mm: Make generic weak get_user_pages_fast and EXPORT_GPL it

Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.

Export the symbol to modules so lguest can use it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2008-08-12 17:52:52 -05:00
parent 40c42076eb
commit 912985dce4
6 changed files with 16 additions and 29 deletions

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@ -42,9 +42,6 @@ config GENERIC_HARDIRQS
bool
default y
config HAVE_GET_USER_PAGES_FAST
def_bool PPC64
config HAVE_SETUP_PER_CPU_AREA
def_bool PPC64

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@ -22,7 +22,6 @@ config X86
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_IOREMAP_PROT
select HAVE_GET_USER_PAGES_FAST
select HAVE_KPROBES
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_KRETPROBES

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@ -1,7 +1,6 @@
obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
pat.o pgtable.o
pat.o pgtable.o gup.o
obj-$(CONFIG_HAVE_GET_USER_PAGES_FAST) += gup.o
obj-$(CONFIG_X86_32) += pgtable_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o

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@ -834,7 +834,6 @@ extern int mprotect_fixup(struct vm_area_struct *vma,
struct vm_area_struct **pprev, unsigned long start,
unsigned long end, unsigned long newflags);
#ifdef CONFIG_HAVE_GET_USER_PAGES_FAST
/*
* get_user_pages_fast provides equivalent functionality to get_user_pages,
* operating on current and current->mm (force=0 and doesn't return any vmas).
@ -848,25 +847,6 @@ extern int mprotect_fixup(struct vm_area_struct *vma,
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages);
#else
/*
* Should probably be moved to asm-generic, and architectures can include it if
* they don't implement their own get_user_pages_fast.
*/
#define get_user_pages_fast(start, nr_pages, write, pages) \
({ \
struct mm_struct *mm = current->mm; \
int ret; \
\
down_read(&mm->mmap_sem); \
ret = get_user_pages(current, mm, start, nr_pages, \
write, 0, pages, NULL); \
up_read(&mm->mmap_sem); \
\
ret; \
})
#endif
/*
* A callback you can register to apply pressure to ageable caches.
*

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@ -77,9 +77,6 @@ config FLAT_NODE_MEM_MAP
def_bool y
depends on !SPARSEMEM
config HAVE_GET_USER_PAGES_FAST
bool
#
# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
# to represent different areas of memory. This variable allows

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@ -171,3 +171,18 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
mm->unmap_area = arch_unmap_area;
}
#endif
int __attribute__((weak)) get_user_pages_fast(unsigned long start,
int nr_pages, int write, struct page **pages)
{
struct mm_struct *mm = current->mm;
int ret;
down_read(&mm->mmap_sem);
ret = get_user_pages(current, mm, start, nr_pages,
write, 0, pages, NULL);
up_read(&mm->mmap_sem);
return ret;
}
EXPORT_SYMBOL_GPL(get_user_pages_fast);