diff mbox

PCI: xgene: fix breakage from generic config usage

Message ID 1425507864-22055-1-git-send-email-msalter@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mark Salter March 4, 2015, 10:24 p.m. UTC
Commit 350f8be5bb402 ("PCI: xgene: Convert to use generic config
accessors") breaks PCI on the X-Gene platform. It creates two
problems with the xgene_pcie_map_bus() function. First, it returns
an int but should return a void __iomem *, but that's just a
compile-time warning. The breakage is caused by the offset not
being added to the base of the config map. So all config reads
and writes operate on the first four bytes of config space. This
patch fixes both issues.

Signed-off-by: Mark Salter <msalter@redhat.com>
---
 drivers/pci/host/pci-xgene.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Comments

Feng Kan March 5, 2015, 4:54 p.m. UTC | #1
Acked-by: Feng Kan <fkan@apm.com>

On Wed, Mar 4, 2015 at 2:24 PM, Mark Salter <msalter@redhat.com> wrote:
> Commit 350f8be5bb402 ("PCI: xgene: Convert to use generic config
> accessors") breaks PCI on the X-Gene platform. It creates two
> problems with the xgene_pcie_map_bus() function. First, it returns
> an int but should return a void __iomem *, but that's just a
> compile-time warning. The breakage is caused by the offset not
> being added to the base of the config map. So all config reads
> and writes operate on the first four bytes of config space. This
> patch fixes both issues.
>
> Signed-off-by: Mark Salter <msalter@redhat.com>
> ---
>  drivers/pci/host/pci-xgene.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
> index 52bb25c..b87f80b 100644
> --- a/drivers/pci/host/pci-xgene.c
> +++ b/drivers/pci/host/pci-xgene.c
> @@ -129,17 +129,21 @@ static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
>         return false;
>  }
>
> -static int xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> -                             int offset)
> +static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> +                                       int offset)
>  {
>         struct xgene_pcie_port *port = bus->sysdata;
> +       void __iomem *base;
>
>         if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up ||
>             xgene_pcie_hide_rc_bars(bus, offset))
>                 return NULL;
>
>         xgene_pcie_set_rtdid_reg(bus, devfn);
> -       return xgene_pcie_get_cfg_base(bus);
> +       base = xgene_pcie_get_cfg_base(bus);
> +       if (base)
> +               base += offset;
> +       return base;
>  }
>
>  static struct pci_ops xgene_pcie_ops = {
> --
> 1.8.3.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Bjorn Helgaas March 6, 2015, 5:04 p.m. UTC | #2
On Wed, Mar 04, 2015 at 05:24:24PM -0500, Mark Salter wrote:
> Commit 350f8be5bb402 ("PCI: xgene: Convert to use generic config
> accessors") breaks PCI on the X-Gene platform. It creates two
> problems with the xgene_pcie_map_bus() function. First, it returns
> an int but should return a void __iomem *, but that's just a
> compile-time warning. The breakage is caused by the offset not
> being added to the base of the config map. So all config reads
> and writes operate on the first four bytes of config space. This
> patch fixes both issues.
> 
> Signed-off-by: Mark Salter <msalter@redhat.com>

I forgot to copy you, Mark, but I applied Feng's earlier patch [1], which I
think is equivalent to yours.

[1] https://patchwork.ozlabs.org/patch/440759/

> ---
>  drivers/pci/host/pci-xgene.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
> index 52bb25c..b87f80b 100644
> --- a/drivers/pci/host/pci-xgene.c
> +++ b/drivers/pci/host/pci-xgene.c
> @@ -129,17 +129,21 @@ static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
>  	return false;
>  }
>  
> -static int xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> -			      int offset)
> +static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> +					int offset)
>  {
>  	struct xgene_pcie_port *port = bus->sysdata;
> +	void __iomem *base;
>  
>  	if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up ||
>  	    xgene_pcie_hide_rc_bars(bus, offset))
>  		return NULL;
>  
>  	xgene_pcie_set_rtdid_reg(bus, devfn);
> -	return xgene_pcie_get_cfg_base(bus);
> +	base = xgene_pcie_get_cfg_base(bus);
> +	if (base)
> +		base += offset;
> +	return base;
>  }
>  
>  static struct pci_ops xgene_pcie_ops = {
> -- 
> 1.8.3.1
>
diff mbox

Patch

diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
index 52bb25c..b87f80b 100644
--- a/drivers/pci/host/pci-xgene.c
+++ b/drivers/pci/host/pci-xgene.c
@@ -129,17 +129,21 @@  static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
 	return false;
 }
 
-static int xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
-			      int offset)
+static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+					int offset)
 {
 	struct xgene_pcie_port *port = bus->sysdata;
+	void __iomem *base;
 
 	if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up ||
 	    xgene_pcie_hide_rc_bars(bus, offset))
 		return NULL;
 
 	xgene_pcie_set_rtdid_reg(bus, devfn);
-	return xgene_pcie_get_cfg_base(bus);
+	base = xgene_pcie_get_cfg_base(bus);
+	if (base)
+		base += offset;
+	return base;
 }
 
 static struct pci_ops xgene_pcie_ops = {