/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2014 ARM Limited
 */

#include <linux/ctype.h>
#include <linux/hrtimer.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define CCN_NUM_XP_PORTS 2
#define CCN_NUM_VCS 4
#define CCN_NUM_REGIONS 256
#define CCN_REGION_SIZE 0x10000

#define CCN_ALL_OLY_ID                  0xff00
#define CCN_ALL_OLY_ID__OLY_ID__SHIFT                   0
#define CCN_ALL_OLY_ID__OLY_ID__MASK                    0x1f
#define CCN_ALL_OLY_ID__NODE_ID__SHIFT                  8
#define CCN_ALL_OLY_ID__NODE_ID__MASK                   0x3f

#define CCN_MN_ERRINT_STATUS            0x0008
#define CCN_MN_ERRINT_STATUS__INTREQ__DESSERT           0x11
#define CCN_MN_ERRINT_STATUS__ALL_ERRORS__ENABLE        0x02
#define CCN_MN_ERRINT_STATUS__ALL_ERRORS__DISABLED      0x20
#define CCN_MN_ERRINT_STATUS__ALL_ERRORS__DISABLE       0x22
#define CCN_MN_ERRINT_STATUS__CORRECTED_ERRORS_ENABLE   0x04
#define CCN_MN_ERRINT_STATUS__CORRECTED_ERRORS_DISABLED 0x40
#define CCN_MN_ERRINT_STATUS__CORRECTED_ERRORS_DISABLE  0x44
#define CCN_MN_ERRINT_STATUS__PMU_EVENTS__ENABLE        0x08
#define CCN_MN_ERRINT_STATUS__PMU_EVENTS__DISABLED      0x80
#define CCN_MN_ERRINT_STATUS__PMU_EVENTS__DISABLE       0x88
#define CCN_MN_OLY_COMP_LIST_63_0       0x01e0
#define CCN_MN_ERR_SIG_VAL_63_0         0x0300
#define CCN_MN_ERR_SIG_VAL_63_0__DT                     (1 << 1)

#define CCN_DT_ACTIVE_DSM               0x0000
#define CCN_DT_ACTIVE_DSM__DSM_ID__SHIFT(n)             ((n) * 8)
#define CCN_DT_ACTIVE_DSM__DSM_ID__MASK                 0xff
#define CCN_DT_CTL                      0x0028
#define CCN_DT_CTL__DT_EN                               (1 << 0)
#define CCN_DT_PMEVCNT(n)               (0x0100 + (n) * 0x8)
#define CCN_DT_PMCCNTR                  0x0140
#define CCN_DT_PMCCNTRSR                0x0190
#define CCN_DT_PMOVSR                   0x0198
#define CCN_DT_PMOVSR_CLR               0x01a0
#define CCN_DT_PMOVSR_CLR__MASK                         0x1f
#define CCN_DT_PMCR                     0x01a8
#define CCN_DT_PMCR__OVFL_INTR_EN                       (1 << 6)
#define CCN_DT_PMCR__PMU_EN                             (1 << 0)
#define CCN_DT_PMSR                     0x01b0
#define CCN_DT_PMSR_REQ                 0x01b8
#define CCN_DT_PMSR_CLR                 0x01c0

#define CCN_HNF_PMU_EVENT_SEL           0x0600
#define CCN_HNF_PMU_EVENT_SEL__ID__SHIFT(n)             ((n) * 4)
#define CCN_HNF_PMU_EVENT_SEL__ID__MASK                 0xf

