powerpc: Remove CONFIG_PPC601_SYNC_FIX

This config option isn't in any defconfig.

The very first versions of Powerpc 601 have a bug which
requires additional sync before and/or after some instructions.

This was more than 25 years ago and time has come to retire
those buggy versions of the 601 from the kernel.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/55b46bff16705b1ae7bf0a60ccd522b1010ebf75.1601362098.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/ppc_asm.h

@@ -382,15 +382,9 @@ GLUE(.,name):
 #endif
 
 /* various errata or part fixups */
-#ifdef CONFIG_PPC601_SYNC_FIX
-#define SYNC		sync; isync
-#define SYNC_601	sync
-#define ISYNC_601	isync
-#else
 #define	SYNC
 #define SYNC_601
 #define ISYNC_601
-#endif
 
 #if defined(CONFIG_PPC_CELL) || defined(CONFIG_PPC_FSL_BOOK3E)
 #define MFTB(dest)			\

arch/powerpc/platforms/Kconfig

@@ -199,21 +199,6 @@ source "drivers/cpuidle/Kconfig"
 
 endmenu
 
-config PPC601_SYNC_FIX
-	bool "Workarounds for PPC601 bugs"
-	depends on PPC_BOOK3S_601 && PPC_PMAC
-	default y
-	help
-	  Some versions of the PPC601 (the first PowerPC chip) have bugs which
-	  mean that extra synchronization instructions are required near
-	  certain instructions, typically those that make major changes to the
-	  CPU state.  These extra instructions reduce performance slightly.
-	  If you say N here, these extra instructions will not be included,
-	  resulting in a kernel which will run faster but may not run at all
-	  on some systems with the PPC601 chip.
-
-	  If in doubt, say Y here.
-
 config TAU
 	bool "On-chip CPU temperature sensor support"
 	depends on PPC_BOOK3S_32