x86/irq/vector: Initialize matrix allocator

Initialize the matrix allocator and add the proper accounting points to the
code.

No functional change, just preparation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213155.108410660@linutronix.de

arch/x86/Kconfig

@@ -92,6 +92,7 @@ config X86
 	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_IOMAP
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
+	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
 	select GENERIC_IRQ_MIGRATION		if SMP
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW

arch/x86/include/asm/apic.h

@@ -169,6 +169,10 @@ static inline int apic_is_clustered_box(void)
 #endif
 
 extern int setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask);
+extern void lapic_assign_system_vectors(void);
+extern void lapic_assign_legacy_vector(unsigned int isairq, bool replace);
+extern void lapic_online(void);
+extern void lapic_offline(void);
 
 #else /* !CONFIG_X86_LOCAL_APIC */
 static inline void lapic_shutdown(void) { }
@@ -179,6 +183,8 @@ static inline void disable_local_APIC(void) { }
 # define setup_secondary_APIC_clock x86_init_noop
 static inline void lapic_update_tsc_freq(void) { }
 static inline void apic_intr_mode_init(void) { }
+static inline void lapic_assign_system_vectors(void) { }
+static inline void lapic_assign_legacy_vector(unsigned int i, bool r) { }
 #endif /* !CONFIG_X86_LOCAL_APIC */
 
 #ifdef CONFIG_X86_X2APIC

arch/x86/include/asm/hw_irq.h

@@ -15,6 +15,8 @@
 
 #include <asm/irq_vectors.h>
 
+#define IRQ_MATRIX_BITS		NR_VECTORS
+
 #ifndef __ASSEMBLY__
 
 #include <linux/percpu.h>
@@ -130,7 +132,6 @@ extern struct irq_cfg *irq_cfg(unsigned int irq);
 extern struct irq_cfg *irqd_cfg(struct irq_data *irq_data);
 extern void lock_vector_lock(void);
 extern void unlock_vector_lock(void);
-extern void setup_vector_irq(int cpu);
 #ifdef CONFIG_SMP
 extern void send_cleanup_vector(struct irq_cfg *);
 extern void irq_complete_move(struct irq_cfg *cfg);

arch/x86/kernel/apic/vector.c

@@ -36,6 +36,7 @@ EXPORT_SYMBOL_GPL(x86_vector_domain);
 static DEFINE_RAW_SPINLOCK(vector_lock);
 static cpumask_var_t vector_cpumask, vector_searchmask, searched_cpumask;
 static struct irq_chip lapic_controller;
+static struct irq_matrix *vector_matrix;
 #ifdef CONFIG_SMP
 static DEFINE_PER_CPU(struct hlist_head, cleanup_list);
 #endif
@@ -404,6 +405,36 @@ int __init arch_probe_nr_irqs(void)
 	return legacy_pic->probe();
 }
 
+void lapic_assign_legacy_vector(unsigned int irq, bool replace)
+{
+	/*
+	 * Use assign system here so it wont get accounted as allocated
+	 * and moveable in the cpu hotplug check and it prevents managed
+	 * irq reservation from touching it.
+	 */
+	irq_matrix_assign_system(vector_matrix, ISA_IRQ_VECTOR(irq), replace);
+}
+
+void __init lapic_assign_system_vectors(void)
+{
+	unsigned int i, vector = 0;
+
+	for_each_set_bit_from(vector, system_vectors, NR_VECTORS)
+		irq_matrix_assign_system(vector_matrix, vector, false);
+
+	if (nr_legacy_irqs() > 1)
+		lapic_assign_legacy_vector(PIC_CASCADE_IR, false);
+
+	/* System vectors are reserved, online it */
+	irq_matrix_online(vector_matrix);
+
+	/* Mark the preallocated legacy interrupts */
+	for (i = 0; i < nr_legacy_irqs(); i++) {
+		if (i != PIC_CASCADE_IR)
+			irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i));
+	}
+}
+
 int __init arch_early_irq_init(void)
 {
 	struct fwnode_handle *fn;
@@ -423,6 +454,14 @@ int __init arch_early_irq_init(void)
 	BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
 	BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
 
+	/*
+	 * Allocate the vector matrix allocator data structure and limit the
+	 * search area.
+	 */
+	vector_matrix = irq_alloc_matrix(NR_VECTORS, FIRST_EXTERNAL_VECTOR,
+					 FIRST_SYSTEM_VECTOR);
+	BUG_ON(!vector_matrix);
+
 	return arch_early_ioapic_init();
 }
 
@@ -454,14 +493,16 @@ static struct irq_desc *__setup_vector_irq(int vector)
 	return irq_to_desc(isairq);
 }
 
-/*
- * Setup the vector to irq mappings. Must be called with vector_lock held.
- */
-void setup_vector_irq(int cpu)
+/* Online the local APIC infrastructure and initialize the vectors */
+void lapic_online(void)
 {
 	unsigned int vector;
 
 	lockdep_assert_held(&vector_lock);
+
+	/* Online the vector matrix array for this CPU */
+	irq_matrix_online(vector_matrix);
+
 	/*
 	 * The interrupt affinity logic never targets interrupts to offline
 	 * CPUs. The exception are the legacy PIC interrupts. In general
@@ -482,6 +523,13 @@ void setup_vector_irq(int cpu)
 	vector_update_shutdown_irqs();
 }
 
+void lapic_offline(void)
+{
+	lock_vector_lock();
+	irq_matrix_offline(vector_matrix);
+	unlock_vector_lock();
+}
+
 static int apic_retrigger_irq(struct irq_data *irqd)
 {
 	struct apic_chip_data *apicd = apic_chip_data(irqd);

arch/x86/kernel/i8259.c

@@ -113,6 +113,7 @@ static void make_8259A_irq(unsigned int irq)
 	io_apic_irqs &= ~(1<<irq);
 	irq_set_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
 	enable_irq(irq);
+	lapic_assign_legacy_vector(irq, true);
 }
 
 /*

arch/x86/kernel/irqinit.c

@@ -90,6 +90,7 @@ void __init native_init_IRQ(void)
 	x86_init.irqs.pre_vector_init();
 
 	idt_setup_apic_and_irq_gates();
+	lapic_assign_system_vectors();
 
 	if (!acpi_ioapic && !of_ioapic && nr_legacy_irqs())
 		setup_irq(2, &irq2);

arch/x86/kernel/smpboot.c

@@ -260,7 +260,7 @@ static void notrace start_secondary(void *unused)
 	 * from seeing a half valid vector space.
 	 */
 	lock_vector_lock();
-	setup_vector_irq(smp_processor_id());
+	lapic_online();
 	set_cpu_online(smp_processor_id(), true);
 	unlock_vector_lock();
 	cpu_set_state_online(smp_processor_id());
@@ -1518,6 +1518,7 @@ void cpu_disable_common(void)
 	remove_cpu_from_maps(cpu);
 	unlock_vector_lock();
 	fixup_irqs();
+	lapic_offline();
 }
 
 int native_cpu_disable(void)