#define CCN_XP_DT_CONFIG                0x0300
#define CCN_XP_DT_CONFIG__DT_CFG__SHIFT(n)              ((n) * 4)
#define CCN_XP_DT_CONFIG__DT_CFG__MASK                  0xf
#define CCN_XP_DT_CONFIG__DT_CFG__PASS_THROUGH          0x0
#define CCN_XP_DT_CONFIG__DT_CFG__WATCHPOINT_0_OR_1     0x1
#define CCN_XP_DT_CONFIG__DT_CFG__WATCHPOINT(n)         (0x2 + (n))
#define CCN_XP_DT_CONFIG__DT_CFG__XP_PMU_EVENT(n)       (0x4 + (n))
#define CCN_XP_DT_CONFIG__DT_CFG__DEVICE_PMU_EVENT(d, n) (0x8 + (d) * 4 + (n))
#define CCN_XP_DT_INTERFACE_SEL         0x0308
#define CCN_XP_DT_INTERFACE_SEL__DT_IO_SEL__SHIFT(n)    (0 + (n) * 8)
#define CCN_XP_DT_INTERFACE_SEL__DT_IO_SEL__MASK        0x1
#define CCN_XP_DT_INTERFACE_SEL__DT_DEV_SEL__SHIFT(n)   (1 + (n) * 8)
#define CCN_XP_DT_INTERFACE_SEL__DT_DEV_SEL__MASK       0x1
#define CCN_XP_DT_INTERFACE_SEL__DT_VC_SEL__SHIFT(n)    (2 + (n) * 8)
#define CCN_XP_DT_INTERFACE_SEL__DT_VC_SEL__MASK        0x3
#define CCN_XP_DT_CMP_VAL_L(n)          (0x0310 + (n) * 0x40)
#define CCN_XP_DT_CMP_VAL_H(n)          (0x0318 + (n) * 0x40)
#define CCN_XP_DT_CMP_MASK_L(n)         (0x0320 + (n) * 0x40)
#define CCN_XP_DT_CMP_MASK_H(n)         (0x0328 + (n) * 0x40)
#define CCN_XP_DT_CONTROL               0x0370
#define CCN_XP_DT_CONTROL__DT_ENABLE                    (1 << 0)
#define CCN_XP_DT_CONTROL__WP_ARM_SEL__SHIFT(n)         (12 + (n) * 4)
#define CCN_XP_DT_CONTROL__WP_ARM_SEL__MASK             0xf
#define CCN_XP_DT_CONTROL__WP_ARM_SEL__ALWAYS           0xf
#define CCN_XP_PMU_EVENT_SEL            0x0600
#define CCN_XP_PMU_EVENT_SEL__ID__SHIFT(n)              ((n) * 7)
#define CCN_XP_PMU_EVENT_SEL__ID__MASK                  0x3f

#define CCN_SBAS_PMU_EVENT_SEL          0x0600
#define CCN_SBAS_PMU_EVENT_SEL__ID__SHIFT(n)            ((n) * 4)
#define CCN_SBAS_PMU_EVENT_SEL__ID__MASK                0xf

#define CCN_RNI_PMU_EVENT_SEL           0x0600
#define CCN_RNI_PMU_EVENT_SEL__ID__SHIFT(n)             ((n) * 4)
#define CCN_RNI_PMU_EVENT_SEL__ID__MASK                 0xf

#define CCN_TYPE_MN     0x01
#define CCN_TYPE_DT     0x02
#define CCN_TYPE_HNF    0x04
#define CCN_TYPE_HNI    0x05
#define CCN_TYPE_XP     0x08
#define CCN_TYPE_SBSX   0x0c
#define CCN_TYPE_SBAS   0x10
#define CCN_TYPE_RNI_1P 0x14
#define CCN_TYPE_RNI_2P 0x15
#define CCN_TYPE_RNI_3P 0x16
#define CCN_TYPE_RND_1P 0x18 /* RN-D = RN-I + DVM */
#define CCN_TYPE_RND_2P 0x19
#define CCN_TYPE_RND_3P 0x1a
#define CCN_TYPE_CYCLES 0xff /* Pseudotype */

#define CCN_EVENT_WATCHPOINT 0xfe /* Pseudoevent */

#define CCN_NUM_PMU_EVENTS              4
#define CCN_NUM_XP_WATCHPOINTS          2 /* See DT.dbg_id.num_watchpoints */
#define CCN_NUM_PMU_EVENT_COUNTERS      8 /* See DT.dbg_id.num_pmucntr */
#define CCN_IDX_PMU_CYCLE_COUNTER       CCN_NUM_PMU_EVENT_COUNTERS

