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090e77e166
Most architectures define kmap_prot to be PAGE_KERNEL. Let sparc and xtensa define there own and define PAGE_KERNEL as the default if not overridden. [akpm@linux-foundation.org: coding style fixes] Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian König <christian.koenig@amd.com> Cc: Chris Zankel <chris@zankel.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200507150004.1423069-16-ira.weiny@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_HIGHMEM_H
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#define _ASM_HIGHMEM_H
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#include <asm/kmap_types.h>
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#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE)
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#define LAST_PKMAP PTRS_PER_PTE
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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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#define flush_cache_kmaps() \
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do { \
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if (cache_is_vivt()) \
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flush_cache_all(); \
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} while (0)
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extern pte_t *pkmap_page_table;
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/*
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* The reason for kmap_high_get() is to ensure that the currently kmap'd
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* page usage count does not decrease to zero while we're using its
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* existing virtual mapping in an atomic context. With a VIVT cache this
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* is essential to do, but with a VIPT cache this is only an optimization
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* so not to pay the price of establishing a second mapping if an existing
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* one can be used. However, on platforms without hardware TLB maintenance
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* broadcast, we simply cannot use ARCH_NEEDS_KMAP_HIGH_GET at all since
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* the locking involved must also disable IRQs which is incompatible with
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* the IPI mechanism used by global TLB operations.
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*/
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#define ARCH_NEEDS_KMAP_HIGH_GET
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#if defined(CONFIG_SMP) && defined(CONFIG_CPU_TLB_V6)
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#undef ARCH_NEEDS_KMAP_HIGH_GET
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#if defined(CONFIG_HIGHMEM) && defined(CONFIG_CPU_CACHE_VIVT)
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#error "The sum of features in your kernel config cannot be supported together"
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#endif
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#endif
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/*
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* Needed to be able to broadcast the TLB invalidation for kmap.
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*/
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#ifdef CONFIG_ARM_ERRATA_798181
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#undef ARCH_NEEDS_KMAP_HIGH_GET
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#endif
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#ifdef ARCH_NEEDS_KMAP_HIGH_GET
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extern void *kmap_high_get(struct page *page);
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#else
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static inline void *kmap_high_get(struct page *page)
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{
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return NULL;
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}
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#endif
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/*
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* The following functions are already defined by <linux/highmem.h>
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* when CONFIG_HIGHMEM is not set.
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*/
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#ifdef CONFIG_HIGHMEM
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extern void *kmap_atomic_pfn(unsigned long pfn);
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#endif
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#endif
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