s390/mm: convert to the generic get_user_pages_fast code

Define the gup_fast_permitted to check against the asce_limit of the mm attached to the current task, then replace the s390 specific gup code with the generic implementation in mm/gup.c. Signed-off-by: Martin Schwidefsky <[email protected]>
torvalds · Apr 23, 2019 · 1a42010 · 1a42010
1 parent d1874a0
commit 1a42010
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Showing 4 changed files with 14 additions and 292 deletions.
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
@@ -149,6 +149,7 @@ config S390
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_GCC_PLUGINS
+	select HAVE_GENERIC_GUP
 	select HAVE_KERNEL_BZIP2
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZ4

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
@@ -1265,6 +1265,18 @@ static inline pte_t *pte_offset(pmd_t *pmd, unsigned long address)
 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
 #define pte_unmap(pte) do { } while (0)
 
+static inline bool gup_fast_permitted(unsigned long start, int nr_pages)
+{
+	unsigned long len, end;
+
+	len = (unsigned long) nr_pages << PAGE_SHIFT;
+	end = start + len;
+	if (end < start)
+		return false;
+	return end <= current->mm->context.asce_limit;
+}
+#define gup_fast_permitted gup_fast_permitted
+
 #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot))
 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
 #define pte_page(x) pfn_to_page(pte_pfn(x))

diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
@@ -4,7 +4,7 @@
 #
 
 obj-y		:= init.o fault.o extmem.o mmap.o vmem.o maccess.o
-obj-y		+= page-states.o gup.o pageattr.o pgtable.o pgalloc.o
+obj-y		+= page-states.o pageattr.o pgtable.o pgalloc.o
 
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o

diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c