2018-10-14 07:52:55

by Christoph Hellwig

[permalink] [raw]
Subject: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

We already build the swiotlb code for 32b-t kernels with PAE support,
but the code to actually use swiotlb has only been enabled for 64-bit
kernel for an unknown reason.

Before Linux 4.18 we papers over this fact because the networking code,
the scsi layer and some random block drivers implenented their own
bounce buffering scheme.

Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")
Fixes: ab74cfeb ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
Reported-by: tedheadster <[email protected]>
Tested-by: tedheadster <[email protected]>
---
arch/x86/kernel/pci-swiotlb.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 661583662430..71c0b01d93b1 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
int __init pci_swiotlb_detect_4gb(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
-#ifdef CONFIG_X86_64
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
-#endif

/*
* If SME is active then swiotlb will be set to 1 so that bounce
--
2.19.1



2018-10-14 08:14:40

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

On Sun, 14 Oct 2018, Christoph Hellwig wrote:

> We already build the swiotlb code for 32b-t kernels with PAE support,
> but the code to actually use swiotlb has only been enabled for 64-bit
> kernel for an unknown reason.
>
> Before Linux 4.18 we papers over this fact because the networking code,
> the scsi layer and some random block drivers implenented their own
> bounce buffering scheme.
>
> Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")
> Fixes: ab74cfeb ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
> Reported-by: tedheadster <[email protected]>
> Tested-by: tedheadster <[email protected]>

I'll add your SOB when picking this up :)

> ---
> arch/x86/kernel/pci-swiotlb.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
> index 661583662430..71c0b01d93b1 100644
> --- a/arch/x86/kernel/pci-swiotlb.c
> +++ b/arch/x86/kernel/pci-swiotlb.c
> @@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
> int __init pci_swiotlb_detect_4gb(void)
> {
> /* don't initialize swiotlb if iommu=off (no_iommu=1) */
> -#ifdef CONFIG_X86_64
> if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
> swiotlb = 1;
> -#endif
>
> /*
> * If SME is active then swiotlb will be set to 1 so that bounce
> --
> 2.19.1
>
>

2018-10-14 08:16:17

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

On Sun, Oct 14, 2018 at 10:13:31AM +0200, Thomas Gleixner wrote:
> On Sun, 14 Oct 2018, Christoph Hellwig wrote:
>
> > We already build the swiotlb code for 32b-t kernels with PAE support,
> > but the code to actually use swiotlb has only been enabled for 64-bit
> > kernel for an unknown reason.
> >
> > Before Linux 4.18 we papers over this fact because the networking code,
> > the scsi layer and some random block drivers implenented their own
> > bounce buffering scheme.
> >
> > Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")
> > Fixes: ab74cfeb ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
> > Reported-by: tedheadster <[email protected]>
> > Tested-by: tedheadster <[email protected]>
>
> I'll add your SOB when picking this up :)

Thanks. Here it is in writing:

Signed-off-by: Christoph Hellwig <[email protected]>

2018-10-14 08:59:45

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

On Sun, 14 Oct 2018, Christoph Hellwig wrote:

> On Sun, Oct 14, 2018 at 10:13:31AM +0200, Thomas Gleixner wrote:
> > On Sun, 14 Oct 2018, Christoph Hellwig wrote:
> >
> > > We already build the swiotlb code for 32b-t kernels with PAE support,
> > > but the code to actually use swiotlb has only been enabled for 64-bit
> > > kernel for an unknown reason.
> > >
> > > Before Linux 4.18 we papers over this fact because the networking code,
> > > the scsi layer and some random block drivers implenented their own
> > > bounce buffering scheme.
> > >
> > > Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")

Please use the first 12 characters of the commit SHA for fixes tags in the
future, as documented. No need to resend, I fixed it up for you and added a
Cc: stable as well

Thanks,

tglx

2018-10-14 09:05:14

by Ingo Molnar

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels


* Thomas Gleixner <[email protected]> wrote:

> On Sun, 14 Oct 2018, Christoph Hellwig wrote:
>
> > On Sun, Oct 14, 2018 at 10:13:31AM +0200, Thomas Gleixner wrote:
> > > On Sun, 14 Oct 2018, Christoph Hellwig wrote:
> > >
> > > > We already build the swiotlb code for 32b-t kernels with PAE support,
> > > > but the code to actually use swiotlb has only been enabled for 64-bit
> > > > kernel for an unknown reason.
> > > >
> > > > Before Linux 4.18 we papers over this fact because the networking code,
> > > > the scsi layer and some random block drivers implenented their own
> > > > bounce buffering scheme.
> > > >
> > > > Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")
>
> Please use the first 12 characters of the commit SHA for fixes tags in the
> future, as documented. No need to resend, I fixed it up for you and added a
> Cc: stable as well

For those who have their ~/.gitconfig's from ancient Git history, this can be done via:

git config --global core.abbrev 12

Thanks,

Ingo

Subject: [tip:x86/urgent] x86/swiotlb: Enable swiotlb for > 4GiG ram on 32-bit kernels

Commit-ID: ab555321e4ddc7f6f17f6c80dfaad228883a8e7c
Gitweb: https://git.kernel.org/tip/ab555321e4ddc7f6f17f6c80dfaad228883a8e7c
Author: Christoph Hellwig <[email protected]>
AuthorDate: Sun, 14 Oct 2018 09:52:08 +0200
Committer: Thomas Gleixner <[email protected]>
CommitDate: Sun, 14 Oct 2018 11:11:23 +0200

x86/swiotlb: Enable swiotlb for > 4GiG ram on 32-bit kernels

We already build the swiotlb code for 32b-t kernels with PAE support,
but the code to actually use swiotlb has only been enabled for 64-bit
kernel for an unknown reason.

