sparc64: refactor code in init_64.c

The sparc64 allmodconfig build broke due to enabling of the
branch_tracer that does some very clever things with
all if conditions. This caused my gcc 3.4.5 to be so confused that
it emitted two warnings:

arch/sparc/mm/init_64.c: In function `update_mmu_cache':
arch/sparc/mm/init_64.c:271: warning: 'pg_flags' might be used uninitialized in this function
arch/sparc/mm/init_64.c:272: warning: 'page' might be used uninitialized in this function

And with -Werror this broke the build.

Refactor code so it:
1) becomes more readable
2) no longer emit a warning with the branch_tracer enabled

The refactoring uses a small helper function (flush_dcache()).

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 11 deletions

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 6ea73da29312..6ffc7e911d50 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -258,21 +258,16 @@ static inline void tsb_insert(struct tsb *ent, unsigned long tag, unsigned long
 unsigned long _PAGE_ALL_SZ_BITS __read_mostly;
 unsigned long _PAGE_SZBITS __read_mostly;
 
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
+static void flush_dcache(unsigned long pfn)
 {
-        struct mm_struct *mm;
-        struct tsb *tsb;
-        unsigned long tag, flags;
-        unsigned long tsb_index, tsb_hash_shift;
+        struct page *page;
 
-        if (tlb_type != hypervisor) {
-                unsigned long pfn = pte_pfn(pte);
+        page = pfn_to_page(pfn);
+        if (page && page_mapping(page)) {
                 unsigned long pg_flags;
-                struct page *page;
 
-                if (pfn_valid(pfn) &&
-                    (page = pfn_to_page(pfn), page_mapping(page)) &&
-                    ((pg_flags = page->flags) & (1UL << PG_dcache_dirty))) {
+                pg_flags = page->flags;
+                if (pg_flags & (1UL << PG_dcache_dirty)) {
                         int cpu = ((pg_flags >> PG_dcache_cpu_shift) &
                                    PG_dcache_cpu_mask);
                         int this_cpu = get_cpu();
@@ -290,6 +285,21 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t p
                         put_cpu();
                 }
         }
+}
+
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
+{
+        struct mm_struct *mm;
+        struct tsb *tsb;
+        unsigned long tag, flags;
+        unsigned long tsb_index, tsb_hash_shift;
+
+        if (tlb_type != hypervisor) {
+                unsigned long pfn = pte_pfn(pte);
+
+                if (pfn_valid(pfn))
+                        flush_dcache(pfn);
+        }
 
         mm = vma->vm_mm;