svn commit: r346063 - head/sys/dev/acpica

[John Baldwin]

Author: jhb
Date: Tue Apr  9 19:22:08 2019
New Revision: 346063
URL: https://svnweb.freebsd.org/changeset/base/346063

Log:
  Don't pre-reserve resources for CPU devices when they are set.
  
  CPUs can use shared (RF_SHAREABLE) resources for the I/O port used for
  entering and exiting C states.  If this I/O port is included in an ACPI
  system resource device, then this happens to still work, but if the port
  wasn't part of a system resource device, only the first CPU could allocate
  the I/O port and use C states since resource_list_reserve() was always
  allocating the resource from nexus0 without RF_SHAREABLE.  By avoiding
  the reservation, the flags from the bus_alloc_resource() in the CPU driver
  (which include RF_SHAREABLE) are honored.
  
  PR:		236513
  Reported by:	stockhausen at collogia.de
  Sleuthing by:	avg
  Reviewed by:	avg
  MFC after:	2 weeks

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

Modified: head/sys/dev/acpica/acpi.c
==============================================================================
--- head/sys/dev/acpica/acpi.c	Tue Apr  9 18:07:17 2019	(r346062)
+++ head/sys/dev/acpica/acpi.c	Tue Apr  9 19:22:08 2019	(r346063)
@@ -1353,6 +1353,14 @@ acpi_set_resource(device_t dev, device_t child, int ty
 	return (0);
 
     /*
+     * Don't reserve resources for CPU devices.  Some of these
+     * resources need to be allocated as shareable, but reservations
+     * are always non-shareable.
+     */
+    if (device_get_devclass(child) == devclass_find("cpu"))
+	return (0);
+
+    /*
      * Reserve the resource.
      *
      * XXX: Ignores failure for now.  Failure here is probably a