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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> | |
1da177e4 LT |
11 | #include <linux/smp.h> |
12 | #include <asm/ptrace.h> | |
1da177e4 LT |
13 | |
14 | #include "op_impl.h" | |
15 | ||
16 | ||
17 | /* Compute all of the registers in preparation for enabling profiling. */ | |
18 | ||
19 | static void | |
20 | ev4_reg_setup(struct op_register_config *reg, | |
21 | struct op_counter_config *ctr, | |
22 | struct op_system_config *sys) | |
23 | { | |
24 | unsigned long ctl = 0, count, hilo; | |
25 | ||
26 | /* Select desired events. We've mapped the event numbers | |
27 | such that they fit directly into the event selection fields. | |
28 | ||
29 | Note that there is no "off" setting. In both cases we select | |
30 | the EXTERNAL event source, hoping that it'll be the lowest | |
31 | frequency, and set the frequency counter to LOW. The interrupts | |
32 | for these "disabled" counter overflows are ignored by the | |
33 | interrupt handler. | |
34 | ||
35 | This is most irritating, because the hardware *can* enable and | |
36 | disable the interrupts for these counters independently, but the | |
37 | wrperfmon interface doesn't allow it. */ | |
38 | ||
39 | ctl |= (ctr[0].enabled ? ctr[0].event << 8 : 14 << 8); | |
40 | ctl |= (ctr[1].enabled ? (ctr[1].event - 16) << 32 : 7ul << 32); | |
41 | ||
42 | /* EV4 can not read or write its counter registers. The only | |
43 | thing one can do at all is see if you overflow and get an | |
44 | interrupt. We can set the width of the counters, to some | |
45 | extent. Take the interrupt count selected by the user, | |
46 | map it onto one of the possible values, and write it back. */ | |
47 | ||
48 | count = ctr[0].count; | |
49 | if (count <= 4096) | |
50 | count = 4096, hilo = 1; | |
51 | else | |
52 | count = 65536, hilo = 0; | |
53 | ctr[0].count = count; | |
54 | ctl |= (ctr[0].enabled && hilo) << 3; | |
55 | ||
56 | count = ctr[1].count; | |
57 | if (count <= 256) | |
58 | count = 256, hilo = 1; | |
59 | else | |
60 | count = 4096, hilo = 0; | |
61 | ctr[1].count = count; | |
62 | ctl |= (ctr[1].enabled && hilo); | |
63 | ||
64 | reg->mux_select = ctl; | |
65 | ||
66 | /* Select performance monitoring options. */ | |
67 | /* ??? Need to come up with some mechanism to trace only | |
68 | selected processes. EV4 does not have a mechanism to | |
69 | select kernel or user mode only. For now, enable always. */ | |
70 | reg->proc_mode = 0; | |
71 | ||
72 | /* Frequency is folded into mux_select for EV4. */ | |
73 | reg->freq = 0; | |
74 | ||
75 | /* See above regarding no writes. */ | |
76 | reg->reset_values = 0; | |
77 | reg->need_reset = 0; | |
78 | ||
79 | } | |
80 | ||
81 | /* Program all of the registers in preparation for enabling profiling. */ | |
82 | ||
83 | static void | |
84 | ev4_cpu_setup(void *x) | |
85 | { | |
86 | struct op_register_config *reg = x; | |
87 | ||
88 | wrperfmon(2, reg->mux_select); | |
89 | wrperfmon(3, reg->proc_mode); | |
90 | } | |
91 | ||
92 | static void | |
93 | ev4_handle_interrupt(unsigned long which, struct pt_regs *regs, | |
94 | struct op_counter_config *ctr) | |
95 | { | |
96 | /* EV4 can't properly disable counters individually. | |
97 | Discard "disabled" events now. */ | |
98 | if (!ctr[which].enabled) | |
99 | return; | |
100 | ||
101 | /* Record the sample. */ | |
102 | oprofile_add_sample(regs, which); | |
103 | } | |
104 | ||
105 | ||
106 | struct op_axp_model op_model_ev4 = { | |
107 | .reg_setup = ev4_reg_setup, | |
108 | .cpu_setup = ev4_cpu_setup, | |
109 | .reset_ctr = NULL, | |
110 | .handle_interrupt = ev4_handle_interrupt, | |
111 | .cpu_type = "alpha/ev4", | |
112 | .num_counters = 2, | |
113 | .can_set_proc_mode = 0, | |
114 | }; |