linux/arch/arm/kernel/smp_tlb.c
Catalin Marinas 3eb0be3042 ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum()
Commit 93dc688 (ARM: 7684/1: errata: Workaround for Cortex-A15 erratum
798181 (TLBI/DSB operations)) introduces calls to smp_processor_id() and
smp_call_function_many() with preemption enabled. This patch disables
preemption and also optimises the smp_processor_id() call in
broadcast_tlb_mm_a15_erratum(). The broadcast_tlb_a15_erratum() function
is changed to use smp_call_function() which disables preemption.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Geoff Levand <geoff@infradead.org>
Reported-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-04-25 13:15:15 +01:00

209 lines
4.6 KiB
C

/*
* linux/arch/arm/kernel/smp_tlb.c
*
* Copyright (C) 2002 ARM Limited, All Rights Reserved.
*
* 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.
*/
#include <linux/preempt.h>
#include <linux/smp.h>
#include <asm/smp_plat.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
/**********************************************************************/
/*
* TLB operations
*/
struct tlb_args {
struct vm_area_struct *ta_vma;
unsigned long ta_start;
unsigned long ta_end;
};
static inline void ipi_flush_tlb_all(void *ignored)
{
local_flush_tlb_all();
}
static inline void ipi_flush_tlb_mm(void *arg)
{
struct mm_struct *mm = (struct mm_struct *)arg;
local_flush_tlb_mm(mm);
}
static inline void ipi_flush_tlb_page(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_page(ta->ta_vma, ta->ta_start);
}
static inline void ipi_flush_tlb_kernel_page(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_kernel_page(ta->ta_start);
}
static inline void ipi_flush_tlb_range(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
}
static inline void ipi_flush_tlb_kernel_range(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
}
static inline void ipi_flush_bp_all(void *ignored)
{
local_flush_bp_all();
}
#ifdef CONFIG_ARM_ERRATA_798181
static int erratum_a15_798181(void)
{
unsigned int midr = read_cpuid_id();
/* Cortex-A15 r0p0..r3p2 affected */
if ((midr & 0xff0ffff0) != 0x410fc0f0 || midr > 0x413fc0f2)
return 0;
return 1;
}
#else
static int erratum_a15_798181(void)
{
return 0;
}
#endif
static void ipi_flush_tlb_a15_erratum(void *arg)
{
dmb();
}
static void broadcast_tlb_a15_erratum(void)
{
if (!erratum_a15_798181())
return;
dummy_flush_tlb_a15_erratum();
smp_call_function(ipi_flush_tlb_a15_erratum, NULL, 1);
}
static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
{
int cpu, this_cpu;
cpumask_t mask = { CPU_BITS_NONE };
if (!erratum_a15_798181())
return;
dummy_flush_tlb_a15_erratum();
this_cpu = get_cpu();
for_each_online_cpu(cpu) {
if (cpu == this_cpu)
continue;
/*
* We only need to send an IPI if the other CPUs are running
* the same ASID as the one being invalidated. There is no
* need for locking around the active_asids check since the
* switch_mm() function has at least one dmb() (as required by
* this workaround) in case a context switch happens on
* another CPU after the condition below.
*/
if (atomic64_read(&mm->context.id) ==
atomic64_read(&per_cpu(active_asids, cpu)))
cpumask_set_cpu(cpu, &mask);
}
smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
put_cpu();
}
void flush_tlb_all(void)
{
if (tlb_ops_need_broadcast())
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
else
local_flush_tlb_all();
broadcast_tlb_a15_erratum();
}
void flush_tlb_mm(struct mm_struct *mm)
{
if (tlb_ops_need_broadcast())
on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1);
else
local_flush_tlb_mm(mm);
broadcast_tlb_mm_a15_erratum(mm);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_vma = vma;
ta.ta_start = uaddr;
on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page,
&ta, 1);
} else
local_flush_tlb_page(vma, uaddr);
broadcast_tlb_mm_a15_erratum(vma->vm_mm);
}
void flush_tlb_kernel_page(unsigned long kaddr)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_start = kaddr;
on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
} else
local_flush_tlb_kernel_page(kaddr);
broadcast_tlb_a15_erratum();
}
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_vma = vma;
ta.ta_start = start;
ta.ta_end = end;
on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_range,
&ta, 1);
} else
local_flush_tlb_range(vma, start, end);
broadcast_tlb_mm_a15_erratum(vma->vm_mm);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_start = start;
ta.ta_end = end;
on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
} else
local_flush_tlb_kernel_range(start, end);
broadcast_tlb_a15_erratum();
}
void flush_bp_all(void)
{
if (tlb_ops_need_broadcast())
on_each_cpu(ipi_flush_bp_all, NULL, 1);
else
local_flush_bp_all();
}