sh: Factor in cpu id for selection of cache colour fixmap.

In the SMP VIPT case the page copy/clear ops still perform colouring,
care needs to be taken that CPUs don't end up stepping on each other,
so we give them a bit of room to work with.

At the same time, we reduce the worst-case colouring given that these
pages are always consumed.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/fixmap.h

@@ -14,9 +14,9 @@
 #define _ASM_FIXMAP_H
 
 #include <linux/kernel.h>
+#include <linux/threads.h>
 #include <asm/page.h>
 #ifdef CONFIG_HIGHMEM
-#include <linux/threads.h>
 #include <asm/kmap_types.h>
 #endif
 
@@ -46,9 +46,9 @@
  * fix-mapped?
  */
 enum fixed_addresses {
-#define FIX_N_COLOURS 16
+#define FIX_N_COLOURS 8
 	FIX_CMAP_BEGIN,
-	FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,
+	FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS),
 	FIX_UNCACHED,
 #ifdef CONFIG_HIGHMEM
 	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */

arch/sh/mm/kmap.c

@@ -39,7 +39,9 @@ void *kmap_coherent(struct page *page, unsigned long addr)
 	pagefault_disable();
 
 	idx = FIX_CMAP_END -
-		((addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT);
+		(((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
+		 (FIX_N_COLOURS * smp_processor_id()));
+
 	vaddr = __fix_to_virt(idx);
 
 	BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));