socsvn commit: r269884 - in soc2014/astarasikov/head/sys/arm: arm include

[astarasikov at FreeBSD.org]

Author: astarasikov
Date: Sun Jun 22 21:04:13 2014
New Revision: 269884
URL: http://svnweb.FreeBSD.org/socsvn/?view=rev&rev=269884

Log:
  arm: do not use performance counters in QEMU
  
  	Currently Android Emulator and older versions of QEMU will trap
  	if performance counters are accessed via CP15. This patch provides
  	a workaround for it.
  

Modified:
  soc2014/astarasikov/head/sys/arm/arm/cpufunc.c
  soc2014/astarasikov/head/sys/arm/include/cpu.h

Modified: soc2014/astarasikov/head/sys/arm/arm/cpufunc.c
==============================================================================
--- soc2014/astarasikov/head/sys/arm/arm/cpufunc.c	Sun Jun 22 21:03:09 2014	(r269883)
+++ soc2014/astarasikov/head/sys/arm/arm/cpufunc.c	Sun Jun 22 21:04:13 2014	(r269884)
@@ -1405,6 +1405,9 @@
 static __inline void
 cpu_scc_setup_ccnt(void)
 {
+#if defined(QEMU_WORKAROUNDS)
+	return;
+#else
 /* This is how you give userland access to the CCNT and PMCn
  * registers.
  * BEWARE! This gives write access also, which may not be what
@@ -1427,6 +1430,7 @@
 			: "r"(0xFFFFFFFF),
 			  "r"(0x00000005),
 			  "r"(0x80000000));
+#endif
 }
 #endif
 

Modified: soc2014/astarasikov/head/sys/arm/include/cpu.h
==============================================================================
--- soc2014/astarasikov/head/sys/arm/include/cpu.h	Sun Jun 22 21:03:09 2014	(r269883)
+++ soc2014/astarasikov/head/sys/arm/include/cpu.h	Sun Jun 22 21:04:13 2014	(r269884)
@@ -15,9 +15,15 @@
 get_cyclecount(void)
 {
 /* This '#if' asks the question 'Does CP15/SCC include performance counters?' */
-#if defined(CPU_ARM1136) || defined(CPU_ARM1176) \
+
+/* QEMU has got support for emulating performance counters
+ * around march 2014. Android Emulator is lagging behind and will
+ * die with 'unimplemented cp15 register read' trap.
+ * Maybe one day we can revert QEMU_WORKAROUNDS */
+#if (defined(CPU_ARM1136) || defined(CPU_ARM1176) \
  || defined(CPU_MV_PJ4B) \
- || defined(CPU_CORTEXA) || defined(CPU_KRAIT)
+ || defined(CPU_CORTEXA) || defined(CPU_KRAIT)) \
+ && !defined(QEMU_WORKAROUNDS)
 	uint32_t ccnt;
 	uint64_t ccnt64;