arch/powerpc/oprofile/common.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PPC 64 oprofile support:
 * Copyright (C) 2004 Anton Blanchard <anton@au.ibm.com>, IBM
 * PPC 32 oprofile support: (based on PPC 64 support)
 * Copyright (C) Freescale Semiconductor, Inc 2004
 *	Author: Andy Fleming
 *
 * Based on alpha version.
 */

#include <linux/oprofile.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <asm/ptrace.h>
#include <asm/pmc.h>
#include <asm/cputable.h>
#include <asm/oprofile_impl.h>
#include <asm/firmware.h>

static struct op_powerpc_model *model;

static struct op_counter_config ctr[OP_MAX_COUNTER];
static struct op_system_config sys;

static int op_per_cpu_rc;

static void op_handle_interrupt(struct pt_regs *regs)
{
	model->handle_interrupt(regs, ctr);
}

static void op_powerpc_cpu_setup(void *dummy)
{
	int ret;

	ret = model->cpu_setup(ctr);

	if (ret != 0)
		op_per_cpu_rc = ret;
}

static int op_powerpc_setup(void)
{
	int err;

	op_per_cpu_rc = 0;

	/* Grab the hardware */
	err = reserve_pmc_hardware(op_handle_interrupt);
	if (err)
		return err;

	/* Pre-compute the values to stuff in the hardware registers.  */
	op_per_cpu_rc = model->reg_setup(ctr, &sys, model->num_counters);

	if (op_per_cpu_rc)
		goto out;

	/* Configure the registers on all cpus.	 If an error occurs on one
	 * of the cpus, op_per_cpu_rc will be set to the error */
	on_each_cpu(op_powerpc_cpu_setup, NULL, 1);

out:	if (op_per_cpu_rc) {
		/* error on setup release the performance counter hardware */
		release_pmc_hardware();
	}

	return op_per_cpu_rc;
}

static void op_powerpc_shutdown(void)
{
	release_pmc_hardware();
}

static void op_powerpc_cpu_start(void *dummy)
{
	/* If any of the cpus have return an error, set the
	 * global flag to the error so it can be returned
	 * to the generic OProfile caller.
	 */
	int ret;

	ret = model->start(ctr);
	if (ret != 0)
		op_per_cpu_rc = ret;
}

static int op_powerpc_start(void)
{
	op_per_cpu_rc = 0;

	if (model->global_start)
		return model->global_start(ctr);
	if (model->start) {
		on_each_cpu(op_powerpc_cpu_start, NULL, 1);
		return op_per_cpu_rc;
	}
	return -EIO; /* No start function is defined for this
			power architecture */
}

static inline void op_powerpc_cpu_stop(void *dummy)
{
	model->stop();
}

static void op_powerpc_stop(void)
{
	if (model->stop)
		on_each_cpu(op_powerpc_cpu_stop, NULL, 1);
        if (model->global_stop)
                model->global_stop();
}

static int op_powerpc_create_files(struct dentry *root)
{
	int i;

#ifdef CONFIG_PPC64
	/*
	 * There is one mmcr0, mmcr1 and mmcra for setting the events for
	 * all of the counters.
	 */
	oprofilefs_create_ulong(root, "mmcr0", &sys.mmcr0);
	oprofilefs_create_ulong(root, "mmcr1", &sys.mmcr1);
	oprofilefs_create_ulong(root, "mmcra", &sys.mmcra);
#ifdef CONFIG_OPROFILE_CELL
	/* create a file the user tool can check to see what level of profiling
	 * support exits with this kernel. Initialize bit mask to indicate
	 * what support the kernel has:
	 * bit 0      -  Supports SPU event profiling in addition to PPU
	 *               event and cycles; and SPU cycle profiling
	 * bits 1-31  -  Currently unused.
	 *
	 * If the file does not exist, then the kernel only supports SPU
	 * cycle profiling, PPU event and cycle profiling.
	 */
	oprofilefs_create_ulong(root, "cell_support", &sys.cell_support);
	sys.cell_support = 0x1; /* Note, the user OProfile tool must check
				 * that this bit is set before attempting to
				 * user SPU event profiling.  Older kernels
				 * will not have this file, hence the user
				 * tool is not allowed to do SPU event
				 * profiling on older kernels.  Older kernels
				 * will accept SPU events but collected data
				 * is garbage.
				 */
#endif
#endif

	for (i = 0; i < model->num_counters; ++i) {
		struct dentry *dir;
		char buf[4];

		snprintf(buf, sizeof buf, "%d", i);
		dir = oprofilefs_mkdir(root, buf);

		oprofilefs_create_ulong(dir, "enabled", &ctr[i].enabled);
		oprofilefs_create_ulong(dir, "event", &ctr[i].event);
		oprofilefs_create_ulong(dir, "count", &ctr[i].count);

		/*
		 * Classic PowerPC doesn't support per-counter
		 * control like this, but the options are
		 * expected, so they remain.  For Freescale
		 * Book-E style performance monitors, we do
		 * support them.
		 */
		oprofilefs_create_ulong(dir, "kernel", &ctr[i].kernel);
		oprofilefs_create_ulong(dir, "user", &ctr[i].user);

		oprofilefs_create_ulong(dir, "unit_mask", &ctr[i].unit_mask);
	}

	oprofilefs_create_ulong(root, "enable_kernel", &sys.enable_kernel);
	oprofilefs_create_ulong(root, "enable_user", &sys.enable_user);

	/* Default to tracing both kernel and user */
	sys.enable_kernel = 1;
	sys.enable_user = 1;

	return 0;
}

int __init oprofile_arch_init(struct oprofile_operations *ops)
{
	if (!cur_cpu_spec->oprofile_cpu_type)
		return -ENODEV;

	switch (cur_cpu_spec->oprofile_type) {
#ifdef CONFIG_PPC_BOOK3S_64
#ifdef CONFIG_OPROFILE_CELL
		case PPC_OPROFILE_CELL:
			if (firmware_has_feature(FW_FEATURE_LPAR))
				return -ENODEV;
			model = &op_model_cell;
			ops->sync_start = model->sync_start;
			ops->sync_stop = model->sync_stop;
			break;
#endif
		case PPC_OPROFILE_POWER4:
			model = &op_model_power4;
			break;
		case PPC_OPROFILE_PA6T:
			model = &op_model_pa6t;
			break;
#endif
#ifdef CONFIG_PPC_BOOK3S_32
		case PPC_OPROFILE_G4:
			model = &op_model_7450;
			break;
#endif
#if defined(CONFIG_FSL_EMB_PERFMON)
		case PPC_OPROFILE_FSL_EMB:
			model = &op_model_fsl_emb;
			break;
#endif
		default:
			return -ENODEV;
	}

	model->num_counters = cur_cpu_spec->num_pmcs;

	ops->cpu_type = cur_cpu_spec->oprofile_cpu_type;
	ops->create_files = op_powerpc_create_files;
	ops->setup = op_powerpc_setup;
	ops->shutdown = op_powerpc_shutdown;
	ops->start = op_powerpc_start;
	ops->stop = op_powerpc_stop;
	ops->backtrace = op_powerpc_backtrace;

	printk(KERN_DEBUG "oprofile: using %s performance monitoring.\n",
	       ops->cpu_type);

	return 0;
}

void oprofile_arch_exit(void)
{
}