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>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 63c9caf..587da5e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -42,9 +42,6 @@
bool
default y
-config HAVE_GET_USER_PAGES_FAST
- def_bool PPC64
-
config HAVE_SETUP_PER_CPU_AREA
def_bool PPC64
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3d0f2b6..ac2fb06 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -22,7 +22,6 @@
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
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 2977ea3..dfb932d 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -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
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 335288bf..fa65160 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -834,7 +834,6 @@
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 @@
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.
*
diff --git a/mm/Kconfig b/mm/Kconfig
index 446c658..0bd9c2d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -77,9 +77,6 @@
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
diff --git a/mm/util.c b/mm/util.c
index 9341ca7..cb00b74 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -171,3 +171,18 @@
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);