Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /** |
| 2 | * @file arch/alpha/oprofile/op_model_ev4.c |
| 3 | * |
| 4 | * @remark Copyright 2002 OProfile authors |
| 5 | * @remark Read the file COPYING |
| 6 | * |
| 7 | * @author Richard Henderson <rth@twiddle.net> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/oprofile.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/smp.h> |
| 13 | #include <asm/ptrace.h> |
| 14 | #include <asm/system.h> |
| 15 | |
| 16 | #include "op_impl.h" |
| 17 | |
| 18 | |
| 19 | /* Compute all of the registers in preparation for enabling profiling. */ |
| 20 | |
| 21 | static void |
| 22 | ev4_reg_setup(struct op_register_config *reg, |
| 23 | struct op_counter_config *ctr, |
| 24 | struct op_system_config *sys) |
| 25 | { |
| 26 | unsigned long ctl = 0, count, hilo; |
| 27 | |
| 28 | /* Select desired events. We've mapped the event numbers |
| 29 | such that they fit directly into the event selection fields. |
| 30 | |
| 31 | Note that there is no "off" setting. In both cases we select |
| 32 | the EXTERNAL event source, hoping that it'll be the lowest |
| 33 | frequency, and set the frequency counter to LOW. The interrupts |
| 34 | for these "disabled" counter overflows are ignored by the |
| 35 | interrupt handler. |
| 36 | |
| 37 | This is most irritating, because the hardware *can* enable and |
| 38 | disable the interrupts for these counters independently, but the |
| 39 | wrperfmon interface doesn't allow it. */ |
| 40 | |
| 41 | ctl |= (ctr[0].enabled ? ctr[0].event << 8 : 14 << 8); |
| 42 | ctl |= (ctr[1].enabled ? (ctr[1].event - 16) << 32 : 7ul << 32); |
| 43 | |
| 44 | /* EV4 can not read or write its counter registers. The only |
| 45 | thing one can do at all is see if you overflow and get an |
| 46 | interrupt. We can set the width of the counters, to some |
| 47 | extent. Take the interrupt count selected by the user, |
| 48 | map it onto one of the possible values, and write it back. */ |
| 49 | |
| 50 | count = ctr[0].count; |
| 51 | if (count <= 4096) |
| 52 | count = 4096, hilo = 1; |
| 53 | else |
| 54 | count = 65536, hilo = 0; |
| 55 | ctr[0].count = count; |
| 56 | ctl |= (ctr[0].enabled && hilo) << 3; |
| 57 | |
| 58 | count = ctr[1].count; |
| 59 | if (count <= 256) |
| 60 | count = 256, hilo = 1; |
| 61 | else |
| 62 | count = 4096, hilo = 0; |
| 63 | ctr[1].count = count; |
| 64 | ctl |= (ctr[1].enabled && hilo); |
| 65 | |
| 66 | reg->mux_select = ctl; |
| 67 | |
| 68 | /* Select performance monitoring options. */ |
| 69 | /* ??? Need to come up with some mechanism to trace only |
| 70 | selected processes. EV4 does not have a mechanism to |
| 71 | select kernel or user mode only. For now, enable always. */ |
| 72 | reg->proc_mode = 0; |
| 73 | |
| 74 | /* Frequency is folded into mux_select for EV4. */ |
| 75 | reg->freq = 0; |
| 76 | |
| 77 | /* See above regarding no writes. */ |
| 78 | reg->reset_values = 0; |
| 79 | reg->need_reset = 0; |
| 80 | |
| 81 | } |
| 82 | |
| 83 | /* Program all of the registers in preparation for enabling profiling. */ |
| 84 | |
| 85 | static void |
| 86 | ev4_cpu_setup(void *x) |
| 87 | { |
| 88 | struct op_register_config *reg = x; |
| 89 | |
| 90 | wrperfmon(2, reg->mux_select); |
| 91 | wrperfmon(3, reg->proc_mode); |
| 92 | } |
| 93 | |
| 94 | static void |
| 95 | ev4_handle_interrupt(unsigned long which, struct pt_regs *regs, |
| 96 | struct op_counter_config *ctr) |
| 97 | { |
| 98 | /* EV4 can't properly disable counters individually. |
| 99 | Discard "disabled" events now. */ |
| 100 | if (!ctr[which].enabled) |
| 101 | return; |
| 102 | |
| 103 | /* Record the sample. */ |
| 104 | oprofile_add_sample(regs, which); |
| 105 | } |
| 106 | |
| 107 | |
| 108 | struct op_axp_model op_model_ev4 = { |
| 109 | .reg_setup = ev4_reg_setup, |
| 110 | .cpu_setup = ev4_cpu_setup, |
| 111 | .reset_ctr = NULL, |
| 112 | .handle_interrupt = ev4_handle_interrupt, |
| 113 | .cpu_type = "alpha/ev4", |
| 114 | .num_counters = 2, |
| 115 | .can_set_proc_mode = 0, |
| 116 | }; |