/**
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* @file arch/alpha/oprofile/op_model_ev4.c
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*
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* @remark Copyright 2002 OProfile authors
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* @remark Read the file COPYING
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*
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* @author Richard Henderson <rth@twiddle.net>
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*/
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#include <linux/oprofile.h>
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#include <linux/smp.h>
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#include <asm/ptrace.h>
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#include "op_impl.h"
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/* Compute all of the registers in preparation for enabling profiling. */
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static void
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ev4_reg_setup(struct op_register_config *reg,
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struct op_counter_config *ctr,
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struct op_system_config *sys)
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{
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unsigned long ctl = 0, count, hilo;
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/* Select desired events. We've mapped the event numbers
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such that they fit directly into the event selection fields.
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Note that there is no "off" setting. In both cases we select
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the EXTERNAL event source, hoping that it'll be the lowest
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frequency, and set the frequency counter to LOW. The interrupts
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for these "disabled" counter overflows are ignored by the
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interrupt handler.
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This is most irritating, because the hardware *can* enable and
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disable the interrupts for these counters independently, but the
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wrperfmon interface doesn't allow it. */
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ctl |= (ctr[0].enabled ? ctr[0].event << 8 : 14 << 8);
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ctl |= (ctr[1].enabled ? (ctr[1].event - 16) << 32 : 7ul << 32);
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/* EV4 can not read or write its counter registers. The only
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thing one can do at all is see if you overflow and get an
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interrupt. We can set the width of the counters, to some
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extent. Take the interrupt count selected by the user,
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map it onto one of the possible values, and write it back. */
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count = ctr[0].count;
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if (count <= 4096)
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count = 4096, hilo = 1;
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else
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count = 65536, hilo = 0;
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ctr[0].count = count;
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ctl |= (ctr[0].enabled && hilo) << 3;
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count = ctr[1].count;
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if (count <= 256)
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count = 256, hilo = 1;
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else
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count = 4096, hilo = 0;
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ctr[1].count = count;
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ctl |= (ctr[1].enabled && hilo);
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reg->mux_select = ctl;
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/* Select performance monitoring options. */
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/* ??? Need to come up with some mechanism to trace only
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selected processes. EV4 does not have a mechanism to
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select kernel or user mode only. For now, enable always. */
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reg->proc_mode = 0;
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/* Frequency is folded into mux_select for EV4. */
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reg->freq = 0;
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/* See above regarding no writes. */
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reg->reset_values = 0;
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reg->need_reset = 0;
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}
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/* Program all of the registers in preparation for enabling profiling. */
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static void
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ev4_cpu_setup(void *x)
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{
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struct op_register_config *reg = x;
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wrperfmon(2, reg->mux_select);
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wrperfmon(3, reg->proc_mode);
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}
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static void
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ev4_handle_interrupt(unsigned long which, struct pt_regs *regs,
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struct op_counter_config *ctr)
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{
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/* EV4 can't properly disable counters individually.
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Discard "disabled" events now. */
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if (!ctr[which].enabled)
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return;
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/* Record the sample. */
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oprofile_add_sample(regs, which);
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}
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struct op_axp_model op_model_ev4 = {
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.reg_setup = ev4_reg_setup,
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.cpu_setup = ev4_cpu_setup,
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.reset_ctr = NULL,
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.handle_interrupt = ev4_handle_interrupt,
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.cpu_type = "alpha/ev4",
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.num_counters = 2,
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.can_set_proc_mode = 0,
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};
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