[PATCH 3/8] SPU add getcwd support mainly via an assist call

[Patrick Mansfield <patmans at us dot ibm dot com>]

Add spu getcwd support, mainly via an assist call.

libgloss ChangeLog:

2007-06-18 Patrick Mansfield <patmans@us.ibm.com>

	* spu/jsre.h: Add JSRE_GETCWD.
	* spu/getcwd.c: New file, implement getcwd with help from an
	assist call.
	* spu/Makefile.in: Add getcwd.

Index: quilt/libgloss/spu/Makefile.in
===================================================================
--- quilt.orig/libgloss/spu/Makefile.in
+++ quilt/libgloss/spu/Makefile.in
@@ -56,7 +56,7 @@ OBJCOPY = `t='$(program_transform_name)'
 # object files needed
 OBJS = \
 	access.o chdir.o chmod.o chown.o close.o dup.o exit.o fchdir.o \
-	fchmod.o fchown.o fstat.o ftruncate.o getpagesize.o getpid.o \
+	fchmod.o fchown.o fstat.o ftruncate.o getcwd.o getpagesize.o getpid.o \
 	gettimeofday.o isatty.o kill.o lchown.o lseek.o mkdir.o \
 	mknod.o nanosleep.o open.o read.o rmdir.o sbrk.o stat.o syscalls.o \
 	unlink.o write.o
Index: quilt/libgloss/spu/getcwd.c
===================================================================
--- /dev/null
+++ quilt/libgloss/spu/getcwd.c
@@ -0,0 +1,109 @@
+/*
+  Copyright 2007
+  International Business Machines Corporation,
+  Sony Computer Entertainment, Incorporated,
+  Toshiba Corporation,
+
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+  notice, this list of conditions and the following disclaimer in the
+  documentation and/or other materials provided with the distribution.
+    * Neither the names of the copyright holders nor the names of their
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+  PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+  OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include "jsre.h"
+
+#define ALLOC_BASE  64
+#define ALLOC_INCR  64
+
+typedef struct
+{
+  unsigned int buf;
+  unsigned int pad0[3];
+  unsigned int size;
+  unsigned int pad1[3];
+} syscall_getcwd_t;
+
+char *
+getcwd (char *buf, size_t size)
+{
+  syscall_getcwd_t sys;
+  int retry_alloc, local_alloc;
+  char *newbuf;
+  char *res;
+
+  /*
+   * Do not let the ppu side allocate memory, since it has to be used on
+   * the SPU (must be in LS), and it can't easily be freed on the spu
+   * side. So check for NULL buf, handle allocations here, and only call
+   * the assist call with a non-NULL buf.
+   */
+  retry_alloc = 0;
+  local_alloc = 0;
+  if (!buf) {
+    local_alloc = 1;
+    if (size == 0) {
+      retry_alloc = 1;
+      size = ALLOC_BASE;
+    }
+    buf = malloc (size);
+    if (!buf) {
+      /*
+       * Leave errno as set by malloc.
+       */
+      return NULL;
+    }
+  }
+
+  /*
+   * Let the assist call check for error cases, specifically let it handle
+   * non-NULL buf and size of zero.
+   */
+
+  sys.buf = (unsigned int) buf;
+  sys.size = (unsigned int) size;
+  res = (char*) __send_to_ppe (JSRE_POSIX1_SIGNALCODE, JSRE_GETCWD, &sys);
+
+  while (!res && retry_alloc && errno == ERANGE) {
+    size += ALLOC_INCR;
+    newbuf = realloc (buf, size);
+    if (!newbuf) {
+      free (buf);
+      return NULL;
+    }
+    buf = newbuf;
+
+    sys.buf = (unsigned int) buf;
+    sys.size = (unsigned int) size;
+    res = (char*) __send_to_ppe (JSRE_POSIX1_SIGNALCODE, JSRE_GETCWD, &sys);
+  }
+
+  if (!res && local_alloc) {
+    free (buf);
+  }
+
+  return res;
+}
Index: quilt/libgloss/spu/jsre.h
===================================================================
--- quilt.orig/libgloss/spu/jsre.h
+++ quilt/libgloss/spu/jsre.h
@@ -62,6 +62,7 @@ Author: Andreas Neukoetter (ti95neuk@de.
 #define JSRE_CHOWN 40
 #define JSRE_FCHOWN 41
 #define JSRE_LCHOWN 42
+#define JSRE_GETCWD 43
 
 typedef struct {
     unsigned int dev;