3, a1, 8;							      \
+    l32i     a4, a1, 12;						      \
+    l32i     a5, a1, 16;						      \
+    l32i     a6, a1, 20;						      \
+    l32i     a7, a1, 24;						      \
+    DO_CALL (syscall_name, args);					      \
+    s32i     a2, a1, 4;							      \
+    mov      a2, a10;							      \
+    CDISABLE;								      \
+    l32i     a2, a1, 4;							      \
+    l32i     a0, a1, 0;							      \
+    addi     a1, a1, 32;						      \
+    bgez     a2, .Lpseudo_end;                                                \
+    movi     a4, -4095;							      \
+    blt      a2, a4, .Lpseudo_end;                                            \
+    j        SYSCALL_ERROR_LABEL;					      \
+  .Lpseudo_end:
+
+# define CENABLE	movi    a0, CENABLE_FUNC;		\
+			callx0  a0
+# define CDISABLE	movi    a0, CDISABLE_FUNC;		\
+			callx0  a0
+#else
+#error Unsupported Xtensa ABI
+#endif
 
 # ifdef IS_IN_libpthread
 #  define CENABLE_FUNC	__pthread_enable_asynccancel
@@ -74,11 +133,6 @@
 #  error Unsupported library
 # endif
 
-# define CENABLE	movi    a8, CENABLE_FUNC;		\
-			callx8  a8
-# define CDISABLE	movi    a8, CDISABLE_FUNC;		\
-			callx8  a8
-
 # if defined IS_IN_libpthread || !defined NOT_IN_libc
 #  ifndef __ASSEMBLER__
 extern int __local_multiple_threads attribute_hidden;
diff --git a/libpthread/nptl/sysdeps/xtensa/pthread_spin_lock.S b/libpthread/nptl/sysdeps/xtensa/pthread_spin_lock.S
index 1e220a863..10b1c00f5 100644
--- a/libpthread/nptl/sysdeps/xtensa/pthread_spin_lock.S
+++ b/libpthread/nptl/sysdeps/xtensa/pthread_spin_lock.S
@@ -16,13 +16,10 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
-	.text
-	.align 4
-
-	.globl pthread_spin_lock
-pthread_spin_lock:
+#include <sysdep.h>
 
-	entry	a1, 16
+	.text
+ENTRY (pthread_spin_lock)
 
 	movi	a3, 0
 	wsr 	a3, scompare1
@@ -31,7 +28,6 @@ pthread_spin_lock:
 	bnez	a3, 1b
 	movi	a2, 0
 
-	retw
+	abi_ret
 
-	.type pthread_spin_lock, @function
-	.size pthread_spin_lock, .-pthread_spin_lock
+END (pthread_spin_lock)
diff --git a/libpthread/nptl/sysdeps/xtensa/pthread_spin_trylock.S b/libpthread/nptl/sysdeps/xtensa/pthread_spin_trylock.S
index a736b010f..4742bdb1c 100644
--- a/libpthread/nptl/sysdeps/xtensa/pthread_spin_trylock.S
+++ b/libpthread/nptl/sysdeps/xtensa/pthread_spin_trylock.S
@@ -18,14 +18,10 @@
 
 #define _ERRNO_H 1
 #include <bits/errno.h>
+#include <sysdep.h>
 
 	.text
-	.align 4
-
-	.globl pthread_spin_trylock
-pthread_spin_trylock:
-
-	entry	a1, 16
+ENTRY (pthread_spin_trylock)
 
 	movi	a3, 0
 	wsr 	a3, scompare1
@@ -34,7 +30,6 @@ pthread_spin_trylock:
 	movi	a2, EBUSY
 	moveqz	a2, a3, a3
 
-	retw
+	abi_ret
 
-	.type pthread_spin_trylock, @function
-	.size pthread_spin_trylock, .-pthread_spin_trylock
+END (pthread_spin_trylock)