diff mbox

[RFC,V5,1/5] PCI: Embed pci_ecam_ops in pci_config_window structure

Message ID 1470661541-26270-2-git-send-email-tn@semihalf.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Tomasz Nowicki Aug. 8, 2016, 1:05 p.m. UTC
pci_config_window keeps pointer to pci_ecam_ops and every time
we want to deallocate pci_config_window (pci_ecam_free()) we need to make
sure to free pci_ecam_ops in case it was dynamically allocated prior to
pci_ecam_create() call.

To avoid that extra effort, embed pci_ecam_ops in pci_config_window,
instead of just a pointer.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
To: Jayachandran C <jchandra@broadcom.com>
---
 arch/arm64/kernel/pci.c  | 2 +-
 drivers/pci/ecam.c       | 6 +++---
 include/linux/pci-ecam.h | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

Comments

Bjorn Helgaas Sept. 1, 2016, 6:23 p.m. UTC | #1
On Mon, Aug 08, 2016 at 03:05:37PM +0200, Tomasz Nowicki wrote:
> pci_config_window keeps pointer to pci_ecam_ops and every time
> we want to deallocate pci_config_window (pci_ecam_free()) we need to make
> sure to free pci_ecam_ops in case it was dynamically allocated prior to
> pci_ecam_create() call.

I think this is a theoretical problem, right?  All the current callers
pass a pointer to a static pci_ecam_ops struct that does not need to
be deallocated.

I see that the next patch uses a pci_ecam_ops struct on the stack,
which would definitely cause issues without this patch, so I agree we
need something like this; I'm just trying to make the changelog make
more sense.

> To avoid that extra effort, embed pci_ecam_ops in pci_config_window,
> instead of just a pointer.
> 
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> To: Jayachandran C <jchandra@broadcom.com>

This looks like an editing mistake?

> ---
>  arch/arm64/kernel/pci.c  | 2 +-
>  drivers/pci/ecam.c       | 6 +++---
>  include/linux/pci-ecam.h | 2 +-
>  3 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index acf3872..981e828 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -183,7 +183,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  		return NULL;
>  	}
>  
> -	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
> +	acpi_pci_root_ops.pci_ops = &ri->cfg->ops.pci_ops;
>  	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
>  				   ri->cfg);
>  	if (!bus)
> diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> index 43ed08d..24242f0 100644
> --- a/drivers/pci/ecam.c
> +++ b/drivers/pci/ecam.c
> @@ -52,7 +52,7 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
>  		return ERR_PTR(-ENOMEM);
>  
>  	cfg->parent = dev;
> -	cfg->ops = ops;
> +	cfg->ops = *ops;
>  	cfg->busr.start = busr->start;
>  	cfg->busr.end = busr->end;
>  	cfg->busr.flags = IORESOURCE_BUS;
> @@ -138,7 +138,7 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
>  			       int where)
>  {
>  	struct pci_config_window *cfg = bus->sysdata;
> -	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
> +	unsigned int devfn_shift = cfg->ops.bus_shift - 8;
>  	unsigned int busn = bus->number;
>  	void __iomem *base;
>  
> @@ -149,7 +149,7 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
>  	if (per_bus_mapping)
>  		base = cfg->winp[busn];
>  	else
> -		base = cfg->win + (busn << cfg->ops->bus_shift);
> +		base = cfg->win + (busn << cfg->ops.bus_shift);
>  	return base + (devfn << devfn_shift) + where;
>  }
>  
> diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
> index 7adad20..0ce2920 100644
> --- a/include/linux/pci-ecam.h
> +++ b/include/linux/pci-ecam.h
> @@ -39,7 +39,7 @@ struct pci_config_window {
>  	struct resource			res;
>  	struct resource			busr;
>  	void				*priv;
> -	struct pci_ecam_ops		*ops;
> +	struct pci_ecam_ops		ops;
>  	union {
>  		void __iomem		*win;	/* 64-bit single mapping */
>  		void __iomem		**winp; /* 32-bit per-bus mapping */
> -- 
> 1.9.1
> 
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Lorenzo Pieralisi Sept. 2, 2016, 3:38 p.m. UTC | #2
On Thu, Sep 01, 2016 at 01:23:45PM -0500, Bjorn Helgaas wrote:
> On Mon, Aug 08, 2016 at 03:05:37PM +0200, Tomasz Nowicki wrote:
> > pci_config_window keeps pointer to pci_ecam_ops and every time
> > we want to deallocate pci_config_window (pci_ecam_free()) we need to make
> > sure to free pci_ecam_ops in case it was dynamically allocated prior to
> > pci_ecam_create() call.
> 
> I think this is a theoretical problem, right?  All the current callers
> pass a pointer to a static pci_ecam_ops struct that does not need to
> be deallocated.
> 
> I see that the next patch uses a pci_ecam_ops struct on the stack,

I asked Tomasz why we need to have pci_ecam_ops on the stack in the
first place since I do not think it is needed, or nicer (actually I
think it is not nice at all, what's the problem in making it static ?).

Anyway, that's part of this thread but I think Tomasz was looking
more for feedback/agreement on the whole quirks mechanism to check
if it is fine, more below.

> which would definitely cause issues without this patch, so I agree we
> need something like this; I'm just trying to make the changelog make
> more sense.
> 
> > To avoid that extra effort, embed pci_ecam_ops in pci_config_window,
> > instead of just a pointer.
> > 
> > Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> > To: Jayachandran C <jchandra@broadcom.com>
> 
> This looks like an editing mistake?

Yes it is.

I think the most important bit about this series is to agree on
whether it is ok to keep quirks in drivers/pci/host/mcfg-quirks.c
or we need to find a different dir for it, and of course to make
sure the quirks mechanism is fine with everyone.

Thanks !
Lorenzo

> >  arch/arm64/kernel/pci.c  | 2 +-
> >  drivers/pci/ecam.c       | 6 +++---
> >  include/linux/pci-ecam.h | 2 +-
> >  3 files changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> > index acf3872..981e828 100644
> > --- a/arch/arm64/kernel/pci.c
> > +++ b/arch/arm64/kernel/pci.c
> > @@ -183,7 +183,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> >  		return NULL;
> >  	}
> >  
> > -	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
> > +	acpi_pci_root_ops.pci_ops = &ri->cfg->ops.pci_ops;
> >  	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
> >  				   ri->cfg);
> >  	if (!bus)
> > diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> > index 43ed08d..24242f0 100644
> > --- a/drivers/pci/ecam.c
> > +++ b/drivers/pci/ecam.c
> > @@ -52,7 +52,7 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
> >  		return ERR_PTR(-ENOMEM);
> >  
> >  	cfg->parent = dev;
> > -	cfg->ops = ops;
> > +	cfg->ops = *ops;
> >  	cfg->busr.start = busr->start;
> >  	cfg->busr.end = busr->end;
> >  	cfg->busr.flags = IORESOURCE_BUS;
> > @@ -138,7 +138,7 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
> >  			       int where)
> >  {
> >  	struct pci_config_window *cfg = bus->sysdata;
> > -	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
> > +	unsigned int devfn_shift = cfg->ops.bus_shift - 8;
> >  	unsigned int busn = bus->number;
> >  	void __iomem *base;
> >  
> > @@ -149,7 +149,7 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
> >  	if (per_bus_mapping)
> >  		base = cfg->winp[busn];
> >  	else
> > -		base = cfg->win + (busn << cfg->ops->bus_shift);
> > +		base = cfg->win + (busn << cfg->ops.bus_shift);
> >  	return base + (devfn << devfn_shift) + where;
> >  }
> >  
> > diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
> > index 7adad20..0ce2920 100644
> > --- a/include/linux/pci-ecam.h
> > +++ b/include/linux/pci-ecam.h
> > @@ -39,7 +39,7 @@ struct pci_config_window {
> >  	struct resource			res;
> >  	struct resource			busr;
> >  	void				*priv;
> > -	struct pci_ecam_ops		*ops;
> > +	struct pci_ecam_ops		ops;
> >  	union {
> >  		void __iomem		*win;	/* 64-bit single mapping */
> >  		void __iomem		**winp; /* 32-bit per-bus mapping */
> > -- 
> > 1.9.1
> > 
> 
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Bjorn Helgaas Sept. 5, 2016, 2:22 a.m. UTC | #3
On Fri, Sep 02, 2016 at 04:38:45PM +0100, Lorenzo Pieralisi wrote:
> On Thu, Sep 01, 2016 at 01:23:45PM -0500, Bjorn Helgaas wrote:
> > On Mon, Aug 08, 2016 at 03:05:37PM +0200, Tomasz Nowicki wrote:
> > > pci_config_window keeps pointer to pci_ecam_ops and every time
> > > we want to deallocate pci_config_window (pci_ecam_free()) we need to make
> > > sure to free pci_ecam_ops in case it was dynamically allocated prior to
> > > pci_ecam_create() call.
> > 
> > I think this is a theoretical problem, right?  All the current callers
> > pass a pointer to a static pci_ecam_ops struct that does not need to
> > be deallocated.
> > 
> > I see that the next patch uses a pci_ecam_ops struct on the stack,
> 
> I asked Tomasz why we need to have pci_ecam_ops on the stack in the
> first place since I do not think it is needed, or nicer (actually I
> think it is not nice at all, what's the problem in making it static ?).

If it's useful to copy the struct instead of saving the pointer, that's
fine.  I just want the changelog to match the diff.

Bjorn
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diff mbox

Patch

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index acf3872..981e828 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -183,7 +183,7 @@  struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 		return NULL;
 	}
 
-	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
+	acpi_pci_root_ops.pci_ops = &ri->cfg->ops.pci_ops;
 	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
 				   ri->cfg);
 	if (!bus)
diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
index 43ed08d..24242f0 100644
--- a/drivers/pci/ecam.c
+++ b/drivers/pci/ecam.c
@@ -52,7 +52,7 @@  struct pci_config_window *pci_ecam_create(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	cfg->parent = dev;
-	cfg->ops = ops;
+	cfg->ops = *ops;
 	cfg->busr.start = busr->start;
 	cfg->busr.end = busr->end;
 	cfg->busr.flags = IORESOURCE_BUS;
@@ -138,7 +138,7 @@  void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
 			       int where)
 {
 	struct pci_config_window *cfg = bus->sysdata;
-	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
+	unsigned int devfn_shift = cfg->ops.bus_shift - 8;
 	unsigned int busn = bus->number;
 	void __iomem *base;
 
@@ -149,7 +149,7 @@  void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
 	if (per_bus_mapping)
 		base = cfg->winp[busn];
 	else
-		base = cfg->win + (busn << cfg->ops->bus_shift);
+		base = cfg->win + (busn << cfg->ops.bus_shift);
 	return base + (devfn << devfn_shift) + where;
 }
 
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
index 7adad20..0ce2920 100644
--- a/include/linux/pci-ecam.h
+++ b/include/linux/pci-ecam.h
@@ -39,7 +39,7 @@  struct pci_config_window {
 	struct resource			res;
 	struct resource			busr;
 	void				*priv;
-	struct pci_ecam_ops		*ops;
+	struct pci_ecam_ops		ops;
 	union {
 		void __iomem		*win;	/* 64-bit single mapping */
 		void __iomem		**winp; /* 32-bit per-bus mapping */