Re: [Xen-devel] [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
On Wed, Mar 25, 2015 at 04:03:46PM -0400, Konrad Rzeszutek Wilk wrote:
> On Fri, Mar 20, 2015 at 04:17:54PM -0700, Luis R. Rodriguez wrote:
> > From: "Luis R. Rodriguez"
> >
> > This lets drivers take advanate of PAT when available. This
>
> s/advanate/advantage/
Amended.
> > should help with the transition of converting video drivers over
> > to ioremap_wc() to help with the goal of eventually using
> > _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
> > ioremap_nocache() (de33c442e)
>
> Please mention the title of the patch too:
>
> "x86 PAT: fix performance drop for glx, use UC minus for ioremap(),
> ioremap_nocache() and pci_mmap_page_range()"
Added.
> >
> > Cc: Suresh Siddha
> > Cc: Venkatesh Pallipadi
> > Cc: Ingo Molnar
> > Cc: Thomas Gleixner
> > Cc: Juergen Gross
> > Cc: Daniel Vetter
> > Cc: Andy Lutomirski
> > Cc: Dave Airlie
> > Cc: Antonino Daplas
> > Cc: Jean-Christophe Plagniol-Villard
> > Cc: Tomi Valkeinen
> > Cc: linux-fb...@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Luis R. Rodriguez
> > ---
> > drivers/pci/pci.c | 14 ++
> > include/linux/pci.h | 1 +
> > 2 files changed, 15 insertions(+)
> >
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index 81f06e8..6afd507 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev,
> > int bar)
> > pci_resource_len(pdev, bar));
> > }
> > EXPORT_SYMBOL_GPL(pci_ioremap_bar);
> > +
> > +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
> > +{
> > + /*
> > +* Make sure the BAR is actually a memory resource, not an IO resource
> > +*/
> > + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
> > + WARN_ON(1);
>
> Would it be better to use dev_warn ? That way you can see which BDF it is?
>
> Thought WARN will give a nice stack-trace that should easily point to the
> driver so perhaps not.. Either way - up to you.
I'm sticking to the style and use as with pci_ioremap_bar(). Whatever we pick
we should make both use the same. More information is always better and
since we do have dev_warn(), it would be nice to use that however within
its use on both pci_ioremap_wc_bar() and pci_ioremap_bar() we have
a use of the pdev with pci_resource_flags() and I believe if pdev is NULL
we'd get a NULL dereference (dev_driver_string() is used), so it would
seem it might be best to stick with a simple WARN_ON(). Arjan, any
preference? Obviously if pdev is NULL your driver is dumb but as folks
develop drivers this should be expected.
Luis
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Re: [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
On Fri, Mar 20, 2015 at 04:50:32PM -0700, Andy Lutomirski wrote:
> On Fri, Mar 20, 2015 at 4:17 PM, Luis R. Rodriguez
> wrote:
> > From: "Luis R. Rodriguez"
> >
> > This lets drivers take advanate of PAT when available. This
> > should help with the transition of converting video drivers over
> > to ioremap_wc() to help with the goal of eventually using
> > _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
> > ioremap_nocache() (de33c442e)
> >
> > Cc: Suresh Siddha
> > Cc: Venkatesh Pallipadi
> > Cc: Ingo Molnar
> > Cc: Thomas Gleixner
> > Cc: Juergen Gross
> > Cc: Daniel Vetter
> > Cc: Andy Lutomirski
> > Cc: Dave Airlie
> > Cc: Antonino Daplas
> > Cc: Jean-Christophe Plagniol-Villard
> > Cc: Tomi Valkeinen
> > Cc: linux-fb...@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Luis R. Rodriguez
> > ---
> > drivers/pci/pci.c | 14 ++
> > include/linux/pci.h | 1 +
> > 2 files changed, 15 insertions(+)
> >
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index 81f06e8..6afd507 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev,
> > int bar)
> > pci_resource_len(pdev, bar));
> > }
> > EXPORT_SYMBOL_GPL(pci_ioremap_bar);
> > +
> > +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
> > +{
> > + /*
> > +* Make sure the BAR is actually a memory resource, not an IO
> > resource
> > +*/
> > + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
> > + WARN_ON(1);
> > + return NULL;
> > + }
>
> if (WARN_ON(...))?
Sure, they are equivalent however this follows the same exact style as
pci_ioremap_bar() so if we change this one might as well change the style of
pci_ioremap_bar() as well. Let me know if there is any preference. I personally
don't mind the extra line as it shortens the check.
Luis
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Re: [Xen-devel] [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
On Fri, Mar 20, 2015 at 04:17:54PM -0700, Luis R. Rodriguez wrote:
> From: "Luis R. Rodriguez"
>
> This lets drivers take advanate of PAT when available. This
s/advanate/advantage/
> should help with the transition of converting video drivers over
> to ioremap_wc() to help with the goal of eventually using
> _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
> ioremap_nocache() (de33c442e)
Please mention the title of the patch too:
"x86 PAT: fix performance drop for glx, use UC minus for ioremap(),
ioremap_nocache() and pci_mmap_page_range()"
>
> Cc: Suresh Siddha
> Cc: Venkatesh Pallipadi
> Cc: Ingo Molnar
> Cc: Thomas Gleixner
> Cc: Juergen Gross
> Cc: Daniel Vetter
> Cc: Andy Lutomirski
> Cc: Dave Airlie
> Cc: Antonino Daplas
> Cc: Jean-Christophe Plagniol-Villard
> Cc: Tomi Valkeinen
> Cc: linux-fb...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez
> ---
> drivers/pci/pci.c | 14 ++
> include/linux/pci.h | 1 +
> 2 files changed, 15 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 81f06e8..6afd507 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int
> bar)
>pci_resource_len(pdev, bar));
> }
> EXPORT_SYMBOL_GPL(pci_ioremap_bar);
> +
> +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
> +{
> + /*
> + * Make sure the BAR is actually a memory resource, not an IO resource
> + */
> + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
> + WARN_ON(1);
Would it be better to use dev_warn ? That way you can see which BDF it is?
Thought WARN will give a nice stack-trace that should easily point to the
driver so perhaps not.. Either way - up to you.
> + return NULL;
> + }
> + return ioremap_wc(pci_resource_start(pdev, bar),
> + pci_resource_len(pdev, bar));
> +}
> +EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
> #endif
>
> #define PCI_FIND_CAP_TTL 48
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 211e9da..c235b09 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1667,6 +1667,7 @@ static inline void pci_mmcfg_late_init(void) { }
> int pci_ext_cfg_avail(void);
>
> void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
> +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
>
> #ifdef CONFIG_PCI_IOV
> int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
> --
> 2.3.2.209.gd67f9d5.dirty
>
>
> ___
> Xen-devel mailing list
> xen-de...@lists.xen.org
> http://lists.xen.org/xen-devel
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Re: [PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
On Fri, Mar 20, 2015 at 4:17 PM, Luis R. Rodriguez
wrote:
> From: "Luis R. Rodriguez"
>
> This lets drivers take advanate of PAT when available. This
> should help with the transition of converting video drivers over
> to ioremap_wc() to help with the goal of eventually using
> _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
> ioremap_nocache() (de33c442e)
>
> Cc: Suresh Siddha
> Cc: Venkatesh Pallipadi
> Cc: Ingo Molnar
> Cc: Thomas Gleixner
> Cc: Juergen Gross
> Cc: Daniel Vetter
> Cc: Andy Lutomirski
> Cc: Dave Airlie
> Cc: Antonino Daplas
> Cc: Jean-Christophe Plagniol-Villard
> Cc: Tomi Valkeinen
> Cc: linux-fb...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez
> ---
> drivers/pci/pci.c | 14 ++
> include/linux/pci.h | 1 +
> 2 files changed, 15 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 81f06e8..6afd507 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int
> bar)
> pci_resource_len(pdev, bar));
> }
> EXPORT_SYMBOL_GPL(pci_ioremap_bar);
> +
> +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
> +{
> + /*
> +* Make sure the BAR is actually a memory resource, not an IO resource
> +*/
> + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
> + WARN_ON(1);
> + return NULL;
> + }
if (WARN_ON(...))?
--Andy
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[PATCH v1 04/47] pci: add pci_ioremap_wc_bar()
From: "Luis R. Rodriguez"
This lets drivers take advanate of PAT when available. This
should help with the transition of converting video drivers over
to ioremap_wc() to help with the goal of eventually using
_PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
ioremap_nocache() (de33c442e)
Cc: Suresh Siddha
Cc: Venkatesh Pallipadi
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Juergen Gross
Cc: Daniel Vetter
Cc: Andy Lutomirski
Cc: Dave Airlie
Cc: Antonino Daplas
Cc: Jean-Christophe Plagniol-Villard
Cc: Tomi Valkeinen
Cc: linux-fb...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez
---
drivers/pci/pci.c | 14 ++
include/linux/pci.h | 1 +
2 files changed, 15 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 81f06e8..6afd507 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int
bar)
pci_resource_len(pdev, bar));
}
EXPORT_SYMBOL_GPL(pci_ioremap_bar);
+
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
+{
+ /*
+* Make sure the BAR is actually a memory resource, not an IO resource
+*/
+ if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
+ WARN_ON(1);
+ return NULL;
+ }
+ return ioremap_wc(pci_resource_start(pdev, bar),
+ pci_resource_len(pdev, bar));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
#endif
#define PCI_FIND_CAP_TTL 48
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 211e9da..c235b09 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1667,6 +1667,7 @@ static inline void pci_mmcfg_late_init(void) { }
int pci_ext_cfg_avail(void);
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
#ifdef CONFIG_PCI_IOV
int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
--
2.3.2.209.gd67f9d5.dirty
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