![Peter Zijlstra](/assets/img/avatar_default.png)
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>
168 lines
4.6 KiB
C
168 lines
4.6 KiB
C
/* highmem.h: virtual kernel memory mappings for high memory
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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* - Derived from include/asm-i386/highmem.h
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*
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* See Documentation/frv/mmu-layout.txt for more information.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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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/init.h>
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#include <linux/highmem.h>
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#include <asm/mem-layout.h>
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#include <asm/spr-regs.h>
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#include <asm/mb-regs.h>
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#define NR_TLB_LINES 64 /* number of lines in the TLB */
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#ifndef __ASSEMBLY__
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#include <linux/interrupt.h>
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#include <asm/kmap_types.h>
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#include <asm/pgtable.h>
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#ifdef CONFIG_DEBUG_HIGHMEM
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#define HIGHMEM_DEBUG 1
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#else
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#define HIGHMEM_DEBUG 0
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#endif
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/* declarations for highmem.c */
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extern unsigned long highstart_pfn, highend_pfn;
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#define kmap_prot PAGE_KERNEL
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#define kmap_pte ______kmap_pte_in_TLB
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extern pte_t *pkmap_page_table;
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#define flush_cache_kmaps() do { } while (0)
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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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#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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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(struct page *page);
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extern void kunmap(struct page *page);
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extern struct page *kmap_atomic_to_page(void *ptr);
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#endif /* !__ASSEMBLY__ */
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/*
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* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
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* gives a more generic (and caching) interface. But kmap_atomic can
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* be used in IRQ contexts, so in some (very limited) cases we need
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* it.
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*/
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#define KMAP_ATOMIC_CACHE_DAMR 8
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#ifndef __ASSEMBLY__
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#define __kmap_atomic_primary(type, paddr, ampr) \
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({ \
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unsigned long damlr, dampr; \
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\
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dampr = paddr | xAMPRx_L | xAMPRx_M | xAMPRx_S | xAMPRx_SS_16Kb | xAMPRx_V; \
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\
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if (type != __KM_CACHE) \
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asm volatile("movgs %0,dampr"#ampr :: "r"(dampr) : "memory"); \
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else \
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asm volatile("movgs %0,iampr"#ampr"\n" \
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"movgs %0,dampr"#ampr"\n" \
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:: "r"(dampr) : "memory" \
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); \
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\
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asm("movsg damlr"#ampr",%0" : "=r"(damlr)); \
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\
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/*printk("DAMR"#ampr": PRIM sl=%d L=%08lx P=%08lx\n", type, damlr, dampr);*/ \
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\
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(void *) damlr; \
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})
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#define __kmap_atomic_secondary(slot, paddr) \
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({ \
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unsigned long damlr = KMAP_ATOMIC_SECONDARY_FRAME + (slot) * PAGE_SIZE; \
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unsigned long dampr = paddr | xAMPRx_L | xAMPRx_M | xAMPRx_S | xAMPRx_SS_16Kb | xAMPRx_V; \
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\
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asm volatile("movgs %0,tplr \n" \
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"movgs %1,tppr \n" \
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"tlbpr %0,gr0,#2,#1" \
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: : "r"(damlr), "r"(dampr) : "memory"); \
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\
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/*printk("TLB: SECN sl=%d L=%08lx P=%08lx\n", slot, damlr, dampr);*/ \
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\
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(void *) damlr; \
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})
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static inline void *kmap_atomic_primary(struct page *page, enum km_type type)
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{
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unsigned long paddr;
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pagefault_disable();
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paddr = page_to_phys(page);
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switch (type) {
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case 0: return __kmap_atomic_primary(0, paddr, 2);
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case 1: return __kmap_atomic_primary(1, paddr, 3);
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case 2: return __kmap_atomic_primary(2, paddr, 4);
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case 3: return __kmap_atomic_primary(3, paddr, 5);
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default:
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BUG();
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return NULL;
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}
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}
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#define __kunmap_atomic_primary(type, ampr) \
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do { \
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asm volatile("movgs gr0,dampr"#ampr"\n" ::: "memory"); \
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if (type == __KM_CACHE) \
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asm volatile("movgs gr0,iampr"#ampr"\n" ::: "memory"); \
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} while(0)
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#define __kunmap_atomic_secondary(slot, vaddr) \
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do { \
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asm volatile("tlbpr %0,gr0,#4,#1" : : "r"(vaddr) : "memory"); \
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} while(0)
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static inline void kunmap_atomic_primary(void *kvaddr, enum km_type type)
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{
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switch (type) {
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case 0: __kunmap_atomic_primary(0, 2); break;
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case 1: __kunmap_atomic_primary(1, 3); break;
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case 2: __kunmap_atomic_primary(2, 4); break;
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case 3: __kunmap_atomic_primary(3, 5); break;
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default:
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BUG();
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}
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pagefault_enable();
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}
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void *__kmap_atomic(struct page *page);
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void __kunmap_atomic(void *kvaddr);
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#endif /* !__ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* _ASM_HIGHMEM_H */
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