1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
22f2f371fSMichal Simek /*
32f2f371fSMichal Simek  * highmem.h: virtual kernel memory mappings for high memory
42f2f371fSMichal Simek  *
52f2f371fSMichal Simek  * Used in CONFIG_HIGHMEM systems for memory pages which
62f2f371fSMichal Simek  * are not addressable by direct kernel virtual addresses.
72f2f371fSMichal Simek  *
82f2f371fSMichal Simek  * Copyright (C) 1999 Gerhard Wichert, Siemens AG
92f2f371fSMichal Simek  *		      Gerhard.Wichert@pdb.siemens.de
102f2f371fSMichal Simek  *
112f2f371fSMichal Simek  *
122f2f371fSMichal Simek  * Redesigned the x86 32-bit VM architecture to deal with
132f2f371fSMichal Simek  * up to 16 Terabyte physical memory. With current x86 CPUs
142f2f371fSMichal Simek  * we now support up to 64 Gigabytes physical RAM.
152f2f371fSMichal Simek  *
162f2f371fSMichal Simek  * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
172f2f371fSMichal Simek  */
182f2f371fSMichal Simek #ifndef _ASM_HIGHMEM_H
192f2f371fSMichal Simek #define _ASM_HIGHMEM_H
202f2f371fSMichal Simek 
212f2f371fSMichal Simek #ifdef __KERNEL__
222f2f371fSMichal Simek 
232f2f371fSMichal Simek #include <linux/init.h>
242f2f371fSMichal Simek #include <linux/interrupt.h>
252f2f371fSMichal Simek #include <linux/uaccess.h>
262f2f371fSMichal Simek #include <asm/fixmap.h>
272f2f371fSMichal Simek 
282f2f371fSMichal Simek extern pte_t *pkmap_page_table;
292f2f371fSMichal Simek 
302f2f371fSMichal Simek /*
312f2f371fSMichal Simek  * Right now we initialize only a single pte table. It can be extended
322f2f371fSMichal Simek  * easily, subsequent pte tables have to be allocated in one physical
332f2f371fSMichal Simek  * chunk of RAM.
342f2f371fSMichal Simek  */
352f2f371fSMichal Simek /*
362f2f371fSMichal Simek  * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
372f2f371fSMichal Simek  * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
382f2f371fSMichal Simek  * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
392f2f371fSMichal Simek  * in case of 16K/64K/256K page sizes.
402f2f371fSMichal Simek  */
412f2f371fSMichal Simek 
422f2f371fSMichal Simek #define PKMAP_ORDER	PTE_SHIFT
432f2f371fSMichal Simek #define LAST_PKMAP	(1 << PKMAP_ORDER)
442f2f371fSMichal Simek 
452f2f371fSMichal Simek #define PKMAP_BASE	((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
462f2f371fSMichal Simek 								& PMD_MASK)
472f2f371fSMichal Simek 
482f2f371fSMichal Simek #define LAST_PKMAP_MASK	(LAST_PKMAP - 1)
492f2f371fSMichal Simek #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
502f2f371fSMichal Simek #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
512f2f371fSMichal Simek 
522f2f371fSMichal Simek #define flush_cache_kmaps()	{ flush_icache(); flush_dcache(); }
532f2f371fSMichal Simek 
54*7ac1b26bSThomas Gleixner #define arch_kmap_local_post_map(vaddr, pteval)	\
55*7ac1b26bSThomas Gleixner 	local_flush_tlb_page(NULL, vaddr);
56*7ac1b26bSThomas Gleixner #define arch_kmap_local_post_unmap(vaddr)	\
57*7ac1b26bSThomas Gleixner 	local_flush_tlb_page(NULL, vaddr);
58*7ac1b26bSThomas Gleixner 
592f2f371fSMichal Simek #endif /* __KERNEL__ */
602f2f371fSMichal Simek 
612f2f371fSMichal Simek #endif /* _ASM_HIGHMEM_H */
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