From: Sebastian Ott Date: Tue, 26 Feb 2019 16:07:32 +0100 Subject: s390/pci: add parameter to force floating irqs Git-commit: fbfe07d440f2c55070a0358f66560bb4f9fb92e7 Patch-mainline: v5.2-rc1 References: jsc#SLE-5789 FATE#327042 bsc#1134730 LTC#173388 Provide a kernel parameter to force the usage of floating interrupts. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky Acked-by: Petr Tesarik --- Documentation/admin-guide/kernel-parameters.txt | 1 + arch/s390/include/asm/pci.h | 1 + arch/s390/pci/pci.c | 5 +++++ arch/s390/pci/pci_irq.c | 3 +++ 4 files changed, 10 insertions(+) --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3199,6 +3199,7 @@ Adding the window is slightly risky (it may conflict with unreported devices), so this taints the kernel. + force_floating [S390] Force usage of floating interrupts. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -157,6 +157,7 @@ static inline bool zdev_enabled(struct z } extern const struct attribute_group *zpci_attr_groups[]; +extern unsigned int s390_pci_force_floating __initdata; /* ----------------------------------------------------------------------------- Prototypes --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -714,6 +714,7 @@ static void zpci_mem_exit(void) } static unsigned int s390_pci_probe __initdata = 1; +unsigned int s390_pci_force_floating __initdata; static unsigned int s390_pci_initialized; char * __init pcibios_setup(char *str) @@ -722,6 +723,10 @@ char * __init pcibios_setup(char *str) s390_pci_probe = 0; return NULL; } + if (!strcmp(str, "force_floating")) { + s390_pci_force_floating = 1; + return NULL; + } return str; } --- a/arch/s390/pci/pci_irq.c +++ b/arch/s390/pci/pci_irq.c @@ -433,6 +433,9 @@ int __init zpci_irq_init(void) int rc; irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING; + if (s390_pci_force_floating) + irq_delivery = FLOATING; + if (irq_delivery == DIRECTED) zpci_airq.handler = zpci_directed_irq_handler;