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powerpc/mm: Make switch_mm_irqs_off() out of line

It's too big to be inline, there is no reason to keep it
that way.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Rework to incorporate the comment changes via fixes branch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Benjamin Herrenschmidt 2017-07-24 14:28:03 +10:00 committed by Michael Ellerman
parent a619e59c07
commit 3a2df3798d
3 changed files with 102 additions and 88 deletions

View File

@ -77,93 +77,8 @@ extern void switch_cop(struct mm_struct *next);
extern int use_cop(unsigned long acop, struct mm_struct *mm);
extern void drop_cop(unsigned long acop, struct mm_struct *mm);
#if defined(CONFIG_PPC32)
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm)
{
/* 32-bit keeps track of the current PGDIR in the thread struct */
tsk->thread.pgdir = mm->pgd;
}
#elif defined(CONFIG_PPC_BOOK3E_64)
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm)
{
/* 64-bit Book3E keeps track of current PGD in the PACA */
get_paca()->pgd = mm->pgd;
}
#else
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm) { }
#endif
#ifdef CONFIG_PPC_BOOK3S_64
static inline void inc_mm_active_cpus(struct mm_struct *mm)
{
atomic_inc(&mm->context.active_cpus);
}
#else
static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
#endif
/*
* switch_mm is the entry point called from the architecture independent
* code in kernel/sched/core.c
*/
static inline void switch_mm_irqs_off(struct mm_struct *prev,
struct mm_struct *next,
struct task_struct *tsk)
{
bool new_on_cpu = false;
/* Mark this context has been used on the new CPU */
if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) {
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
inc_mm_active_cpus(next);
/*
* This full barrier orders the store to the cpumask above vs
* a subsequent operation which allows this CPU to begin loading
* translations for next.
*
* When using the radix MMU that operation is the load of the
* MMU context id, which is then moved to SPRN_PID.
*
* For the hash MMU it is either the first load from slb_cache
* in switch_slb(), and/or the store of paca->mm_ctx_id in
* copy_mm_to_paca().
*
* On the read side the barrier is in pte_xchg(), which orders
* the store to the PTE vs the load of mm_cpumask.
*/
smp_mb();
new_on_cpu = true;
}
/* Some subarchs need to track the PGD elsewhere */
switch_mm_pgdir(tsk, next);
/* Nothing else to do if we aren't actually switching */
if (prev == next)
return;
/* We must stop all altivec streams before changing the HW
* context
*/
#ifdef CONFIG_ALTIVEC
if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile ("dssall");
#endif /* CONFIG_ALTIVEC */
if (new_on_cpu)
radix_kvm_prefetch_workaround(next);
/*
* The actual HW switching method differs between the various
* sub architectures. Out of line for now
*/
switch_mmu_context(prev, next, tsk);
}
extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk);
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)

View File

@ -8,7 +8,7 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
obj-y := fault.o mem.o pgtable.o mmap.o \
init_$(BITS).o pgtable_$(BITS).o \
init-common.o
init-common.o mmu_context.o
obj-$(CONFIG_PPC_MMU_NOHASH) += mmu_context_nohash.o tlb_nohash.o \
tlb_nohash_low.o
obj-$(CONFIG_PPC_BOOK3E) += tlb_low_$(BITS)e.o

View File

@ -0,0 +1,99 @@
/*
* Common implementation of switch_mm_irqs_off
*
* Copyright IBM Corp. 2017
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/mm.h>
#include <linux/cpu.h>
#include <asm/mmu_context.h>
#if defined(CONFIG_PPC32)
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm)
{
/* 32-bit keeps track of the current PGDIR in the thread struct */
tsk->thread.pgdir = mm->pgd;
}
#elif defined(CONFIG_PPC_BOOK3E_64)
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm)
{
/* 64-bit Book3E keeps track of current PGD in the PACA */
get_paca()->pgd = mm->pgd;
}
#else
static inline void switch_mm_pgdir(struct task_struct *tsk,
struct mm_struct *mm) { }
#endif
#ifdef CONFIG_PPC_BOOK3S_64
static inline void inc_mm_active_cpus(struct mm_struct *mm)
{
atomic_inc(&mm->context.active_cpus);
}
#else
static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
#endif
void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
bool new_on_cpu = false;
/* Mark this context has been used on the new CPU */
if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) {
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
inc_mm_active_cpus(next);
/*
* This full barrier orders the store to the cpumask above vs
* a subsequent operation which allows this CPU to begin loading
* translations for next.
*
* When using the radix MMU that operation is the load of the
* MMU context id, which is then moved to SPRN_PID.
*
* For the hash MMU it is either the first load from slb_cache
* in switch_slb(), and/or the store of paca->mm_ctx_id in
* copy_mm_to_paca().
*
* On the read side the barrier is in pte_xchg(), which orders
* the store to the PTE vs the load of mm_cpumask.
*/
smp_mb();
new_on_cpu = true;
}
/* Some subarchs need to track the PGD elsewhere */
switch_mm_pgdir(tsk, next);
/* Nothing else to do if we aren't actually switching */
if (prev == next)
return;
/*
* We must stop all altivec streams before changing the HW
* context
*/
if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile ("dssall");
if (new_on_cpu)
radix_kvm_prefetch_workaround(next);
/*
* The actual HW switching method differs between the various
* sub architectures. Out of line for now
*/
switch_mmu_context(prev, next, tsk);
}