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authorJiang Liu <jiang.liu@linux.intel.com>2014-11-12 11:39:03 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-11-23 13:01:47 +0100
commitf3cf8bb0d6c3c11ddedf01f02f856f2ae8c33aa4 (patch)
treef61cecf6747f73d028a5f5e87f25a5cede929c39 /kernel/irq/msi.c
parent9dde55b72dc80bfae4280ddce5dbd69ba8240813 (diff)
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>
Diffstat (limited to 'kernel/irq/msi.c')
-rw-r--r--kernel/irq/msi.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
new file mode 100644
index 000000000000..5e0cef4741d9
--- /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 */