Module: xenomai-head
Branch: master
Commit: 9c09db6b8be5cc369fe0e94895c92a156ac0196d
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=9c09db6b8be5cc369fe0e94895c92a156ac0196d
Author: Philippe Gerum <r...@xenomai.org>
Date: Tue Oct 27 15:14:06 2009 +0100
arm: introduce support for freerunning countdown TSC
---
include/asm-arm/syscall.h | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/include/asm-arm/syscall.h b/include/asm-arm/syscall.h
index 9d5bcad..2ff4a28 100644
--- a/include/asm-arm/syscall.h
+++ b/include/asm-arm/syscall.h
@@ -224,6 +224,7 @@ static inline int __xn_interrupted_p(struct pt_regs *regs)
#define XENOMAI_SYSARCH_ATOMIC_SET_MASK 1
#define XENOMAI_SYSARCH_ATOMIC_CLEAR_MASK 2
#define XENOMAI_SYSARCH_XCHG 3
+#define XENOMAI_SYSARCH_TSCINFO 4
struct __xn_tscinfo {
int type; /* Must remain first member */
@@ -245,8 +246,7 @@ struct __xn_tscinfo {
#define __XN_TSC_TYPE_FREERUNNING 1
#define __XN_TSC_TYPE_DECREMENTER 2
#define __XN_TSC_TYPE_FREERUNNING_FAST_WRAP 3
-
-#define XENOMAI_SYSARCH_TSCINFO 4
+#define __XN_TSC_TYPE_FREERUNNING_COUNTDOWN 4
#ifndef __KERNEL__
#include <stdio.h>
@@ -279,6 +279,20 @@ static inline unsigned long long __xn_rdtsc(void)
if ((counter & mask) < ((unsigned) result & mask))
result += mask + 1ULL;
return (result & ~((unsigned long long) mask)) | (counter & mask);
+#elif XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING_COUNTDOWN
+ volatile unsigned long long *const tscp = __xn_tscinfo.u.fr.tsc;
+ volatile unsigned *const counterp = __xn_tscinfo.u.fr.counter;
+ const unsigned mask = __xn_tscinfo.u.fr.mask;
+ register unsigned long long result;
+ unsigned counter;
+
+ __asm__ ("ldmia %1, %M0\n": "=r"(result): "r"(tscp), "m"(*tscp));
+ __asm__ __volatile__ ("" : /* */ : /* */ : "memory");
+ counter = mask - *counterp;
+
+ if ((counter & mask) > ((unsigned) result & mask))
+ result += mask + 1ULL;
+ return (result & ~((unsigned long long) mask)) | (counter & mask);
#elif XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING_FAST_WRAP
volatile unsigned long long *const tscp = __xn_tscinfo.u.fr.tsc;
volatile unsigned *const counterp = __xn_tscinfo.u.fr.counter;
@@ -353,9 +367,11 @@ static inline void xeno_arm_features_check(void)
page_size = sysconf(_SC_PAGESIZE);
switch(__xn_tscinfo.type) {
-#if XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING \
+#if XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING \
+ || XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING_COUNTDOWN \
|| XNARCH_ARM_TSC_TYPE == __XN_TSC_TYPE_FREERUNNING_FAST_WRAP
- case __XN_TSC_TYPE_FREERUNNING: {
+ case __XN_TSC_TYPE_FREERUNNING:
+ case __XN_TSC_TYPE_FREERUNNING_COUNTDOWN: {
unsigned long phys_addr;
phys_addr = (unsigned long) __xn_tscinfo.u.fr.counter;
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