Release 4.14 arch/powerpc/oprofile/cell/spu_profiler.c
/*
* Cell Broadband Engine OProfile Support
*
* (C) Copyright IBM Corporation 2006
*
* Authors: Maynard Johnson <maynardj@us.ibm.com>
* Carl Love <carll@us.ibm.com>
*
* 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.
*/
#include <linux/hrtimer.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <asm/cell-pmu.h>
#include <asm/time.h>
#include "pr_util.h"
#define SCALE_SHIFT 14
static u32 *samples;
/* spu_prof_running is a flag used to indicate if spu profiling is enabled
* or not. It is set by the routines start_spu_profiling_cycles() and
* start_spu_profiling_events(). The flag is cleared by the routines
* stop_spu_profiling_cycles() and stop_spu_profiling_events(). These
* routines are called via global_start() and global_stop() which are called in
* op_powerpc_start() and op_powerpc_stop(). These routines are called once
* per system as a result of the user starting/stopping oprofile. Hence, only
* one CPU per user at a time will be changing the value of spu_prof_running.
* In general, OProfile does not protect against multiple users trying to run
* OProfile at a time.
*/
int spu_prof_running;
static unsigned int profiling_interval;
#define NUM_SPU_BITS_TRBUF 16
#define SPUS_PER_TB_ENTRY 4
#define SPU_PC_MASK 0xFFFF
DEFINE_SPINLOCK(oprof_spu_smpl_arry_lck);
static unsigned long oprof_spu_smpl_arry_lck_flags;
void set_spu_profiling_frequency(unsigned int freq_khz, unsigned int cycles_reset)
{
unsigned long ns_per_cyc;
if (!freq_khz)
freq_khz = ppc_proc_freq/1000;
/* To calculate a timeout in nanoseconds, the basic
* formula is ns = cycles_reset * (NSEC_PER_SEC / cpu frequency).
* To avoid floating point math, we use the scale math
* technique as described in linux/jiffies.h. We use
* a scale factor of SCALE_SHIFT, which provides 4 decimal places
* of precision. This is close enough for the purpose at hand.
*
* The value of the timeout should be small enough that the hw
* trace buffer will not get more than about 1/3 full for the
* maximum user specified (the LFSR value) hw sampling frequency.
* This is to ensure the trace buffer will never fill even if the
* kernel thread scheduling varies under a heavy system load.
*/
ns_per_cyc = (USEC_PER_SEC << SCALE_SHIFT)/freq_khz;
profiling_interval = (ns_per_cyc * cycles_reset) >> SCALE_SHIFT;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 48 | 97.96% | 1 | 50.00% |
| Frederik Schwarzer | 1 | 2.04% | 1 | 50.00% |
| Total | 49 | 100.00% | 2 | 100.00% |
/*
* Extract SPU PC from trace buffer entry
*/
static void spu_pc_extract(int cpu, int entry)
{
/* the trace buffer is 128 bits */
u64 trace_buffer[2];
u64 spu_mask;
int spu;
spu_mask = SPU_PC_MASK;
/* Each SPU PC is 16 bits; hence, four spus in each of
* the two 64-bit buffer entries that make up the
* 128-bit trace_buffer entry. Process two 64-bit values
* simultaneously.
* trace[0] SPU PC contents are: 0 1 2 3
* trace[1] SPU PC contents are: 4 5 6 7
*/
cbe_read_trace_buffer(cpu, trace_buffer);
for (spu = SPUS_PER_TB_ENTRY-1; spu >= 0; spu--) {
/* spu PC trace entry is upper 16 bits of the
* 18 bit SPU program counter
*/
samples[spu * TRACE_ARRAY_SIZE + entry]
= (spu_mask & trace_buffer[0]) << 2;
samples[(spu + SPUS_PER_TB_ENTRY) * TRACE_ARRAY_SIZE + entry]
= (spu_mask & trace_buffer[1]) << 2;
trace_buffer[0] = trace_buffer[0] >> NUM_SPU_BITS_TRBUF;
trace_buffer[1] = trace_buffer[1] >> NUM_SPU_BITS_TRBUF;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 123 | 100.00% | 1 | 100.00% |
| Total | 123 | 100.00% | 1 | 100.00% |
static int cell_spu_pc_collection(int cpu)
{
u32 trace_addr;
int entry;
/* process the collected SPU PC for the node */
entry = 0;
trace_addr = cbe_read_pm(cpu, trace_address);
while (!(trace_addr & CBE_PM_TRACE_BUF_EMPTY)) {
/* there is data in the trace buffer to process */
spu_pc_extract(cpu, entry);
entry++;
if (entry >= TRACE_ARRAY_SIZE)
/* spu_samples is full */
break;
trace_addr = cbe_read_pm(cpu, trace_address);
}
return entry;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 71 | 100.00% | 1 | 100.00% |
| Total | 71 | 100.00% | 1 | 100.00% |
static enum hrtimer_restart profile_spus(struct hrtimer *timer)
{
ktime_t kt;
int cpu, node, k, num_samples, spu_num;
if (!spu_prof_running)
goto stop;
for_each_online_cpu(cpu) {
if (cbe_get_hw_thread_id(cpu))
continue;
node = cbe_cpu_to_node(cpu);
/* There should only be one kernel thread at a time processing
* the samples. In the very unlikely case that the processing
* is taking a very long time and multiple kernel threads are
* started to process the samples. Make sure only one kernel
* thread is working on the samples array at a time. The
* sample array must be loaded and then processed for a given
* cpu. The sample array is not per cpu.
