[MIPS] Do not use drop_mmu_context to flusing other task's VIPT I-cache.
c-r4k.c and c-sb1.c use drop_mmu_context() to flush virtually tagged
I-caches, but this does not work for flushing other task's icache. This
is for example triggered by copy_to_user_page() called from ptrace(2).
Use indexed flush for such cases.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/c-sb1.c b/arch/mips/mm/c-sb1.c
index 4bd9ad8..16bad7c 100644
--- a/arch/mips/mm/c-sb1.c
+++ b/arch/mips/mm/c-sb1.c
@@ -155,6 +155,26 @@
}
/*
+ * Invalidate a range of the icache. The addresses are virtual, and
+ * the cache is virtually indexed and tagged. However, we don't
+ * necessarily have the right ASID context, so use index ops instead
+ * of hit ops.
+ */
+static inline void __sb1_flush_icache_range(unsigned long start,
+ unsigned long end)
+{
+ start &= ~(icache_line_size - 1);
+ end = (end + icache_line_size - 1) & ~(icache_line_size - 1);
+
+ while (start != end) {
+ cache_set_op(Index_Invalidate_I, start & icache_index_mask);
+ start += icache_line_size;
+ }
+ mispredict();
+ sync();
+}
+
+/*
* Flush the icache for a given physical page. Need to writeback the
* dcache first, then invalidate the icache. If the page isn't
* executable, nothing is required.
@@ -173,8 +193,11 @@
/*
* Bumping the ASID is probably cheaper than the flush ...
*/
- if (cpu_context(cpu, vma->vm_mm) != 0)
- drop_mmu_context(vma->vm_mm, cpu);
+ if (vma->vm_mm == current->active_mm) {
+ if (cpu_context(cpu, vma->vm_mm) != 0)
+ drop_mmu_context(vma->vm_mm, cpu);
+ } else
+ __sb1_flush_icache_range(addr, addr + PAGE_SIZE);
}
#ifdef CONFIG_SMP
@@ -210,26 +233,6 @@
__attribute__((alias("local_sb1_flush_cache_page")));
#endif
-/*
- * Invalidate a range of the icache. The addresses are virtual, and
- * the cache is virtually indexed and tagged. However, we don't
- * necessarily have the right ASID context, so use index ops instead
- * of hit ops.
- */
-static inline void __sb1_flush_icache_range(unsigned long start,
- unsigned long end)
-{
- start &= ~(icache_line_size - 1);
- end = (end + icache_line_size - 1) & ~(icache_line_size - 1);
-
- while (start != end) {
- cache_set_op(Index_Invalidate_I, start & icache_index_mask);
- start += icache_line_size;
- }
- mispredict();
- sync();
-}
-
/*
* Invalidate all caches on this CPU
@@ -326,9 +329,12 @@
* If there's a context, bump the ASID (cheaper than a flush,
* since we don't know VAs!)
*/
- if (cpu_context(cpu, vma->vm_mm) != 0) {
- drop_mmu_context(vma->vm_mm, cpu);
- }
+ if (vma->vm_mm == current->active_mm) {
+ if (cpu_context(cpu, vma->vm_mm) != 0)
+ drop_mmu_context(vma->vm_mm, cpu);
+ } else
+ __sb1_flush_icache_range(start, start + PAGE_SIZE);
+
}
#ifdef CONFIG_SMP