[PATCH] PCI: dwc: don't assume the ops field in dw_pcie always exists

[PATCH] PCI: dwc: don't assume the ops field in dw_pcie always exists

[Ioana Ciornei]

The blamed commit assumes that the ops field from dw_pcie is always
populated. This is not the case for the layerscape-pcie driver which
does not provide a dw_pcie_ops structure. The newly added
dw_pcie_parent_bus_offset() function tries to dereference pci->ops
which, in this case, is NULL.

Fix this by first checking if pci->ops is valid before dereferencing it.

Fixes: ed6509230934 ("PCI: dwc: Add dw_pcie_parent_bus_offset() checking and debug")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
---
 drivers/pci/controller/dwc/pcie-designware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index e68e2aac210f..b5fd44c0d6ad 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -1170,7 +1170,7 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci,
 
 	of_property_read_reg(np, index, &reg_addr, NULL);
 
-	fixup = pci->ops->cpu_addr_fixup;
+	fixup = pci->ops ? pci->ops->cpu_addr_fixup : 0;
 	if (fixup) {
 		fixup_addr = fixup(pci, cpu_phy_addr);
 		if (reg_addr == fixup_addr) {
-- 
2.34.1

Re: [PATCH] PCI: dwc: don't assume the ops field in dw_pcie always exists

[Frank Li]

On Wed, Mar 19, 2025 at 03:43:39PM +0200, Ioana Ciornei wrote:
> The blamed commit assumes that the ops field from dw_pcie is always
> populated. This is not the case for the layerscape-pcie driver which
> does not provide a dw_pcie_ops structure. The newly added
> dw_pcie_parent_bus_offset() function tries to dereference pci->ops
> which, in this case, is NULL.
>
> Fix this by first checking if pci->ops is valid before dereferencing it.
>
> Fixes: ed6509230934 ("PCI: dwc: Add dw_pcie_parent_bus_offset() checking and debug")
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

Bjorn: you may squah to previous's commit.

Frank

>  drivers/pci/controller/dwc/pcie-designware.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index e68e2aac210f..b5fd44c0d6ad 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -1170,7 +1170,7 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci,
>
>  	of_property_read_reg(np, index, &reg_addr, NULL);
>
> -	fixup = pci->ops->cpu_addr_fixup;
> +	fixup = pci->ops ? pci->ops->cpu_addr_fixup : 0;
>  	if (fixup) {
>  		fixup_addr = fixup(pci, cpu_phy_addr);
>  		if (reg_addr == fixup_addr) {
> --
> 2.34.1
>

Re: [PATCH] PCI: dwc: don't assume the ops field in dw_pcie always exists

[Bjorn Helgaas]

On Wed, Mar 19, 2025 at 03:43:39PM +0200, Ioana Ciornei wrote:
> The blamed commit assumes that the ops field from dw_pcie is always
> populated. This is not the case for the layerscape-pcie driver which
> does not provide a dw_pcie_ops structure. The newly added
> dw_pcie_parent_bus_offset() function tries to dereference pci->ops
> which, in this case, is NULL.
> 
> Fix this by first checking if pci->ops is valid before dereferencing it.
> 
> Fixes: ed6509230934 ("PCI: dwc: Add dw_pcie_parent_bus_offset() checking and debug")
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>

Thank you very much!  Squashed into the "PCI: dwc: Add
dw_pcie_parent_bus_offset() checking and debug" commit so there will
be no bisection hole for this.

> ---
>  drivers/pci/controller/dwc/pcie-designware.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index e68e2aac210f..b5fd44c0d6ad 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -1170,7 +1170,7 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci,
>  
>  	of_property_read_reg(np, index, &reg_addr, NULL);
>  
> -	fixup = pci->ops->cpu_addr_fixup;
> +	fixup = pci->ops ? pci->ops->cpu_addr_fixup : 0;
>  	if (fixup) {
>  		fixup_addr = fixup(pci, cpu_phy_addr);
>  		if (reg_addr == fixup_addr) {
> -- 
> 2.34.1
>