From 15516a3b8633a32f03a82a2db23b87cf9600514c Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 27 Oct 2014 13:21:46 +0800 Subject: [PATCH] x86, irq, ACPI: Implement interfaces to support ACPI based IOAPIC hot-removal Implement acpi_unregister_ioapic() to support ACPI based IOAPIC hot-removal. An IOAPIC could only be removed when all its pins are unused. 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 Cc: Pavel Machek Cc: Grant Likely Cc: Prarit Bhargava Link: http://lkml.kernel.org/r/1414387308-27148-17-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 | 13 +++++++--- arch/x86/kernel/apic/io_apic.c | 55 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h index 94d05bd6586f..ce63cf34c93c 100644 --- a/arch/x86/include/asm/io_apic.h +++ b/arch/x86/include/asm/io_apic.h @@ -190,6 +190,7 @@ extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags); 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_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 0b993511e0c5..5427d9b70f75 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -810,15 +810,20 @@ int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base) return ret; } - EXPORT_SYMBOL(acpi_register_ioapic); int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base) { - /* TBD */ - return -EINVAL; -} + int ret = -ENOSYS; + +#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC + mutex_lock(&acpi_ioapic_lock); + ret = mp_unregister_ioapic(gsi_base); + mutex_unlock(&acpi_ioapic_lock); +#endif + return ret; +} EXPORT_SYMBOL(acpi_unregister_ioapic); static int __init acpi_parse_sbf(struct acpi_table_header *table) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 826f44f0a2bf..06a0a6ce6750 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -112,6 +112,7 @@ static struct ioapic { struct ioapic_domain_cfg irqdomain_cfg; struct irq_domain *irqdomain; struct mp_pin_info *pin_info; + struct resource *iomem_res; } ioapics[MAX_IO_APICS]; #define mpc_ioapic_ver(ioapic_idx) ioapics[ioapic_idx].mp_config.apicver @@ -250,6 +251,12 @@ static void alloc_ioapic_saved_registers(int idx) pr_err("IOAPIC %d: suspend/resume impossible!\n", idx); } +static void free_ioapic_saved_registers(int idx) +{ + kfree(ioapics[idx].saved_registers); + ioapics[idx].saved_registers = NULL; +} + int __init arch_early_irq_init(void) { struct irq_cfg *cfg; @@ -2973,6 +2980,16 @@ static int mp_irqdomain_create(int ioapic) return 0; } +static void ioapic_destroy_irqdomain(int idx) +{ + if (ioapics[idx].irqdomain) { + irq_domain_remove(ioapics[idx].irqdomain); + ioapics[idx].irqdomain = NULL; + } + kfree(ioapics[idx].pin_info); + ioapics[idx].pin_info = NULL; +} + void __init setup_IO_APIC(void) { int ioapic; @@ -3743,6 +3760,7 @@ static struct resource * __init ioapic_setup_resources(void) snprintf(mem, IOAPIC_RESOURCE_NAME_SIZE, "IOAPIC %u", i); mem += IOAPIC_RESOURCE_NAME_SIZE; num++; + ioapics[i].iomem_res = res; } ioapic_resources = res; @@ -3971,6 +3989,43 @@ int mp_register_ioapic(int id, u32 address, u32 gsi_base, return 0; } +int mp_unregister_ioapic(u32 gsi_base) +{ + int ioapic, pin; + int found = 0; + struct mp_pin_info *pin_info; + + for_each_ioapic(ioapic) + if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) { + found = 1; + break; + } + if (!found) { + pr_warn("can't find IOAPIC for GSI %d\n", gsi_base); + return -ENODEV; + } + + for_each_pin(ioapic, pin) { + pin_info = mp_pin_info(ioapic, pin); + if (pin_info->count) { + pr_warn("pin%d on IOAPIC%d is still in use.\n", + pin, ioapic); + return -EBUSY; + } + } + + /* Mark entry not present */ + ioapics[ioapic].nr_registers = 0; + ioapic_destroy_irqdomain(ioapic); + free_ioapic_saved_registers(ioapic); + if (ioapics[ioapic].iomem_res) + release_resource(ioapics[ioapic].iomem_res); + clear_fixmap(FIX_IO_APIC_BASE_0 + ioapic); + memset(&ioapics[ioapic], 0, sizeof(ioapics[ioapic])); + + return 0; +} + int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq, irq_hw_number_t hwirq) { -- 2.11.0