From 27ef71dc2229797478a5969437c4e4421b87c708 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 23 Aug 2004 21:12:38 -0700 Subject: [PATCH] [PATCH] flexible-mmap for ppc64 From: Implement the new address space layout for 32-bit apps running on ppc64. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ppc64/mm/Makefile | 2 +- arch/ppc64/mm/mmap.c | 86 +++++++++++++++++++++++++++++++++++ include/asm-ppc64/processor.h | 2 + 3 files changed, 89 insertions(+), 1 deletion(-) create mode 100644 arch/ppc64/mm/mmap.c diff --git a/arch/ppc64/mm/Makefile b/arch/ppc64/mm/Makefile index 4e47f66faa0d1..d63dc4421f39a 100644 --- a/arch/ppc64/mm/Makefile +++ b/arch/ppc64/mm/Makefile @@ -5,6 +5,6 @@ EXTRA_CFLAGS += -mno-minimal-toc obj-y := fault.o init.o imalloc.o hash_utils.o hash_low.o tlb.o \ - slb_low.o slb.o stab.o + slb_low.o slb.o stab.o mmap.o obj-$(CONFIG_DISCONTIGMEM) += numa.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/ppc64/mm/mmap.c b/arch/ppc64/mm/mmap.c new file mode 100644 index 0000000000000..f90dd1f7ab569 --- /dev/null +++ b/arch/ppc64/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 + */ + +#include +#include + +/* + * 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->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->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; + } +} diff --git a/include/asm-ppc64/processor.h b/include/asm-ppc64/processor.h index 7f8884145ff1d..b8e80dfc96f30 100644 --- a/include/asm-ppc64/processor.h +++ b/include/asm-ppc64/processor.h @@ -628,6 +628,8 @@ static inline void prefetchw(const void *x) #endif /* ASSEMBLY */ +#define HAVE_ARCH_PICK_MMAP_LAYOUT + /* * Number of entries in the SLB. If this ever changes we should handle * it with a use a cpu feature fixup. -- 2.53.0