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Date:      Sun, 8 Apr 2018 16:46:24 +0000 (UTC)
From:      Justin Hibbits <jhibbits@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r332287 - head/sys/powerpc/powerpc
Message-ID:  <201804081646.w38GkOY6002912@repo.freebsd.org>
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Author: jhibbits
Date: Sun Apr  8 16:46:24 2018
New Revision: 332287
URL: https://svnweb.freebsd.org/changeset/base/332287

Log:
  powerpc64: Avoid calling isync twice
  
  Summary:
  It is not necessary to call isync() after calling mtmsr() function, mainly
  because the mtmsr() calls 'isync' internally to synchronize the machine state
  register. Other than that, isync() just calls the 'isync' instruction, thus,
  the 'isync' instruction is being called twice, and that seems to be unnecessary.
  
  This patch just remove the unecessary calls to isync() after mtmsr().
  
  Submitted by:	Breno Leitao
  Differential Revision: https://reviews.freebsd.org/D14583

Modified:
  head/sys/powerpc/powerpc/altivec.c
  head/sys/powerpc/powerpc/cpu.c
  head/sys/powerpc/powerpc/fpu.c

Modified: head/sys/powerpc/powerpc/altivec.c
==============================================================================
--- head/sys/powerpc/powerpc/altivec.c	Sun Apr  8 16:43:56 2018	(r332286)
+++ head/sys/powerpc/powerpc/altivec.c	Sun Apr  8 16:46:24 2018	(r332287)
@@ -58,7 +58,6 @@ save_vec_int(struct thread *td)
 	 */
 	msr = mfmsr();
 	mtmsr(msr | PSL_VEC);
-	isync();
 
 	/*
 	 * Save the vector registers and VSCR to the PCB
@@ -120,7 +119,6 @@ enable_vec(struct thread *td)
 	 */
 	msr = mfmsr();
 	mtmsr(msr | PSL_VEC);
-	isync();
 
 	/*
 	 * Restore VSCR by first loading it into a vector and then into VSCR.

Modified: head/sys/powerpc/powerpc/cpu.c
==============================================================================
--- head/sys/powerpc/powerpc/cpu.c	Sun Apr  8 16:43:56 2018	(r332286)
+++ head/sys/powerpc/powerpc/cpu.c	Sun Apr  8 16:46:24 2018	(r332287)
@@ -710,7 +710,6 @@ cpu_idle_60x(sbintime_t sbt)
 	default:
 		powerpc_sync();
 		mtmsr(msr | PSL_POW);
-		isync();
 		break;
 	}
 #endif
@@ -739,7 +738,6 @@ cpu_idle_booke(sbintime_t sbt)
 	default:
 		powerpc_sync();
 		mtmsr(msr | PSL_WE);
-		isync();
 		break;
 	}
 #endif

Modified: head/sys/powerpc/powerpc/fpu.c
==============================================================================
--- head/sys/powerpc/powerpc/fpu.c	Sun Apr  8 16:43:56 2018	(r332286)
+++ head/sys/powerpc/powerpc/fpu.c	Sun Apr  8 16:46:24 2018	(r332287)
@@ -87,7 +87,6 @@ enable_fpu(struct thread *td)
 		mtmsr(msr | PSL_FP | PSL_VSX);
 	else
 		mtmsr(msr | PSL_FP);
-	isync();
 
 	/*
 	 * Load the floating point registers and FPSCR from the PCB.
@@ -143,7 +142,6 @@ save_fpu(struct thread *td)
 		mtmsr(msr | PSL_FP | PSL_VSX);
 	else
 		mtmsr(msr | PSL_FP);
-	isync();
 
 	/*
 	 * Save the floating-point registers and FPSCR to the PCB

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