parisc: Improve dcache flush on PA8800/PA8900

Commit Message

James Bottomley Feb. 10, 2011, 4:03 p.m. UTC

None

Patch

diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 3f11331..c60cc42 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -276,10 +276,13 @@  __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
 void flush_dcache_page(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
-	struct vm_area_struct *mpnt;
+	struct vm_area_struct *mpnt = NULL;
 	struct prio_tree_iter iter;
 	unsigned long offset;
-	unsigned long addr, old_addr = 0;
+	unsigned long addr = 0;
+#ifdef DEBUG_ALIASES
+	unsigned long old_addr = 0;
+#endif
 	pgoff_t pgoff;
 
 	if (mapping && !mapping_mapped(mapping)) {
@@ -304,14 +307,25 @@  void flush_dcache_page(struct page *page)
 		offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
 		addr = mpnt->vm_start + offset;
 
+#ifdef DEBUG_ALIASES
 		if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
 			__flush_cache_page(mpnt, addr, page_to_phys(page));
 			if (old_addr)
 				printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
 			old_addr = addr;
 		}
+#else
+		break;
+#endif
 	}
 	flush_dcache_mmap_unlock(mapping);
+#ifndef DEBUG_ALIASES
+	/* since we have only one page, flush outside the lock.  If the loop
+	 * didn't happen (no mappings), mpnt will be NULL */
+	if (mpnt)
+		__flush_cache_page(mpnt, addr, page_to_phys(page));
+#endif
+
 }
 EXPORT_SYMBOL(flush_dcache_page);