1 files changed, 65 insertions, 0 deletions
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
new file mode 100644
index 000000000..73fd7cc99
--- /dev/null
+++ b/arch/sh/mm/kmap.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/sh/mm/kmap.c
+ *
+ * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
+ * Copyright (C) 2002 - 2009  Paul Mundt
+ */
+#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>
+
+static pte_t *kmap_coherent_pte;
+
+void __init kmap_coherent_init(void)
+{
+	unsigned long vaddr;
+
+	/* cache the first coherent kmap pte */
+	vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
+	kmap_coherent_pte = virt_to_kpte(vaddr);
+}
+
+void *kmap_coherent(struct page *page, unsigned long addr)
+{
+	enum fixed_addresses idx;
+	unsigned long vaddr;
+
+	BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
+
+	preempt_disable();
+	pagefault_disable();
+
+	idx = FIX_CMAP_END -
+		(((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)));
+	set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
+
+	return (void *)vaddr;
+}
+
+void kunmap_coherent(void *kvaddr)
+{
+	if (kvaddr >= (void *)FIXADDR_START) {
+		unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
+		enum fixed_addresses idx = __virt_to_fix(vaddr);
+
+		/* XXX.. Kill this later, here for sanity at the moment.. */
+		__flush_purge_region((void *)vaddr, PAGE_SIZE);
+
+		pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
+		local_flush_tlb_one(get_asid(), vaddr);
+	}
+
+	pagefault_enable();
+	preempt_enable();
+}