Before Linux 4.18 we paper over this fact because the networking code,
the scsi layer and some random block drivers implemented their own
bounce buffering scheme.

Fixes: 21e07dba9fb1 ("scsi: reduce use of block bounce buffers")
Fixes: ab74cfebafa3 ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
Reported-by: tedheadster <[email protected]>
Tested-by: tedheadster <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

---
arch/x86/kernel/pci-swiotlb.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 661583662430..71c0b01d93b1 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
int __init pci_swiotlb_detect_4gb(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
-#ifdef CONFIG_X86_64
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
-#endif

/*
* If SME is active then swiotlb will be set to 1 so that bounce

2018-10-14 12:51:18

by tedheadster

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

Please change:

Reported-by: tedheadster <[email protected]>
Tested-by: tedheadster <[email protected]>

to

Reported-by: Matthew Whitehead <[email protected]>
Tested-by: Matthew Whitehead <[email protected]>

- Matthew

Subject: [tip:x86/urgent] x86/swiotlb: Enable swiotlb for > 4GiG ram on 32-bit kernels

Commit-ID: 6f3bc8028570e4c326030e8795dbcd57c561b723
Gitweb: https://git.kernel.org/tip/6f3bc8028570e4c326030e8795dbcd57c561b723
Author: Christoph Hellwig <[email protected]>
AuthorDate: Sun, 14 Oct 2018 09:52:08 +0200
Committer: Thomas Gleixner <[email protected]>
CommitDate: Mon, 15 Oct 2018 10:55:03 +0200

x86/swiotlb: Enable swiotlb for > 4GiG ram on 32-bit kernels

We already build the swiotlb code for 32b-t kernels with PAE support,
but the code to actually use swiotlb has only been enabled for 64-bit
kernel for an unknown reason.

Before Linux 4.18 we paper over this fact because the networking code,
the scsi layer and some random block drivers implemented their own
bounce buffering scheme.

Fixes: 21e07dba9fb1 ("scsi: reduce use of block bounce buffers")
Fixes: ab74cfebafa3 ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
Reported-by: Matthew Whitehead <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Matthew Whitehead <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/kernel/pci-swiotlb.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 661583662430..71c0b01d93b1 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
int __init pci_swiotlb_detect_4gb(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
-#ifdef CONFIG_X86_64
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
-#endif

/*
* If SME is active then swiotlb will be set to 1 so that bounce

2018-10-15 18:53:29

by Konrad Rzeszutek Wilk

[permalink] [raw]
Subject: Re: [PATCH] x86: enable swiotlb for > 4GiG ram on 32-bit kernels

On 10/14/18 3:52 AM, Christoph Hellwig wrote:
> We already build the swiotlb code for 32b-t kernels with PAE support,
> but the code to actually use swiotlb has only been enabled for 64-bit
> kernel for an unknown reason.
>
> Before Linux 4.18 we papers over this fact because the networking code,
> the scsi layer and some random block drivers implenented their own
> bounce buffering scheme.
>
> Fixes: 21e07dba ("scsi: reduce use of block bounce buffers")
> Fixes: ab74cfeb ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
> Reported-by: tedheadster <[email protected]>
> Tested-by: tedheadster <[email protected]>

Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>

But since it is already in 'tip' feel free to ignore my tag.

Thanks!
> ---
> arch/x86/kernel/pci-swiotlb.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
> index 661583662430..71c0b01d93b1 100644
> --- a/arch/x86/kernel/pci-swiotlb.c
> +++ b/arch/x86/kernel/pci-swiotlb.c
> @@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
> int __init pci_swiotlb_detect_4gb(void)
> {
> /* don't initialize swiotlb if iommu=off (no_iommu=1) */
> -#ifdef CONFIG_X86_64
> if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
> swiotlb = 1;
> -#endif
>
> /*
> * If SME is active then swiotlb will be set to 1 so that bounce
>


Subject: [tip:x86/urgent] x86/swiotlb: Enable swiotlb for > 4GiG RAM on 32-bit kernels

Commit-ID: 485734f3fc77c1eb77ffe138c027b9a4bf0178f3
Gitweb: https://git.kernel.org/tip/485734f3fc77c1eb77ffe138c027b9a4bf0178f3
Author: Christoph Hellwig <[email protected]>
AuthorDate: Sun, 14 Oct 2018 09:52:08 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 19 Oct 2018 07:49:32 +0200

x86/swiotlb: Enable swiotlb for > 4GiG RAM on 32-bit kernels

We already build the swiotlb code for 32-bit kernels with PAE support,
but the code to actually use swiotlb has only been enabled for 64-bit
kernels for an unknown reason.

Before Linux v4.18 we paper over this fact because the networking code,
the SCSI layer and some random block drivers implemented their own
bounce buffering scheme.

[ mingo: Changelog fixes. ]

Fixes: 21e07dba9fb1 ("scsi: reduce use of block bounce buffers")
Fixes: ab74cfebafa3 ("net: remove the PCI_DMA_BUS_IS_PHYS check in illegal_highdma")
Reported-by: Matthew Whitehead <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Matthew Whitehead <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/pci-swiotlb.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 661583662430..71c0b01d93b1 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,10 +42,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
int __init pci_swiotlb_detect_4gb(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
-#ifdef CONFIG_X86_64
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
swiotlb = 1;
-#endif

/*
* If SME is active then swiotlb will be set to 1 so that bounce