svn commit: r332733 - head/sys/dev/acpica

[John Baldwin]

Author: jhb
Date: Wed Apr 18 18:36:26 2018
New Revision: 332733
URL: https://svnweb.freebsd.org/changeset/base/332733

Log:
  Workaround fixed I/O port resources encoded as I/O port ranges in _CRS.
  
  ACPI I/O port descriptors use _MIN and _MAX fields to specify the set
  of allowable base (start) addresses for an I/O port resource along with
  a _LEN field specifying the length.  A fixed resource is supposed to be
  encoded with _MIN == _MAX, but some buggy firmwares instead set _MAX to
  the end of the fixed range.  Relocating I/O ranges only make sense in
  _PRS (possible resource settings), not in _CRS (current resource settings),
  so if an I/O port range with _MAX set set to the end of the range is
  present in _CRS, treat it as a fixed I/O port resource starting at
  _MIN.
  
  PR:		224096
  Submitted by:	Harald Böhm <harald at boehm.codes>
  Pointy hat to:	jhb (taking so long to actually commit this)
  MFC after:	1 week

Modified:
  head/sys/dev/acpica/acpi_resource.c

Modified: head/sys/dev/acpica/acpi_resource.c
==============================================================================
--- head/sys/dev/acpica/acpi_resource.c	Wed Apr 18 16:27:06 2018	(r332732)
+++ head/sys/dev/acpica/acpi_resource.c	Wed Apr 18 18:36:26 2018	(r332733)
@@ -530,6 +530,24 @@ acpi_res_set_iorange(device_t dev, void *context, uint
 
     if (cp == NULL)
 	return;
+
+    /*
+     * XXX: Some BIOSes contain buggy _CRS entries where fixed I/O
+     * ranges have the maximum base address (_MAX) to the end of the
+     * I/O range instead of the start.  These are then treated as a
+     * relocatable I/O range rather than a fixed I/O resource.  As a
+     * workaround, treat I/O resources encoded this way as fixed I/O
+     * ports.
+     */
+    if (high == (low + length)) {
+	if (bootverbose)
+	    device_printf(dev,
+		"_CRS has fixed I/O port range defined as relocatable\n");
+
+	bus_set_resource(dev, SYS_RES_IOPORT, cp->ar_nio++, low, length);
+	return;
+    }
+
     device_printf(dev, "I/O range not supported\n");
 }