PCI: cadence: Check for the existence of cdns_pcie::ops before using it

cdns_pcie::ops might not be populated by all the Cadence glue drivers. This
is going to be true for the upcoming Sophgo platform which doesn't set the
ops.

Hence, add a check to prevent NULL pointer dereference.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
[mani: reworded subject and description]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/35182ee1d972dfcd093a964e11205efcebbdc044.1757643388.git.unicorn_wang@outlook.com

Author: unicornx

drivers/pci/controller/cadence/pcie-cadence-host.c

@@ -531,7 +531,7 @@ static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(0), addr1);
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(0), desc1);
 
-	if (pcie->ops->cpu_addr_fixup)
+	if (pcie->ops && pcie->ops->cpu_addr_fixup)
 		cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
 
 	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(12) |

drivers/pci/controller/cadence/pcie-cadence.c

@@ -92,7 +92,7 @@ void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 busnr, u8 fn,
 	cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(r), desc1);
 
 	/* Set the CPU address */
-	if (pcie->ops->cpu_addr_fixup)
+	if (pcie->ops && pcie->ops->cpu_addr_fixup)
 		cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
 
 	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(nbits) |
@@ -123,7 +123,7 @@ void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie,
 	}
 
 	/* Set the CPU address */
-	if (pcie->ops->cpu_addr_fixup)
+	if (pcie->ops && pcie->ops->cpu_addr_fixup)
 		cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
 
 	addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(17) |

drivers/pci/controller/cadence/pcie-cadence.h

@@ -468,21 +468,21 @@ static inline u32 cdns_pcie_ep_fn_readl(struct cdns_pcie *pcie, u8 fn, u32 reg)
 
 static inline int cdns_pcie_start_link(struct cdns_pcie *pcie)
 {
-	if (pcie->ops->start_link)
+	if (pcie->ops && pcie->ops->start_link)
 		return pcie->ops->start_link(pcie);
 
 	return 0;
 }
 
 static inline void cdns_pcie_stop_link(struct cdns_pcie *pcie)
 {
-	if (pcie->ops->stop_link)
+	if (pcie->ops && pcie->ops->stop_link)
 		pcie->ops->stop_link(pcie);
 }
 
 static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
 {
-	if (pcie->ops->link_up)
+	if (pcie->ops && pcie->ops->link_up)
 		return pcie->ops->link_up(pcie);
 
 	return true;