[PATCH] x86_64 irq: Safely cleanup an irq after moving it. (61014292) · Commits · 戴 / test

arch/x86_64/kernel/entry.S

+3 −0

Original line number	Diff line number	Diff line
		@@ -675,6 +675,9 @@ END(invalidate_interrupt\num)
		ENTRY(call_function_interrupt)
		apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt
		END(call_function_interrupt)
		ENTRY(irq_move_cleanup_interrupt)
		apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt
		END(irq_move_cleanup_interrupt)
		#endif

		ENTRY(apic_timer_interrupt)

arch/x86_64/kernel/i8259.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -450,6 +450,7 @@ void spurious_interrupt(void);
		void error_interrupt(void);
		void reschedule_interrupt(void);
		void call_function_interrupt(void);
		void irq_move_cleanup_interrupt(void);
		void invalidate_interrupt0(void);
		void invalidate_interrupt1(void);
		void invalidate_interrupt2(void);
		@@ -537,6 +538,9 @@ void __init init_IRQ(void)

		/* IPI for generic function call */
		set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);

		/* Low priority IPI to cleanup after moving an irq */
		set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
		#endif
		set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
		set_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);

arch/x86_64/kernel/io_apic.c

+73 −5

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@
		#include <acpi/acpi_bus.h>
		#endif

		#include <asm/idle.h>
		#include <asm/io.h>
		#include <asm/smp.h>
		#include <asm/desc.h>
		@@ -49,7 +50,10 @@

		struct irq_cfg {
		cpumask_t domain;
		cpumask_t old_domain;
		unsigned move_cleanup_count;
		u8 vector;
		u8 move_in_progress : 1;
		};

		/* irq_cfg is indexed by the sum of all RTEs in all I/O APICs. */
		@@ -652,7 +656,6 @@ static int __assign_irq_vector(int irq, cpumask_t mask)
		* 0x80, because int 0x80 is hm, kind of importantish. ;)
		*/
		static int current_vector = FIRST_DEVICE_VECTOR, current_offset = 0;
		cpumask_t old_mask = CPU_MASK_NONE;
		unsigned int old_vector;
		int cpu;
		struct irq_cfg *cfg;
		@@ -663,18 +666,20 @@ static int __assign_irq_vector(int irq, cpumask_t mask)
		/* Only try and allocate irqs on cpus that are present */
		cpus_and(mask, mask, cpu_online_map);

		if ((cfg->move_in_progress) \|\| cfg->move_cleanup_count)
		return -EBUSY;

		old_vector = cfg->vector;
		if (old_vector) {
		cpumask_t tmp;
		cpus_and(tmp, cfg->domain, mask);
		if (!cpus_empty(tmp))
		return 0;
		cpus_and(old_mask, cfg->domain, cpu_online_map);
		}

		for_each_cpu_mask(cpu, mask) {
		cpumask_t domain, new_mask;
		int new_cpu, old_cpu;
		int new_cpu;
		int vector, offset;

		domain = vector_allocation_domain(cpu);
		@@ -699,8 +704,10 @@ next:
		/* Found one! */
		current_vector = vector;
		current_offset = offset;
		for_each_cpu_mask(old_cpu, old_mask)
		per_cpu(vector_irq, old_cpu)[old_vector] = -1;
		if (old_vector) {
		cfg->move_in_progress = 1;
		cfg->old_domain = cfg->domain;
		}
		for_each_cpu_mask(new_cpu, new_mask)
		per_cpu(vector_irq, new_cpu)[vector] = irq;
		cfg->vector = vector;
		@@ -1360,8 +1367,68 @@ static int ioapic_retrigger_irq(unsigned int irq)
		* races.
		*/

		#ifdef CONFIG_SMP
		asmlinkage void smp_irq_move_cleanup_interrupt(void)
		{
		unsigned vector, me;
		ack_APIC_irq();
		exit_idle();
		irq_enter();

		me = smp_processor_id();
		for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
		unsigned int irq;
		struct irq_desc *desc;
		struct irq_cfg *cfg;
		irq = __get_cpu_var(vector_irq)[vector];
		if (irq >= NR_IRQS)
		continue;

		desc = irq_desc + irq;
		cfg = irq_cfg + irq;
		spin_lock(&desc->lock);
		if (!cfg->move_cleanup_count)
		goto unlock;

		if ((vector == cfg->vector) && cpu_isset(me, cfg->domain))
		goto unlock;

		__get_cpu_var(vector_irq)[vector] = -1;
		cfg->move_cleanup_count--;
		unlock:
		spin_unlock(&desc->lock);
		}

		irq_exit();
		}

		static void irq_complete_move(unsigned int irq)
		{
		struct irq_cfg *cfg = irq_cfg + irq;
		unsigned vector, me;

		if (likely(!cfg->move_in_progress))
		return;

		vector = ~get_irq_regs()->orig_rax;
		me = smp_processor_id();
		if ((vector == cfg->vector) &&
		cpu_isset(smp_processor_id(), cfg->domain)) {
		cpumask_t cleanup_mask;

		cpus_and(cleanup_mask, cfg->old_domain, cpu_online_map);
		cfg->move_cleanup_count = cpus_weight(cleanup_mask);
		send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
		cfg->move_in_progress = 0;
		}
		}
		#else
		static inline void irq_complete_move(unsigned int irq) {}
		#endif

		static void ack_apic_edge(unsigned int irq)
		{
		irq_complete_move(irq);
		move_native_irq(irq);
		ack_APIC_irq();
		}
		@@ -1370,6 +1437,7 @@ static void ack_apic_level(unsigned int irq)
		{
		int do_unmask_irq = 0;

		irq_complete_move(irq);
		#if defined(CONFIG_GENERIC_PENDING_IRQ) \|\| defined(CONFIG_IRQBALANCE)
		/* If we are moving the irq we need to mask it */
		if (unlikely(irq_desc[irq].status & IRQ_MOVE_PENDING)) {

include/asm-x86_64/hw_irq.h

+7 −2

Original line number	Diff line number	Diff line
		@@ -32,10 +32,15 @@
		#define IA32_SYSCALL_VECTOR 0x80


		/* Reserve the lowest usable priority level 0x20 - 0x2f for triggering
		* cleanup after irq migration.
		*/
		#define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR

		/*
		* Vectors 0x20-0x2f are used for ISA interrupts.
		*/
		#define IRQ0_VECTOR FIRST_EXTERNAL_VECTOR
		#define IRQ0_VECTOR FIRST_EXTERNAL_VECTOR + 0x10
		#define IRQ1_VECTOR IRQ0_VECTOR + 1
		#define IRQ2_VECTOR IRQ0_VECTOR + 2
		#define IRQ3_VECTOR IRQ0_VECTOR + 3
		@@ -82,7 +87,7 @@

		/*
		* First APIC vector available to drivers: (vectors 0x30-0xee)
		* we start at 0x31 to spread out vectors evenly between priority
		* we start at 0x41 to spread out vectors evenly between priority
		* levels. (0x80 is the syscall vector)
		*/
		#define FIRST_DEVICE_VECTOR (IRQ15_VECTOR + 2)

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