Rework how the nexus(4) device works on x86 to better handle the idea of

different "platforms" on x86 machines.  The existing code already handles
having two platforms: ACPI and legacy.  However, the existing approach was
rather hardcoded and difficult to extend.  These changes take the approach
that each x86 hardware platform should provide its own nexus(4) driver (it
can inherit most of its behavior from the default legacy nexus(4) driver)
which is responsible for probing for the platform and performing
appropriate platform-specific setup during attach (such as adding a
platform-specific bus device).  This does mean changing the x86 platform
busses to no longer use an identify routine for probing, but to move that
logic into their matching nexus(4) driver instead.
- Make the default nexus(4) driver in nexus.c on i386 and amd64 handle the
  legacy platform.  It's probe routine now returns BUS_PROBE_GENERIC so it
  can be overriden.
- Expose a nexus_init_resources() routine which initializes the various
  resource managers so that subclassed nexus(4) drivers can invoke it from
  their attach routine.
- The legacy nexus(4) driver explicitly adds a legacy0 device in its
  attach routine.
- The ACPI driver no longer contains an new-bus identify method.  Instead
  it exposes a public function (acpi_identify()) which is a probe routine
  that the MD nexus(4) drivers can use to probe for ACPI.  All of the
  probe logic in acpi_probe() is now moved into acpi_identify() and
  acpi_probe() is just a stub.
- On i386 and amd64, an ACPI-specific nexus(4) driver checks for ACPI via
  acpi_identify() and claims the nexus0 device if the probe succeeds.  It
  then explicitly adds an acpi0 device in its attach routine.
- The legacy(4) driver no longer knows anything about the acpi0 device.
- On ia64 if acpi_identify() fails you basically end up with no devices.
  This matches the previous behavior where the old acpi_identify() would
  fail to add an acpi0 device again leaving you with no devices.

Discussed with:	imp
Silence on:	arch@

1 files changed, 45 insertions, 0 deletions

diff --git a/sys/i386/include/nexusvar.h b/sys/i386/include/nexusvar.h
new file mode 100644
index 0000000..c39a686
--- /dev/null
+++ b/sys/i386/include/nexusvar.h
@@ -0,0 +1,45 @@
+/*-
+ * Copyright 1998 Massachusetts Institute of Technology
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby
+ * granted, provided that both the above copyright notice and this
+ * permission notice appear in all copies, that both the above
+ * copyright notice and this permission notice appear in all
+ * supporting documentation, and that the name of M.I.T. not be used
+ * in advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.  M.I.T. makes
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
+ * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
+ * SHALL M.I.T. 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 _MACHINE_NEXUSVAR_H_
+#define	_MACHINE_NEXUSVAR_H_
+
+struct nexus_device {
+	struct resource_list	nx_resources;
+};
+
+DECLARE_CLASS(nexus_driver);
+
+extern struct rman irq_rman, drq_rman, port_rman, mem_rman;
+
+void	nexus_init_resources(void);
+
+#endif /* !_MACHINE_NEXUSVAR_H_ */