linux/arch/arm/include/asm/mmu.h
Catalin Marinas 11805bcfa4 ARM: 5905/1: ARM: Global ASID allocation on SMP
The current ASID allocation algorithm doesn't ensure the notification
of the other CPUs when the ASID rolls over. This may lead to two
processes using the same ASID (but different generation) or multiple
threads of the same process using different ASIDs.

This patch adds the broadcasting of the ASID rollover event to the
other CPUs. To avoid a race on multiple CPUs modifying "cpu_last_asid"
during the handling of the broadcast, the ASID numbering now starts at
"smp_processor_id() + 1". At rollover, the cpu_last_asid will be set
to NR_CPUS.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:51 +00:00

34 lines
523 B
C

#ifndef __ARM_MMU_H
#define __ARM_MMU_H
#ifdef CONFIG_MMU
typedef struct {
#ifdef CONFIG_CPU_HAS_ASID
unsigned int id;
spinlock_t id_lock;
#endif
unsigned int kvm_seq;
} mm_context_t;
#ifdef CONFIG_CPU_HAS_ASID
#define ASID(mm) ((mm)->context.id & 255)
#else
#define ASID(mm) (0)
#endif
#else
/*
* From nommu.h:
* Copyright (C) 2002, David McCullough <davidm@snapgear.com>
* modified for 2.6 by Hyok S. Choi <hyok.choi@samsung.com>
*/
typedef struct {
unsigned long end_brk;
} mm_context_t;
#endif
#endif