From bc07844a33734c4b2f32ef26d942d2f3ef9302ea Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 29 Aug 2009 18:09:57 +0200 Subject: x86: Distangle ioapic and i8259 The proposed Moorestown support patches use an extra feature flag mechanism to make the ioapic work w/o an i8259. There is a much simpler solution. Most i8259 specific functions are already called dependend on the irq number less than NR_IRQS_LEGACY. Replacing that constant by a read_mostly variable which can be set to 0 by the platform setup code allows us to achieve the same without any special feature flags. That trivial change allows us to proceed with MRST w/o doing a full blown overhaul of the ioapic code which would delay MRST unduly. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/io_apic.h | 2 ++ arch/x86/kernel/apic/io_apic.c | 41 +++++++++++++++++++++++++++++------------ 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h index 2b8aeb89933..e1f89a1a07e 100644 --- a/arch/x86/include/asm/io_apic.h +++ b/arch/x86/include/asm/io_apic.h @@ -143,6 +143,8 @@ extern int noioapicreroute; /* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */ extern int timer_through_8259; +extern void io_apic_disable_legacy(void); + /* * If we use the IO-APIC for IRQ routing, disable automatic * assignment of PCI IRQ's. diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 5f4687187ce..6c961290a5f 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -91,6 +91,11 @@ struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES]; /* # of MP IRQ source entries */ int mp_irq_entries; +/* Number of legacy interrupts */ +static int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY; +/* GSI interrupts */ +static int nr_irqs_gsi = NR_IRQS_LEGACY; + #if defined (CONFIG_MCA) || defined (CONFIG_EISA) int mp_bus_id_to_type[MAX_MP_BUSSES]; #endif @@ -172,6 +177,12 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = { [15] = { .vector = IRQ15_VECTOR, }, }; +void __init io_apic_disable_legacy(void) +{ + nr_legacy_irqs = 0; + nr_irqs_gsi = 0; +} + int __init arch_early_irq_init(void) { struct irq_cfg *cfg; @@ -189,7 +200,7 @@ int __init arch_early_irq_init(void) desc->chip_data = &cfg[i]; zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node); zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node); - if (i < NR_IRQS_LEGACY) + if (i < nr_legacy_irqs) cpumask_setall(cfg[i].domain); } @@ -883,7 +894,7 @@ static int __init find_isa_irq_apic(int irq, int type) */ static int EISA_ELCR(unsigned int irq) { - if (irq < NR_IRQS_LEGACY) { + if (irq < nr_legacy_irqs) { unsigned int port = 0x4d0 + (irq >> 3); return (inb(port) >> (irq & 7)) & 1; } @@ -1480,7 +1491,7 @@ static void setup_IO_APIC_irq(int apic_id, int pin, unsigned int irq, struct irq } ioapic_register_intr(irq, desc, trigger); - if (irq < NR_IRQS_LEGACY) + if (irq < nr_legacy_irqs) disable_8259A_irq(irq); ioapic_write_entry(apic_id, pin, entry); @@ -1851,7 +1862,7 @@ __apicdebuginit(void) print_PIC(void) unsigned int v; unsigned long flags; - if (apic_verbosity == APIC_QUIET) + if (apic_verbosity == APIC_QUIET || !nr_legacy_irqs) return; printk(KERN_DEBUG "\nprinting PIC contents\n"); @@ -1914,6 +1925,10 @@ void __init enable_IO_APIC(void) spin_unlock_irqrestore(&ioapic_lock, flags); nr_ioapic_registers[apic] = reg_01.bits.entries+1; } + + if (!nr_legacy_irqs) + return; + for(apic = 0; apic < nr_ioapics; apic++) { int pin; /* See if any of the pins is in ExtINT mode */ @@ -1968,6 +1983,9 @@ void disable_IO_APIC(void) */ clear_IO_APIC(); + if (!nr_legacy_irqs) + return; + /* * If the i8259 is routed through an IOAPIC * Put that IOAPIC in virtual wire mode @@ -2198,7 +2216,7 @@ static unsigned int startup_ioapic_irq(unsigned int irq) struct irq_cfg *cfg; spin_lock_irqsave(&ioapic_lock, flags); - if (irq < NR_IRQS_LEGACY) { + if (irq < nr_legacy_irqs) { disable_8259A_irq(irq); if (i8259A_irq_pending(irq)) was_pending = 1; @@ -2709,7 +2727,7 @@ static inline void init_IO_APIC_traps(void) * so default to an old-fashioned 8259 * interrupt if we can.. */ - if (irq < NR_IRQS_LEGACY) + if (irq < nr_legacy_irqs) make_8259A_irq(irq); else /* Strange. Oh, well.. */ @@ -3045,7 +3063,7 @@ out: * the I/O APIC in all cases now. No actual device should request * it anyway. --macro */ -#define PIC_IRQS (1 << PIC_CASCADE_IR) +#define PIC_IRQS (1UL << PIC_CASCADE_IR) void __init setup_IO_APIC(void) { @@ -3053,8 +3071,7 @@ void __init setup_IO_APIC(void) /* * calling enable_IO_APIC() is moved to setup_local_APIC for BP */ - - io_apic_irqs = ~PIC_IRQS; + io_apic_irqs = nr_legacy_irqs ? ~PIC_IRQS : ~0UL; apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n"); /* @@ -3065,7 +3082,8 @@ void __init setup_IO_APIC(void) sync_Arb_IDs(); setup_IO_APIC_irqs(); init_IO_APIC_traps(); - check_timer(); + if (nr_legacy_irqs) + check_timer(); } /* @@ -3166,7 +3184,6 @@ static int __init ioapic_init_sysfs(void) device_initcall(ioapic_init_sysfs); -static int nr_irqs_gsi = NR_IRQS_LEGACY; /* * Dynamic irq allocate and deallocation */ @@ -3907,7 +3924,7 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq, /* * IRQs < 16 are already in the irq_2_pin[] map */ - if (irq >= NR_IRQS_LEGACY) { + if (irq >= nr_legacy_irqs) { cfg = desc->chip_data; add_pin_to_irq_node(cfg, node, ioapic, pin); } -- cgit v1.2.3