m68k: mm: Unify Motorola MMU page setup
Seeing how there are 5 copies of this magic code, one of which is
unexplainably different, unify and document things.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200131125403.597688427@infradead.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 4857985..be61f35 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -45,6 +45,28 @@ unsigned long mm_cachebits;
EXPORT_SYMBOL(mm_cachebits);
#endif
+
+/*
+ * Motorola 680x0 user's manual recommends using uncached memory for address
+ * translation tables.
+ *
+ * Seeing how the MMU can be external on (some of) these chips, that seems like
+ * a very important recommendation to follow. Provide some helpers to combat
+ * 'variation' amongst the users of this.
+ */
+
+void mmu_page_ctor(void *page)
+{
+ __flush_page_to_ram(page);
+ flush_tlb_kernel_page(page);
+ nocache_page(page);
+}
+
+void mmu_page_dtor(void *page)
+{
+ cache_page(page);
+}
+
/* size of memory already mapped in head.S */
extern __initdata unsigned long m68k_init_mapped_size;
@@ -60,9 +82,7 @@ static pte_t * __init kernel_page_table(void)
__func__, PAGE_SIZE, PAGE_SIZE);
clear_page(ptablep);
- __flush_page_to_ram(ptablep);
- flush_tlb_kernel_page(ptablep);
- nocache_page(ptablep);
+ mmu_page_ctor(ptablep);
return ptablep;
}
@@ -106,9 +126,7 @@ static pmd_t * __init kernel_ptr_table(void)
__func__, PAGE_SIZE, PAGE_SIZE);
clear_page(last_pgtable);
- __flush_page_to_ram(last_pgtable);
- flush_tlb_kernel_page(last_pgtable);
- nocache_page(last_pgtable);
+ mmu_page_ctor(last_pgtable);
}
return last_pgtable;
