1 files changed, 30 insertions, 9 deletions

diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index a2dc7f9ecc51..0f4095d7ac8b 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -2,7 +2,7 @@
  * arch/sh/mm/cache.c
  *
  * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
- * Copyright (C) 2002 - 2009  Paul Mundt
+ * Copyright (C) 2002 - 2010  Paul Mundt
  *
  * Released under the terms of the GNU GPL v2.0.
  */
@@ -27,8 +27,11 @@ void (*local_flush_icache_page)(void *args) = cache_noop;
 void (*local_flush_cache_sigtramp)(void *args) = cache_noop;
 
 void (*__flush_wback_region)(void *start, int size);
+EXPORT_SYMBOL(__flush_wback_region);
 void (*__flush_purge_region)(void *start, int size);
+EXPORT_SYMBOL(__flush_purge_region);
 void (*__flush_invalidate_region)(void *start, int size);
+EXPORT_SYMBOL(__flush_invalidate_region);
 
 static inline void noop__flush_region(void *start, int size)
 {
@@ -38,8 +41,17 @@ static inline void cacheop_on_each_cpu(void (*func) (void *info), void *info,
                                    int wait)
 {
         preempt_disable();
-        smp_call_function(func, info, wait);
+
+        /*
+         * It's possible that this gets called early on when IRQs are
+         * still disabled due to ioremapping by the boot CPU, so don't
+         * even attempt IPIs unless there are other CPUs online.
+         */
+        if (num_online_cpus() > 1)
+                smp_call_function(func, info, wait);
+
         func(info);
+
         preempt_enable();
 }
 
@@ -130,12 +142,8 @@ void __update_cache(struct vm_area_struct *vma,
         page = pfn_to_page(pfn);
         if (pfn_valid(pfn)) {
                 int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
-                if (dirty) {
-                        unsigned long addr = (unsigned long)page_address(page);
-
-                        if (pages_do_alias(addr, address & PAGE_MASK))
-                                __flush_purge_region((void *)addr, PAGE_SIZE);
-                }
+                if (dirty)
+                        __flush_purge_region(page_address(page), PAGE_SIZE);
         }
 }
 
@@ -161,14 +169,21 @@ void flush_cache_all(void)
 {
         cacheop_on_each_cpu(local_flush_cache_all, NULL, 1);
 }
+EXPORT_SYMBOL(flush_cache_all);
 
 void flush_cache_mm(struct mm_struct *mm)
 {
+        if (boot_cpu_data.dcache.n_aliases == 0)
+                return;
+
         cacheop_on_each_cpu(local_flush_cache_mm, mm, 1);
 }
 
 void flush_cache_dup_mm(struct mm_struct *mm)
 {
+        if (boot_cpu_data.dcache.n_aliases == 0)
+                return;
+
         cacheop_on_each_cpu(local_flush_cache_dup_mm, mm, 1);
 }
 
@@ -195,11 +210,13 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 
         cacheop_on_each_cpu(local_flush_cache_range, (void *)&data, 1);
 }
+EXPORT_SYMBOL(flush_cache_range);
 
 void flush_dcache_page(struct page *page)
 {
         cacheop_on_each_cpu(local_flush_dcache_page, page, 1);
 }
+EXPORT_SYMBOL(flush_dcache_page);
 
 void flush_icache_range(unsigned long start, unsigned long end)
 {
@@ -265,7 +282,11 @@ static void __init emit_cache_params(void)
 
 void __init cpu_cache_init(void)
 {
-        unsigned int cache_disabled = !(__raw_readl(CCR) & CCR_CACHE_ENABLE);
+        unsigned int cache_disabled = 0;
+
+#ifdef CCR
+        cache_disabled = !(__raw_readl(CCR) & CCR_CACHE_ENABLE);
+#endif
 
         compute_alias(&boot_cpu_data.icache);
         compute_alias(&boot_cpu_data.dcache);