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MIPS: Alchemy: get rid of allow_au1k_wait 

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@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Manuel Lauss 2009-08-22 18:09:27 +02:00 committed by Ralf Baechle
parent 9d24bafb0d
commit 2882b0c63a
2 changed files with 14 additions and 14 deletions
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15
arch/mips/alchemy/common/time.c
View File

@ -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 +152,17 @@ 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;
}

13
arch/mips/kernel/cpu-probe.c
View File

@ -91,16 +91,13 @@ static void rm7k_wait_irqoff(void)
local_irq_enable();
}
/* The Au1xxx wait is available only if using 32khz counter or
* external timer source, but specifically not CP0 Counter. */
int allow_au1k_wait;
/*
* The Au1xxx wait is available only if using 32khz counter or
* 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"