linux/arch/frv/include/asm/highmem.h
Peter Zijlstra 3e4d3af501 mm: stack based kmap_atomic()
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>
2010-10-26 16:52:08 -07:00

168 lines
4.6 KiB
C

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