kernel_optimize_test/arch/arm/include/asm/highmem.h
Catalin Marinas 93dc68876b ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)
On Cortex-A15 (r0p0..r3p2) the TLBI/DSB are not adequately shooting down
all use of the old entries. This patch implements the erratum workaround
which consists of:

1. Dummy TLBIMVAIS and DSB on the CPU doing the TLBI operation.
2. Send IPI to the CPUs that are running the same mm (and ASID) as the
   one being invalidated (or all the online CPUs for global pages).
3. CPU receiving the IPI executes a DMB and CLREX (part of the exception
   return code already).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-04-03 16:45:49 +01:00

74 lines
2.2 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
/*
* Needed to be able to broadcast the TLB invalidation for kmap.
*/
#ifdef CONFIG_ARM_ERRATA_798181
#undef ARCH_NEEDS_KMAP_HIGH_GET
#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