cpu_has_tsc cleanup

PATCH In review john stultz 2 participants 2 messages Aug 8, 2002

Subsystems (2)

Char and misc drivers Random number driver

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john stultz

author

2002-08-08 00:14 UTC #0 lore raw

PATCH 1/1 cpu_has_tsc cleanup

Marcelo,

Here is a trivial cleanup patch that replaces:

	test_bit(X86_FEATURE_TSC, &boot_cpu_data.x86_capability)

w/ the cpu_has_tsc macro.

I believe this was originally by Brian Gerst for 2.5

thanks
-john

drivers/char/joystick/analog.c +3 -4

diff -Nru a/drivers/char/joystick/analog.c b/drivers/char/joystick/analog.c
@@ -137,10 +137,9 @@
  */
 
 #ifdef __i386__
-#define TSC_PRESENT	(test_bit(X86_FEATURE_TSC, &boot_cpu_data.x86_capability))
-#define GET_TIME(x)	do { if (TSC_PRESENT) rdtscl(x); else { outb(0, 0x43); x = inb(0x40); x |= inb(0x40) << 8; } } while (0)
-#define DELTA(x,y)	(TSC_PRESENT?((y)-(x)):((x)-(y)+((x)<(y)?1193180L/HZ:0)))
-#define TIME_NAME	(TSC_PRESENT?"TSC":"PIT")
+#define GET_TIME(x)	do { if (cpu_has_tsc) rdtscl(x); else { outb(0, 0x43); x = inb(0x40); x |= inb(0x40) << 8; } } while (0)
+#define DELTA(x,y)	(cpu_has_tsc?((y)-(x)):((x)-(y)+((x)<(y)?1193180L/HZ:0)))
+#define TIME_NAME	(cpu_has_tsc?"TSC":"PIT")
 #elif __x86_64__
 #define GET_TIME(x)	rdtscl(x)
 #define DELTA(x,y)	((y)-(x))

drivers/char/random.c +1 -1

diff -Nru a/drivers/char/random.c b/drivers/char/random.c
@@ -735,7 +735,7 @@
 	int		entropy = 0;
 
 #if defined (__i386__)
-	if ( test_bit(X86_FEATURE_TSC, &boot_cpu_data.x86_capability) ) {
+	if (cpu_has_tsc) {
 		__u32 high;
 		rdtsc(time, high);
 		num ^= high;

george anzinger

2002-08-08 19:53 UTC #1 lore raw

Quoted 9 lines · john stultz

Marcelo,
Here is a trivial cleanup patch that replaces:
        test_bit(X86_FEATURE_TSC, &boot_cpu_data.x86_capability)
w/ the cpu_has_tsc macro.
I believe this was originally by Brian Gerst for 2.5

This patch has a problem in the TSC not defined case in that it access the PIT with out taking the required
locks. spin_lock_irq(&i8253_lock) is used to protect
the PIT...

Signature · 5 lines

George Anzinger   [email protected]
High-res-timers: 
http://sourceforge.net/projects/high-res-timers/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml