svn commit: r365481 - in head/sys/powerpc: aim powerpc

[Brandon Bergren]

Author: bdragon
Date: Tue Sep  8 22:59:43 2020
New Revision: 365481
URL: https://svnweb.freebsd.org/changeset/base/365481

Log:
  [PowerPC64] Hide dssall instruction from llvm assembler
  
  When doing a build for a modern CPUTYPE, llvm will throw errors if obsolete
  instructions are used, even if they will never run due to runtime checks.
  
  Hiding the dssall instruction from the assembler fixes kernel build when
  overriding CPUTYPE, without having any effect on the generated binary.
  
  This has been in my local tree for over a year and is well tested across
  a variety of machines.
  
  Sponsored by:	Tag1 Consulting, Inc.

Modified:
  head/sys/powerpc/aim/aim_machdep.c
  head/sys/powerpc/powerpc/cpu.c

Modified: head/sys/powerpc/aim/aim_machdep.c
==============================================================================
--- head/sys/powerpc/aim/aim_machdep.c	Tue Sep  8 22:50:24 2020	(r365480)
+++ head/sys/powerpc/aim/aim_machdep.c	Tue Sep  8 22:59:43 2020	(r365481)
@@ -629,7 +629,8 @@ flush_disable_caches(void)
 	mtspr(SPR_MSSCR0, msscr0);
 	powerpc_sync();
 	isync();
-	__asm__ __volatile__("dssall; sync");
+	/* 7e00066c: dssall */
+	__asm__ __volatile__(".long 0x7e00066c; sync");
 	powerpc_sync();
 	isync();
 	__asm__ __volatile__("dcbf 0,%0" :: "r"(0));

Modified: head/sys/powerpc/powerpc/cpu.c
==============================================================================
--- head/sys/powerpc/powerpc/cpu.c	Tue Sep  8 22:50:24 2020	(r365480)
+++ head/sys/powerpc/powerpc/cpu.c	Tue Sep  8 22:59:43 2020	(r365481)
@@ -753,8 +753,9 @@ cpu_idle_60x(sbintime_t sbt)
 	case MPC7450:
 	case MPC7455:
 	case MPC7457:
+		/* 0x7e00066c: dssall */
 		__asm __volatile("\
-			    dssall; sync; mtmsr %0; isync"
+			    .long 0x7e00066c; sync; mtmsr %0; isync"
 			    :: "r"(msr | PSL_POW));
 		break;
 	default: