1 files changed, 48 insertions, 0 deletions
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
new file mode 100644
index 000000000..4284cd59e
--- /dev/null
+++ b/arch/nds32/mm/highmem.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/export.h>
+#include <linux/highmem.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/memblock.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+{
+	unsigned int idx;
+	unsigned long vaddr, pte;
+	int type;
+	pte_t *ptep;
+
+	type = kmap_atomic_idx_push();
+
+	idx = type + KM_TYPE_NR * smp_processor_id();
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+	pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
+	ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+	set_pte(ptep, pte);
+
+	__nds32__tlbop_inv(vaddr);
+	__nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
+	__nds32__tlbop_rwr(pte);
+	__nds32__isb();
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_high_prot);
+
+void kunmap_atomic_high(void *kvaddr)
+{
+	if (kvaddr >= (void *)FIXADDR_START) {
+		unsigned long vaddr = (unsigned long)kvaddr;
+		pte_t *ptep;
+		kmap_atomic_idx_pop();
+		__nds32__tlbop_inv(vaddr);
+		__nds32__isb();
+		ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
+		set_pte(ptep, 0);
+	}
+}
+EXPORT_SYMBOL(kunmap_atomic_high);