Enhance PCI MSI core to support hierarchy irqdomain, so the common
code could be shared among architectures.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
drivers/pci/Kconfig | 4 ++
drivers/pci/msi.c | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/msi.h | 11 +++++
3 files changed, 141 insertions(+)
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index b9db0f2ce11f..022e89745f86 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -16,6 +16,10 @@ config PCI_MSI
If you don't know what to do here, say Y.
+config PCI_MSI_IRQ_DOMAIN
+ bool
+ depends on PCI_MSI && IRQ_DOMAIN_HIERARCHY
+
config PCI_DEBUG
bool "PCI Debugging"
depends on PCI && DEBUG_KERNEL
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index da181c59394b..7423ee16972f 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -19,6 +19,7 @@
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/irqdomain.h>
#include "pci.h"
@@ -1098,3 +1099,128 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
return nvec;
}
EXPORT_SYMBOL(pci_enable_msix_range);
+
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+static inline irq_hw_number_t
+msi_get_hwirq(struct pci_dev *pdev, struct msi_desc *msidesc)
+{
+ return (irq_hw_number_t)msidesc->msi_attrib.entry_nr |
+ PCI_DEVID(pdev->bus->number, pdev->devfn) << 11 |
+ (pci_domain_nr(pdev->bus) & 0xFFFFFFFF) << 27;
+}
+
+static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ int i, ret;
+ irq_hw_number_t hwirq = arch_msi_irq_domain_get_hwirq(arg);
+
+ if (irq_find_mapping(domain, hwirq) > 0)
+ return -EEXIST;
+
+ ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+ if (ret >= 0)
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_hwirq_and_chip(domain, virq + i,
+ hwirq + i, &msi_chip, (void *)(long)i);
+ __irq_set_handler(virq + i, handle_edge_irq, 0, "edge");
+ }
+
+ return ret;
+}
+
+static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ int i;
+
+ for (i = 0; i < nr_irqs; i++) {
+ struct msi_desc *msidesc = irq_get_msi_desc(virq);
+
+ if (msidesc)
+ msidesc->irq = 0;
+ }
+ irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+static int msi_domain_activate(struct irq_domain *domain,
+ struct irq_data *irq_data)
+{
+ int ret = 0;
+ struct msi_msg msg;
+
+ /*
+ * irq_data->chip_data is MSI/MSIx offset.
+ * MSI-X message is written per-IRQ, the offset is always 0.
+ * MSI message denotes a contiguous group of IRQs, written for 0th IRQ.
+ */
+ if (!irq_data->chip_data) {
+ ret = irq_chip_compose_msi_msg(irq_data, &msg);
+ if (ret == 0)
+ write_msi_msg(irq_data->irq, &msg);
+ }
+
+ return ret;
+}
+
+static int msi_domain_deactivate(struct irq_domain *domain,
+ struct irq_data *irq_data)
+{
+ struct msi_msg msg;
+
+ if (irq_data->chip_data) {
+ memset(&msg, 0, sizeof(msg));
+ write_msi_msg(irq_data->irq, &msg);
+ }
+
+ return 0;
+}
+
+static struct irq_domain_ops msi_domain_ops = {
+ .alloc = msi_domain_alloc,
+ .free = msi_domain_free,
+ .activate = msi_domain_activate,
+ .deactivate = msi_domain_deactivate,
+};
+
+struct irq_domain *msi_create_irq_domain(struct irq_domain *parent)
+{
+ struct irq_domain *domain;
+
+ domain = irq_domain_add_tree(NULL, &msi_domain_ops, NULL);
+ if (domain)
+ domain->parent = parent;
+
+ return domain;
+}
+
+int msi_irq_domain_alloc_irqs(struct irq_domain *domain, int type,
+ struct pci_dev *dev, void *arg)
+{
+ int i, virq;
+ struct msi_desc *msidesc;
+ int node = dev_to_node(&dev->dev);
+
+ list_for_each_entry(msidesc, &dev->msi_list, list) {
+ arch_msi_irq_domain_set_hwirq(arg, msi_get_hwirq(dev, msidesc));
+ virq = irq_domain_alloc_irqs(domain, msidesc->nvec_used,
+ node, arg);
+ if (virq < 0) {
+ /* Special handling for pci_enable_msi_range(). */
+ return (type == PCI_CAP_ID_MSI &&
+ msidesc->nvec_used > 1) ? 1 : -ENOSPC;
+ }
+ for (i = 0; i < msidesc->nvec_used; i++)
+ irq_set_msi_desc_off(virq + i, i, msidesc);
+ }
+
+ list_for_each_entry(msidesc, &dev->msi_list, list)
+ if (msidesc->nvec_used == 1)
+ dev_dbg(&dev->dev, "irq %d for MSI/MSI-X\n", virq);
+ else
+ dev_dbg(&dev->dev, "irq [%d-%d] for MSI/MSI-X\n",
+ virq, virq + msidesc->nvec_used - 1);
+
+ return 0;
+}
+#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 44f4746d033b..05dcd425f82b 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -75,4 +75,15 @@ struct msi_chip {
void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
};
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+extern struct irq_chip msi_chip;
+
+extern struct irq_domain *msi_create_irq_domain(struct irq_domain *parent);
+extern int msi_irq_domain_alloc_irqs(struct irq_domain *domain, int type,
+ struct pci_dev *dev, void *arg);
+
+extern irq_hw_number_t arch_msi_irq_domain_get_hwirq(void *arg);
+extern void arch_msi_irq_domain_set_hwirq(void *arg, irq_hw_number_t hwirq);
+#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
+
#endif /* LINUX_MSI_H */
--
1.7.10.4
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