Patchwork [PATCHv8,07/19] arm: pci: add a align_resource hook

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Submitter Thomas Petazzoni
Date April 9, 2013, 9:06 p.m.
Message ID <1365541601-14095-8-git-send-email-thomas.petazzoni@free-electrons.com>
Download mbox | patch
Permalink /patch/235235/
State Not Applicable
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Comments

Thomas Petazzoni - April 9, 2013, 9:06 p.m.
The PCI specifications says that an I/O region must be aligned on a 4
KB boundary, and a memory region aligned on a 1 MB boundary.

However, the Marvell PCIe interfaces rely on address decoding windows
(which allow to associate a range of physical addresses with a given
device). For PCIe memory windows, those windows are defined with a 1
MB granularity (which matches the PCI specs), but PCIe I/O windows can
only be defined with a 64 KB granularity, so they have to be 64 KB
aligned. We therefore need to tell the PCI core about this special
alignement requirement.

The PCI core already calls pcibios_align_resource() in the ARM PCI
core, specifically for such purposes. So this patch extends the ARM
PCI core so that it calls a ->align_resource() hook registered by the
PCI driver, exactly like the existing ->map_irq() and ->swizzle()
hooks.

A particular PCI driver can register a align_resource() hook, and do
its own specific alignement, depending on the specific constraints of
the underlying hardware.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Russell King <linux@arm.linux.org.uk>
---
 arch/arm/include/asm/mach/pci.h |   11 +++++++++++
 arch/arm/kernel/bios32.c        |    6 ++++++
 2 files changed, 17 insertions(+)
Jason - April 15, 2013, 4:36 p.m.
Russell,

Thanks for applying this patch (7683/1) to your tree.  I see it's in
your for-next, which I understand *isn't* stable.

  029baf1 ARM: 7683/1: pci: add a align_resource hook

Is there a stable branch I could depend on for the rest of this series
(particularly, patch 10)?  It looks like you applied it to your misc
branch, but that's not currently available.

thx,

Jason.

On Tue, Apr 09, 2013 at 11:06:28PM +0200, Thomas Petazzoni wrote:
> The PCI specifications says that an I/O region must be aligned on a 4
> KB boundary, and a memory region aligned on a 1 MB boundary.
> 
> However, the Marvell PCIe interfaces rely on address decoding windows
> (which allow to associate a range of physical addresses with a given
> device). For PCIe memory windows, those windows are defined with a 1
> MB granularity (which matches the PCI specs), but PCIe I/O windows can
> only be defined with a 64 KB granularity, so they have to be 64 KB
> aligned. We therefore need to tell the PCI core about this special
> alignement requirement.
> 
> The PCI core already calls pcibios_align_resource() in the ARM PCI
> core, specifically for such purposes. So this patch extends the ARM
> PCI core so that it calls a ->align_resource() hook registered by the
> PCI driver, exactly like the existing ->map_irq() and ->swizzle()
> hooks.
> 
> A particular PCI driver can register a align_resource() hook, and do
> its own specific alignement, depending on the specific constraints of
> the underlying hardware.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> ---
>  arch/arm/include/asm/mach/pci.h |   11 +++++++++++
>  arch/arm/kernel/bios32.c        |    6 ++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> index 5cf2e97..7d2c3c8 100644
> --- a/arch/arm/include/asm/mach/pci.h
> +++ b/arch/arm/include/asm/mach/pci.h
> @@ -30,6 +30,11 @@ struct hw_pci {
>  	void		(*postinit)(void);
>  	u8		(*swizzle)(struct pci_dev *dev, u8 *pin);
>  	int		(*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin);
> +	resource_size_t (*align_resource)(struct pci_dev *dev,
> +					  const struct resource *res,
> +					  resource_size_t start,
> +					  resource_size_t size,
> +					  resource_size_t align);
>  };
>  
>  /*
> @@ -51,6 +56,12 @@ struct pci_sys_data {
>  	u8		(*swizzle)(struct pci_dev *, u8 *);
>  					/* IRQ mapping				*/
>  	int		(*map_irq)(const struct pci_dev *, u8, u8);
> +					/* Resource alignement requirements	*/
> +	resource_size_t (*align_resource)(struct pci_dev *dev,
> +					  const struct resource *res,
> +					  resource_size_t start,
> +					  resource_size_t size,
> +					  resource_size_t align);
>  	void		*private_data;	/* platform controller private data	*/
>  };
>  
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index a1f73b5..b2ed73c 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -462,6 +462,7 @@ static void pcibios_init_hw(struct hw_pci *hw, struct list_head *head)
>  		sys->busnr   = busnr;
>  		sys->swizzle = hw->swizzle;
>  		sys->map_irq = hw->map_irq;
> +		sys->align_resource = hw->align_resource;
>  		INIT_LIST_HEAD(&sys->resources);
>  
>  		if (hw->private_data)
> @@ -574,6 +575,8 @@ char * __init pcibios_setup(char *str)
>  resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>  				resource_size_t size, resource_size_t align)
>  {
> +	struct pci_dev *dev = data;
> +	struct pci_sys_data *sys = dev->sysdata;
>  	resource_size_t start = res->start;
>  
>  	if (res->flags & IORESOURCE_IO && start & 0x300)
> @@ -581,6 +584,9 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>  
>  	start = (start + align - 1) & ~(align - 1);
>  
> +	if (sys->align_resource)
> +		return sys->align_resource(dev, res, start, size, align);
> +
>  	return start;
>  }
>  
> -- 
> 1.7.9.5
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Jason - April 17, 2013, 2:08 p.m.
Russell,

