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powerpc: Eliminate unused do_gtod variable

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Since we started using the generic timekeeping code, we haven't had a
powerpc-specific version of do_gettimeofday, and hence there is now
nothing that reads the do_gtod variable in arch/powerpc/kernel/time.c.
This therefore removes it and the code that sets it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras 2008-10-28 00:18:11 +00:00
parent 597bc5c00b
commit 3cc698789a
2 changed files with 0 additions and 55 deletions
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20
arch/powerpc/include/asm/time.h
View File

@ -48,26 +48,6 @@ extern unsigned long ppc_proc_freq;
extern unsigned long ppc_tb_freq; extern unsigned long ppc_tb_freq;
#define DEFAULT_TB_FREQ 125000000UL #define DEFAULT_TB_FREQ 125000000UL
/*
* By putting all of this stuff into a single struct we
* reduce the number of cache lines touched by do_gettimeofday.
* Both by collecting all of the data in one cache line and
* by touching only one TOC entry on ppc64.
*/
struct gettimeofday_vars {
u64 tb_to_xs;
u64 stamp_xsec;
u64 tb_orig_stamp;
};
struct gettimeofday_struct {
unsigned long tb_ticks_per_sec;
struct gettimeofday_vars vars[2];
struct gettimeofday_vars * volatile varp;
unsigned var_idx;
unsigned tb_to_us;
};
struct div_result { struct div_result {
u64 result_high; u64 result_high;
u64 result_low; u64 result_low;

35
arch/powerpc/kernel/time.c
View File

@ -164,8 +164,6 @@ static u64 tb_to_ns_scale __read_mostly;
static unsigned tb_to_ns_shift __read_mostly; static unsigned tb_to_ns_shift __read_mostly;
static unsigned long boot_tb __read_mostly; static unsigned long boot_tb __read_mostly;
static struct gettimeofday_struct do_gtod;
extern struct timezone sys_tz; extern struct timezone sys_tz;
static long timezone_offset; static long timezone_offset;
@ -415,31 +413,9 @@ void udelay(unsigned long usecs)
} }
EXPORT_SYMBOL(udelay); EXPORT_SYMBOL(udelay);
/*
* There are two copies of tb_to_xs and stamp_xsec so that no
* lock is needed to access and use these values in
* do_gettimeofday. We alternate the copies and as long as a
* reasonable time elapses between changes, there will never
* be inconsistent values. ntpd has a minimum of one minute
* between updates.
*/
static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
u64 new_tb_to_xs) u64 new_tb_to_xs)
{ {
unsigned temp_idx;
struct gettimeofday_vars *temp_varp;
temp_idx = (do_gtod.var_idx == 0);
temp_varp = &do_gtod.vars[temp_idx];
temp_varp->tb_to_xs = new_tb_to_xs;
temp_varp->tb_orig_stamp = new_tb_stamp;
temp_varp->stamp_xsec = new_stamp_xsec;
smp_mb();
do_gtod.varp = temp_varp;
do_gtod.var_idx = temp_idx;
/* /*
* tb_update_count is used to allow the userspace gettimeofday code * tb_update_count is used to allow the userspace gettimeofday code
* to assure itself that it sees a consistent view of the tb_to_xs and * to assure itself that it sees a consistent view of the tb_to_xs and
@ -515,9 +491,7 @@ static int __init iSeries_tb_recal(void)
tb_ticks_per_sec = new_tb_ticks_per_sec; tb_ticks_per_sec = new_tb_ticks_per_sec;
calc_cputime_factors(); calc_cputime_factors();
div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres );
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
tb_to_xs = divres.result_low; tb_to_xs = divres.result_low;
do_gtod.varp->tb_to_xs = tb_to_xs;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
vdso_data->tb_to_xs = tb_to_xs; vdso_data->tb_to_xs = tb_to_xs;
} }
@ -989,15 +963,6 @@ void __init time_init(void)
sys_tz.tz_dsttime = 0; sys_tz.tz_dsttime = 0;
} }
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
__get_cpu_var(last_jiffy) = tb_last_jiffy;
do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
do_gtod.varp->tb_to_xs = tb_to_xs;
do_gtod.tb_to_us = tb_to_us;
vdso_data->tb_orig_stamp = tb_last_jiffy; vdso_data->tb_orig_stamp = tb_last_jiffy;
vdso_data->tb_update_count = 0; vdso_data->tb_update_count = 0;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;