Thread: [linuxsh-dev] cache-sh4.c

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OK, I've fixed cache-sh4.c.  The problem was confusion of virtual
address and physcall address.

Note that new flush_cache_range is quite slow for exec.  It's two to
four time slower than simple flush_cache_all implementation.

New flush_cache_range would be good if we want cache to have valid
data (avoid flushing), but it takes long time for SuperH to handle
cache.

2002-03-26  NIIBE Yutaka  <gn...@m1...>

	* arch/sh/mm/cache-sh4.c (flush_cache_mm): Don't check
	mm->context, it's for TLB handling.
	(flush_cache_range): Likewise.
	(flush_cache_mm): Fix the comment.  The alias issue is there
	for write-through cache too. 
	(flush_cache_range): Don't handle in P2.

2002-03-26  NIIBE Yutaka  <gn...@m1...>

	* arch/sh/mm/cache-sh4.c (flush_cache_range): Bug fix.
	Handle the case where PMD is none or bad.
	The argument to __flush_icache_page/__flush_dcache_page
	is physical address (was: virtual address).

Index: arch/sh/mm/cache-sh4.c
===================================================================
RCS file: /cvsroot/linuxsh/linux/arch/sh/mm/cache-sh4.c,v
retrieving revision 1.6
diff -u -3 -p -r1.6 cache-sh4.c

--- arch/sh/mm/cache-sh4.c	22 Mar 2002 12:57:10 -0000	1.6
+++ arch/sh/mm/cache-sh4.c	26 Mar 2002 05:43:03 -0000
@@ -298,15 +298,13 @@ void flush_cache_mm(struct mm_struct *mm
 	 * FIXME: Really, the optimal solution here would be able to flush out
 	 * individual lines created by the specified context, but this isn't
 	 * feasible for a number of architectures (such as MIPS, and some
-	 * SPARC) .. is this possible for SuperH? (This is a non-issue if the
-	 * SH4 cache is configured in write-through mode).
+	 * SPARC) .. is this possible for SuperH?
 	 *
-	 * In the meantime, we'll just flush all of the caches if we have a
-	 * valid mm context.. this seems to be the simplest way to avoid at
-	 * least a few wasted cache flushes. -Lethal
+	 * In the meantime, we'll just flush all of the caches.. this
+	 * seems to be the simplest way to avoid at least a few wasted
+	 * cache flushes. -Lethal
 	 */
-	if (mm->context != 0)
-		flush_cache_all();
+	flush_cache_all();
 }
 
 /*
@@ -324,35 +322,28 @@ void flush_cache_range(struct vm_area_st
 	unsigned long flags;
 	struct mm_struct *mm = vma->vm_mm;
 
-	if (mm->context == 0)
-		return;
-
 	start &= PAGE_MASK;
 
-	if (mm->context != current->active_mm->context) {
-		flush_cache_all();
-	} else {
-		pgd_t *pgd;
-		pmd_t *pmd;
+	save_and_cli(flags);
+	for (; start < end; start += PAGE_SIZE) {
+		pgd_t *pgd = pgd_offset(mm, start);
+		pmd_t *pmd = pmd_offset(pgd, start);
 		pte_t *pte;
+		unsigned long phys;
 
-		save_and_cli(flags);
-		jump_to_P2();
-
-		for (start; start < end; start += PAGE_SIZE) {
-			pgd = pgd_offset(mm, start);
-			pmd = pmd_offset(pgd, start);
-			pte = pte_offset_kernel(pmd, start);
-
-			if (pte_val(*pte) & _PAGE_PRESENT) {
-				__flush_icache_page(start);
-				__flush_dcache_page(start);
-			}
+		if (pmd_none(*pmd) || pmd_bad(*pmd)) {
+			start &= ~((1 << PMD_SHIFT) -1);
+			start += (1 << PMD_SHIFT);
+			continue;
+		}
+		pte = pte_offset_kernel(pmd, start);
+		phys = pte_val(*pte)&PTE_PHYS_MASK;
+		if (pte_val(*pte) & _PAGE_PRESENT) {
+			__flush_icache_page(phys);
+			__flush_dcache_page(phys);
 		}
-
-		back_to_P1();
-		restore_flags(flags);
 	}
+	restore_flags(flags);
 }
 
 /*