I saw you were back online this morning, could you please consider the
following request?

On Mon, Apr 15, 2013 at 12:36:09PM -0400, Jason Cooper wrote:
> Russell,
> 
> Thanks for applying this patch (7683/1) to your tree.  I see it's in
> your for-next, which I understand *isn't* stable.
> 
>   029baf1 ARM: 7683/1: pci: add a align_resource hook
> 
> Is there a stable branch I could depend on for the rest of this series
> (particularly, patch 10)?  It looks like you applied it to your misc
> branch, but that's not currently available.

I'd really like to get this in for v3.10.  As Thomas has mentioned
before, the series has had plenty of review on the list.

thx,

Jason.

> On Tue, Apr 09, 2013 at 11:06:28PM +0200, Thomas Petazzoni wrote:
> > The PCI specifications says that an I/O region must be aligned on a 4
> > KB boundary, and a memory region aligned on a 1 MB boundary.
> > 
> > However, the Marvell PCIe interfaces rely on address decoding windows
> > (which allow to associate a range of physical addresses with a given
> > device). For PCIe memory windows, those windows are defined with a 1
> > MB granularity (which matches the PCI specs), but PCIe I/O windows can
> > only be defined with a 64 KB granularity, so they have to be 64 KB
> > aligned. We therefore need to tell the PCI core about this special
> > alignement requirement.
> > 
> > The PCI core already calls pcibios_align_resource() in the ARM PCI
> > core, specifically for such purposes. So this patch extends the ARM
> > PCI core so that it calls a ->align_resource() hook registered by the
> > PCI driver, exactly like the existing ->map_irq() and ->swizzle()
> > hooks.
> > 
> > A particular PCI driver can register a align_resource() hook, and do
> > its own specific alignement, depending on the specific constraints of
> > the underlying hardware.
> > 
> > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> > Cc: Russell King <linux@arm.linux.org.uk>
> > ---
> >  arch/arm/include/asm/mach/pci.h |   11 +++++++++++
> >  arch/arm/kernel/bios32.c        |    6 ++++++
> >  2 files changed, 17 insertions(+)
> > 
> > diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> > index 5cf2e97..7d2c3c8 100644
> > --- a/arch/arm/include/asm/mach/pci.h
> > +++ b/arch/arm/include/asm/mach/pci.h
> > @@ -30,6 +30,11 @@ struct hw_pci {
> >  	void		(*postinit)(void);
> >  	u8		(*swizzle)(struct pci_dev *dev, u8 *pin);
> >  	int		(*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin);
> > +	resource_size_t (*align_resource)(struct pci_dev *dev,
> > +					  const struct resource *res,
> > +					  resource_size_t start,
> > +					  resource_size_t size,
> > +					  resource_size_t align);
> >  };
> >  
> >  /*
> > @@ -51,6 +56,12 @@ struct pci_sys_data {
> >  	u8		(*swizzle)(struct pci_dev *, u8 *);
> >  					/* IRQ mapping				*/
> >  	int		(*map_irq)(const struct pci_dev *, u8, u8);
> > +					/* Resource alignement requirements	*/
> > +	resource_size_t (*align_resource)(struct pci_dev *dev,
> > +					  const struct resource *res,
> > +					  resource_size_t start,
> > +					  resource_size_t size,
> > +					  resource_size_t align);
> >  	void		*private_data;	/* platform controller private data	*/
> >  };
> >  
> > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> > index a1f73b5..b2ed73c 100644
> > --- a/arch/arm/kernel/bios32.c
> > +++ b/arch/arm/kernel/bios32.c
> > @@ -462,6 +462,7 @@ static void pcibios_init_hw(struct hw_pci *hw, struct list_head *head)
> >  		sys->busnr   = busnr;
> >  		sys->swizzle = hw->swizzle;
> >  		sys->map_irq = hw->map_irq;
> > +		sys->align_resource = hw->align_resource;
> >  		INIT_LIST_HEAD(&sys->resources);
> >  
> >  		if (hw->private_data)
> > @@ -574,6 +575,8 @@ char * __init pcibios_setup(char *str)
> >  resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> >  				resource_size_t size, resource_size_t align)
> >  {
> > +	struct pci_dev *dev = data;
> > +	struct pci_sys_data *sys = dev->sysdata;
> >  	resource_size_t start = res->start;
> >  
> >  	if (res->flags & IORESOURCE_IO && start & 0x300)
> > @@ -581,6 +584,9 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> >  
> >  	start = (start + align - 1) & ~(align - 1);
> >  
> > +	if (sys->align_resource)
> > +		return sys->align_resource(dev, res, start, size, align);
> > +
> >  	return start;
> >  }
> >  
> > -- 
> > 1.7.9.5
> > 
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Russell King - ARM Linux - April 19, 2013, 2:33 p.m.
On Mon, Apr 15, 2013 at 12:36:09PM -0400, Jason Cooper wrote:
> Russell,
> 
> Thanks for applying this patch (7683/1) to your tree.  I see it's in
> your for-next, which I understand *isn't* stable.

That is correct.

>   029baf1 ARM: 7683/1: pci: add a align_resource hook
> 
> Is there a stable branch I could depend on for the rest of this series
> (particularly, patch 10)?  It looks like you applied it to your misc
> branch, but that's not currently available.

I will have to look at that; as I'm still catching up with mail three
days after having returned and there's still quite an amount outstanding,
it's going to be a while before I can look at this.  Given that we're at
-rc7 and the amount of outstanding mail, it's likely that may happen
after the merge window has opened.

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Patch

diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 5cf2e97..7d2c3c8 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -30,6 +30,11 @@  struct hw_pci {
 	void		(*postinit)(void);
 	u8		(*swizzle)(struct pci_dev *dev, u8 *pin);
 	int		(*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin);
+	resource_size_t (*align_resource)(struct pci_dev *dev,
+					  const struct resource *res,
+					  resource_size_t start,
+					  resource_size_t size,
+					  resource_size_t align);
 };
 
 /*
@@ -51,6 +56,12 @@  struct pci_sys_data {
 	u8		(*swizzle)(struct pci_dev *, u8 *);
 					/* IRQ mapping				*/
 	int		(*map_irq)(const struct pci_dev *, u8, u8);
+					/* Resource alignement requirements	*/
+	resource_size_t (*align_resource)(struct pci_dev *dev,
+					  const struct resource *res,
+					  resource_size_t start,
+					  resource_size_t size,
+					  resource_size_t align);
 	void		*private_data;	/* platform controller private data	*/
 };
 
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index a1f73b5..b2ed73c 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -462,6 +462,7 @@  static void pcibios_init_hw(struct hw_pci *hw, struct list_head *head)
 		sys->busnr   = busnr;
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;
+		sys->align_resource = hw->align_resource;
 		INIT_LIST_HEAD(&sys->resources);
 
 		if (hw->private_data)
@@ -574,6 +575,8 @@  char * __init pcibios_setup(char *str)
 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 				resource_size_t size, resource_size_t align)
 {
+	struct pci_dev *dev = data;
+	struct pci_sys_data *sys = dev->sysdata;
 	resource_size_t start = res->start;
 
 	if (res->flags & IORESOURCE_IO && start & 0x300)
@@ -581,6 +584,9 @@  resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 
 	start = (start + align - 1) & ~(align - 1);
 
+	if (sys->align_resource)
+		return sys->align_resource(dev, res, start, size, align);
+
 	return start;
 }