[patch RFC 34/38] x86/msi: Let pci_msi_prepare() handle non-PCI MSI

[Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

Rename it to x86_msi_prepare() and handle the allocation type setup
depending on the device type.

Add a new arch_msi_prepare define which will be utilized by the upcoming
device MSI support. Define it to NULL if not provided by an architecture in
the generic MSI header.

One arch specific function for MSI support is truly enough.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-hyperv@xxxxxxxxxxxxxxx
---
 arch/x86/include/asm/msi.h          |    4 +++-
 arch/x86/kernel/apic/msi.c          |   27 ++++++++++++++++++++-------
 drivers/pci/controller/pci-hyperv.c |    2 +-
 include/linux/msi.h                 |    4 ++++
 4 files changed, 28 insertions(+), 9 deletions(-)

--- a/arch/x86/include/asm/msi.h
+++ b/arch/x86/include/asm/msi.h
@@ -6,7 +6,9 @@
 
 typedef struct irq_alloc_info msi_alloc_info_t;
 
-int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+int x86_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
                    msi_alloc_info_t *arg);
 
+#define arch_msi_prepare               x86_msi_prepare
+
 #endif /* _ASM_X86_MSI_H */
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -182,26 +182,39 @@ static struct irq_chip pci_msi_controlle
        .flags                  = IRQCHIP_SKIP_SET_WAKE,
 };
 
-int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
-                   msi_alloc_info_t *arg)
+static void pci_msi_prepare(struct device *dev, msi_alloc_info_t *arg)
 {
-       struct pci_dev *pdev = to_pci_dev(dev);
-       struct msi_desc *desc = first_pci_msi_entry(pdev);
+       struct msi_desc *desc = first_msi_entry(dev);
 
-       init_irq_alloc_info(arg, NULL);
        if (desc->msi_attrib.is_msix) {
                arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
        } else {
                arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
                arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
        }
+}
+
+static void dev_msi_prepare(struct device *dev, msi_alloc_info_t *arg)
+{
+       arg->type = X86_IRQ_ALLOC_TYPE_DEV_MSI;
+}
+
+int x86_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+                   msi_alloc_info_t *arg)
+{
+       init_irq_alloc_info(arg, NULL);
+
+       if (dev_is_pci(dev))
+               pci_msi_prepare(dev, arg);
+       else
+               dev_msi_prepare(dev, arg);
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(pci_msi_prepare);
+EXPORT_SYMBOL_GPL(x86_msi_prepare);
 
 static struct msi_domain_ops pci_msi_domain_ops = {
-       .msi_prepare    = pci_msi_prepare,
+       .msi_prepare    = x86_msi_prepare,
 };
 
 static struct msi_domain_info pci_msi_domain_info = {
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1532,7 +1532,7 @@ static struct irq_chip hv_msi_irq_chip =
 };
 
 static struct msi_domain_ops hv_msi_ops = {
-       .msi_prepare    = pci_msi_prepare,
+       .msi_prepare    = arch_msi_prepare,
        .msi_free       = hv_msi_free,
 };
 
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -430,4 +430,8 @@ static inline struct irq_domain *pci_msi
 }
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
 
+#ifndef arch_msi_prepare
+# define arch_msi_prepare      NULL
+#endif
+
 #endif /* LINUX_MSI_H */