Commit 16b7b2ac authored by Atsushi Nemoto's avatar Atsushi Nemoto Committed by Ralf Baechle

[MIPS] Fixup migration to GENERIC_TIME

Since we already moved to GENERIC_TIME, we should implement alternatives
of old do_gettimeoffset routines to get sub-jiffies resolution from
gettimeofday().  This patch includes:

 * MIPS clocksource support (based on works by Manish Lachwani).
 * remove unused gettimeoffset routines and related codes.
 * remove unised 64bit do_div64_32().
 * simplify mips_hpt_init. (no argument needed, __init tag)
 * simplify c0_hpt_timer_init. (no need to write to c0_count)
 * remove some hpt_init routines.
 * mips_hpt_mask variable to specify bitmask of hpt value.
 * convert jmr3927_do_gettimeoffset to jmr3927_hpt_read.
 * convert ip27_do_gettimeoffset to ip27_hpt_read.
 * convert bcm1480_do_gettimeoffset to bcm1480_hpt_read.
 * simplify sb1250 hpt functions. (no need to subtract and shift)
Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 70e46f48
......@@ -38,19 +38,14 @@ The new time code provide the following services:
a) Implements functions required by Linux common code:
time_init
do_gettimeofday
do_settimeofday
b) provides an abstraction of RTC and null RTC implementation as default.
extern unsigned long (*rtc_get_time)(void);
extern int (*rtc_set_time)(unsigned long);
c) a set of gettimeoffset functions for different CPUs and different
needs.
d) high-level and low-level timer interrupt routines where the timer
interrupt source may or may not be the CPU timer. The high-level
routine is dispatched through do_IRQ() while the low-level is
c) high-level and low-level timer interrupt routines where the timer
interrupt source may or may not be the CPU timer. The high-level
routine is dispatched through do_IRQ() while the low-level is
dispatched in assemably code (usually int-handler.S)
......@@ -73,8 +68,7 @@ the following functions or values:
c) (optional) board-specific RTC routines.
d) (optional) mips_hpt_frequency - It must be definied if the board
is using CPU counter for timer interrupt or it is using fixed rate
gettimeoffset().
is using CPU counter for timer interrupt.
PORTING GUIDE
......@@ -89,16 +83,6 @@ Step 1: decide how you like to implement the time services.
If the answer is no, you need a timer to provide the timer interrupt
at 100 HZ speed.
You cannot use the fast gettimeoffset functions, i.e.,
unsigned long fixed_rate_gettimeoffset(void);
unsigned long calibrate_div32_gettimeoffset(void);
unsigned long calibrate_div64_gettimeoffset(void);
You can use null_gettimeoffset() will gives the same time resolution as
jiffy. Or you can implement your own gettimeoffset (probably based on
some ad hoc hardware on your machine.)
c) The following sub steps assume your CPU has counter register.
Do you plan to use the CPU counter register as the timer interrupt
or use an exnternal timer?
......@@ -123,8 +107,8 @@ Step 3: implement rtc routines, board_time_init() and plat_timer_setup()
board_time_init() -
a) (optional) set up RTC routines,
b) (optional) calibrate and set the mips_hpt_frequency
(only needed if you intended to use fixed_rate_gettimeoffset
or use cpu counter as timer interrupt source)
(only needed if you intended to use cpu counter as timer interrupt
source)
plat_timer_setup() -
a) (optional) over-write any choices made above by time_init().
......@@ -154,8 +138,8 @@ for some of the functions in time.c.
For example, you may define your own timer interrupt routine, which does
some of its own processing and then calls timer_interrupt().
You can also over-ride any of the built-in functions (gettimeoffset,
RTC routines and/or timer interrupt routine).
You can also over-ride any of the built-in functions (RTC routines
and/or timer interrupt routine).
PORTING NOTES FOR SMP
......@@ -187,10 +171,3 @@ You need to decide on your timer interrupt sources.
You can also do the low-level version of those interrupt routines,
following similar dispatching routes described above.
Note about do_gettimeoffset():
It is very likely the CPU counter registers are not sync'ed up in a SMP box.
Therefore you cannot really use the many of the existing routines that
are based on CPU counter. You should wirte your own gettimeoffset rouinte
if you want intra-jiffy resolution.
......@@ -53,9 +53,6 @@ static unsigned long r4k_cur; /* What counter should be at next timer irq */
int no_au1xxx_32khz;
extern int allow_au1k_wait; /* default off for CP0 Counter */
/* Cycle counter value at the previous timer interrupt.. */
static unsigned int timerhi = 0, timerlo = 0;
#ifdef CONFIG_PM
#if HZ < 100 || HZ > 1000
#error "unsupported HZ value! Must be in [100,1000]"
......@@ -90,10 +87,6 @@ void mips_timer_interrupt(void)
goto null;
do {
count = read_c0_count();
timerhi += (count < timerlo); /* Wrap around */
timerlo = count;
kstat_this_cpu.irqs[irq]++;
do_timer(1);
#ifndef CONFIG_SMP
......@@ -297,88 +290,6 @@ unsigned long cal_r4koff(void)
return (cpu_speed / HZ);
}
/* This is for machines which generate the exact clock. */
#define USECS_PER_JIFFY (1000000/HZ)
#define USECS_PER_JIFFY_FRAC (0x100000000LL*1000000/HZ&0xffffffff)
static unsigned long
div64_32(unsigned long v1, unsigned long v2, unsigned long v3)
{
unsigned long r0;
do_div64_32(r0, v1, v2, v3);
return r0;
}
static unsigned long do_fast_cp0_gettimeoffset(void)
{
u32 count;
unsigned long res, tmp;
unsigned long r0;
/* Last jiffy when do_fast_gettimeoffset() was called. */
static unsigned long last_jiffies=0;
unsigned long quotient;
/*
* Cached "1/(clocks per usec)*2^32" value.
* It has to be recalculated once each jiffy.
*/
static unsigned long cached_quotient=0;
tmp = jiffies;
quotient = cached_quotient;
if (tmp && last_jiffies != tmp) {
last_jiffies = tmp;
if (last_jiffies != 0) {
r0 = div64_32(timerhi, timerlo, tmp);
quotient = div64_32(USECS_PER_JIFFY, USECS_PER_JIFFY_FRAC, r0);
cached_quotient = quotient;
}
}
/* Get last timer tick in absolute kernel time */
count = read_c0_count();
/* .. relative to previous jiffy (32 bits is enough) */
count -= timerlo;
__asm__("multu\t%1,%2\n\t"
"mfhi\t%0"
: "=r" (res)
: "r" (count), "r" (quotient)
: "hi", "lo", GCC_REG_ACCUM);
/*
* Due to possible jiffies inconsistencies, we need to check
* the result so that we'll get a timer that is monotonic.
*/
if (res >= USECS_PER_JIFFY)
res = USECS_PER_JIFFY-1;
return res;
}
#ifdef CONFIG_PM
static unsigned long do_fast_pm_gettimeoffset(void)
{
unsigned long pc0;
unsigned long offset;
pc0 = au_readl(SYS_TOYREAD);
au_sync();
offset = pc0 - last_pc0;
if (offset > 2*MATCH20_INC) {
printk("huge offset %x, last_pc0 %x last_match20 %x pc0 %x\n",
(unsigned)offset, (unsigned)last_pc0,
(unsigned)last_match20, (unsigned)pc0);
}
offset = (unsigned long)((offset * 305) / 10);
return offset;
}
#endif
void __init plat_timer_setup(struct irqaction *irq)
{
unsigned int est_freq;
......@@ -416,7 +327,6 @@ void __init plat_timer_setup(struct irqaction *irq)
unsigned int c0_status;
printk("WARNING: no 32KHz clock found.\n");
do_gettimeoffset = do_fast_cp0_gettimeoffset;
/* Ensure we get CPO_COUNTER interrupts.
