patch-2.4.20 linux-2.4.20/arch/mips/sgi-ip27/ip27-timer.c
Next file: linux-2.4.20/arch/mips/sgi-ip32/Makefile
Previous file: linux-2.4.20/arch/mips/sgi-ip27/ip27-setup.c
Back to the patch index
Back to the overall index
- Lines: 240
- Date:
Thu Nov 28 15:53:10 2002
- Orig file:
linux-2.4.19/arch/mips/sgi-ip27/ip27-timer.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/arch/mips/sgi-ip27/ip27-timer.c linux-2.4.20/arch/mips/sgi-ip27/ip27-timer.c
@@ -0,0 +1,239 @@
+/*
+ * Copytight (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
+ * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/param.h>
+#include <linux/timex.h>
+#include <linux/mm.h>
+
+#include <asm/time.h>
+#include <asm/pgtable.h>
+#include <asm/sgialib.h>
+#include <asm/sn/ioc3.h>
+#include <asm/m48t35.h>
+#include <asm/sn/klconfig.h>
+#include <asm/sn/arch.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/sn_private.h>
+#include <asm/sn/sn0/ip27.h>
+#include <asm/sn/sn0/hub.h>
+
+/*
+ * This is a hack; we really need to figure these values out dynamically
+ *
+ * Since 800 ns works very well with various HUB frequencies, such as
+ * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
+ *
+ * Ralf: which clock rate is used to feed the counter?
+ */
+#define NSEC_PER_CYCLE 800
+#define NSEC_PER_SEC 1000000000
+#define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE)
+#define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ)
+
+static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */
+static long last_rtc_update; /* Last time the rtc clock got updated */
+
+extern rwlock_t xtime_lock;
+extern volatile unsigned long wall_jiffies;
+
+
+static int set_rtc_mmss(unsigned long nowtime)
+{
+ int retval = 0;
+ int real_seconds, real_minutes, cmos_minutes;
+ struct m48t35_rtc *rtc;
+ nasid_t nid;
+
+ nid = get_nasid();
+ rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
+ IOC3_BYTEBUS_DEV0);
+
+ rtc->control |= M48T35_RTC_READ;
+ cmos_minutes = rtc->min;
+ BCD_TO_BIN(cmos_minutes);
+ rtc->control &= ~M48T35_RTC_READ;
+
+ /*
+ * Since we're only adjusting minutes and seconds, don't interfere with
+ * hour overflow. This avoids messing with unknown time zones but
+ * requires your RTC not to be off by more than 15 minutes
+ */
+ real_seconds = nowtime % 60;
+ real_minutes = nowtime / 60;
+ if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
+ real_minutes += 30; /* correct for half hour time zone */
+ real_minutes %= 60;
+
+ if (abs(real_minutes - cmos_minutes) < 30) {
+ BIN_TO_BCD(real_seconds);
+ BIN_TO_BCD(real_minutes);
+ rtc->control |= M48T35_RTC_SET;
+ rtc->sec = real_seconds;
+ rtc->min = real_minutes;
+ rtc->control &= ~M48T35_RTC_SET;
+ } else {
+ printk(KERN_WARNING
+ "set_rtc_mmss: can't update from %d to %d\n",
+ cmos_minutes, real_minutes);
+ retval = -1;
+ }
+
+ return retval;
+}
+
+void rt_timer_interrupt(struct pt_regs *regs)
+{
+ int cpu = smp_processor_id();
+ int cpuA = ((cputoslice(cpu)) == 0);
+ int irq = 9; /* XXX Assign number */
+
+ irq_enter(cpu, irq);
+ write_lock(&xtime_lock);
+
+again:
+ LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */
+ ct_cur[cpu] += CYCLES_PER_JIFFY;
+ LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]);
+
+ if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu])
+ goto again;
+
+ kstat.irqs[cpu][irq]++; /* kstat only for bootcpu? */
+
+ if (cpu == 0)
+ do_timer(regs);
+
+#ifdef CONFIG_SMP
+ update_process_times(user_mode(regs));
+#endif /* CONFIG_SMP */
+
+ /*
+ * If we have an externally synchronized Linux clock, then update
+ * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+ * called as close as possible to when a second starts.
+ */
+ if ((time_status & STA_UNSYNC) == 0 &&
+ xtime.tv_sec > last_rtc_update + 660) {
+ if (xtime.tv_usec >= 1000000 - ((unsigned) tick) / 2) {
+ if (set_rtc_mmss(xtime.tv_sec + 1) == 0)
+ last_rtc_update = xtime.tv_sec;
+ else
+ last_rtc_update = xtime.tv_sec - 600;
+ } else if (xtime.tv_usec <= ((unsigned) tick) / 2) {
+ if (set_rtc_mmss(xtime.tv_sec) == 0)
+ last_rtc_update = xtime.tv_sec;
+ else
+ last_rtc_update = xtime.tv_sec - 600;
+ }
+ }
+
+ write_unlock(&xtime_lock);
+ irq_exit(cpu, irq);
+
+ if (softirq_pending(cpu))
+ do_softirq();
+}
+
+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>
+#include <asm/sn/sn0/hubni.h>
+#include <asm/sn/sn0/hubio.h>
+#include <asm/pci/bridge.h>
+
+static __init unsigned long get_m48t35_time(void)
+{
+ unsigned int year, month, date, hour, min, sec;
+ struct m48t35_rtc *rtc;
+ nasid_t nid;
+
+ nid = get_nasid();
+ rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
+ IOC3_BYTEBUS_DEV0);
+
+ rtc->control |= M48T35_RTC_READ;
+ sec = rtc->sec;
+ min = rtc->min;
+ hour = rtc->hour;
+ date = rtc->date;
+ month = rtc->month;
+ year = rtc->year;
+ rtc->control &= ~M48T35_RTC_READ;
+
+ BCD_TO_BIN(sec);
+ BCD_TO_BIN(min);
+ BCD_TO_BIN(hour);
+ BCD_TO_BIN(date);
+ BCD_TO_BIN(month);
+ BCD_TO_BIN(year);
+
+ year += 1970;
+
+ return mktime(year, month, date, hour, min, sec);
+}
+
+void __init ip27_time_init(void)
+{
+ xtime.tv_sec = get_m48t35_time();
+ xtime.tv_usec = 0;
+
+ do_gettimeoffset = ip27_do_gettimeoffset;
+}
+
+void __init cpu_time_init(void)
+{
+ lboard_t *board;
+ klcpu_t *cpu;
+ int cpuid;
+
+ /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */
+ board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
+ if (!board)
+ panic("Can't find board info for myself.");
+
+ cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
+ cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
+ if (!cpu)
+ panic("No information about myself?");
+
+ printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
+
+ set_cp0_status(SRB_TIMOCLK);
+}
+
+void __init hub_rtc_init(cnodeid_t cnode)
+{
+ /*
+ * We only need to initialize the current node.
+ * If this is not the current node then it is a cpuless
+ * node and timeouts will not happen there.
+ */
+ if (get_compact_nodeid() == cnode) {
+ int cpu = smp_processor_id();
+ LOCAL_HUB_S(PI_RT_EN_A, 1);
+ LOCAL_HUB_S(PI_RT_EN_B, 1);
+ LOCAL_HUB_S(PI_PROF_EN_A, 0);
+ LOCAL_HUB_S(PI_PROF_EN_B, 0);
+ ct_cur[cpu] = CYCLES_PER_JIFFY;
+ LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]);
+ LOCAL_HUB_S(PI_RT_COUNT, 0);
+ LOCAL_HUB_S(PI_RT_PEND_A, 0);
+ LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]);
+ LOCAL_HUB_S(PI_RT_COUNT, 0);
+ LOCAL_HUB_S(PI_RT_PEND_B, 0);
+ }
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)