From 95d9c3f0e4546eaec0977f3b387549a8463cd49f Mon Sep 17 00:00:00 2001 From: Siddharth Vadapalli Date: Wed, 29 Oct 2025 13:34:51 +0530 Subject: PCI: keystone: Exit ks_pcie_probe() for invalid mode Commit under Fixes introduced support for PCIe EP mode on AM654x platforms. When the mode happens to be either "DW_PCIE_RC_TYPE" or "DW_PCIE_EP_TYPE", the PCIe Controller is configured accordingly. However, when the mode is neither of them, an error message is displayed, but the driver probe succeeds. Since this "invalid" mode is not associated with a functional PCIe Controller, the probe should fail. Fix the behavior by exiting "ks_pcie_probe()" with the return value of "-EINVAL" in addition to displaying the existing error message when the mode is invalid. Fixes: 23284ad677a9 ("PCI: keystone: Add support for PCIe EP in AM654x Platforms") Signed-off-by: Siddharth Vadapalli Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20251029080547.1253757-4-s-vadapalli@ti.com --- drivers/pci/controller/dwc/pci-keystone.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/pci/controller/dwc') diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index eb00aa380722..25b8193ffbcf 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -1337,6 +1337,8 @@ static int ks_pcie_probe(struct platform_device *pdev) break; default: dev_err(dev, "INVALID device type %d\n", mode); + ret = -EINVAL; + goto err_get_sync; } ks_pcie_enable_error_irq(ks_pcie); -- cgit From 5aa84c034a36fc67afd6c2048404716083fff75a Mon Sep 17 00:00:00 2001 From: Siddharth Vadapalli Date: Wed, 29 Oct 2025 13:34:50 +0530 Subject: PCI: dwc: Export dw_pcie_allocate_domains() and dw_pcie_ep_raise_msix_irq() The pci-keystone.c driver uses the functions 'dw_pcie_allocate_domains()' and 'dw_pcie_ep_raise_msix_irq()'. Export them in preparation for enabling the pci-keystone.c driver to be built as a loadable module. Signed-off-by: Siddharth Vadapalli Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20251029080547.1253757-3-s-vadapalli@ti.com --- drivers/pci/controller/dwc/pcie-designware-ep.c | 1 + drivers/pci/controller/dwc/pcie-designware-host.c | 1 + 2 files changed, 2 insertions(+) (limited to 'drivers/pci/controller/dwc') diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index 7f2112c2fb21..19571ac2b961 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -797,6 +797,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no, return 0; } +EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_msix_irq); /** * dw_pcie_ep_cleanup - Cleanup DWC EP resources after fundamental reset diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 20c9333bcb1c..d74bc571f65d 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -232,6 +232,7 @@ int dw_pcie_allocate_domains(struct dw_pcie_rp *pp) return 0; } +EXPORT_SYMBOL_GPL(dw_pcie_allocate_domains); void dw_pcie_free_msi(struct dw_pcie_rp *pp) { -- cgit From bc10d0ad540df599a3ab154f0255d901d3c2b030 Mon Sep 17 00:00:00 2001 From: Siddharth Vadapalli Date: Wed, 29 Oct 2025 13:34:52 +0530 Subject: PCI: keystone: Add support to build as a loadable module The 'pci-keystone.c' driver is the application/glue/wrapper driver for the Designware PCIe Controllers on TI SoCs. Now that all of the helper APIs that the 'pci-keystone.c' driver depends upon have been exported for use, enable support to build the driver as a loadable module. When building the driver as a module, the functions marked by the '__init' keyword may be invoked after the init memory has been freed by the kernel. This results will result in an exception of the form: Unable to handle kernel paging request at virtual address ... Mem abort info: ... pc : ks_pcie_host_init+0x0/0x540 lr : dw_pcie_host_init+0x170/0x498 ... ks_pcie_host_init+0x0/0x540 (P) ks_pcie_probe+0x728/0x84c platform_probe+0x5c/0x98 really_probe+0xbc/0x29c __driver_probe_device+0x78/0x12c driver_probe_device+0xd8/0x15c To address this, introduce a new function namely 'ks_pcie_init()' to register the 'fault handler' while removing the '__init' keyword from existing functions. Note that hook_fault_code() is defined as '__init' function. Since the init functions should never be called during runtime (after init memory freeing stage), the driver is made as a built-in if CONFIG_ARM (where hook_fault_code() is used) is selected. Signed-off-by: Siddharth Vadapalli [mani: added a note about hook_fault_code()] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20251029080547.1253757-5-s-vadapalli@ti.com --- drivers/pci/controller/dwc/Kconfig | 15 ++++-- drivers/pci/controller/dwc/Makefile | 3 ++ drivers/pci/controller/dwc/pci-keystone.c | 78 ++++++++++++++++++------------- 3 files changed, 59 insertions(+), 37 deletions(-) (limited to 'drivers/pci/controller/dwc') diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index 349d4657393c..c5bc2f0b1f39 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig @@ -482,15 +482,21 @@ config PCI_DRA7XX_EP to enable device-specific features PCI_DRA7XX_EP