1 /**
2 * @file arch/alpha/oprofile/op_model_ev67.c
3 *
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author Richard Henderson <rth@twiddle.net>
8 * @author Falk Hueffner <falk@debian.org>
9 */
10
11 #include <linux/oprofile.h>
12 #include <linux/init.h>
13 #include <linux/smp.h>
14 #include <asm/ptrace.h>
15 #include <asm/system.h>
16
17 #include "op_impl.h"
18
19
20 /* Compute all of the registers in preparation for enabling profiling. */
21
22 static void
ev67_reg_setup(struct op_register_config * reg,struct op_counter_config * ctr,struct op_system_config * sys)23 ev67_reg_setup(struct op_register_config *reg,
24 struct op_counter_config *ctr,
25 struct op_system_config *sys)
26 {
27 unsigned long ctl, reset, need_reset, i;
28
29 /* Select desired events. */
30 ctl = 1UL << 4; /* Enable ProfileMe mode. */
31
32 /* The event numbers are chosen so we can use them directly if
33 PCTR1 is enabled. */
34 if (ctr[1].enabled) {
35 ctl |= (ctr[1].event & 3) << 2;
36 } else {
37 if (ctr[0].event == 0) /* cycles */
38 ctl |= 1UL << 2;
39 }
40 reg->mux_select = ctl;
41
42 /* Select logging options. */
43 /* ??? Need to come up with some mechanism to trace only
44 selected processes. EV67 does not have a mechanism to
45 select kernel or user mode only. For now, enable always. */
46 reg->proc_mode = 0;
47
48 /* EV67 cannot change the width of the counters as with the
49 other implementations. But fortunately, we can write to
50 the counters and set the value such that it will overflow
51 at the right time. */
52 reset = need_reset = 0;
53 for (i = 0; i < 2; ++i) {
54 unsigned long count = ctr[i].count;
55 if (!ctr[i].enabled)
56 continue;
57
58 if (count > 0x100000)
59 count = 0x100000;
60 ctr[i].count = count;
61 reset |= (0x100000 - count) << (i ? 6 : 28);
62 if (count != 0x100000)
63 need_reset |= 1 << i;
64 }
65 reg->reset_values = reset;
66 reg->need_reset = need_reset;
67 }
68
69 /* Program all of the registers in preparation for enabling profiling. */
70
71 static void
ev67_cpu_setup(void * x)72 ev67_cpu_setup (void *x)
73 {
74 struct op_register_config *reg = x;
75
76 wrperfmon(2, reg->mux_select);
77 wrperfmon(3, reg->proc_mode);
78 wrperfmon(6, reg->reset_values | 3);
79 }
80
81 /* CTR is a counter for which the user has requested an interrupt count
82 in between one of the widths selectable in hardware. Reset the count
83 for CTR to the value stored in REG->RESET_VALUES. */
84
85 static void
ev67_reset_ctr(struct op_register_config * reg,unsigned long ctr)86 ev67_reset_ctr(struct op_register_config *reg, unsigned long ctr)
87 {
88 wrperfmon(6, reg->reset_values | (1 << ctr));
89 }
90
91 /* ProfileMe conditions which will show up as counters. We can also
92 detect the following, but it seems unlikely that anybody is
93 interested in counting them:
94 * Reset
95 * MT_FPCR (write to floating point control register)
96 * Arithmetic trap
97 * Dstream Fault
98 * Machine Check (ECC fault, etc.)
99 * OPCDEC (illegal opcode)
100 * Floating point disabled
101 * Differentiate between DTB single/double misses and 3 or 4 level
102 page tables
103 * Istream access violation
104 * Interrupt
105 * Icache Parity Error.
106 * Instruction killed (nop, trapb)
107
108 Unfortunately, there seems to be no way to detect Dcache and Bcache
109 misses; the latter could be approximated by making the counter
110 count Bcache misses, but that is not precise.
111
112 We model this as 20 counters:
113 * PCTR0
114 * PCTR1
115 * 9 ProfileMe events, induced by PCTR0
116 * 9 ProfileMe events, induced by PCTR1
117 */
118
119 enum profileme_counters {
120 PM_STALLED, /* Stalled for at least one cycle
121 between the fetch and map stages */
122 PM_TAKEN, /* Conditional branch taken */
123 PM_MISPREDICT, /* Branch caused mispredict trap */
124 PM_ITB_MISS, /* ITB miss */
125 PM_DTB_MISS, /* DTB miss */
126 PM_REPLAY, /* Replay trap */
127 PM_LOAD_STORE, /* Load-store order trap */
128 PM_ICACHE_MISS, /* Icache miss */
129 PM_UNALIGNED, /* Unaligned Load/Store */
130 PM_NUM_COUNTERS
131 };
132
133 static inline void
op_add_pm(unsigned long pc,int kern,unsigned long counter,struct op_counter_config * ctr,unsigned long event)134 op_add_pm(unsigned long pc, int kern, unsigned long counter,
135 struct op_counter_config *ctr, unsigned long event)
136 {
137 unsigned long fake_counter = 2 + event;
138 if (counter == 1)
139 fake_counter += PM_NUM_COUNTERS;
140 if (ctr[fake_counter].enabled)
141 oprofile_add_pc(pc, kern, fake_counter);
142 }
143
144 static void
ev67_handle_interrupt(unsigned long which,struct pt_regs * regs,struct op_counter_config * ctr)145 ev67_handle_interrupt(unsigned long which, struct pt_regs *regs,
146 struct op_counter_config *ctr)
147 {
148 unsigned long pmpc, pctr_ctl;
149 int kern = !user_mode(regs);
150 int mispredict = 0;
151 union {
152 unsigned long v;
153 struct {
154 unsigned reserved: 30; /* 0-29 */
155 unsigned overcount: 3; /* 30-32 */
156 unsigned icache_miss: 1; /* 33 */
157 unsigned trap_type: 4; /* 34-37 */
158 unsigned load_store: 1; /* 38 */
159 unsigned trap: 1; /* 39 */
160 unsigned mispredict: 1; /* 40 */
161 } fields;
162 } i_stat;
163
164 enum trap_types {
165 TRAP_REPLAY,
166 TRAP_INVALID0,
167 TRAP_DTB_DOUBLE_MISS_3,
168 TRAP_DTB_DOUBLE_MISS_4,
169 TRAP_FP_DISABLED,
170 TRAP_UNALIGNED,
171 TRAP_DTB_SINGLE_MISS,
172 TRAP_DSTREAM_FAULT,
173 TRAP_OPCDEC,
174 TRAP_INVALID1,
175 TRAP_MACHINE_CHECK,
176 TRAP_INVALID2,
177 TRAP_ARITHMETIC,
178 TRAP_INVALID3,
179 TRAP_MT_FPCR,
180 TRAP_RESET
181 };
182
183 pmpc = wrperfmon(9, 0);
184 /* ??? Don't know how to handle physical-mode PALcode address. */
185 if (pmpc & 1)
186 return;
187 pmpc &= ~2; /* clear reserved bit */
188
189 i_stat.v = wrperfmon(8, 0);
190 if (i_stat.fields.trap) {
191 switch (i_stat.fields.trap_type) {
192 case TRAP_INVALID1:
193 case TRAP_INVALID2:
194 case TRAP_INVALID3:
195 /* Pipeline redirection ocurred. PMPC points
196 to PALcode. Recognize ITB miss by PALcode
197 offset address, and get actual PC from
198 EXC_ADDR. */
199 oprofile_add_pc(regs->pc, kern, which);
200 if ((pmpc & ((1 << 15) - 1)) == 581)
201 op_add_pm(regs->pc, kern, which,
202 ctr, PM_ITB_MISS);
203 /* Most other bit and counter values will be
204 those for the first instruction in the
205 fault handler, so we're done. */
206 return;
207 case TRAP_REPLAY:
208 op_add_pm(pmpc, kern, which, ctr,
209 (i_stat.fields.load_store
210 ? PM_LOAD_STORE : PM_REPLAY));
211 break;
212 case TRAP_DTB_DOUBLE_MISS_3:
213 case TRAP_DTB_DOUBLE_MISS_4:
214 case TRAP_DTB_SINGLE_MISS:
215 op_add_pm(pmpc, kern, which, ctr, PM_DTB_MISS);
216 break;
217 case TRAP_UNALIGNED:
218 op_add_pm(pmpc, kern, which, ctr, PM_UNALIGNED);
219 break;
220 case TRAP_INVALID0:
221 case TRAP_FP_DISABLED:
222 case TRAP_DSTREAM_FAULT:
223 case TRAP_OPCDEC:
224 case TRAP_MACHINE_CHECK:
225 case TRAP_ARITHMETIC:
226 case TRAP_MT_FPCR:
227 case TRAP_RESET:
228 break;
229 }
230
231 /* ??? JSR/JMP/RET/COR or HW_JSR/HW_JMP/HW_RET/HW_COR
232 mispredicts do not set this bit but can be
233 recognized by the presence of one of these
234 instructions at the PMPC location with bit 39
235 set. */
236 if (i_stat.fields.mispredict) {
237 mispredict = 1;
238 op_add_pm(pmpc, kern, which, ctr, PM_MISPREDICT);
239 }
240 }
241
242 oprofile_add_pc(pmpc, kern, which);
243
244 pctr_ctl = wrperfmon(5, 0);
245 if (pctr_ctl & (1UL << 27))
246 op_add_pm(pmpc, kern, which, ctr, PM_STALLED);
247
248 /* Unfortunately, TAK is undefined on mispredicted branches.
249 ??? It is also undefined for non-cbranch insns, should
250 check that. */
251 if (!mispredict && pctr_ctl & (1UL << 0))
252 op_add_pm(pmpc, kern, which, ctr, PM_TAKEN);
253 }
254
255 struct op_axp_model op_model_ev67 = {
256 .reg_setup = ev67_reg_setup,
257 .cpu_setup = ev67_cpu_setup,
258 .reset_ctr = ev67_reset_ctr,
259 .handle_interrupt = ev67_handle_interrupt,
260 .cpu_type = "alpha/ev67",
261 .num_counters = 20,
262 .can_set_proc_mode = 0,
263 };
264