/*
 * 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.
 *
 * 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/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_RS64:
                        model = &op_model_rs64;
                        break;
                case PPC_OPROFILE_POWER4:
                        model = &op_model_power4;
                        break;
                case PPC_OPROFILE_PA6T:
                        model = &op_model_pa6t;
                        break;
#endif
#ifdef CONFIG_6xx
                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)
{
}