PCI/MSI: Enhance core to support hierarchy irqdomain

Enhance PCI MSI core to support hierarchy irqdomain, so the common
code can be shared across architectures.

[ 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/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 82f95f4..cced842 100644 (file)
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -17,6 +17,11 @@ config PCI_MSI
 
           If you don't know what to do here, say Y.
 
+config PCI_MSI_IRQ_DOMAIN
+       bool
+       depends on PCI_MSI
+       select GENERIC_MSI_IRQ_DOMAIN
+
 config PCI_DEBUG
        bool "PCI Debugging"
        depends on PCI && DEBUG_KERNEL

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 103700e..36b0c2e 100644 (file)
--- 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"
 
@@ -1091,3 +1092,170 @@ 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
+/**
+ * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
+ * @irq_data:  Pointer to interrupt data of the MSI interrupt
+ * @msg:       Pointer to the message
+ */
+void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
+{
+       struct msi_desc *desc = irq_data->msi_desc;
+
+       /*
+        * For MSI-X desc->irq is always equal to irq_data->irq. For
+        * MSI only the first interrupt of MULTI MSI passes the test.
+        */
+       if (desc->irq == irq_data->irq)
+               __pci_write_msi_msg(desc, msg);
+}
+
+/**
+ * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
+ * @dev:       Pointer to the PCI device
+ * @desc:      Pointer to the msi descriptor
+ *
+ * The ID number is only used within the irqdomain.
+ */
+irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
+                                         struct msi_desc *desc)
+{
+       return (irq_hw_number_t)desc->msi_attrib.entry_nr |
+               PCI_DEVID(dev->bus->number, dev->devfn) << 11 |
+               (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
+}
+
+static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)
+{
+       return !desc->msi_attrib.is_msix && desc->nvec_used > 1;
+}
+
+/**
+ * pci_msi_domain_check_cap - Verify that @domain supports the capabilities for @dev
+ * @domain:    The interrupt domain to check
+ * @info:      The domain info for verification
+ * @dev:       The device to check
+ *
+ * Returns:
+ *  0 if the functionality is supported
+ *  1 if Multi MSI is requested, but the domain does not support it
+ *  -ENOTSUPP otherwise
+ */
+int pci_msi_domain_check_cap(struct irq_domain *domain,
+                            struct msi_domain_info *info, struct device *dev)
+{
+       struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev));
+
+       /* Special handling to support pci_enable_msi_range() */
+       if (pci_msi_desc_is_multi_msi(desc) &&
+           !(info->flags & MSI_FLAG_MULTI_PCI_MSI))
+               return 1;
+       else if (desc->msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX))
+               return -ENOTSUPP;
+
+       return 0;
+}
+
+static int pci_msi_domain_handle_error(struct irq_domain *domain,
+                                      struct msi_desc *desc, int error)
+{
+       /* Special handling to support pci_enable_msi_range() */
+       if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC)
+               return 1;
+
+       return error;
+}
+
+#ifdef GENERIC_MSI_DOMAIN_OPS
+static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
+                                   struct msi_desc *desc)
+{
+       arg->desc = desc;
+       arg->hwirq = pci_msi_domain_calc_hwirq(msi_desc_to_pci_dev(desc),
+                                              desc);
+}
+#else
+#define pci_msi_domain_set_desc                NULL
+#endif
+
+static struct msi_domain_ops pci_msi_domain_ops_default = {
+       .set_desc       = pci_msi_domain_set_desc,
+       .msi_check      = pci_msi_domain_check_cap,
+       .handle_error   = pci_msi_domain_handle_error,
+};
+
+static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
+{
+       struct msi_domain_ops *ops = info->ops;
+
+       if (ops == NULL) {
+               info->ops = &pci_msi_domain_ops_default;
+       } else {
+               if (ops->set_desc == NULL)
+                       ops->set_desc = pci_msi_domain_set_desc;
+               if (ops->msi_check == NULL)
+                       ops->msi_check = pci_msi_domain_check_cap;
+               if (ops->handle_error == NULL)
+                       ops->handle_error = pci_msi_domain_handle_error;
+       }
+}
+
+static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
+{
+       struct irq_chip *chip = info->chip;
+
+       BUG_ON(!chip);
+       if (!chip->irq_write_msi_msg)
+               chip->irq_write_msi_msg = pci_msi_domain_write_msg;
+}
+
+/**
+ * pci_msi_create_irq_domain - Creat a MSI interrupt domain
+ * @node:      Optional device-tree node of the interrupt controller
+ * @info:      MSI domain info
+ * @parent:    Parent irq domain
+ *
+ * Updates the domain and chip ops and creates a MSI interrupt domain.
+ *
+ * Returns:
+ * A domain pointer or NULL in case of failure.
+ */
+struct irq_domain *pci_msi_create_irq_domain(struct device_node *node,
+                                            struct msi_domain_info *info,
+                                            struct irq_domain *parent)
+{
+       if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
+               pci_msi_domain_update_dom_ops(info);
+       if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
+               pci_msi_domain_update_chip_ops(info);
+
+       return msi_create_irq_domain(node, info, parent);
+}
+
+/**
+ * pci_msi_domain_alloc_irqs - Allocate interrupts for @dev in @domain
+ * @domain:    The interrupt domain to allocate from
+ * @dev:       The device for which to allocate
+ * @nvec:      The number of interrupts to allocate
+ * @type:      Unused to allow simpler migration from the arch_XXX interfaces
+ *
+ * Returns:
+ * A virtual interrupt number or an error code in case of failure
+ */
+int pci_msi_domain_alloc_irqs(struct irq_domain *domain, struct pci_dev *dev,
+                             int nvec, int type)
+{
+       return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
+}
+
+/**
+ * pci_msi_domain_free_irqs - Free interrupts for @dev in @domain
+ * @domain:    The interrupt domain
+ * @dev:       The device for which to free interrupts
+ */
+void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev)
+{
+       msi_domain_free_irqs(domain, &dev->dev);
+}
+#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 0098e2c..1628788 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -220,4 +220,18 @@ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);
 
 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
 
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg);
+struct irq_domain *pci_msi_create_irq_domain(struct device_node *node,
+                                            struct msi_domain_info *info,
+                                            struct irq_domain *parent);
+int pci_msi_domain_alloc_irqs(struct irq_domain *domain, struct pci_dev *dev,
+                             int nvec, int type);
+void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev);
+irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
+                                         struct msi_desc *desc);
+int pci_msi_domain_check_cap(struct irq_domain *domain,
+                            struct msi_domain_info *info, struct device *dev);
+#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
+
 #endif /* LINUX_MSI_H */