[patch 1/2] bootmem: add alloc_bootmem_align()

[patch 1/2] bootmem: add alloc_bootmem_align()

[Suresh Siddha]

[-- Attachment #1: add_alloc_bootmem_align.patch --]
[-- Type: text/plain, Size: 737 bytes --]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
---
 include/linux/bootmem.h |    2 ++
 1 file changed, 2 insertions(+)

Index: tree/include/linux/bootmem.h
===================================================================
--- tree.orig/include/linux/bootmem.h
+++ tree/include/linux/bootmem.h
@@ -105,6 +105,8 @@ extern void *__alloc_bootmem_low_node(pg
 
 #define alloc_bootmem(x) \
 	__alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
+#define alloc_bootmem_align(x, align) \
+	__alloc_bootmem(x, align, __pa(MAX_DMA_ADDRESS))
 #define alloc_bootmem_nopanic(x) \
 	__alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
 #define alloc_bootmem_pages(x) \

[patch 2/2] xsave: use alloc_bootmem_align() instead of alloc_bootmem()

[Suresh Siddha]

[-- Attachment #1: xsave_use_alloc_bootmem_align.patch --]
[-- Type: text/plain, Size: 1030 bytes --]

Alignment of alloc_bootmem() depends on the value of L1_CACHE_SHIFT. What
we need here is 64byte alignment. Use alloc_bootmem_align() instead.

This fixes a kernel boot crash reported by Jody when the cpu in .config
is set to MPENTIUMII

Reported-by: Jody Bruchon <jody@nctritech.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/kernel/xsave.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: tree/arch/x86/kernel/xsave.c
===================================================================
--- tree.orig/arch/x86/kernel/xsave.c
+++ tree/arch/x86/kernel/xsave.c
@@ -394,7 +394,8 @@ static void __init setup_xstate_init(voi
 	 * Setup init_xstate_buf to represent the init state of
 	 * all the features managed by the xsave
 	 */
-	init_xstate_buf = alloc_bootmem(xstate_size);
+	init_xstate_buf = alloc_bootmem_align(xstate_size,
+					      __alignof__(struct xsave_struct));
 	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
 
 	clts();

Re: [patch 1/2] bootmem: add alloc_bootmem_align()

[H. Peter Anvin]

On 11/16/2010 01:23 PM, Suresh Siddha wrote:
> Index: tree/include/linux/bootmem.h
> ===================================================================
> --- tree.orig/include/linux/bootmem.h
> +++ tree/include/linux/bootmem.h
> @@ -105,6 +105,8 @@ extern void *__alloc_bootmem_low_node(pg
>  
>  #define alloc_bootmem(x) \
>  	__alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
> +#define alloc_bootmem_align(x, align) \
> +	__alloc_bootmem(x, align, __pa(MAX_DMA_ADDRESS))
>  #define alloc_bootmem_nopanic(x) \
>  	__alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
>  #define alloc_bootmem_pages(x) \

  [...]

>  	 */
> -	init_xstate_buf = alloc_bootmem(xstate_size);
> +	init_xstate_buf = alloc_bootmem_align(xstate_size,
> +					      __alignof__(struct xsave_struct));
>  	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;

Perhaps it would make even more sense to have:

#define alloc_bootmem_alignof(x, type) \
	__alloc_bootmem(x, __alignof__(type), __pa(MAX_DMA_ADDRESS))


?

	-hpa

Re: [patch 1/2] bootmem: add alloc_bootmem_align()

[Suresh Siddha]

On Tue, 2010-11-16 at 14:14 -0800, H. Peter Anvin wrote:
> On 11/16/2010 01:23 PM, Suresh Siddha wrote:
> > Index: tree/include/linux/bootmem.h
> > ===================================================================
> > --- tree.orig/include/linux/bootmem.h
> > +++ tree/include/linux/bootmem.h
> > @@ -105,6 +105,8 @@ extern void *__alloc_bootmem_low_node(pg
> >  
> >  #define alloc_bootmem(x) \
> >  	__alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
> > +#define alloc_bootmem_align(x, align) \
> > +	__alloc_bootmem(x, align, __pa(MAX_DMA_ADDRESS))
> >  #define alloc_bootmem_nopanic(x) \
> >  	__alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
> >  #define alloc_bootmem_pages(x) \
> 
>   [...]
> 
> >  	 */
> > -	init_xstate_buf = alloc_bootmem(xstate_size);
> > +	init_xstate_buf = alloc_bootmem_align(xstate_size,
> > +					      __alignof__(struct xsave_struct));
> >  	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
> 
> Perhaps it would make even more sense to have:
> 
> #define alloc_bootmem_alignof(x, type) \
> 	__alloc_bootmem(x, __alignof__(type), __pa(MAX_DMA_ADDRESS))
> 

Wanted to keep it broad so that more people can start using it.

For example, most of the current x86 uses of alloc_bootmem_pages() (or
the __alloc_bootmem() calls in other architectures) can be replaced with
alloc_bootmem_align() and most of them don't have a relevant type to
describe the alignment.

thanks,
suresh

[tip:x86/urgent] bootmem: Add alloc_bootmem_align()

[tip-bot for Suresh Siddha]

Commit-ID:  53dde5f385bc56e312f78b7cb25ffaf8efd4735d
Gitweb:     http://git.kernel.org/tip/53dde5f385bc56e312f78b7cb25ffaf8efd4735d
Author:     Suresh Siddha <suresh.b.siddha@intel.com>
AuthorDate: Tue, 16 Nov 2010 13:23:50 -0800
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 13 Dec 2010 16:11:13 -0800

bootmem: Add alloc_bootmem_align()

Add an alloc_bootmem_align() interface to allocate bootmem with
specified alignment.  This is necessary to be able to allocate the
xsave area in a subsequent patch.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20101116212441.977574826@sbsiddha-MOBL3.sc.intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org>
---
 include/linux/bootmem.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 266ab92..499dfe9 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -105,6 +105,8 @@ extern void *__alloc_bootmem_low_node(pg_data_t *pgdat,
 
 #define alloc_bootmem(x) \
 	__alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
+#define alloc_bootmem_align(x, align) \
+	__alloc_bootmem(x, align, __pa(MAX_DMA_ADDRESS))
 #define alloc_bootmem_nopanic(x) \
 	__alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))
 #define alloc_bootmem_pages(x) \

[tip:x86/urgent] x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()

[tip-bot for Suresh Siddha]

Commit-ID:  10340ae130fb70352eae1ae8a00b7906d91bf166
Gitweb:     http://git.kernel.org/tip/10340ae130fb70352eae1ae8a00b7906d91bf166
Author:     Suresh Siddha <suresh.b.siddha@intel.com>
AuthorDate: Tue, 16 Nov 2010 13:23:51 -0800
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 13 Dec 2010 16:13:11 -0800

x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()

Alignment of alloc_bootmem() depends on the value of
L1_CACHE_SHIFT. What we need here, however, is 64 byte alignment.  Use
alloc_bootmem_align() and explicitly specify the alignment instead.

This fixes a kernel boot crash reported by Jody when the cpu in .config
is set to MPENTIUMII but the kernel is booted on a xsave-capable CPU.

Reported-by: Jody Bruchon <jody@nctritech.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20101116212442.059967454@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org>
---
 arch/x86/kernel/xsave.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 9c253bd..5471285 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -394,7 +394,8 @@ static void __init setup_xstate_init(void)
 	 * Setup init_xstate_buf to represent the init state of
 	 * all the features managed by the xsave
 	 */
-	init_xstate_buf = alloc_bootmem(xstate_size);
+	init_xstate_buf = alloc_bootmem_align(xstate_size,
+					      __alignof__(struct xsave_struct));
 	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
 
 	clts();