mmap64 implementation for Linux/CRIS.

sysdeps/unix/sysv/linux/cris/mmap64.S

@@ -0,0 +1,91 @@
+/* Copyright (C) 2001 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+
+#include "kernel-features.h"
+
+#include <asm/errno.h>
+
+/* Rather than dragging in yet another kernel file, <asm/page.h>, we
+   define it here.  Provide for easy override.  */
+#ifndef PAGE_SHIFT
+#define PAGE_SHIFT 13
+#endif
+
+/* This is: __ptr_t
+   __mmap64 (__ptr_t addr, size_t len, int prot, int flags, int fd,
+	     off64_t offset);  */
+
+/* This was done in C, but the resulting code didn't look anywhere near
+   nice, and mmap64 is important enough to have fast code.  Rather than
+   fixing (the generic bits in) gcc, we make sure not to depend on it by
+   writing code that GCC cannot reasonably generate.  */
+
+	.syntax no_register_prefix
+
+ENTRY	(__mmap64)
+
+	move	[sp],mof
+	move.d	[sp+4],r9
+	
+	/* Only accept an offset being a multiple of PAGE_SIZE, ditto address.  */
+	btstq	(PAGE_SHIFT - 1),r9
+	bne	1f
+	lsrq	PAGE_SHIFT,r9
+
+	btstq	(PAGE_SHIFT - 1),r10
+	bne	1f
+	move.d	r9,[sp]
+
+	/* We have to store the adjusted part somewhere we can "or" from.
+	   No registers available, so let's re-use the incoming low-part
+	   parameter location.  */
+	move.d	[sp+8],r9
+
+	swapwbr	r9
+	/* Check if the highest bits (now the lowest bits) are zero.  They
+	   must be, since we're actually calling a system function
+	   specifying the size in *pages* in a single dword.  Thus you can
+	   mmap64 PAGE_SIZE * 4 Gbyte.  */
+	btstq	(PAGE_SHIFT - 1),r9
+	bne	1f
+	swapwbr	r9
+
+	lslq	(32 - PAGE_SHIFT),r9
+	or.d	[sp],r9
+	move	srp,[sp]
+	move	r9,srp
+
+	movu.b	SYS_ify (mmap2),r9
+	break	13
+
+	cmps.w	-4096,r10
+	bhs	0f
+	move	[sp],srp
+
+	Ret
+	nop
+
+/* Local error handler.  */
+1:
+	movs.w -EINVAL,r10
+	/* Drop through into the ordinary error handler.  */
+PSEUDO_END (__mmap64)
+
+weak_alias (__mmap64, mmap64)