67 строки
2.0 KiB
C
67 строки
2.0 KiB
C
#ifndef _ASM_HIGHMEM_H
|
|
#define _ASM_HIGHMEM_H
|
|
|
|
#include <asm/kmap_types.h>
|
|
|
|
#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE)
|
|
#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))
|
|
|
|
#define kmap_prot PAGE_KERNEL
|
|
|
|
#define flush_cache_kmaps() \
|
|
do { \
|
|
if (cache_is_vivt()) \
|
|
flush_cache_all(); \
|
|
} while (0)
|
|
|
|
extern pte_t *pkmap_page_table;
|
|
|
|
extern void *kmap_high(struct page *page);
|
|
extern void kunmap_high(struct page *page);
|
|
|
|
/*
|
|
* The reason for kmap_high_get() is to ensure that the currently kmap'd
|
|
* page usage count does not decrease to zero while we're using its
|
|
* existing virtual mapping in an atomic context. With a VIVT cache this
|
|
* is essential to do, but with a VIPT cache this is only an optimization
|
|
* so not to pay the price of establishing a second mapping if an existing
|
|
* one can be used. However, on platforms without hardware TLB maintenance
|
|
* broadcast, we simply cannot use ARCH_NEEDS_KMAP_HIGH_GET at all since
|
|
* the locking involved must also disable IRQs which is incompatible with
|
|
* the IPI mechanism used by global TLB operations.
|
|
*/
|
|
#define ARCH_NEEDS_KMAP_HIGH_GET
|
|
#if defined(CONFIG_SMP) && defined(CONFIG_CPU_TLB_V6)
|
|
#undef ARCH_NEEDS_KMAP_HIGH_GET
|
|
#if defined(CONFIG_HIGHMEM) && defined(CONFIG_CPU_CACHE_VIVT)
|
|
#error "The sum of features in your kernel config cannot be supported together"
|
|
#endif
|
|
#endif
|
|
|
|
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
|
|
extern void *kmap_high_get(struct page *page);
|
|
#else
|
|
static inline void *kmap_high_get(struct page *page)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* The following functions are already defined by <linux/highmem.h>
|
|
* when CONFIG_HIGHMEM is not set.
|
|
*/
|
|
#ifdef CONFIG_HIGHMEM
|
|
extern void *kmap(struct page *page);
|
|
extern void kunmap(struct page *page);
|
|
extern void *__kmap_atomic(struct page *page);
|
|
extern void __kunmap_atomic(void *kvaddr);
|
|
extern void *kmap_atomic_pfn(unsigned long pfn);
|
|
extern struct page *kmap_atomic_to_page(const void *ptr);
|
|
#endif
|
|
|
|
#endif
|