*/
spin_lock_irqsave(&oprof_spu_smpl_arry_lck,
oprof_spu_smpl_arry_lck_flags);
num_samples = cell_spu_pc_collection(cpu);
if (num_samples == 0) {
spin_unlock_irqrestore(&oprof_spu_smpl_arry_lck,
oprof_spu_smpl_arry_lck_flags);
continue;
}
for (k = 0; k < SPUS_PER_NODE; k++) {
spu_num = k + (node * SPUS_PER_NODE);
spu_sync_buffer(spu_num,
samples + (k * TRACE_ARRAY_SIZE),
num_samples);
}
spin_unlock_irqrestore(&oprof_spu_smpl_arry_lck,
oprof_spu_smpl_arry_lck_flags);
}
smp_wmb(); /* insure spu event buffer updates are written */
/* don't want events intermingled... */
kt = profiling_interval;
if (!spu_prof_running)
goto stop;
hrtimer_forward(timer, timer->base->get_time(), kt);
return HRTIMER_RESTART;
stop:
printk(KERN_INFO "SPU_PROF: spu-prof timer ending\n");
return HRTIMER_NORESTART;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 175 | 96.69% | 1 | 50.00% |
| Carl E. Love | 6 | 3.31% | 1 | 50.00% |
| Total | 181 | 100.00% | 2 | 100.00% |
static struct hrtimer timer;
/*
* Entry point for SPU cycle profiling.
* NOTE: SPU profiling is done system-wide, not per-CPU.
*
* cycles_reset is the count value specified by the user when
* setting up OProfile to count SPU_CYCLES.
*/
int start_spu_profiling_cycles(unsigned int cycles_reset)
{
ktime_t kt;
pr_debug("timer resolution: %lu\n", TICK_NSEC);
kt = profiling_interval;
hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer_set_expires(&timer, kt);
timer.function = profile_spus;
/* Allocate arrays for collecting SPU PC samples */
samples = kzalloc(SPUS_PER_NODE *
TRACE_ARRAY_SIZE * sizeof(u32), GFP_KERNEL);
if (!samples)
return -ENOMEM;
spu_prof_running = 1;
hrtimer_start(&timer, kt, HRTIMER_MODE_REL);
schedule_delayed_work(&spu_work, DEFAULT_TIMER_EXPIRE);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 84 | 85.71% | 1 | 25.00% |
| Carl E. Love | 9 | 9.18% | 2 | 50.00% |
| Arjan van de Ven | 5 | 5.10% | 1 | 25.00% |
| Total | 98 | 100.00% | 4 | 100.00% |
/*
* Entry point for SPU event profiling.
* NOTE: SPU profiling is done system-wide, not per-CPU.
*
* cycles_reset is the count value specified by the user when
* setting up OProfile to count SPU_CYCLES.
*/
void start_spu_profiling_events(void)
{
spu_prof_running = 1;
schedule_delayed_work(&spu_work, DEFAULT_TIMER_EXPIRE);
return;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Carl E. Love | 19 | 95.00% | 1 | 50.00% |
| Bob Nelson | 1 | 5.00% | 1 | 50.00% |
| Total | 20 | 100.00% | 2 | 100.00% |
void stop_spu_profiling_cycles(void)
{
spu_prof_running = 0;
hrtimer_cancel(&timer);
kfree(samples);
pr_debug("SPU_PROF: stop_spu_profiling_cycles issued\n");
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 25 | 92.59% | 1 | 50.00% |
| Carl E. Love | 2 | 7.41% | 1 | 50.00% |
| Total | 27 | 100.00% | 2 | 100.00% |
void stop_spu_profiling_events(void)
{
spu_prof_running = 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Carl E. Love | 11 | 100.00% | 1 | 100.00% |
| Total | 11 | 100.00% | 1 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Bob Nelson | 585 | 90.42% | 1 | 12.50% |
| Carl E. Love | 52 | 8.04% | 3 | 37.50% |
| Arjan van de Ven | 5 | 0.77% | 1 | 12.50% |
| Michael Neuling | 3 | 0.46% | 1 | 12.50% |
| Daniel Axtens | 1 | 0.15% | 1 | 12.50% |
| Frederik Schwarzer | 1 | 0.15% | 1 | 12.50% |
| Total | 647 | 100.00% | 8 | 100.00% |
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