sh: Provide the kmap_coherent() interface generically.
This plugs in kmap_coherent() for the non-SH4 cases to permit the
pg-mmu.c bits to be used generically across all CPUs. SH-5 is still in
the TODO state, but will move over to fixmap and the generic interface
gradually.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
new file mode 100644
index 0000000..3eecf0d
--- /dev/null
+++ b/arch/sh/mm/kmap.c
@@ -0,0 +1,64 @@
+/*
+ * arch/sh/mm/kmap.c
+ *
+ * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
+ * Copyright (C) 2002 - 2009 Paul Mundt
+ *
+ * Released under the terms of the GNU GPL v2.0.
+ */
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+
+#define kmap_get_fixmap_pte(vaddr) \
+ pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
+
+static pte_t *kmap_coherent_pte;
+
+void __init kmap_coherent_init(void)
+{
+ unsigned long vaddr;
+
+ if (!boot_cpu_data.dcache.n_aliases)
+ return;
+
+ /* cache the first coherent kmap pte */
+ vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
+ kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
+}
+
+void *kmap_coherent(struct page *page, unsigned long addr)
+{
+ enum fixed_addresses idx;
+ unsigned long vaddr, flags;
+ pte_t pte;
+
+ BUG_ON(test_bit(PG_dcache_dirty, &page->flags));
+
+ inc_preempt_count();
+
+ idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
+ vaddr = __fix_to_virt(FIX_CMAP_END - idx);
+ pte = mk_pte(page, PAGE_KERNEL);
+
+ local_irq_save(flags);
+ flush_tlb_one(get_asid(), vaddr);
+ local_irq_restore(flags);
+
+ update_mmu_cache(NULL, vaddr, pte);
+
+ set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
+
+ return (void *)vaddr;
+}
+
+void kunmap_coherent(void)
+{
+ dec_preempt_count();
+ preempt_check_resched();
+}