This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / mips / sibyte / bcm1480 / time.c

diff --git a/arch/mips/sibyte/bcm1480/time.c b/arch/mips/sibyte/bcm1480/time.c
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+++ b/arch/mips/sibyte/bcm1480/time.c
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+/*
+ * Copyright (C) 2000,2001,2004 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * These are routines to set up and handle interrupts from the
+ * bcm1480 general purpose timer 0.  We're using the timer as a
+ * system clock, so we set it up to run at 100 Hz.  On every
+ * interrupt, we update our idea of what the time of day is,
+ * then call do_timer() in the architecture-independent kernel
+ * code to do general bookkeeping (e.g. update jiffies, run
+ * bottom halves, etc.)
+ */
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/irq.h>
+#include <asm/ptrace.h>
+#include <asm/addrspace.h>
+#include <asm/time.h>
+#include <asm/io.h>
+
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/bcm1480_int.h>
+#include <asm/sibyte/bcm1480_scd.h>
+
+#include <asm/sibyte/sb1250.h>
+
+
+#define IMR_IP2_VAL    K_BCM1480_INT_MAP_I0
+#define IMR_IP3_VAL    K_BCM1480_INT_MAP_I1
+#define IMR_IP4_VAL    K_BCM1480_INT_MAP_I2
+
+extern int bcm1480_steal_irq(int irq);
+
+void bcm1480_time_init(void)
+{
+       int cpu = smp_processor_id();
+       int irq = K_BCM1480_INT_TIMER_0+cpu;
+
+       /* Only have 4 general purpose timers */
+       if (cpu > 3) {
+               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 */
+       __raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
+             + (irq<<3)));
+
+       /* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
+       /* 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
+               , IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
+
+       /* Set the timer running */
+       __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
+             IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+
+       bcm1480_unmask_irq(cpu, irq);
+       bcm1480_steal_irq(irq);
+       /*
+        * This interrupt is "special" in that it doesn't use the request_irq
+        * way to hook the irq line.  The timer interrupt is initialized early
+        * enough to make this a major pain, and it's also firing enough to
+        * warrant a bit of special case code.  bcm1480_timer_interrupt is
+        * called directly from irq_handler.S when IP[4] is set during an
+        * interrupt
+        */
+}
+
+#include <asm/sibyte/sb1250.h>
+
+void bcm1480_timer_interrupt(struct pt_regs *regs)
+{
+       int cpu = smp_processor_id();
+       int irq = K_BCM1480_INT_TIMER_0+cpu;
+
+       /* Reset the timer */
+       __raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
+             IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+
+       /*
+        * CPU 0 handles the global timer interrupt job
+        */
+       if (cpu == 0) {
+               ll_timer_interrupt(irq, regs);
+       }
+
+       /*
+        * every CPU should do profiling and process accouting
+        */
+       ll_local_timer_interrupt(irq, regs);
+}
+
+/*
+ * 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)
+{
+       unsigned long count =
+               __raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
+
+       return 1000000/HZ - count;
+}