[tip:x86/apic] x86/irq: Implement callbacks to enable hierarchical irqdomains on IOAPICs

[tip-bot for Jiang Liu <tipbot@zytor.com>]

Commit-ID:  49c7e60022912d10da88ba67e8eb2927f1143f6a
Gitweb:     http://git.kernel.org/tip/49c7e60022912d10da88ba67e8eb2927f1143f6a
Author:     Jiang Liu <jiang.liu@linux.intel.com>
AuthorDate: Mon, 13 Apr 2015 14:11:55 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 24 Apr 2015 15:36:51 +0200

x86/irq: Implement callbacks to enable hierarchical irqdomains on IOAPICs

Implement required callbacks to prepare for enabling hierarchical
irqdomains on IOAPICs. After the conversion we can remove quite some
code from the old implementation.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Cohen <david.a.cohen@linux.intel.com>
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Grant Likely <grant.likely@linaro.org>
Link: http://lkml.kernel.org/r/1428905519-23704-34-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/io_apic.h |  10 +++
 arch/x86/kernel/apic/io_apic.c | 159 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 166 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 1fbeda5..ecc1926 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -96,6 +96,7 @@ struct IR_IO_APIC_route_entry {
 } __attribute__ ((packed));
 
 struct irq_alloc_info;
+struct irq_data;
 
 #define IOAPIC_AUTO     -1
 #define IOAPIC_EDGE     0
@@ -206,6 +207,15 @@ 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);
+extern int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
+			      unsigned int nr_irqs, void *arg);
+extern void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
+			      unsigned int nr_irqs);
+extern void mp_irqdomain_activate(struct irq_domain *domain,
+				  struct irq_data *irq_data);
+extern void mp_irqdomain_deactivate(struct irq_domain *domain,
+				    struct irq_data *irq_data);
+extern int mp_irqdomain_ioapic_idx(struct irq_domain *domain);
 extern void ioapic_set_alloc_attr(struct irq_alloc_info *info,
 				  int node, int trigger, int polarity);
 extern int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 5c953bb..3406dbe 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -78,6 +78,13 @@ static DEFINE_MUTEX(ioapic_mutex);
 static unsigned int ioapic_dynirq_base;
 static int ioapic_initialized;
 
+struct mp_chip_data {
+	struct IO_APIC_route_entry entry;
+	int trigger;
+	int polarity;
+	bool isa_irq;
+};
+
 struct mp_pin_info {
 	int trigger;
 	int polarity;
@@ -949,11 +956,28 @@ void ioapic_set_alloc_attr(struct irq_alloc_info *info, int node,
 	info->ioapic_valid = 1;
 }
 
+static void mp_register_handler(unsigned int irq, unsigned long trigger)
+{
+	irq_flow_handler_t hdl;
+	bool fasteoi;
+
+	if (trigger) {
+		irq_set_status_flags(irq, IRQ_LEVEL);
+		fasteoi = true;
+	} else {
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+		fasteoi = false;
+	}
+
+	hdl = fasteoi ? handle_fasteoi_irq : handle_edge_irq;
+	__irq_set_handler(irq, hdl, 0, fasteoi ? "fasteoi" : "edge");
+}
+
 static int alloc_irq_from_domain(struct irq_domain *domain, u32 gsi, int pin,
 				 struct irq_alloc_info *info)
 {
 	int irq = -1;
-	int ioapic = (int)(long)domain->host_data;
+	int ioapic = mp_irqdomain_ioapic_idx(domain);
 	int type = ioapics[ioapic].irqdomain_cfg.type;
 
 	switch (type) {
@@ -3029,7 +3053,7 @@ static inline void set_io_apic_irq_attr(struct io_apic_irq_attr *irq_attr,
 int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
 		     irq_hw_number_t hwirq)
 {
-	int ioapic = (int)(long)domain->host_data;
+	int ioapic = mp_irqdomain_ioapic_idx(domain);
 	struct mp_pin_info *info = mp_pin_info(ioapic, hwirq);
 	struct io_apic_irq_attr attr;
 
@@ -3067,7 +3091,7 @@ void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq)
 {
 	struct irq_data *data = irq_get_irq_data(virq);
 	struct irq_cfg *cfg = irq_cfg(virq);
-	int ioapic = (int)(long)domain->host_data;
+	int ioapic = mp_irqdomain_ioapic_idx(domain);
 	int pin = (int)data->hwirq;
 
 	ioapic_mask_entry(ioapic, pin);
@@ -3076,6 +3100,130 @@ void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq)
 	arch_teardown_hwirq(virq);
 }
 
