diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/powerpc/oprofile/cell/spu_profiler.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/powerpc/oprofile/cell/spu_profiler.c')
-rw-r--r-- | kernel/arch/powerpc/oprofile/cell/spu_profiler.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/oprofile/cell/spu_profiler.c b/kernel/arch/powerpc/oprofile/cell/spu_profiler.c new file mode 100644 index 000000000..b129d007e --- /dev/null +++ b/kernel/arch/powerpc/oprofile/cell/spu_profiler.c @@ -0,0 +1,252 @@ +/* + * 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); +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; + +} + +/* + * 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; + } +} + +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; +} + + +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 = ktime_set(0, 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; +} + +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 = ktime_set(0, 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; +} + +/* + * 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; +} + +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"); +} + +void stop_spu_profiling_events(void) +{ + spu_prof_running = 0; +} |