// SPDX-License-Identifier: GPL-2.0
/*
 * Performance event support for s390x
 *
 *  Copyright IBM Corp. 2012, 2013
 *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
 */
#define pr_fmt(fmt) "perf: " fmt

#include <linux/kernel.h>
#include <linux/perf_event.h>
#include <linux/kvm_host.h>
#include <linux/percpu.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/sysfs.h>
#include <asm/stacktrace.h>
#include <asm/irq.h>
#include <asm/cpu_mf.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sysinfo.h>
#include <asm/unwind.h>

static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
{
        struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];

        if (!stack)
                return NULL;

        return (struct kvm_s390_sie_block *)stack->sie_control_block;
}

static bool is_in_guest(struct pt_regs *regs)
{
        if (user_mode(regs))
                return false;
#if IS_ENABLED(CONFIG_KVM)
        return instruction_pointer(regs) == (unsigned long) &sie_exit;
#else
        return false;
#endif
}

static unsigned long guest_is_user_mode(struct pt_regs *regs)
{
        return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
}

static unsigned long instruction_pointer_guest(struct pt_regs *regs)
{
        return sie_block(regs)->gpsw.addr;
}

unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
{
        return is_in_guest(regs) ? instruction_pointer_guest(regs)
                                 : instruction_pointer(regs);
}

static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
{
        return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
                                        : PERF_RECORD_MISC_GUEST_KERNEL;
}

static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
{
        struct perf_sf_sde_regs *sde_regs;
        unsigned long flags;

        sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
        if (sde_regs->in_guest)
                flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
                                        : PERF_RECORD_MISC_GUEST_KERNEL;
        else
                flags = user_mode(regs) ? PERF_RECORD_MISC_USER
                                        : PERF_RECORD_MISC_KERNEL;
        return flags;
}

unsigned long perf_arch_misc_flags(struct pt_regs *regs)
{
        /* Check if the cpum_sf PMU has created the pt_regs structure.
         * In this case, perf misc flags can be easily extracted.  Otherwise,
         * do regular checks on the pt_regs content.
         */
        if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
                if (!regs->gprs[15])
                        return perf_misc_flags_sf(regs);

        if (is_in_guest(regs))
                return perf_misc_guest_flags(regs);

        return user_mode(regs) ? PERF_RECORD_MISC_USER
                               : PERF_RECORD_MISC_KERNEL;
}

static void print_debug_cf(void)
{
        struct cpumf_ctr_info cf_info;
        int cpu = smp_processor_id();

        memset(&cf_info, 0, sizeof(cf_info));
        if (!qctri(&cf_info))
                pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
                        cpu, cf_info.cfvn, cf_info.csvn,
                        cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
}

static void print_debug_sf(void)
{
        struct hws_qsi_info_block si;
        int cpu = smp_processor_id();

        memset(&si, 0, sizeof(si));
        if (qsi(&si))
                return;

        pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
                cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
                si.cpu_speed);

        if (si.as)
                pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
                        " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
                        si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
        if (si.ad)
                pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
                        " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
                        si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
}

void perf_event_print_debug(void)
{
        unsigned long flags;

        local_irq_save(flags);
        if (cpum_cf_avail())
                print_debug_cf();
        if (cpum_sf_avail())
                print_debug_sf();
        local_irq_restore(flags);
}

/* Service level infrastructure */
static void sl_print_counter(struct seq_file *m)
{
        struct cpumf_ctr_info ci;

        memset(&ci, 0, sizeof(ci));
        if (qctri(&ci))
                return;

        seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
                   "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
}

static void sl_print_sampling(struct seq_file *m)
{
        struct hws_qsi_info_block si;

        memset(&si, 0, sizeof(si));
        if (qsi(&si))
                return;

        if (!si.as && !si.ad)
                return;

        seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
                   " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
                   si.cpu_speed);
        if (si.as)
                seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
                           " sample_size=%u\n", si.bsdes);
        if (si.ad)
                seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
                           " sample_size=%u\n", si.dsdes);
}

static void service_level_perf_print(struct seq_file *m,
                                     struct service_level *sl)
{
        if (cpum_cf_avail())
                sl_print_counter(m);
        if (cpum_sf_avail())
                sl_print_sampling(m);
}

static struct service_level service_level_perf = {
        .seq_print = service_level_perf_print,
};

static int __init service_level_perf_register(void)
{
        return register_service_level(&service_level_perf);
}
arch_initcall(service_level_perf_register);

void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
                           struct pt_regs *regs)
{
        struct unwind_state state;
        unsigned long addr;

        unwind_for_each_frame(&state, current, regs, 0) {
                addr = unwind_get_return_address(&state);
                if (!addr || perf_callchain_store(entry, addr))
                        return;
        }
}

void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
                         struct pt_regs *regs)
{
        arch_stack_walk_user_common(NULL, NULL, entry, regs, true);
}

/* Perf definitions for PMU event attributes in sysfs */
ssize_t cpumf_events_sysfs_show(struct device *dev,
                                struct device_attribute *attr, char *page)
{
        struct perf_pmu_events_attr *pmu_attr;

        pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
        return sysfs_emit(page, "event=0x%04llx\n", pmu_attr->id);
}