+static void mp_irqdomain_get_attr(u32 gsi, struct mp_chip_data *data,
+				 struct irq_alloc_info *info)
+{
+	if (info && info->ioapic_valid) {
+		data->trigger = info->ioapic_trigger;
+		data->polarity = info->ioapic_polarity;
+	} else if (acpi_get_override_irq(gsi, &data->trigger,
+					 &data->polarity) < 0) {
+		/* PCI interrupts are always polarity one level triggered. */
+		data->trigger = 1;
+		data->polarity = 1;
+	}
+}
+
+static void mp_setup_entry(struct irq_cfg *cfg, struct mp_chip_data *data,
+			   struct IO_APIC_route_entry *entry)
+{
+	memset(entry, 0, sizeof(*entry));
+	entry->delivery_mode = apic->irq_delivery_mode;
+	entry->dest_mode     = apic->irq_dest_mode;
+	entry->dest	     = cfg->dest_apicid;
+	entry->vector	     = cfg->vector;
+	entry->mask	     = 0;	/* enable IRQ */
+	entry->trigger	     = data->trigger;
+	entry->polarity	     = data->polarity;
+	/*
+	 * Mask level triggered irqs.
+	 * Use IRQ_DELAYED_DISABLE for edge triggered irqs.
+	 */
+	if (data->trigger)
+		entry->mask = 1;
+}
+
+int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
+		       unsigned int nr_irqs, void *arg)
+{
+	int ret, ioapic, pin;
+	struct irq_cfg *cfg;
+	struct irq_data *irq_data;
+	struct mp_chip_data *data;
+	struct irq_alloc_info *info = arg;
+
+	if (!info || nr_irqs > 1)
+		return -EINVAL;
+	irq_data = irq_domain_get_irq_data(domain, virq);
+	if (!irq_data)
+		return -EINVAL;
+
+	ioapic = mp_irqdomain_ioapic_idx(domain);
+	pin = info->ioapic_pin;
+	if (irq_find_mapping(domain, (irq_hw_number_t)pin) > 0)
+		return -EEXIST;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	info->ioapic_entry = &data->entry;
+	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
+	if (ret < 0) {
+		kfree(data);
+		return ret;
+	}
+
+	irq_data->hwirq = info->ioapic_pin;
+	irq_data->chip = &ioapic_chip;
+	irq_data->chip_data = data;
+	mp_irqdomain_get_attr(mp_pin_to_gsi(ioapic, pin), data, info);
+
+	cfg = irqd_cfg(irq_data);
+	add_pin_to_irq_node(cfg, info->ioapic_node, ioapic, pin);
+	if (info->ioapic_entry)
+		mp_setup_entry(cfg, data, info->ioapic_entry);
+	mp_register_handler(virq, data->trigger);
+	if (virq < nr_legacy_irqs())
+		legacy_pic->mask(virq);
+
+	apic_printk(APIC_VERBOSE, KERN_DEBUG
+		    "IOAPIC[%d]: Set routing entry (%d-%d -> 0x%x -> IRQ %d Mode:%i Active:%i Dest:%d)\n",
+		    ioapic, mpc_ioapic_id(ioapic), pin, cfg->vector,
+		    virq, data->trigger, data->polarity, cfg->dest_apicid);
+
+	return 0;
+}
+
+void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
+		       unsigned int nr_irqs)
+{
+	struct irq_cfg *cfg = irq_cfg(virq);
+	struct irq_data *irq_data;
+
+	BUG_ON(nr_irqs != 1);
+	irq_data = irq_domain_get_irq_data(domain, virq);
+	if (irq_data && irq_data->chip_data) {
+		__remove_pin_from_irq(cfg, mp_irqdomain_ioapic_idx(domain),
+				      (int)irq_data->hwirq);
+		WARN_ON(!list_empty(&cfg->irq_2_pin));
+		kfree(irq_data->chip_data);
+	}
+	irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+void mp_irqdomain_activate(struct irq_domain *domain,
+			   struct irq_data *irq_data)
+{
+	unsigned long flags;
+	struct irq_pin_list *entry;
+	struct mp_chip_data *data = irq_data->chip_data;
+	struct irq_cfg *cfg = irqd_cfg(irq_data);
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	for_each_irq_pin(entry, cfg->irq_2_pin)
+		__ioapic_write_entry(entry->apic, entry->pin, data->entry);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
+void mp_irqdomain_deactivate(struct irq_domain *domain,
+			     struct irq_data *irq_data)
+{
+	/* It won't be called for IRQ with multiple IOAPIC pins associated */
+	ioapic_mask_entry(mp_irqdomain_ioapic_idx(domain),
+			  (int)irq_data->hwirq);
+}
+
 int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node)
 {
 	int ret = 0;
@@ -3104,3 +3252,8 @@ int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node)
 
 	return ret;
 }
+
+int mp_irqdomain_ioapic_idx(struct irq_domain *domain)
+{
+	return (int)(long)domain->host_data;
+}