sh: Lazy dcache writeback optimizations.

This converts the lazy dcache handling to the model described in
Documentation/cachetlb.txt and drops the ptep_get_and_clear() hacks
used for the aliasing dcaches on SH-4 and SH7705 in 32kB mode. As a
bonus, this slightly cuts down on the cache flushing frequency.

With that and the PTEA handling out of the way, the update_mmu_cache()
implementations can be consolidated, and we no longer have to worry
about which configuration the cache is in for the SH7705 case.

And finally, explicitly disable the lazy writeback on SMP (SH-4A).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

4 files changed, 3 insertions, 19 deletions

diff --git a/include/asm-sh/cacheflush.h b/include/asm-sh/cacheflush.h
index 07f62ec9ff0..22f12634975 100644
--- a/include/asm-sh/cacheflush.h
+++ b/include/asm-sh/cacheflush.h
@@ -30,5 +30,8 @@ extern void __flush_invalidate_region(void *start, int size);
 
 #define HAVE_ARCH_UNMAPPED_AREA
 
+/* Page flag for lazy dcache write-back for the aliasing UP caches */
+#define PG_dcache_dirty	PG_arch_1
+
 #endif /* __KERNEL__ */
 #endif /* __ASM_SH_CACHEFLUSH_H */
diff --git a/include/asm-sh/cpu-sh3/cacheflush.h b/include/asm-sh/cpu-sh3/cacheflush.h
index f70d8ef76a1..6fabbba228d 100644
--- a/include/asm-sh/cpu-sh3/cacheflush.h
+++ b/include/asm-sh/cpu-sh3/cacheflush.h
@@ -36,8 +36,6 @@
  /* 32KB cache, 4kb PAGE sizes need to check bit 12 */
 #define CACHE_ALIAS 0x00001000
 
-#define PG_mapped	PG_arch_1
-
 void flush_cache_all(void);
 void flush_cache_mm(struct mm_struct *mm);
 #define flush_cache_dup_mm(mm) flush_cache_mm(mm)
diff --git a/include/asm-sh/cpu-sh4/cacheflush.h b/include/asm-sh/cpu-sh4/cacheflush.h
index b01a10f3122..f563c3bccc4 100644
--- a/include/asm-sh/cpu-sh4/cacheflush.h
+++ b/include/asm-sh/cpu-sh4/cacheflush.h
@@ -38,16 +38,4 @@ void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 /* Initialization of P3 area for copy_user_page */
 void p3_cache_init(void);
 
-#define PG_mapped	PG_arch_1
-
-#ifdef CONFIG_MMU
-extern int remap_area_pages(unsigned long addr, unsigned long phys_addr,
-			    unsigned long size, unsigned long flags);
-#else /* CONFIG_MMU */
-static inline int remap_area_pages(unsigned long addr, unsigned long phys_addr,
-				   unsigned long size, unsigned long flags)
-{
-	return 0;
-}
-#endif /* CONFIG_MMU */
 #endif /* __ASM_CPU_SH4_CACHEFLUSH_H */
diff --git a/include/asm-sh/pgtable.h b/include/asm-sh/pgtable.h
index eba14184baf..3721a4412ce 100644
--- a/include/asm-sh/pgtable.h
+++ b/include/asm-sh/pgtable.h
@@ -583,11 +583,6 @@ struct mm_struct;
 extern unsigned int kobjsize(const void *objp);
 #endif /* !CONFIG_MMU */
 
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
-#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
-extern pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
-#endif
-
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern void paging_init(void);