linux/arch/arm/include/asm/mmu_context.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

118 lines
3.0 KiB
C

/*
* arch/arm/include/asm/mmu_context.h
*
* Copyright (C) 1996 Russell King.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Changelog:
* 27-06-1996 RMK Created
*/
#ifndef __ASM_ARM_MMU_CONTEXT_H
#define __ASM_ARM_MMU_CONTEXT_H
#include <linux/compiler.h>
#include <linux/sched.h>
#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/proc-fns.h>
#include <asm-generic/mm_hooks.h>
void __check_vmalloc_seq(struct mm_struct *mm);
#ifdef CONFIG_CPU_HAS_ASID
void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk);
#define init_new_context(tsk,mm) ({ atomic64_set(&mm->context.id, 0); 0; })
DECLARE_PER_CPU(atomic64_t, active_asids);
#else /* !CONFIG_CPU_HAS_ASID */
#ifdef CONFIG_MMU
static inline void check_and_switch_context(struct mm_struct *mm,
struct task_struct *tsk)
{
if (unlikely(mm->context.vmalloc_seq != init_mm.context.vmalloc_seq))
__check_vmalloc_seq(mm);
if (irqs_disabled())
/*
* cpu_switch_mm() needs to flush the VIVT caches. To avoid
* high interrupt latencies, defer the call and continue
* running with the old mm. Since we only support UP systems
* on non-ASID CPUs, the old mm will remain valid until the
* finish_arch_post_lock_switch() call.
*/
set_ti_thread_flag(task_thread_info(tsk), TIF_SWITCH_MM);
else
cpu_switch_mm(mm->pgd, mm);
}
#define finish_arch_post_lock_switch \
finish_arch_post_lock_switch
static inline void finish_arch_post_lock_switch(void)
{
if (test_and_clear_thread_flag(TIF_SWITCH_MM)) {
struct mm_struct *mm = current->mm;
cpu_switch_mm(mm->pgd, mm);
}
}
#endif /* CONFIG_MMU */
#define init_new_context(tsk,mm) 0
#endif /* CONFIG_CPU_HAS_ASID */
#define destroy_context(mm) do { } while(0)
#define activate_mm(prev,next) switch_mm(prev, next, NULL)
/*
* This is called when "tsk" is about to enter lazy TLB mode.
*
* mm: describes the currently active mm context
* tsk: task which is entering lazy tlb
* cpu: cpu number which is entering lazy tlb
*
* tsk->mm will be NULL
*/
static inline void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}
/*
* This is the actual mm switch as far as the scheduler
* is concerned. No registers are touched. We avoid
* calling the CPU specific function when the mm hasn't
* actually changed.
*/
static inline void
switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
#ifdef CONFIG_MMU
unsigned int cpu = smp_processor_id();
#ifdef CONFIG_SMP
/* check for possible thread migration */
if (!cpumask_empty(mm_cpumask(next)) &&
!cpumask_test_cpu(cpu, mm_cpumask(next)))
__flush_icache_all();
#endif
if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) {
check_and_switch_context(next, tsk);
if (cache_is_vivt())
cpumask_clear_cpu(cpu, mm_cpumask(prev));
}
#endif
}
#define deactivate_mm(tsk,mm) do { } while (0)
#endif