libpayload: Generalize and redistribute timekeeping code

The timekeeping code in libpayload was dependent on rdtsc, and when it was
split up by arch, that code was duplicated even though it was mostly the same.
This change factors out actually reading the count from the timer and the
speed of the timer and puts the definitions of ndelay, udelay, mdelay and
delay into generic code. Then, in x86, the timer_hz and timer_get_raw_value
functions which used to be in depthcharge were moved over to libpayload's
arch/x86/timer.c. In ARM where there isn't a single, canonical timer, those
functions are omitted with the intention that they'll be implemented by a
specific timer driver chosen elsewhere.

Change-Id: I9c919bed712ace941f417c1d58679d667b2d8269
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: http://review.coreboot.org/2717
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 7 insertions, 45 deletions

diff --git a/payloads/libpayload/arch/x86/timer.c b/payloads/libpayload/arch/x86/timer.c
index 40e81c4ced..e0cefb819a 100644
--- a/payloads/libpayload/arch/x86/timer.c
+++ b/payloads/libpayload/arch/x86/timer.c
@@ -28,8 +28,8 @@
  */
 
 /**
- * @file i386/timer.c
- * i386 specific timer routines
+ * @file x86/timer.c
+ * x86 specific timer routines
  */
 
 #include <libpayload.h>
@@ -39,7 +39,7 @@
  * @ingroup arch
  * Global variable containing the speed of the processor in KHz.
  */
-u32 cpu_khz;
+uint32_t cpu_khz;
 
 /**
  * Calculate the speed of the processor for use in delays.
@@ -77,50 +77,12 @@ unsigned int get_cpu_speed(void)
 	return cpu_khz;
 }
 
-static inline void _delay(unsigned long long delta)
+uint64_t timer_hz(void)
 {
-	unsigned long long timeout = rdtsc() + delta;
-	while (rdtsc() < timeout) ;
+	return lib_sysinfo.cpu_khz * 1000;
 }
 
-/**
- * Delay for a specified number of nanoseconds.
- *
- * @param n Number of nanoseconds to delay for.
- */
-void ndelay(unsigned int n)
-{
-	_delay((unsigned long long)n * cpu_khz / 1000000);
-}
-
-/**
- * Delay for a specified number of microseconds.
- *
- * @param n Number of microseconds to delay for.
- */
-void udelay(unsigned int n)
-{
-	_delay((unsigned long long)n * cpu_khz / 1000);
-}
-
-/**
- * Delay for a specified number of milliseconds.
- *
- * @param m Number of milliseconds to delay for.
- */
-void mdelay(unsigned int m)
-{
-	_delay((unsigned long long)m * cpu_khz);
-}
-
-/**
- * Delay for a specified number of seconds.
- *
- * @param s Number of seconds to delay for.
- */
-void delay(unsigned int s)
+uint64_t timer_raw_value(void)
 {
-	int i;
-	for (i=0; i<1000; i++)
-		_delay((unsigned long long)s * cpu_khz);
+	return rdtsc();
 }