must be selected. This uses the DesignWare core. +# ARM32 platforms use hook_fault_code() and cannot support loadable module. config PCI_KEYSTONE bool +# On non-ARM32 platforms, loadable module can be supported. +config PCI_KEYSTONE_TRISTATE + tristate + config PCI_KEYSTONE_HOST - bool "TI Keystone PCIe controller (host mode)" + tristate "TI Keystone PCIe controller (host mode)" depends on ARCH_KEYSTONE || ARCH_K3 || COMPILE_TEST depends on PCI_MSI select PCIE_DW_HOST - select PCI_KEYSTONE + select PCI_KEYSTONE if ARM + select PCI_KEYSTONE_TRISTATE if !ARM help Enables support for the PCIe controller in the Keystone SoC to work in host mode. The PCI controller on Keystone is based on @@ -498,11 +504,12 @@ config PCI_KEYSTONE_HOST DesignWare core functions to implement the driver. config PCI_KEYSTONE_EP - bool "TI Keystone PCIe controller (endpoint mode)" + tristate "TI Keystone PCIe controller (endpoint mode)" depends on ARCH_KEYSTONE || ARCH_K3 || COMPILE_TEST depends on PCI_ENDPOINT select PCIE_DW_EP - select PCI_KEYSTONE + select PCI_KEYSTONE if ARM + select PCI_KEYSTONE_TRISTATE if !ARM help Enables support for the PCIe controller in the Keystone SoC to work in endpoint mode. The PCI controller on Keystone is based diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile index 7ae28f3b0fb3..7c8de0067612 100644 --- a/drivers/pci/controller/dwc/Makefile +++ b/drivers/pci/controller/dwc/Makefile @@ -11,7 +11,10 @@ obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o obj-$(CONFIG_PCIE_FU740) += pcie-fu740.o obj-$(CONFIG_PCI_IMX6) += pci-imx6.o obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o +# ARM32 platforms use hook_fault_code() and cannot support loadable module. obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone.o +# On non-ARM32 platforms, loadable module can be supported. +obj-$(CONFIG_PCI_KEYSTONE_TRISTATE) += pci-keystone.o obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o obj-$(CONFIG_PCI_LAYERSCAPE_EP) += pci-layerscape-ep.o obj-$(CONFIG_PCIE_QCOM_COMMON) += pcie-qcom-common.o diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index 25b8193ffbcf..f86d9111f863 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -777,29 +778,7 @@ err: return ret; } -#ifdef CONFIG_ARM -/* - * When a PCI device does not exist during config cycles, keystone host - * gets a bus error instead of returning 0xffffffff (PCI_ERROR_RESPONSE). - * This handler always returns 0 for this kind of fault. - */ -static int ks_pcie_fault(unsigned long addr, unsigned int fsr, - struct pt_regs *regs) -{ - unsigned long instr = *(unsigned long *) instruction_pointer(regs); - - if ((instr & 0x0e100090) == 0x00100090) { - int reg = (instr >> 12) & 15; - - regs->uregs[reg] = -1; - regs->ARM_pc += 4; - } - - return 0; -} -#endif - -static int __init ks_pcie_init_id(struct keystone_pcie *ks_pcie) +static int ks_pcie_init_id(struct keystone_pcie *ks_pcie) { int ret; unsigned int id; @@ -831,7 +810,7 @@ static int __init ks_pcie_init_id(struct keystone_pcie *ks_pcie) return 0; } -static int __init ks_pcie_host_init(struct dw_pcie_rp *pp) +static int ks_pcie_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct keystone_pcie *ks_pcie = to_keystone_pcie(pci); @@ -861,15 +840,6 @@ static int __init ks_pcie_host_init(struct dw_pcie_rp *pp) if (ret < 0) return ret; -#ifdef CONFIG_ARM - /* - * PCIe access errors that result into OCP errors are caught by ARM as - * "External aborts" - */ - hook_fault_code(17, ks_pcie_fault, SIGBUS, 0, - "Asynchronous external abort"); -#endif - return 0; } @@ -1134,6 +1104,7 @@ static const struct of_device_id ks_pcie_of_match[] = { }, { }, }; +MODULE_DEVICE_TABLE(of, ks_pcie_of_match); static int ks_pcie_probe(struct platform_device *pdev) { @@ -1381,4 +1352,45 @@ static struct platform_driver ks_pcie_driver = { .of_match_table = ks_pcie_of_match, }, }; + +#ifdef CONFIG_ARM +/* + * When a PCI device does not exist during config cycles, keystone host + * gets a bus error instead of returning 0xffffffff (PCI_ERROR_RESPONSE). + * This handler always returns 0 for this kind of fault. + */ +static int ks_pcie_fault(unsigned long addr, unsigned int fsr, + struct pt_regs *regs) +{ + unsigned long instr = *(unsigned long *)instruction_pointer(regs); + + if ((instr & 0x0e100090) == 0x00100090) { + int reg = (instr >> 12) & 15; + + regs->uregs[reg] = -1; + regs->ARM_pc += 4; + } + + return 0; +} + +static int __init ks_pcie_init(void) +{ + /* + * PCIe access errors that result into OCP errors are caught by ARM as + * "External aborts" + */ + if (of_find_matching_node(NULL, ks_pcie_of_match)) + hook_fault_code(17, ks_pcie_fault, SIGBUS, 0, + "Asynchronous external abort"); + + return platform_driver_register(&ks_pcie_driver); +} +device_initcall(ks_pcie_init); +#else builtin_platform_driver(ks_pcie_driver); +#endif + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("PCIe controller driver for Texas Instruments Keystone SoCs"); +MODULE_AUTHOR("Murali Karicheri "); -- cgit