*/
......@@ -441,19 +351,11 @@ void __init plat_timer_setup(struct irqaction *irq)
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
startup_match20_interrupt(counter0_irq);
do_gettimeoffset = do_fast_pm_gettimeoffset;
/* We can use the real 'wait' instruction.
*/
allow_au1k_wait = 1;
}
#else
/* We have to do this here instead of in timer_init because
* the generic code in arch/mips/kernel/time.c will write
* over our function pointer.
*/
do_gettimeoffset = do_fast_cp0_gettimeoffset;
#endif
}
......
......@@ -160,11 +160,6 @@ static unsigned int dec_ioasic_hpt_read(void)
return ioasic_read(IO_REG_FCTR);
}
static void dec_ioasic_hpt_init(unsigned int count)
{
ioasic_write(IO_REG_FCTR, ioasic_read(IO_REG_FCTR) - count);
}
void __init dec_time_init(void)
{
......@@ -174,11 +169,9 @@ void __init dec_time_init(void)
mips_timer_state = dec_timer_state;
mips_timer_ack = dec_timer_ack;
if (!cpu_has_counter && IOASIC) {
if (!cpu_has_counter && IOASIC)
/* For pre-R4k systems we use the I/O ASIC's counter. */
mips_hpt_read = dec_ioasic_hpt_read;
mips_hpt_init = dec_ioasic_hpt_init;
}
/* Set up the rate of periodic DS1287 interrupts. */
CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - __ffs(HZ)), RTC_REG_A);
......
......@@ -170,12 +170,20 @@ static void jmr3927_machine_power_off(void)
while (1);
}
static unsigned int jmr3927_hpt_read(void)
{
/* We assume this function is called xtime_lock held. */
return jiffies * (JMR3927_TIMER_CLK / HZ) + jmr3927_tmrptr->trr;
}
#define USE_RTC_DS1742
#ifdef USE_RTC_DS1742
extern void rtc_ds1742_init(unsigned long base);
#endif
static void __init jmr3927_time_init(void)
{
mips_hpt_read = jmr3927_hpt_read;
mips_hpt_frequency = JMR3927_TIMER_CLK;
#ifdef USE_RTC_DS1742
if (jmr3927_have_nvram()) {
rtc_ds1742_init(JMR3927_IOC_NVRAMB_ADDR);
......@@ -183,12 +191,8 @@ static void __init jmr3927_time_init(void)
#endif
}
unsigned long jmr3927_do_gettimeoffset(void);
void __init plat_timer_setup(struct irqaction *irq)
{
do_gettimeoffset = jmr3927_do_gettimeoffset;
jmr3927_tmrptr->cpra = JMR3927_TIMER_CLK / HZ;
jmr3927_tmrptr->itmr = TXx927_TMTITMR_TIIE | TXx927_TMTITMR_TZCE;
jmr3927_tmrptr->ccdr = JMR3927_TIMER_CCD;
......@@ -200,34 +204,6 @@ void __init plat_timer_setup(struct irqaction *irq)
#define USECS_PER_JIFFY (1000000/HZ)
unsigned long jmr3927_do_gettimeoffset(void)
{
unsigned long count;
unsigned long res = 0;
/* MUST read TRR before TISR. */
count = jmr3927_tmrptr->trr;
if (jmr3927_tmrptr->tisr & TXx927_TMTISR_TIIS) {
/* timer interrupt is pending. use Max value. */
res = USECS_PER_JIFFY - 1;
} else {
/* convert to usec */
/* res = count / (JMR3927_TIMER_CLK / 1000000); */
res = (count << 7) / ((JMR3927_TIMER_CLK << 7) / 1000000);
/*
* Due to possible jiffies inconsistencies, we need to check
* the result so that we'll get a timer that is monotonic.
*/
if (res >= USECS_PER_JIFFY)
res = USECS_PER_JIFFY-1;
}
return res;
}
//#undef DO_WRITE_THROUGH
#define DO_WRITE_THROUGH
#define DO_ENABLE_CACHE
......
