From cffe0a2b5a34c95a4dadc9ec7132690a5b0f6687 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 27 Oct 2014 13:21:42 +0800 Subject: x86, irq: Keep balance of IOAPIC pin reference count To keep balance of IOAPIC pin reference count, we need to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. There are two cases which will cause reentrance. The first case is caused by suspend/hibernation. If pcibios_disable_irq is called during suspending/hibernating, we don't release the assigned IRQ number, otherwise it may break the suspend/hibernation. So late when pcibios_enable_irq is called during resume, we shouldn't allocate IRQ number again. The second case is that function acpi_pci_irq_enable() may be called twice for PCI devices present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() if pci_routeirq is true 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() We can't kill kernel parameter pci_routeirq yet because it's still needed for debugging purpose. So flag irq_managed is introduced to track whether IRQ number is assigned by OS and to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. Signed-off-by: Jiang Liu Cc: Konrad Rzeszutek Wilk Cc: Tony Luck Cc: Joerg Roedel Cc: Greg Kroah-Hartman Cc: Benjamin Herrenschmidt Cc: Rafael J. Wysocki Cc: Bjorn Helgaas Cc: Randy Dunlap Cc: Yinghai Lu Cc: Borislav Petkov Cc: Len Brown Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner --- include/linux/pci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/pci.h b/include/linux/pci.h index a523cee3abb5..c888c5e4e225 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -349,6 +349,7 @@ struct pci_dev { unsigned int __aer_firmware_first:1; unsigned int broken_intx_masking:1; unsigned int io_window_1k:1; /* Intel P2P bridge 1K I/O windows */ + unsigned int irq_managed:1; pci_dev_flags_t dev_flags; atomic_t enable_cnt; /* pci_enable_device has been called */ -- cgit v1.2.3 From e89900c9ad75a1b80e1f1f46ce9c9bb0e7ea1d96 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 27 Oct 2014 13:21:47 +0800 Subject: x86, irq: Introduce helper to check whether an IOAPIC has been registered Introduce acpi_ioapic_registered() to check whether an IOAPIC has already been registered, it will be used when enabling IOAPIC hotplug. Signed-off-by: Jiang Liu Acked-by: Pavel Machek Cc: Konrad Rzeszutek Wilk Cc: Tony Luck Cc: Joerg Roedel Cc: Greg Kroah-Hartman Cc: Benjamin Herrenschmidt Cc: Rafael J. Wysocki Cc: Bjorn Helgaas Cc: Randy Dunlap Cc: Yinghai Lu Cc: Borislav Petkov Cc: Len Brown Cc: Grant Likely Cc: Prarit Bhargava Link: http://lkml.kernel.org/r/1414387308-27148-18-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/io_apic.h | 1 + arch/x86/kernel/acpi/boot.c | 22 ++++++++++++++++++++++ arch/x86/kernel/apic/io_apic.c | 11 +++++++++++ include/linux/acpi.h | 1 + 4 files changed, 35 insertions(+) (limited to 'include') diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h index ce63cf34c93c..0db2b7037e4b 100644 --- a/arch/x86/include/asm/io_apic.h +++ b/arch/x86/include/asm/io_apic.h @@ -191,6 +191,7 @@ extern void mp_unmap_irq(int irq); extern int mp_register_ioapic(int id, u32 address, u32 gsi_base, struct ioapic_domain_cfg *cfg); extern int mp_unregister_ioapic(u32 gsi_base); +extern int mp_ioapic_registered(u32 gsi_base); extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq, irq_hw_number_t hwirq); extern void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq); diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 5427d9b70f75..ddddaed91872 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -826,6 +826,28 @@ int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base) } EXPORT_SYMBOL(acpi_unregister_ioapic); +/** + * acpi_ioapic_registered - Check whether IOAPIC assoicatied with @gsi_base + * has been registered + * @handle: ACPI handle of the IOAPIC deivce + * @gsi_base: GSI base associated with the IOAPIC + * + * Assume caller holds some type of lock to serialize acpi_ioapic_registered() + * with acpi_register_ioapic()/acpi_unregister_ioapic(). + */ +int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base) +{ + int ret = 0; + +#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC + mutex_lock(&acpi_ioapic_lock); + ret = mp_ioapic_registered(gsi_base); + mutex_unlock(&acpi_ioapic_lock); +#endif + + return ret; +} + static int __init acpi_parse_sbf(struct acpi_table_header *table) { struct acpi_table_boot *sb; diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 06a0a6ce6750..1cedf410096e 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -4026,6 +4026,17 @@ int mp_unregister_ioapic(u32 gsi_base) return 0; } +int mp_ioapic_registered(u32 gsi_base) +{ + int ioapic; + + for_each_ioapic(ioapic) + if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) + return 1; + + return 0; +} + int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq, irq_hw_number_t hwirq) { diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 407a12f663eb..a81dd437a53c 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -148,6 +148,7 @@ int acpi_unmap_lsapic(int cpu); int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base); int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base); +int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base); void acpi_irq_stats_init(void); extern u32 acpi_irq_handled; extern u32 acpi_irq_not_handled; -- cgit v1.2.3