ARC: lazy dcache flush broke gdb in non-aliasing configs

gdbserver inserting a breakpoint ends up calling copy_user_page() for a
code page. The generic version of which (non-aliasing config) didn't set
the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for
corresponding dynamic loader code page - causing garbade to be executed.

So now aliasing versions of copy_user_highpage()/clear_page() are made
default. There is no significant overhead since all of special alias
handling code is compiled out for non-aliasing build

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/page.h

@@ -19,13 +19,6 @@
 #define clear_page(paddr)		memset((paddr), 0, PAGE_SIZE)
 #define copy_page(to, from)		memcpy((to), (from), PAGE_SIZE)
 
-#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING
-
-#define clear_user_page(addr, vaddr, pg)	clear_page(addr)
-#define copy_user_page(vto, vfrom, vaddr, pg)	copy_page(vto, vfrom)
-
-#else	/* VIPT aliasing dcache */
-
 struct vm_area_struct;
 struct page;
 
@@ -35,8 +28,6 @@ void copy_user_highpage(struct page *to, struct page *from,
 			unsigned long u_vaddr, struct vm_area_struct *vma);
 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page);
 
-#endif	/* CONFIG_ARC_CACHE_VIPT_ALIASING */
-
 #undef STRICT_MM_TYPECHECKS
 
 #ifdef STRICT_MM_TYPECHECKS

arch/arc/mm/cache_arc700.c

@@ -676,6 +676,17 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 	flush_cache_all();
 }
 
+void flush_anon_page(struct vm_area_struct *vma, struct page *page,
+		     unsigned long u_vaddr)
+{
+	/* TBD: do we really need to clear the kernel mapping */
+	__flush_dcache_page(page_address(page), u_vaddr);
+	__flush_dcache_page(page_address(page), page_address(page));
+
+}
+
+#endif
+
 void copy_user_highpage(struct page *to, struct page *from,
 	unsigned long u_vaddr, struct vm_area_struct *vma)
 {
@@ -725,16 +736,6 @@ void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
 	set_bit(PG_arch_1, &page->flags);
 }
 
-void flush_anon_page(struct vm_area_struct *vma, struct page *page,
-		     unsigned long u_vaddr)
-{
-	/* TBD: do we really need to clear the kernel mapping */
-	__flush_dcache_page(page_address(page), u_vaddr);
-	__flush_dcache_page(page_address(page), page_address(page));
-
-}
-
-#endif
 
 /**********************************************************************
  * Explicit Cache flush request from user space via syscall