This diff is collapsed.
......@@ -41,8 +41,8 @@ extern unsigned int mips_hpt_frequency;
* 1) board_time_init() -
* a) (optional) set up RTC routines,
* b) (optional) calibrate and set the mips_hpt_frequency
* (only needed if you intended to use fixed_rate_gettimeoffset
* or use cpu counter as timer interrupt source)
* (only needed if you intended to use cpu counter as timer interrupt
* source)
*/
void pnx8550_time_init(void)
......
......@@ -3,9 +3,7 @@
#include <asm/pmon.h>
#include <asm/titan_dep.h>
extern unsigned int (*mips_hpt_read)(void);
extern void (*mips_hpt_init)(unsigned int);
#include <asm/time.h>
#define LAUNCHSTACK_SIZE 256
......@@ -101,7 +99,7 @@ void prom_cpus_done(void)
*/
void prom_init_secondary(void)
{
mips_hpt_init(mips_hpt_read());
mips_hpt_init();
set_c0_status(ST0_CO | ST0_IE | ST0_IM);
}
......
......@@ -134,13 +134,6 @@ void ip27_rt_timer_interrupt(void)
irq_exit();
}
unsigned long ip27_do_gettimeoffset(void)
{
unsigned long ct_cur1;
ct_cur1 = REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT) + CYCLES_PER_JIFFY;
return (ct_cur1 - ct_cur[0]) * NSEC_PER_CYCLE / 1000;
}
/* Includes for ioc3_init(). */
#include <asm/sn/types.h>
#include <asm/sn/sn0/addrs.h>
......@@ -248,12 +241,17 @@ void __init plat_timer_setup(struct irqaction *irq)
setup_irq(irqno, &rt_irqaction);
}
static unsigned int ip27_hpt_read(void)
{
return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}
void __init ip27_time_init(void)
{
mips_hpt_read = ip27_hpt_read;
mips_hpt_frequency = CYCLES_PER_SEC;
xtime.tv_sec = get_m48t35_time();
xtime.tv_nsec = 0;
do_gettimeoffset = ip27_do_gettimeoffset;
}
void __init cpu_time_init(void)
......
......@@ -47,6 +47,12 @@
#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
#ifdef CONFIG_SIMULATION
#define BCM1480_HPT_VALUE 50000
#else
#define BCM1480_HPT_VALUE 1000000
#endif
extern int bcm1480_steal_irq(int irq);
void bcm1480_time_init(void)
......@@ -59,11 +65,6 @@ void bcm1480_time_init(void)
BUG();
}
if (!cpu) {
/* Use our own gettimeoffset() routine */
do_gettimeoffset = bcm1480_gettimeoffset;
}
bcm1480_mask_irq(cpu, irq);
/* Map the timer interrupt to ip[4] of this cpu */
......@@ -74,11 +75,7 @@ void bcm1480_time_init(void)
/* Disable the timer and set up the count */
__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
__raw_writeq(
#ifndef CONFIG_SIMULATION
1000000/HZ
#else
50000/HZ
#endif
BCM1480_HPT_VALUE/HZ
, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
/* Set the timer running */
......@@ -122,16 +119,16 @@ void bcm1480_timer_interrupt(void)
}
}
/*
* We use our own do_gettimeoffset() instead of the generic one,
* because the generic one does not work for SMP case.
* In addition, since we use general timer 0 for system time,
* we can get accurate intra-jiffy offset without calibration.
*/
unsigned long bcm1480_gettimeoffset(void)
static unsigned int bcm1480_hpt_read(void)
{
/* We assume this function is called xtime_lock held. */
unsigned long count =
__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
return (jiffies + 1) * (BCM1480_HPT_VALUE / HZ) - count;
}
return 1000000/HZ - count;
void __init bcm1480_hpt_setup(void)
{
mips_hpt_read = bcm1480_hpt_read;
mips_hpt_frequency = BCM1480_HPT_VALUE;
}
......@@ -47,15 +47,11 @@
#define SB1250_HPT_NUM 3
#define SB1250_HPT_VALUE M_SCD_TIMER_CNT /* max value */
#define SB1250_HPT_SHIFT ((sizeof(unsigned int)*8)-V_SCD_TIMER_WIDTH)
extern int sb1250_steal_irq(int irq);
static unsigned int sb1250_hpt_read(void);
static void sb1250_hpt_init(unsigned int);
static unsigned int hpt_offset;
void __init sb1250_hpt_setup(void)
{
......@@ -69,13 +65,9 @@ void __init sb1250_hpt_setup(void)
__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CFG)));
/*
* we need to fill 32 bits, so just use the upper 23 bits and pretend
* the timer is going 512Mhz instead of 1Mhz
*/
mips_hpt_frequency = V_SCD_TIMER_FREQ << SB1250_HPT_SHIFT;
mips_hpt_init = sb1250_hpt_init;
mips_hpt_frequency = V_SCD_TIMER_FREQ;
mips_hpt_read = sb1250_hpt_read;
mips_hpt_mask = M_SCD_TIMER_INIT;
}
}
......@@ -149,11 +141,7 @@ void sb1250_timer_interrupt(void)
/*
* The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over
* again. There's no easy way to set to a specific value so store init value
* in hpt_offset and subtract each time.
*
* Note: Timer isn't full 32bits so shift it into the upper part making
* it appear to run at a higher frequency.
* again.
*/
static unsigned int sb1250_hpt_read(void)
{
......@@ -161,13 +149,5 @@ static unsigned int sb1250_hpt_read(void)
count = G_SCD_TIMER_CNT(__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT))));
count = (SB1250_HPT_VALUE - count) << SB1250_HPT_SHIFT;
return count - hpt_offset;
}
static void sb1250_hpt_init(unsigned int count)
{
hpt_offset = count;
return;
return SB1250_HPT_VALUE - count;
}
......@@ -82,27 +82,6 @@
#if (_MIPS_SZLONG == 64)
/*
* Don't use this one in new code
*/
#define do_div64_32(res, high, low, base) ({ \
unsigned int __quot, __mod; \
unsigned long __div; \
unsigned int __low, __high, __base; \
\
__high = (high); \
__low = (low); \
__div = __high; \
__div = __div << 32 | __low; \
__base = (base); \
\
__mod = __div % __base; \
__div = __div / __base; \
\
__quot = __div; \
(res) = __quot; \
__mod; })
/*
* Hey, we're already 64-bit, no
* need to play games..
......
......@@ -51,8 +51,8 @@ extern void sb1250_mask_irq(int cpu, int irq);
extern void sb1250_unmask_irq(int cpu, int irq);
extern void sb1250_smp_finish(void);
extern void bcm1480_hpt_setup(void);
extern void bcm1480_time_init(void);
extern unsigned long bcm1480_gettimeoffset(void);
extern void bcm1480_mask_irq(int cpu, int irq);
extern void bcm1480_unmask_irq(int cpu, int irq);
extern void bcm1480_smp_finish(void);
......
......@@ -48,7 +48,8 @@ extern void (*mips_timer_ack)(void);
* If mips_hpt_read is NULL, an R4k-compatible timer setup is attempted.
*/
extern unsigned int (*mips_hpt_read)(void);
extern void (*mips_hpt_init)(unsigned int);
extern void (*mips_hpt_init)(void);
extern unsigned int mips_hpt_mask;
/*
* to_tm() converts system time back to (year, mon, day, hour, min, sec).
......@@ -57,13 +58,6 @@ extern void (*mips_hpt_init)(unsigned int);
*/
extern void to_tm(unsigned long tim, struct rtc_time *tm);
/*
* do_gettimeoffset(). By default, this func pointer points to
* do_null_gettimeoffset(), which leads to the same resolution as HZ.
* Higher resolution versions are available, which give ~1us resolution.
*/
extern unsigned long (*do_gettimeoffset)(void);
/*
* high-level timer interrupt routines.
*/
......
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