svn commit: r310700 - head/sys/mips/include

[Alexander Kabaev]

Author: kan
Date: Wed Dec 28 13:48:00 2016
New Revision: 310700
URL: https://svnweb.freebsd.org/changeset/base/310700

Log:
  Be more conservative when enabling write-combining on MIPS
  
  Some MIPS revisions do implement uncached-accelerate caching
  attribute, but place extra requirement on access, such as
  partial-word or out-of-sequence writes potentially having an
  “unpredictable” effects.

Modified:
  head/sys/mips/include/cpuregs.h

Modified: head/sys/mips/include/cpuregs.h
==============================================================================
--- head/sys/mips/include/cpuregs.h	Wed Dec 28 13:28:44 2016	(r310699)
+++ head/sys/mips/include/cpuregs.h	Wed Dec 28 13:48:00 2016	(r310700)
@@ -173,6 +173,7 @@
 
 #if defined(CPU_XBURST)
 #define	MIPS_CCA_UA		0x01
+#define	MIPS_CCA_WC		MIPS_CCA_UA
 #endif
 
 #ifndef	MIPS_CCA_UNCACHED
@@ -192,16 +193,6 @@
 #endif
 #endif
 
-/*
- * Use uncached-accelerated mode for write-combining maps, if one is defined,
- * otherwise fall back to uncached
- */
-#ifndef MIPS_CCA_WC
-#ifdef MIPS_CCA_UA
-#define	MIPS_CCA_WC MIPS_CCA_UA
-#endif
-#endif
-
 #define	MIPS_PHYS_TO_XKPHYS(cca,x) \
 	((0x2ULL << 62) | ((unsigned long long)(cca) << 59) | (x))
 #define	MIPS_PHYS_TO_XKPHYS_CACHED(x) \