highmem.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * highmem.h: virtual kernel memory mappings for high memory
 *
 * Used in CONFIG_HIGHMEM systems for memory pages which
 * are not addressable by direct kernel virtual addresses.
 *
 * Copyright (C) 2025 Loongson Technology Corporation Limited
 */
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H

#ifdef __KERNEL__

#include <asm/kmap_size.h>

#ifndef __ASSEMBLER__

extern pte_t *pkmap_page_table;

#define ARCH_HAS_KMAP_FLUSH_TLB
void kmap_flush_tlb(unsigned long addr);

#endif /* !__ASSEMBLER__ */

/*
 * Right now we initialize only a single pte table. It can be extended
 * easily, subsequent pte tables have to be allocated in one physical
 * chunk of RAM.
 */
#define LAST_PKMAP 1024
#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
#define PKMAP_NR(virt)	((virt - PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))

#define flush_cache_kmaps() do {} while (0)

#define arch_kmap_local_post_map(vaddr, pteval)	local_flush_tlb_one(vaddr)
#define arch_kmap_local_post_unmap(vaddr)	local_flush_tlb_one(vaddr)

#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */