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authorPaul Mackerras <paulus@samba.org>2005-10-10 21:58:35 +1000
committerPaul Mackerras <paulus@samba.org>2005-10-10 21:58:35 +1000
commitab1f9dac6eea25ee59e4c8e1cf0b7476afbbfe07 (patch)
tree03577652197b5e58c348ede3c474bc8dd47e046c /arch/powerpc/mm/mmap.c
parent70d64ceaa1a84d2502405422a4dfd3f87786a347 (diff)
powerpc: Merge arch/ppc64/mm to arch/powerpc/mm
This moves the remaining files in arch/ppc64/mm to arch/powerpc/mm, and arranges that we use them when compiling with ARCH=ppc64. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/mm/mmap.c')
-rw-r--r--arch/powerpc/mm/mmap.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
new file mode 100644
index 000000000000..fe65f522aff3
--- /dev/null
+++ b/arch/powerpc/mm/mmap.c
@@ -0,0 +1,86 @@
+/*
+ * linux/arch/ppc64/mm/mmap.c
+ *
+ * flexible mmap layout support
+ *
+ * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * Started by Ingo Molnar <mingo@elte.hu>
+ */
+
+#include <linux/personality.h>
+#include <linux/mm.h>
+
+/*
+ * Top of mmap area (just below the process stack).
+ *
+ * Leave an at least ~128 MB hole.
+ */
+#define MIN_GAP (128*1024*1024)
+#define MAX_GAP (TASK_SIZE/6*5)
+
+static inline unsigned long mmap_base(void)
+{
+ unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+
+ if (gap < MIN_GAP)
+ gap = MIN_GAP;
+ else if (gap > MAX_GAP)
+ gap = MAX_GAP;
+
+ return TASK_SIZE - (gap & PAGE_MASK);
+}
+
+static inline int mmap_is_legacy(void)
+{
+ /*
+ * Force standard allocation for 64 bit programs.
+ */
+ if (!test_thread_flag(TIF_32BIT))
+ return 1;
+
+ if (current->personality & ADDR_COMPAT_LAYOUT)
+ return 1;
+
+ if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
+ return 1;
+
+ return sysctl_legacy_va_layout;
+}
+
+/*
+ * This function, called very early during the creation of a new
+ * process VM image, sets up which VM layout function to use:
+ */
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+ /*
+ * Fall back to the standard layout if the personality
+ * bit is set, or if the expected stack growth is unlimited:
+ */
+ if (mmap_is_legacy()) {
+ mm->mmap_base = TASK_UNMAPPED_BASE;
+ mm->get_unmapped_area = arch_get_unmapped_area;
+ mm->unmap_area = arch_unmap_area;
+ } else {
+ mm->mmap_base = mmap_base();
+ mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+ mm->unmap_area = arch_unmap_area_topdown;
+ }
+}