3e4d3af501
Keep the current interface but ignore the KM_type and use a stack based approach. The advantage is that we get rid of crappy code like: #define __KM_PTE \ (in_nmi() ? KM_NMI_PTE : \ in_irq() ? KM_IRQ_PTE : \ KM_PTE0) and in general can stop worrying about what context we're in and what kmap slots might be appropriate for that. The downside is that FRV kmap_atomic() gets more expensive. For now we use a CPP trick suggested by Andrew: #define kmap_atomic(page, args...) __kmap_atomic(page) to avoid having to touch all kmap_atomic() users in a single patch. [ not compiled on: - mn10300: the arch doesn't actually build with highmem to begin with ] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
/*
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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/tlbflush.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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BUG_ON(in_interrupt());
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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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static inline struct page *kmap_atomic_to_page(void *ptr)
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{
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unsigned long idx, vaddr = (unsigned long) ptr;
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pte_t *pte;
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if (vaddr < FIXADDR_START)
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return virt_to_page(ptr);
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idx = virt_to_fix(vaddr);
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pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
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return pte_page(*pte);
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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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