01c4b788e0
Patch series "Remove duplicated kmap code", v3. The kmap infrastructure has been copied almost verbatim to every architecture. This series consolidates obvious duplicated code by defining core functions which call into the architectures only when needed. Some of the k[un]map_atomic() implementations have some similarities but the similarities were not sufficient to warrant further changes. In addition we remove a duplicate implementation of kmap() in DRM. This patch (of 15): Replace the use of BUG_ON(in_interrupt()) in the kmap() and kunmap() in favor of might_sleep(). Besides the benefits of might_sleep(), this normalizes the implementations such that they can be made generic in subsequent patches. Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian König <christian.koenig@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Link: http://lkml.kernel.org/r/20200507150004.1423069-1-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20200507150004.1423069-2-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
94 lines
2.4 KiB
C
94 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* highmem.h: virtual kernel memory mappings for high memory
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*
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* PowerPC version, stolen from the i386 version.
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*
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* Used in CONFIG_HIGHMEM systems for memory pages which
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* are not addressable by direct kernel virtual addresses.
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*
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* Copyright (C) 1999 Gerhard Wichert, Siemens AG
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* Gerhard.Wichert@pdb.siemens.de
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*
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*
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* Redesigned the x86 32-bit VM architecture to deal with
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* up to 16 Terrabyte physical memory. With current x86 CPUs
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* we now support up to 64 Gigabytes physical RAM.
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*
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* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
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*/
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#ifndef _ASM_HIGHMEM_H
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#define _ASM_HIGHMEM_H
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#ifdef __KERNEL__
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#include <linux/interrupt.h>
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#include <asm/kmap_types.h>
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#include <asm/cacheflush.h>
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#include <asm/page.h>
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#include <asm/fixmap.h>
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extern pte_t *kmap_pte;
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extern pgprot_t kmap_prot;
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extern pte_t *pkmap_page_table;
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/*
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* Right now we initialize only a single pte table. It can be extended
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* easily, subsequent pte tables have to be allocated in one physical
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* chunk of RAM.
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*/
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/*
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* We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
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* table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
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* and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
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* in case of 16K/64K/256K page sizes.
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*/
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#ifdef CONFIG_PPC_4K_PAGES
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#define PKMAP_ORDER PTE_SHIFT
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#else
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#define PKMAP_ORDER 9
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#endif
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#define LAST_PKMAP (1 << PKMAP_ORDER)
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#ifndef CONFIG_PPC_4K_PAGES
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#define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1))
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#else
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#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
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#endif
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#define LAST_PKMAP_MASK (LAST_PKMAP-1)
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#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
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#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
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extern void *kmap_high(struct page *page);
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extern void kunmap_high(struct page *page);
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extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
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extern void __kunmap_atomic(void *kvaddr);
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static inline void *kmap(struct page *page)
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{
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might_sleep();
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if (!PageHighMem(page))
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return page_address(page);
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return kmap_high(page);
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}
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static inline void kunmap(struct page *page)
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{
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might_sleep();
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if (!PageHighMem(page))
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return;
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kunmap_high(page);
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}
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static inline void *kmap_atomic(struct page *page)
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{
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return kmap_atomic_prot(page, kmap_prot);
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}
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#define flush_cache_kmaps() flush_cache_all()
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#endif /* __KERNEL__ */
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#endif /* _ASM_HIGHMEM_H */
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