svn commit: r277468 - head/sys/powerpc/aim

[Nathan Whitehorn]

Author: nwhitehorn
Date: Wed Jan 21 02:57:54 2015
New Revision: 277468
URL: https://svnweb.freebsd.org/changeset/base/277468

Log:
  On 64-bit PowerPC, use more native forms of the PPC 970 HID restore
  sequences, like are used to read the HIDs. This is both easier to read
  and avoids a miscompilation by GCC in certain circumstances. Also avoid
  double restoration of HID4 and HID5.
  
  MFC after:	2 weeks

Modified:
  head/sys/powerpc/aim/mp_cpudep.c

Modified: head/sys/powerpc/aim/mp_cpudep.c
==============================================================================
--- head/sys/powerpc/aim/mp_cpudep.c	Wed Jan 21 02:56:13 2015	(r277467)
+++ head/sys/powerpc/aim/mp_cpudep.c	Wed Jan 21 02:57:54 2015	(r277468)
@@ -58,7 +58,9 @@ SYSINIT(cpu_save_config, SI_SUB_CPU, SI_
 void
 cpudep_ap_early_bootstrap(void)
 {
+#ifndef __powerpc64__
 	register_t reg;
+#endif
 
 	__asm __volatile("mtsprg 0, %0" :: "r"(ap_pcpu));
 	powerpc_sync();
@@ -69,12 +71,17 @@ cpudep_ap_early_bootstrap(void)
 	case IBM970MP:
 		/* Restore HID4 and HID5, which are necessary for the MMU */
 
+#ifdef __powerpc64__
+		mtspr(SPR_HID4, bsp_state[2]); powerpc_sync(); isync();
+		mtspr(SPR_HID5, bsp_state[3]); powerpc_sync(); isync();
+#else
 		__asm __volatile("ld %0, 16(%2); sync; isync;	\
 		    mtspr %1, %0; sync; isync;"
 		    : "=r"(reg) : "K"(SPR_HID4), "r"(bsp_state));
 		__asm __volatile("ld %0, 24(%2); sync; isync;	\
 		    mtspr %1, %0; sync; isync;"
 		    : "=r"(reg) : "K"(SPR_HID5), "r"(bsp_state));
+#endif
 		powerpc_sync();
 		break;
 	}
@@ -292,9 +299,24 @@ cpudep_ap_setup()
 		/*
 		 * The 970 has strange rules about how to update HID registers.
 		 * See Table 2-3, 970MP manual
+		 *
+		 * Note: HID4 and HID5 restored already in
+		 * cpudep_ap_early_bootstrap()
 		 */
 
 		__asm __volatile("mtasr %0; sync" :: "r"(0));
+	#ifdef __powerpc64__
+		__asm __volatile(" \
+			sync; isync;					\
+			mtspr	%1, %0;					\
+			mfspr	%0, %1;	mfspr	%0, %1;	mfspr	%0, %1;	\
+			mfspr	%0, %1;	mfspr	%0, %1;	mfspr	%0, %1; \
+			sync; isync" 
+		    :: "r"(bsp_state[0]), "K"(SPR_HID0));
+		__asm __volatile("sync; isync;	\
+		    mtspr %1, %0; mtspr %1, %0; sync; isync"
+		    :: "r"(bsp_state[1]), "K"(SPR_HID1));
+	#else
 		__asm __volatile(" \
 			ld	%0,0(%2);				\
 			sync; isync;					\
@@ -306,12 +328,7 @@ cpudep_ap_setup()
 		__asm __volatile("ld %0, 8(%2); sync; isync;	\
 		    mtspr %1, %0; mtspr %1, %0; sync; isync"
 		    : "=r"(reg) : "K"(SPR_HID1), "r"(bsp_state));
-		__asm __volatile("ld %0, 16(%2); sync; isync;	\
-		    mtspr %1, %0; sync; isync;"
-		    : "=r"(reg) : "K"(SPR_HID4), "r"(bsp_state));
-		__asm __volatile("ld %0, 24(%2); sync; isync;	\
-		    mtspr %1, %0; sync; isync;"
-		    : "=r"(reg) : "K"(SPR_HID5), "r"(bsp_state));
+	#endif
 
 		powerpc_sync();
 		break;