Patchwork [20/27] Split init_new_context and destroy_context

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Submitter Alexander Graf
Date Oct. 30, 2009, 3:47 p.m.
Message ID <1256917647-6200-21-git-send-email-agraf@suse.de>
Download mbox | patch
Permalink /patch/37329/
State Superseded
Headers show

Comments

Alexander Graf - Oct. 30, 2009, 3:47 p.m.
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 <agraf@suse.de>
---
 arch/powerpc/include/asm/mmu_context.h |    5 +++++
 arch/powerpc/mm/mmu_context_hash64.c   |   24 +++++++++++++++++++++---
 2 files changed, 26 insertions(+), 3 deletions(-)
Stephen Rothwell - Oct. 31, 2009, 4:40 a.m.
Hi Alexander,

On Fri, 30 Oct 2009 16:47:20 +0100 Alexander Graf <agraf@suse.de> wrote:
>
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -23,6 +23,11 @@ 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);
> +#endif
> +
> +#ifdef CONFIG_PPC_BOOK3S_64

don't add the #endif/#ifdef pair ...
Alexander Graf - Oct. 31, 2009, 9:20 p.m.
Stephen Rothwell wrote:
> Hi Alexander,
>
> On Fri, 30 Oct 2009 16:47:20 +0100 Alexander Graf <agraf@suse.de> wrote:
>   
>> --- a/arch/powerpc/include/asm/mmu_context.h
>> +++ b/arch/powerpc/include/asm/mmu_context.h
>> @@ -23,6 +23,11 @@ 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);
>> +#endif
>> +
>> +#ifdef CONFIG_PPC_BOOK3S_64
>>     
>
> don't add the #endif/#ifdef pair ...

Any other comments? I'd like to wind up a final patch set so I can stop
spamming on all those MLs :-).

Alex
Benjamin Herrenschmidt - Oct. 31, 2009, 9:37 p.m.
On Sat, 2009-10-31 at 22:20 +0100, Alexander Graf wrote:
> Stephen Rothwell wrote:
> > Hi Alexander,
> >
> > On Fri, 30 Oct 2009 16:47:20 +0100 Alexander Graf <agraf@suse.de> wrote:
> >   
> >> --- a/arch/powerpc/include/asm/mmu_context.h
> >> +++ b/arch/powerpc/include/asm/mmu_context.h
> >> @@ -23,6 +23,11 @@ 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);
> >> +#endif
> >> +
> >> +#ifdef CONFIG_PPC_BOOK3S_64
> >>     
> >
> > don't add the #endif/#ifdef pair ...
> 
> Any other comments? I'd like to wind up a final patch set so I can stop
> spamming on all those MLs :-).

Just send an update for -that- patch to the list.

Ben.

Patch

diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index b34e94d..66b35d0 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -23,6 +23,11 @@  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);
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S_64
 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 dbeb86a..b9e4cc2 100644
--- a/arch/powerpc/mm/mmu_context_hash64.c
+++ b/arch/powerpc/mm/mmu_context_hash64.c
@@ -18,6 +18,7 @@ 
 #include <linux/mm.h>
 #include <linux/spinlock.h>
 #include <linux/idr.h>
+#include <linux/module.h>
 
 #include <asm/mmu_context.h>
 
@@ -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;
 }