genirq: Add generic msi irq domain support

Implement the basic functions for MSI interrupt support with
hierarchical interrupt domains.

[ tglx: Extracted and combined from several patches ]

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/msi.h b/include/linux/msi.h
index e0d08517bd3d16a54514014e5c6fc124f00cc609..b5ca2456769cafed4f1b4e29eab326297ccde8bc 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -114,4 +114,49 @@ struct msi_controller {
        void (*teardown_irq)(struct msi_controller *chip, unsigned int irq);
 };
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+struct irq_domain;
+struct irq_chip;
+struct device_node;
+struct msi_domain_info;
+
+/**
+ * struct msi_domain_ops - MSI interrupt domain callbacks
+ * @get_hwirq:         Retrieve the resulting hw irq number
+ * @msi_init:          Domain specific init function for MSI interrupts
+ * @msi_free:          Domain specific function to free a MSI interrupts
+ */
+struct msi_domain_ops {
+       irq_hw_number_t (*get_hwirq)(struct msi_domain_info *info, void *arg);
+       int             (*msi_init)(struct irq_domain *domain,
+                                   struct msi_domain_info *info,
+                                   unsigned int virq, irq_hw_number_t hwirq,
+                                   void *arg);
+       void            (*msi_free)(struct irq_domain *domain,
+                                   struct msi_domain_info *info,
+                                   unsigned int virq);
+};
+
+/**
+ * struct msi_domain_info - MSI interrupt domain data
+ * @ops:       The callback data structure
+ * @chip:      The associated interrupt chip
+ * @data:      Domain specific data
+ */
+struct msi_domain_info {
+       struct msi_domain_ops   *ops;
+       struct irq_chip         *chip;
+       void                    *data;
+};
+
+int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
+                           bool force);
+
+struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
+                                        struct msi_domain_info *info,
+                                        struct irq_domain *parent);
+struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);
+
+#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
+
 #endif /* LINUX_MSI_H */

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 4f2eb2b1f23b8f815dbef60b123c15aaeb49ec05..9a76e3beda5423b7743f1d67a0945755b771c977 100644 (file)
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -60,6 +60,16 @@ config IRQ_DOMAIN_HIERARCHY
        bool
        select IRQ_DOMAIN
 
+# Generic MSI interrupt support
+config GENERIC_MSI_IRQ
+       bool
+
+# Generic MSI hierarchical interrupt domain support
+config GENERIC_MSI_IRQ_DOMAIN
+       bool
+       select IRQ_DOMAIN_HIERARCHY
+       select GENERIC_MSI_IRQ
+
 config HANDLE_DOMAIN_IRQ
        bool
 

diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index fff17381f0afc66739d17eb1a696d701970ec20e..d12123526e2b48b07dbf63274aa03f31dcd215e8 100644 (file)
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
 obj-$(CONFIG_PM_SLEEP) += pm.o
+obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
new file mode 100644 (file)
index 0000000..5e0cef4
--- /dev/null
+++ b/kernel/irq/msi.c
@@ -0,0 +1,141 @@
+/*
+ * linux/kernel/irq/msi.c
+ *
+ * Copyright (C) 2014 Intel Corp.
+ * Author: Jiang Liu <jiang.liu@linux.intel.com>
+ *
+ * This file is licensed under GPLv2.
+ *
+ * This file contains common code to support Message Signalled Interrupt for
+ * PCI compatible and non PCI compatible devices.
+ */
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+/**
+ * msi_domain_set_affinity - Generic affinity setter function for MSI domains
+ * @irq_data:  The irq data associated to the interrupt
+ * @mask:      The affinity mask to set
+ * @force:     Flag to enforce setting (disable online checks)
+ *
+ * Intended to be used by MSI interrupt controllers which are
+ * implemented with hierarchical domains.
+ */
+int msi_domain_set_affinity(struct irq_data *irq_data,
+                           const struct cpumask *mask, bool force)
+{
+       struct irq_data *parent = irq_data->parent_data;
+       struct msi_msg msg;
+       int ret;
+
+       ret = parent->chip->irq_set_affinity(parent, mask, force);
+       if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
+               BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
+               irq_chip_write_msi_msg(irq_data, &msg);
+       }
+
+       return ret;
+}
+
+static void msi_domain_activate(struct irq_domain *domain,
+                               struct irq_data *irq_data)
+{
+       struct msi_msg msg;
+
+       BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
+       irq_chip_write_msi_msg(irq_data, &msg);
+}
+
+static void msi_domain_deactivate(struct irq_domain *domain,
+                                 struct irq_data *irq_data)
+{
+       struct msi_msg msg;
+
+       memset(&msg, 0, sizeof(msg));
+       irq_chip_write_msi_msg(irq_data, &msg);
+}
+
+static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+                           unsigned int nr_irqs, void *arg)
+{
+       struct msi_domain_info *info = domain->host_data;
+       struct msi_domain_ops *ops = info->ops;
+       irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
+       int i, ret;
+
+       if (irq_find_mapping(domain, hwirq) > 0)
+               return -EEXIST;
+
+       ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+       if (ret < 0)
+               return ret;
+
+       for (i = 0; i < nr_irqs; i++) {
+               ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
+               if (ret < 0) {
+                       if (ops->msi_free) {
+                               for (i--; i > 0; i--)
+                                       ops->msi_free(domain, info, virq + i);
+                       }
+                       irq_domain_free_irqs_top(domain, virq, nr_irqs);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
+                           unsigned int nr_irqs)
+{
+       struct msi_domain_info *info = domain->host_data;
+       int i;
+
+       if (info->ops->msi_free) {
+               for (i = 0; i < nr_irqs; i++)
+                       info->ops->msi_free(domain, info, virq + i);
+       }
+       irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+static struct irq_domain_ops msi_domain_ops = {
+       .alloc          = msi_domain_alloc,
+       .free           = msi_domain_free,
+       .activate       = msi_domain_activate,
+       .deactivate     = msi_domain_deactivate,
+};
+
+/**
+ * msi_create_irq_domain - Create a MSI interrupt domain
+ * @of_node:   Optional device-tree node of the interrupt controller
+ * @info:      MSI domain info
+ * @parent:    Parent irq domain
+ */
+struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
+                                        struct msi_domain_info *info,
+                                        struct irq_domain *parent)
+{
+       struct irq_domain *domain;
+
+       domain = irq_domain_add_tree(of_node, &msi_domain_ops, info);
+       if (domain)
+               domain->parent = parent;
+
+       return domain;
+}
+
+/**
+ * msi_get_domain_info - Get the MSI interrupt domain info for @domain
+ * @domain:    The interrupt domain to retrieve data from
+ *
+ * Returns the pointer to the msi_domain_info stored in
+ * @domain->host_data.
+ */
+struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
+{
+       return (struct msi_domain_info *)domain->host_data;
+}
+
+#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */