msi: add Xen MSI implementation

This patch adds support for MSI interrupts when running on Xen. Apart
from adding the Xen related code needed in order to register MSI
interrupts this patch also makes the msi_init function a hook in
init_ops, so different MSI implementations can have different
initialization functions.

Sponsored by: Citrix Systems R&D

xen/interface/physdev.h:
 - Add the MAP_PIRQ_TYPE_MULTI_MSI to map multi-vector MSI to the Xen
   public interface.

x86/include/init.h:
 - Add a hook for setting custom msi_init methods.

amd64/amd64/machdep.c:
i386/i386/machdep.c:
 - Set the default msi_init hook to point to the native MSI
   initialization method.

x86/xen/pv.c:
 - Set the Xen MSI init hook when running as a Xen guest.

x86/x86/local_apic.c:
 - Call the msi_init hook instead of directly calling msi_init.

xen/xen_intr.h:
x86/xen/xen_intr.c:
 - Introduce support for registering/releasing MSI interrupts with
   Xen.
 - The MSI interrupts will use the same PIC as the IO APIC interrupts.

xen/xen_msi.h:
x86/xen/xen_msi.c:
 - Introduce a Xen MSI implementation.

x86/xen/xen_nexus.c:
 - Overwrite the default MSI hooks in the Xen Nexus to use the Xen MSI
   implementation.

x86/xen/xen_pci.c:
 - Introduce a Xen specific PCI bus that inherits from the ACPI PCI
   bus and overwrites the native MSI methods.
 - This is needed because when running under Xen the MSI messages used
   to configure MSI interrupts on PCI devices are written by Xen
   itself.

dev/acpica/acpi_pci.c:
 - Lower the quality of the ACPI PCI bus so the newly introduced Xen
   PCI bus can take over when needed.

conf/files.i386:
conf/files.amd64:
 - Add the newly created files to the build process.

3 files changed, 62 insertions, 0 deletions

diff --git a/sys/xen/interface/physdev.h b/sys/xen/interface/physdev.h
index b78eeba..56b8be0 100644
--- a/sys/xen/interface/physdev.h
+++ b/sys/xen/interface/physdev.h
@@ -151,6 +151,7 @@ DEFINE_XEN_GUEST_HANDLE(physdev_irq_t);
 #define MAP_PIRQ_TYPE_GSI               0x1
 #define MAP_PIRQ_TYPE_UNKNOWN           0x2
 #define MAP_PIRQ_TYPE_MSI_SEG           0x3
+#define MAP_PIRQ_TYPE_MULTI_MSI         0x4
 
 #define PHYSDEVOP_map_pirq               13
 struct physdev_map_pirq {
diff --git a/sys/xen/xen_intr.h b/sys/xen/xen_intr.h
index a1ff666..a29414d 100644
--- a/sys/xen/xen_intr.h
+++ b/sys/xen/xen_intr.h
@@ -224,4 +224,26 @@ void xen_intr_signal(xen_intr_handle_t handle);
  */
 evtchn_port_t xen_intr_port(xen_intr_handle_t handle);
 
+/**
+ * Setup MSI vector interrupt(s).
+ *
+ * \param dev     The device that requests the binding.
+ *
+ * \param vector  Requested initial vector to bind the MSI interrupt(s) to.
+ *
+ * \param count   Number of vectors to allocate.
+ *
+ * \returns  0 on success, otherwise an errno.
+ */
+int xen_register_msi(device_t dev, int vector, int count);
+
+/**
+ * Teardown a MSI vector interrupt.
+ *
+ * \param vector  Requested vector to release.
+ *
+ * \returns  0 on success, otherwise an errno.
+ */
+int xen_release_msi(int vector);
+
 #endif /* _XEN_INTR_H_ */
diff --git a/sys/xen/xen_msi.h b/sys/xen/xen_msi.h
new file mode 100644
index 0000000..baec4c1a
--- /dev/null
+++ b/sys/xen/xen_msi.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef __XEN_MSI_H__
+#define __XEN_MSI_H__
+
+void	xen_msi_init(void);
+int	xen_msi_map(int irq, uint64_t *addr, uint32_t *data);
+int	xen_msi_alloc(device_t dev, int count, int maxcount, int *irqs);
+int	xen_msi_release(int *irqs, int count);
+int	xen_msix_alloc(device_t dev, int *irq);
+int	xen_msix_release(int irq);
+
+#endif /* !__XEN_MSI_H__ */
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