linux/include/asm-frv/highmem.h
David Howells 29da7eb0ec [PATCH] FRV: Use the correct preemption primitives in kmap_atomic() and co
Use inc/dec_preempt_count() rather than preempt_enable/disable() and manually
add in the compiler barriers that were provided by the latter.  This makes FRV
consistent with other archs.

Furthermore, the compiler barrier effects are now there unconditionally - at
least as far as preemption is concerned - because we don't want the compiler
moving memory accesses out of the section of code in which the mapping is in
force - in effect the kmap_atomic() must imply a LOCK-class barrier and the
kunmap_atomic() must imply an UNLOCK-class barrier to the compiler.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-16 08:32:29 -07:00

182 lines
5.3 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/fujitsu/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 <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(struct page *page, enum km_type type)
{
unsigned long paddr;
inc_preempt_count();
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);
case 4: return __kmap_atomic_primary(4, paddr, 6);
case 5: return __kmap_atomic_primary(5, paddr, 7);
case 6: return __kmap_atomic_primary(6, paddr, 8);
case 7: return __kmap_atomic_primary(7, paddr, 9);
case 8: return __kmap_atomic_primary(8, paddr, 10);
case 9 ... 9 + NR_TLB_LINES - 1:
return __kmap_atomic_secondary(type - 9, paddr);
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(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;
case 4: __kunmap_atomic_primary(4, 6); break;
case 5: __kunmap_atomic_primary(5, 7); break;
case 6: __kunmap_atomic_primary(6, 8); break;
case 7: __kunmap_atomic_primary(7, 9); break;
case 8: __kunmap_atomic_primary(8, 10); break;
case 9 ... 9 + NR_TLB_LINES - 1:
__kunmap_atomic_secondary(type - 9, kvaddr);
break;
default:
BUG();
}
dec_preempt_count();
preempt_check_resched();
}
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */