Devices like b44 ethernet can't dma from addresses above 1GB. The driver
handles this cases by falling back to GFP_DMA allocation. But for detecting
the problem it needs to get an indication from dma_mapping_error.
The bug is triggered by using a VMSPLIT option of 2G/2G.
Signed-off-by: Thomas Bogendoerfer <[email protected]>
---
diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h
--- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 00:05:07.000000000 +0200
+++ linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 11:06:14.000000000 +0100
@@ -74,15 +74,13 @@
/* Make sure we keep the same behaviour */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
-#ifdef CONFIG_X86_32
- return 0;
-#else
+#ifdef CONFIG_X86_64
struct dma_mapping_ops *ops = get_dma_ops(dev);
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
- return (dma_addr == bad_dma_address);
#endif
+ return (dma_addr == bad_dma_address);
}
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
On Sat, 29 Nov 2008 13:46:27 +0100 (CET)
Thomas Bogendoerfer <[email protected]> wrote:
> Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> handles this cases by falling back to GFP_DMA allocation. But for detecting
> the problem it needs to get an indication from dma_mapping_error.
> The bug is triggered by using a VMSPLIT option of 2G/2G.
>
> Signed-off-by: Thomas Bogendoerfer <[email protected]>
> ---
>
>
> diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h
> --- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 00:05:07.000000000 +0200
> +++ linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 11:06:14.000000000 +0100
> @@ -74,15 +74,13 @@
> /* Make sure we keep the same behaviour */
> static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> {
> -#ifdef CONFIG_X86_32
> - return 0;
> -#else
> +#ifdef CONFIG_X86_64
> struct dma_mapping_ops *ops = get_dma_ops(dev);
> if (ops->mapping_error)
> return ops->mapping_error(dev, dma_addr);
>
> - return (dma_addr == bad_dma_address);
> #endif
> + return (dma_addr == bad_dma_address);
> }
Surely, 2.6.27.4 needs this fix (and all the stable trees need this
too, I think).
This can't be cleanly applied to the current git (dma-mapping.h was
moved). How about just removing the ifdef? I think that it's clean a
bit.
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 7f225a4..dc22c07 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -71,15 +71,11 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
/* Make sure we keep the same behaviour */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
-#ifdef CONFIG_X86_32
- return 0;
-#else
struct dma_mapping_ops *ops = get_dma_ops(dev);
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
return (dma_addr == bad_dma_address);
-#endif
}
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> handles this cases by falling back to GFP_DMA allocation. But for detecting
> the problem it needs to get an indication from dma_mapping_error.
> The bug is triggered by using a VMSPLIT option of 2G/2G.
Looks like your system uses swiotlb as the dma_ops backend. Its the only
implementation providing the ops->mapping_error callback and does not
use bad_dma_address as the error value.
> Signed-off-by: Thomas Bogendoerfer <[email protected]>
Acked-by: Joerg Roedel <[email protected]>
>
> diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h
> --- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 00:05:07.000000000 +0200
> +++ linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 11:06:14.000000000 +0100
> @@ -74,15 +74,13 @@
> /* Make sure we keep the same behaviour */
> static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> {
> -#ifdef CONFIG_X86_32
> - return 0;
> -#else
> +#ifdef CONFIG_X86_64
> struct dma_mapping_ops *ops = get_dma_ops(dev);
> if (ops->mapping_error)
> return ops->mapping_error(dev, dma_addr);
>
> - return (dma_addr == bad_dma_address);
> #endif
> + return (dma_addr == bad_dma_address);
> }
>
> #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
On Mon, 1 Dec 2008 12:34:51 +0100
Joerg Roedel <[email protected]> wrote:
> On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > the problem it needs to get an indication from dma_mapping_error.
> > The bug is triggered by using a VMSPLIT option of 2G/2G.
>
> Looks like your system uses swiotlb as the dma_ops backend. Its the only
> implementation providing the ops->mapping_error callback and does not
> use bad_dma_address as the error value.
I think that you misunderstand the problem.
He uses X86_32 so swiotlb should not be used (which is available on only
X86_64 and IA64 for now).
b44 needs an address under 1GB so it sets device->dma_mask to
DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
get addresses above 1GB from the networking subsystem. In such case,
nommu_map_single returns bad_dma_address properly, but on X86_32,
dma_mapping_error always returns 0 (success). So b44 wrongly thinks
that the address is under 1GB.
This patch fixes dma_mapping_error() to check a passed address
properly (compares it with bad_dma_address).
As I already wrote, the current git needs a patch modified slightly:
http://marc.info/?l=linux-kernel&m=122797163405377&w=2
> > Signed-off-by: Thomas Bogendoerfer <[email protected]>
>
> Acked-by: Joerg Roedel <[email protected]>
>
> >
> > diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h
> > --- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 00:05:07.000000000 +0200
> > +++ linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 11:06:14.000000000 +0100
> > @@ -74,15 +74,13 @@
> > /* Make sure we keep the same behaviour */
> > static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> > {
> > -#ifdef CONFIG_X86_32
> > - return 0;
> > -#else
> > +#ifdef CONFIG_X86_64
> > struct dma_mapping_ops *ops = get_dma_ops(dev);
> > if (ops->mapping_error)
> > return ops->mapping_error(dev, dma_addr);
> >
> > - return (dma_addr == bad_dma_address);
> > #endif
> > + return (dma_addr == bad_dma_address);
> > }
> >
> > #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
* FUJITA Tomonori <[email protected]> wrote:
> On Mon, 1 Dec 2008 12:34:51 +0100
> Joerg Roedel <[email protected]> wrote:
>
> > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > the problem it needs to get an indication from dma_mapping_error.
> > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> >
> > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > implementation providing the ops->mapping_error callback and does not
> > use bad_dma_address as the error value.
>
> I think that you misunderstand the problem.
>
> He uses X86_32 so swiotlb should not be used (which is available on
> only X86_64 and IA64 for now).
>
> b44 needs an address under 1GB so it sets device->dma_mask to
> DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> get addresses above 1GB from the networking subsystem. In such case,
> nommu_map_single returns bad_dma_address properly, but on X86_32,
> dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> that the address is under 1GB.
>
> This patch fixes dma_mapping_error() to check a passed address
> properly (compares it with bad_dma_address).
>
> As I already wrote, the current git needs a patch modified slightly:
>
> http://marc.info/?l=linux-kernel&m=122797163405377&w=2
i have i queued up in x86/urgent, see below.
Ingo
-------------->
>From 7b1dedca42ac0d0d0be01e39d8461bb53a2389b3 Mon Sep 17 00:00:00 2001
From: Thomas Bogendoerfer <[email protected]>
Date: Sat, 29 Nov 2008 13:46:27 +0100
Subject: [PATCH] x86: fix dma_mapping_error for 32bit x86
Devices like b44 ethernet can't dma from addresses above 1GB. The driver
handles this cases by falling back to GFP_DMA allocation. But for detecting
the problem it needs to get an indication from dma_mapping_error.
The bug is triggered by using a VMSPLIT option of 2G/2G.
Signed-off-by: Thomas Bogendoerfer <[email protected]>
Acked-by: FUJITA Tomonori <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/include/asm/dma-mapping.h | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 7f225a4..097794f 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -71,15 +71,13 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
/* Make sure we keep the same behaviour */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
-#ifdef CONFIG_X86_32
- return 0;
-#else
+#ifdef CONFIG_X86_64
struct dma_mapping_ops *ops = get_dma_ops(dev);
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
- return (dma_addr == bad_dma_address);
#endif
+ return (dma_addr == bad_dma_address);
}
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
On Mon, Dec 01, 2008 at 09:01:06PM +0900, FUJITA Tomonori wrote:
> On Mon, 1 Dec 2008 12:34:51 +0100
> Joerg Roedel <[email protected]> wrote:
>
> > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > the problem it needs to get an indication from dma_mapping_error.
> > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> >
> > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > implementation providing the ops->mapping_error callback and does not
> > use bad_dma_address as the error value.
>
> I think that you misunderstand the problem.
>
> He uses X86_32 so swiotlb should not be used (which is available on only
> X86_64 and IA64 for now).
>
> b44 needs an address under 1GB so it sets device->dma_mask to
> DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> get addresses above 1GB from the networking subsystem. In such case,
> nommu_map_single returns bad_dma_address properly, but on X86_32,
> dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> that the address is under 1GB.
>
> This patch fixes dma_mapping_error() to check a passed address
> properly (compares it with bad_dma_address).
Ah true, thanks. Anyway, the patch also solved the problem with swiotlb
on 64bit.
Joerg
On Mon, 1 Dec 2008 13:55:01 +0100
Ingo Molnar <[email protected]> wrote:
>
> * FUJITA Tomonori <[email protected]> wrote:
>
> > On Mon, 1 Dec 2008 12:34:51 +0100
> > Joerg Roedel <[email protected]> wrote:
> >
> > > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > > the problem it needs to get an indication from dma_mapping_error.
> > > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> > >
> > > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > > implementation providing the ops->mapping_error callback and does not
> > > use bad_dma_address as the error value.
> >
> > I think that you misunderstand the problem.
> >
> > He uses X86_32 so swiotlb should not be used (which is available on
> > only X86_64 and IA64 for now).
> >
> > b44 needs an address under 1GB so it sets device->dma_mask to
> > DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> > get addresses above 1GB from the networking subsystem. In such case,
> > nommu_map_single returns bad_dma_address properly, but on X86_32,
> > dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> > that the address is under 1GB.
> >
> > This patch fixes dma_mapping_error() to check a passed address
> > properly (compares it with bad_dma_address).
> >
> > As I already wrote, the current git needs a patch modified slightly:
> >
> > http://marc.info/?l=linux-kernel&m=122797163405377&w=2
>
> i have i queued up in x86/urgent, see below.
As I wrote, just removing #ifdef is better since:
1) Xen people want swiotlb on X86_32. swiotlb uses ops->mapping_error
so X86_32 also needs to check ops->mapping_error.
2) Removing #ifdef hack is always good.
But this patch fixes the bug and it works for now. And I think that
Thomas tested it. So it's fine to commit this patch by me.
I'll send a patch to remove the ifdef on the top of this patch after
this patch goes into mainline.
>
> -------------->
> From 7b1dedca42ac0d0d0be01e39d8461bb53a2389b3 Mon Sep 17 00:00:00 2001
> From: Thomas Bogendoerfer <[email protected]>
> Date: Sat, 29 Nov 2008 13:46:27 +0100
> Subject: [PATCH] x86: fix dma_mapping_error for 32bit x86
>
> Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> handles this cases by falling back to GFP_DMA allocation. But for detecting
> the problem it needs to get an indication from dma_mapping_error.
> The bug is triggered by using a VMSPLIT option of 2G/2G.
>
> Signed-off-by: Thomas Bogendoerfer <[email protected]>
> Acked-by: FUJITA Tomonori <[email protected]>
> Signed-off-by: Ingo Molnar <[email protected]>
> ---
> arch/x86/include/asm/dma-mapping.h | 6 ++----
> 1 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> index 7f225a4..097794f 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -71,15 +71,13 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
> /* Make sure we keep the same behaviour */
> static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> {
> -#ifdef CONFIG_X86_32
> - return 0;
> -#else
> +#ifdef CONFIG_X86_64
> struct dma_mapping_ops *ops = get_dma_ops(dev);
> if (ops->mapping_error)
> return ops->mapping_error(dev, dma_addr);
>
> - return (dma_addr == bad_dma_address);
> #endif
> + return (dma_addr == bad_dma_address);
> }
>
> #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
On Mon, 1 Dec 2008 13:58:52 +0100
Joerg Roedel <[email protected]> wrote:
> On Mon, Dec 01, 2008 at 09:01:06PM +0900, FUJITA Tomonori wrote:
> > On Mon, 1 Dec 2008 12:34:51 +0100
> > Joerg Roedel <[email protected]> wrote:
> >
> > > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > > the problem it needs to get an indication from dma_mapping_error.
> > > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> > >
> > > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > > implementation providing the ops->mapping_error callback and does not
> > > use bad_dma_address as the error value.
> >
> > I think that you misunderstand the problem.
> >
> > He uses X86_32 so swiotlb should not be used (which is available on only
> > X86_64 and IA64 for now).
> >
> > b44 needs an address under 1GB so it sets device->dma_mask to
> > DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> > get addresses above 1GB from the networking subsystem. In such case,
> > nommu_map_single returns bad_dma_address properly, but on X86_32,
> > dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> > that the address is under 1GB.
> >
> > This patch fixes dma_mapping_error() to check a passed address
> > properly (compares it with bad_dma_address).
>
> Ah true, thanks. Anyway, the patch also solved the problem with swiotlb
> on 64bit.
Can you be specific?
swiotlb's dma_mapping_error on X86_64 doesn't have any problem as far
as I know.
* FUJITA Tomonori <[email protected]> wrote:
> On Mon, 1 Dec 2008 13:55:01 +0100
> Ingo Molnar <[email protected]> wrote:
>
> >
> > * FUJITA Tomonori <[email protected]> wrote:
> >
> > > On Mon, 1 Dec 2008 12:34:51 +0100
> > > Joerg Roedel <[email protected]> wrote:
> > >
> > > > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > > > the problem it needs to get an indication from dma_mapping_error.
> > > > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> > > >
> > > > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > > > implementation providing the ops->mapping_error callback and does not
> > > > use bad_dma_address as the error value.
> > >
> > > I think that you misunderstand the problem.
> > >
> > > He uses X86_32 so swiotlb should not be used (which is available on
> > > only X86_64 and IA64 for now).
> > >
> > > b44 needs an address under 1GB so it sets device->dma_mask to
> > > DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> > > get addresses above 1GB from the networking subsystem. In such case,
> > > nommu_map_single returns bad_dma_address properly, but on X86_32,
> > > dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> > > that the address is under 1GB.
> > >
> > > This patch fixes dma_mapping_error() to check a passed address
> > > properly (compares it with bad_dma_address).
> > >
> > > As I already wrote, the current git needs a patch modified slightly:
> > >
> > > http://marc.info/?l=linux-kernel&m=122797163405377&w=2
> >
> > i have i queued up in x86/urgent, see below.
>
> As I wrote, just removing #ifdef is better since:
>
> 1) Xen people want swiotlb on X86_32. swiotlb uses ops->mapping_error
> so X86_32 also needs to check ops->mapping_error.
>
> 2) Removing #ifdef hack is always good.
>
>
> But this patch fixes the bug and it works for now. And I think that
> Thomas tested it. So it's fine to commit this patch by me.
yeah, i included the tested patch.
> I'll send a patch to remove the ifdef on the top of this patch after
> this patch goes into mainline.
sure - or you can send it against tip/master straight away.
Ingo
On Mon, 1 Dec 2008 15:35:34 +0100
Ingo Molnar <[email protected]> wrote:
>
> * FUJITA Tomonori <[email protected]> wrote:
>
> > On Mon, 1 Dec 2008 13:55:01 +0100
> > Ingo Molnar <[email protected]> wrote:
> >
> > >
> > > * FUJITA Tomonori <[email protected]> wrote:
> > >
> > > > On Mon, 1 Dec 2008 12:34:51 +0100
> > > > Joerg Roedel <[email protected]> wrote:
> > > >
> > > > > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > > > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > > > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > > > > the problem it needs to get an indication from dma_mapping_error.
> > > > > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> > > > >
> > > > > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > > > > implementation providing the ops->mapping_error callback and does not
> > > > > use bad_dma_address as the error value.
> > > >
> > > > I think that you misunderstand the problem.
> > > >
> > > > He uses X86_32 so swiotlb should not be used (which is available on
> > > > only X86_64 and IA64 for now).
> > > >
> > > > b44 needs an address under 1GB so it sets device->dma_mask to
> > > > DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> > > > get addresses above 1GB from the networking subsystem. In such case,
> > > > nommu_map_single returns bad_dma_address properly, but on X86_32,
> > > > dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> > > > that the address is under 1GB.
> > > >
> > > > This patch fixes dma_mapping_error() to check a passed address
> > > > properly (compares it with bad_dma_address).
> > > >
> > > > As I already wrote, the current git needs a patch modified slightly:
> > > >
> > > > http://marc.info/?l=linux-kernel&m=122797163405377&w=2
> > >
> > > i have i queued up in x86/urgent, see below.
> >
> > As I wrote, just removing #ifdef is better since:
> >
> > 1) Xen people want swiotlb on X86_32. swiotlb uses ops->mapping_error
> > so X86_32 also needs to check ops->mapping_error.
> >
> > 2) Removing #ifdef hack is always good.
> >
> >
> > But this patch fixes the bug and it works for now. And I think that
> > Thomas tested it. So it's fine to commit this patch by me.
>
> yeah, i included the tested patch.
>
> > I'll send a patch to remove the ifdef on the top of this patch after
> > this patch goes into mainline.
>
> sure - or you can send it against tip/master straight away.
Ok, here you are.
Note that this is for 2.6.29 (not 2.6.28).
=
From: FUJITA Tomonori <[email protected]>
Subject: [PATCH] x86: remove ifdef CONFIG_X86_64 in dma_mapping_error
This removes ifdef CONFIG_X86_64 in dma_mapping_error():
1) Xen people plan to use swiotlb on X86_32 for Dom0 support. swiotlb
uses ops->mapping_error so X86_32 also needs to check
ops->mapping_error.
2) Removing #ifdef hack is almost always a good thing.
Signed-off-by: FUJITA Tomonori <[email protected]>
---
arch/x86/include/asm/dma-mapping.h | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index ecf8eaf..40d155d 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -72,12 +72,10 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
/* Make sure we keep the same behaviour */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
-#ifdef CONFIG_X86_64
struct dma_mapping_ops *ops = get_dma_ops(dev);
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
-#endif
return (dma_addr == bad_dma_address);
}
--
1.5.5.GIT
* FUJITA Tomonori <[email protected]> wrote:
> On Mon, 1 Dec 2008 15:35:34 +0100
> Ingo Molnar <[email protected]> wrote:
>
> >
> > * FUJITA Tomonori <[email protected]> wrote:
> >
> > > On Mon, 1 Dec 2008 13:55:01 +0100
> > > Ingo Molnar <[email protected]> wrote:
> > >
> > > >
> > > > * FUJITA Tomonori <[email protected]> wrote:
> > > >
> > > > > On Mon, 1 Dec 2008 12:34:51 +0100
> > > > > Joerg Roedel <[email protected]> wrote:
> > > > >
> > > > > > On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote:
> > > > > > > Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> > > > > > > handles this cases by falling back to GFP_DMA allocation. But for detecting
> > > > > > > the problem it needs to get an indication from dma_mapping_error.
> > > > > > > The bug is triggered by using a VMSPLIT option of 2G/2G.
> > > > > >
> > > > > > Looks like your system uses swiotlb as the dma_ops backend. Its the only
> > > > > > implementation providing the ops->mapping_error callback and does not
> > > > > > use bad_dma_address as the error value.
> > > > >
> > > > > I think that you misunderstand the problem.
> > > > >
> > > > > He uses X86_32 so swiotlb should not be used (which is available on
> > > > > only X86_64 and IA64 for now).
> > > > >
> > > > > b44 needs an address under 1GB so it sets device->dma_mask to
> > > > > DMA_30BIT_MASK. With VMSPLIT option of 2G/2G, I guess that b44 could
> > > > > get addresses above 1GB from the networking subsystem. In such case,
> > > > > nommu_map_single returns bad_dma_address properly, but on X86_32,
> > > > > dma_mapping_error always returns 0 (success). So b44 wrongly thinks
> > > > > that the address is under 1GB.
> > > > >
> > > > > This patch fixes dma_mapping_error() to check a passed address
> > > > > properly (compares it with bad_dma_address).
> > > > >
> > > > > As I already wrote, the current git needs a patch modified slightly:
> > > > >
> > > > > http://marc.info/?l=linux-kernel&m=122797163405377&w=2
> > > >
> > > > i have i queued up in x86/urgent, see below.
> > >
> > > As I wrote, just removing #ifdef is better since:
> > >
> > > 1) Xen people want swiotlb on X86_32. swiotlb uses ops->mapping_error
> > > so X86_32 also needs to check ops->mapping_error.
> > >
> > > 2) Removing #ifdef hack is always good.
> > >
> > >
> > > But this patch fixes the bug and it works for now. And I think that
> > > Thomas tested it. So it's fine to commit this patch by me.
> >
> > yeah, i included the tested patch.
> >
> > > I'll send a patch to remove the ifdef on the top of this patch after
> > > this patch goes into mainline.
> >
> > sure - or you can send it against tip/master straight away.
>
> Ok, here you are.
>
> Note that this is for 2.6.29 (not 2.6.28).
thanks, applied to tip/x86/iommu.
Ingo