From e85a47106abb928e048d89d7fa48f982fcb018aa Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Mon, 2 Nov 2009 12:02:30 +0000 Subject: [PATCH] Split init_new_context and destroy_context For KVM we need to allocate a new context id, but don't really care about all the mm context around it. So let's split the alloc and destroy functions for the context id, so we can grab one without allocating an mm context. Signed-off-by: Alexander Graf Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/mmu_context.h | 2 ++ arch/powerpc/mm/mmu_context_hash64.c | 24 +++++++++++++++++++++--- 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index b34e94d94435..26383e0778aa 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -23,6 +23,8 @@ extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm); extern void set_context(unsigned long id, pgd_t *pgd); #ifdef CONFIG_PPC_BOOK3S_64 +extern int __init_new_context(void); +extern void __destroy_context(int context_id); static inline void mmu_context_init(void) { } #else extern void mmu_context_init(void); diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c index dbeb86ac90cd..b9e4cc2c2057 100644 --- a/arch/powerpc/mm/mmu_context_hash64.c +++ b/arch/powerpc/mm/mmu_context_hash64.c @@ -18,6 +18,7 @@ #include #include #include +#include #include @@ -32,7 +33,7 @@ static DEFINE_IDR(mmu_context_idr); #define NO_CONTEXT 0 #define MAX_CONTEXT ((1UL << 19) - 1) -int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +int __init_new_context(void) { int index; int err; @@ -57,6 +58,18 @@ again: return -ENOMEM; } + return index; +} +EXPORT_SYMBOL_GPL(__init_new_context); + +int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +{ + int index; + + index = __init_new_context(); + if (index < 0) + return index; + /* The old code would re-promote on fork, we don't do that * when using slices as it could cause problem promoting slices * that have been forced down to 4K @@ -68,11 +81,16 @@ again: return 0; } -void destroy_context(struct mm_struct *mm) +void __destroy_context(int context_id) { spin_lock(&mmu_context_lock); - idr_remove(&mmu_context_idr, mm->context.id); + idr_remove(&mmu_context_idr, context_id); spin_unlock(&mmu_context_lock); +} +EXPORT_SYMBOL_GPL(__destroy_context); +void destroy_context(struct mm_struct *mm) +{ + __destroy_context(mm->context.id); mm->context.id = NO_CONTEXT; }