Eliminate the 'allow_au1k_wait' variable. MIPS kernel installs the
Alchemy-specific wait code before timer initialization; if the C0
timer must be used for timekeeping the wait function is set to NULL
which means no wait implementation is available.
As a sideeffect, the 'wait instruction available' output in
/proc/cpuinfo now correctly indicates whether 'wait' is usable.
Run-tested on DB1200.
Signed-off-by: Manuel Lauss <manuel.lauss@xxxxxxxxx>
---
arch/mips/alchemy/common/time.c | 14 ++++++++------
arch/mips/kernel/cpu-probe.c | 10 +++-------
2 files changed, 11 insertions(+), 13 deletions(-)
diff --git a/arch/mips/alchemy/common/time.c b/arch/mips/alchemy/common/time.c
index 33fbae7..9fc0d44 100644
--- a/arch/mips/alchemy/common/time.c
+++ b/arch/mips/alchemy/common/time.c
@@ -36,14 +36,13 @@
#include <linux/interrupt.h>
#include <linux/spinlock.h>
+#include <asm/processor.h>
#include <asm/time.h>
#include <asm/mach-au1x00/au1000.h>
/* 32kHz clock enabled and detected */
#define CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
-extern int allow_au1k_wait; /* default off for CP0 Counter */
-
static cycle_t au1x_counter1_read(struct clocksource *cs)
{
return au_readl(SYS_RTCREAD);
@@ -153,13 +152,16 @@ void __init plat_time_init(void)
printk(KERN_INFO "Alchemy clocksource installed\n");
- /* can now use 'wait' */
- allow_au1k_wait = 1;
return;
cntr_err:
- /* counters unusable, use C0 counter */
+ /* MIPS kernel assigns 'au1k_wait' to 'cpu_wait' before this
+ * function is called. Because the Alchemy counters are unusable
+ * the C0 timekeeping code is installed and use of the 'wait'
+ * instruction must be prohibited, which is done most easily by
+ * assigning NULL to cpu_wait.
+ */
+ cpu_wait = NULL;
r4k_clockevent_init();
init_r4k_clocksource();
- allow_au1k_wait = 0;
}
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index b13b8eb..262ea9c 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -91,15 +91,11 @@ static void rm7k_wait_irqoff(void)
}
/* The Au1xxx wait is available only if using 32khz counter or
- * external timer source, but specifically not CP0 Counter. */
-int allow_au1k_wait;
-
+ * external timer source, but specifically not CP0 Counter.
+ * alchemy/common/time.c may override cpu_wait!
+ */
static void au1k_wait(void)
{
- if (!allow_au1k_wait)
- return;
-
- /* using the wait instruction makes CP0 counter unusable */
__asm__(" .set mips3 \n"
" cache 0x14, 0(%0) \n"
" cache 0x14, 32(%0) \n"
--
1.6.3.1