#define CCN_NUM_PREDEFINED_MASKS        4
#define CCN_IDX_MASK_ANY                (CCN_NUM_PMU_EVENT_COUNTERS + 0)
#define CCN_IDX_MASK_EXACT              (CCN_NUM_PMU_EVENT_COUNTERS + 1)
#define CCN_IDX_MASK_ORDER              (CCN_NUM_PMU_EVENT_COUNTERS + 2)
#define CCN_IDX_MASK_OPCODE             (CCN_NUM_PMU_EVENT_COUNTERS + 3)

struct arm_ccn_component {
        void __iomem *base;
        u32 type;

        DECLARE_BITMAP(pmu_events_mask, CCN_NUM_PMU_EVENTS);
        union {
                struct {
                        DECLARE_BITMAP(dt_cmp_mask, CCN_NUM_XP_WATCHPOINTS);
                } xp;
        };
};

#define pmu_to_arm_ccn(_pmu) container_of(container_of(_pmu, \
        struct arm_ccn_dt, pmu), struct arm_ccn, dt)

struct arm_ccn_dt {
        int id;
        void __iomem *base;

        spinlock_t config_lock;

        DECLARE_BITMAP(pmu_counters_mask, CCN_NUM_PMU_EVENT_COUNTERS + 1);
        struct {
                struct arm_ccn_component *source;
                struct perf_event *event;
        } pmu_counters[CCN_NUM_PMU_EVENT_COUNTERS + 1];

        struct {
               u64 l, h;
        } cmp_mask[CCN_NUM_PMU_EVENT_COUNTERS + CCN_NUM_PREDEFINED_MASKS];

        struct hrtimer hrtimer;

        cpumask_t cpu;
        struct hlist_node node;

        struct pmu pmu;
};

struct arm_ccn {
        struct device *dev;
        void __iomem *base;
        unsigned int irq;

        unsigned sbas_present:1;
        unsigned sbsx_present:1;

        int num_nodes;
        struct arm_ccn_component *node;

        int num_xps;
        struct arm_ccn_component *xp;

        struct arm_ccn_dt dt;
        int mn_id;
};

static int arm_ccn_node_to_xp(int node)
{
        return node / CCN_NUM_XP_PORTS;
}

static int arm_ccn_node_to_xp_port(int node)
{
        return node % CCN_NUM_XP_PORTS;
}


/*
 * Bit shifts and masks in these defines must be kept in sync with
 * arm_ccn_pmu_config_set() and CCN_FORMAT_ATTRs below!
 */
#define CCN_CONFIG_NODE(_config)        (((_config) >> 0) & 0xff)
#define CCN_CONFIG_XP(_config)          (((_config) >> 0) & 0xff)
#define CCN_CONFIG_TYPE(_config)        (((_config) >> 8) & 0xff)
#define CCN_CONFIG_EVENT(_config)       (((_config) >> 16) & 0xff)
#define CCN_CONFIG_PORT(_config)        (((_config) >> 24) & 0x3)
#define CCN_CONFIG_BUS(_config)         (((_config) >> 24) & 0x3)
#define CCN_CONFIG_VC(_config)          (((_config) >> 26) & 0x7)
#define CCN_CONFIG_DIR(_config)         (((_config) >> 29) & 0x1)
#define CCN_CONFIG_MASK(_config)        (((_config) >> 30) & 0xf)

static void arm_ccn_pmu_config_set(u64 *config, u32 node_xp, u32 type, u32 port)
{
        *config &= ~((0xff << 0) | (0xff << 8) | (0x3 << 24));
        *config |= (node_xp << 0) | (type << 8) | (port << 24);
}

static ssize_t arm_ccn_pmu_format_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct dev_ext_attribute *ea = container_of(attr,
                        struct dev_ext_attribute, attr);

        return snprintf(buf, PAGE_SIZE, "%s\n", (char *)ea->var);
}

#define CCN_FORMAT_ATTR(_name, _config) \
        struct dev_ext_attribute arm_ccn_pmu_format_attr_##_name = \
                        { __ATTR(_name, S_IRUGO, arm_ccn_pmu_format_show, \
                        NULL), _config }

static CCN_FORMAT_ATTR(node, "config:0-7");
static CCN_FORMAT_ATTR(xp, "config:0-7");
static CCN_FORMAT_ATTR(type, "config:8-15");
static CCN_FORMAT_ATTR(event, "config:16-23");
static CCN_FORMAT_ATTR(port, "config:24-25");
static CCN_FORMAT_ATTR(bus, "config:24-25");
static CCN_FORMAT_ATTR(vc, "config:26-28");
static CCN_FORMAT_ATTR(dir, "config:29-29");
static CCN_FORMAT_ATTR(mask, "config:30-33");
static CCN_FORMAT_ATTR(cmp_l, "config1:0-62");
static CCN_FORMAT_ATTR(cmp_h, "config2:0-59");

static struct attribute *arm_ccn_pmu_format_attrs[] = {
        &arm_ccn_pmu_format_attr_node.attr.attr,
        &arm_ccn_pmu_format_attr_xp.attr.attr,
        &arm_ccn_pmu_format_attr_type.attr.attr,
        &arm_ccn_pmu_format_attr_event.attr.attr,
        &arm_ccn_pmu_format_attr_port.attr.attr,
        &arm_ccn_pmu_format_attr_bus.attr.attr,
        &arm_ccn_pmu_format_attr_vc.attr.attr,
        &arm_ccn_pmu_format_attr_dir.attr.attr,
        &arm_ccn_pmu_format_attr_mask.attr.attr,
        &arm_ccn_pmu_format_attr_cmp_l.attr.attr,
        &arm_ccn_pmu_format_attr_cmp_h.attr.attr,
        NULL
};

static struct attribute_group arm_ccn_pmu_format_attr_group = {
        .name = "format",
        .attrs = arm_ccn_pmu_format_attrs,
};


struct arm_ccn_pmu_event {
        struct device_attribute attr;
        u32 type;
        u32 event;
        int num_ports;
        int num_vcs;
        const char *def;
        int mask;
};

#define CCN_EVENT_ATTR(_name) \
        __ATTR(_name, S_IRUGO, arm_ccn_pmu_event_show, NULL)

/*
 * Events defined in TRM for MN, HN-I and SBSX are actually watchpoints set on
 * their ports in XP they are connected to. For the sake of usability they are
 * explicitly defined here (and translated into a relevant watchpoint in
 * arm_ccn_pmu_event_init()) so the user can easily request them without deep
 * knowledge of the flit format.
 */

#define CCN_EVENT_MN(_name, _def, _mask) { .attr = CCN_EVENT_ATTR(mn_##_name), \
                .type = CCN_TYPE_MN, .event = CCN_EVENT_WATCHPOINT, \
                .num_ports = CCN_NUM_XP_PORTS, .num_vcs = CCN_NUM_VCS, \
                .def = _def, .mask = _mask, }

#define CCN_EVENT_HNI(_name, _def, _mask) { \
                .attr = CCN_EVENT_ATTR(hni_##_name), .type = CCN_TYPE_HNI, \
                .event = CCN_EVENT_WATCHPOINT, .num_ports = CCN_NUM_XP_PORTS, \
                .num_vcs = CCN_NUM_VCS, .def = _def, .mask = _mask, }

#define CCN_EVENT_SBSX(_name, _def, _mask) { \
                .attr = CCN_EVENT_ATTR(sbsx_##_name), .type = CCN_TYPE_SBSX, \
                .event = CCN_EVENT_WATCHPOINT, .num_ports = CCN_NUM_XP_PORTS, \
                .num_vcs = CCN_NUM_VCS, .def = _def, .mask = _mask, }

#define CCN_EVENT_HNF(_name, _event) { .attr = CCN_EVENT_ATTR(hnf_##_name), \
                .type = CCN_TYPE_HNF, .event = _event, }

#define CCN_EVENT_XP(_name, _event) { .attr = CCN_EVENT_ATTR(xp_##_name), \
                .type = CCN_TYPE_XP, .event = _event, \
                .num_ports = CCN_NUM_XP_PORTS, .num_vcs = CCN_NUM_VCS, }

/*
 * RN-I & RN-D (RN-D = RN-I + DVM) nodes have different type ID depending
 * on configuration. One of them is picked to represent the whole group,
 * as they all share the same event types.
 */
#define CCN_EVENT_RNI(_name, _event) { .attr = CCN_EVENT_ATTR(rni_##_name), \
                .type = CCN_TYPE_RNI_3P, .event = _event, }

#define CCN_EVENT_SBAS(_name, _event) { .attr = CCN_EVENT_ATTR(sbas_##_name), \
                .type = CCN_TYPE_SBAS, .event = _event, }

#define CCN_EVENT_CYCLES(_name) { .attr = CCN_EVENT_ATTR(_name), \
                .type = CCN_TYPE_CYCLES }


static ssize_t arm_ccn_pmu_event_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));
        struct arm_ccn_pmu_event *event = container_of(attr,
                        struct arm_ccn_pmu_event, attr);
        ssize_t res;

        res = snprintf(buf, PAGE_SIZE, "type=0x%x", event->type);
        if (event->event)
                res += snprintf(buf + res, PAGE_SIZE - res, ",event=0x%x",
                                event->event);
        if (event->def)
                res += snprintf(buf + res, PAGE_SIZE - res, ",%s",
                                event->def);
        if (event->mask)
                res += snprintf(buf + res, PAGE_SIZE - res, ",mask=0x%x",
                                event->mask);

        /* Arguments required by an event */
        switch (event->type) {
        case CCN_TYPE_CYCLES:
                break;
        case CCN_TYPE_XP:
                res += snprintf(buf + res, PAGE_SIZE - res,
                                ",xp=?,vc=?");
                if (event->event == CCN_EVENT_WATCHPOINT)
                        res += snprintf(buf + res, PAGE_SIZE - res,
                                        ",port=?,dir=?,cmp_l=?,cmp_h=?,mask=?");
                else
                        res += snprintf(buf + res, PAGE_SIZE - res,
                                        ",bus=?");

                break;
        case CCN_TYPE_MN:
                res += snprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
                break;
        default:
                res += snprintf(buf + res, PAGE_SIZE - res, ",node=?");
                break;
        }

        res += snprintf(buf + res, PAGE_SIZE - res, "\n");

        return res;
}

static umode_t arm_ccn_pmu_events_is_visible(struct kobject *kobj,
                                     struct attribute *attr, int index)
{
        struct device *dev = kobj_to_dev(kobj);
        struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));
        struct device_attribute *dev_attr = container_of(attr,
                        struct device_attribute, attr);
        struct arm_ccn_pmu_event *event = container_of(dev_attr,
                        struct arm_ccn_pmu_event, attr);

        if (event->type == CCN_TYPE_SBAS && !ccn->sbas_present)
                return 0;
        if (event->type == CCN_TYPE_SBSX && !ccn->sbsx_present)
                return 0;

        return attr->mode;
}

static struct arm_ccn_pmu_event arm_ccn_pmu_events[] = {
        CCN_EVENT_MN(eobarrier, "dir=1,vc=0,cmp_h=0x1c00", CCN_IDX_MASK_OPCODE),
        CCN_EVENT_MN(ecbarrier, "dir=1,vc=0,cmp_h=0x1e00", CCN_IDX_MASK_OPCODE),
        CCN_EVENT_MN(dvmop, "dir=1,vc=0,cmp_h=0x2800", CCN_IDX_MASK_OPCODE),
        CCN_EVENT_HNI(txdatflits, "dir=1,vc=3", CCN_IDX_MASK_ANY),
        CCN_EVENT_HNI(rxdatflits, "dir=0,vc=3", CCN_IDX_MASK_ANY),
        CCN_EVENT_HNI(txreqflits, "dir=1,vc=0", CCN_IDX_MASK_ANY),
        CCN_EVENT_HNI(rxreqflits, "dir=0,vc=0", CCN_IDX_MASK_ANY),
        CCN_EVENT_HNI(rxreqflits_order, "dir=0,vc=0,cmp_h=0x8000",
                        CCN_IDX_MASK_ORDER),
        CCN_EVENT_SBSX(txdatflits, "dir=1,vc=3", CCN_IDX_MASK_ANY),
        CCN_EVENT_SBSX(rxdatflits, "dir=0,vc=3", CCN_IDX_MASK_ANY),
        CCN_EVENT_SBSX(txreqflits, "dir=1,vc=0", CCN_IDX_MASK_ANY),
        CCN_EVENT_SBSX(rxreqflits, "dir=0,vc=0", CCN_IDX_MASK_ANY),
        CCN_EVENT_SBSX(rxreqflits_order, "dir=0,vc=0,cmp_h=0x8000",
                        CCN_IDX_MASK_ORDER),
        CCN_EVENT_HNF(cache_miss, 0x1),
        CCN_EVENT_HNF(l3_sf_cache_access, 0x02),
        CCN_EVENT_HNF(cache_fill, 0x3),
        CCN_EVENT_HNF(pocq_retry, 0x4),
        CCN_EVENT_HNF(pocq_reqs_recvd, 0x5),
        CCN_EVENT_HNF(sf_hit, 0x6),
        CCN_EVENT_HNF(sf_evictions, 0x7),
        CCN_EVENT_HNF(snoops_sent, 0x8),
        CCN_EVENT_HNF(snoops_broadcast, 0x9),
        CCN_EVENT_HNF(l3_eviction, 0xa),
        CCN_EVENT_HNF(l3_fill_invalid_way, 0xb),
        CCN_EVENT_HNF(mc_retries, 0xc),
        CCN_EVENT_HNF(mc_reqs, 0xd),
        CCN_EVENT_HNF(qos_hh_retry, 0xe),
        CCN_EVENT_RNI(rdata_beats_p0, 0x1),
        CCN_EVENT_RNI(rdata_beats_p1, 0x2),
        CCN_EVENT_RNI(rdata_beats_p2, 0x3),
        CCN_EVENT_RNI(rxdat_flits, 0x4),
        CCN_EVENT_RNI(txdat_flits, 0x5),
        CCN_EVENT_RNI(txreq_flits, 0x6),
        CCN_EVENT_RNI(txreq_flits_retried, 0x7),
        CCN_EVENT_RNI(rrt_full, 0x8),
        CCN_EVENT_RNI(wrt_full, 0x9),
        CCN_EVENT_RNI(txreq_flits_replayed, 0xa),
        CCN_EVENT_XP(upload_starvation, 0x1),
        CCN_EVENT_XP(download_starvation, 0x2),
        CCN_EVENT_XP(respin, 0x3),
        CCN_EVENT_XP(valid_flit, 0x4),
        CCN_EVENT_XP(watchpoint, CCN_EVENT_WATCHPOINT),
        CCN_EVENT_SBAS(rdata_beats_p0, 0x1),
        CCN_EVENT_SBAS(rxdat_flits, 0x4),
        CCN_EVENT_SBAS(txdat_flits, 0x5),
        CCN_EVENT_SBAS(txreq_flits, 0x6),
        CCN_EVENT_SBAS(txreq_flits_retried, 0x7),
        CCN_EVENT_SBAS(rrt_full, 0x8),
        CCN_EVENT_SBAS(wrt_full, 0x9),
        CCN_EVENT_SBAS(txreq_flits_replayed, 0xa),
        CCN_EVENT_CYCLES(cycles),
};

/* Populated in arm_ccn_init() */
static struct attribute
                *arm_ccn_pmu_events_attrs[ARRAY_SIZE(arm_ccn_pmu_events) + 1];

static struct attribute_group arm_ccn_pmu_events_attr_group = {
        .name = "events",
        .is_visible = arm_ccn_pmu_events_is_visible,
        .attrs = arm_ccn_pmu_events_attrs,
};


static u64 *arm_ccn_pmu_get_cmp_mask(struct arm_ccn *ccn, const char *name)
{
        unsigned long i;

        if (WARN_ON(!name || !name[0] || !isxdigit(name[0]) || !name[1]))
                return NULL;
        i = isdigit(name[0]) ? name[0] - '0' : 0xa + tolower(name[0]) - 'a';

        switch (name[1]) {
        case 'l':
                return &ccn->dt.cmp_mask[i].l;
        case 'h':
                return &ccn->dt.cmp_mask[i].h;
        default:
                return NULL;
        }
}

static ssize_t arm_ccn_pmu_cmp_mask_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));
        u64 *mask = arm_ccn_pmu_get_cmp_mask(ccn, attr->attr.name);

        return mask ? snprintf(buf, PAGE_SIZE, "0x%016llx\n", *mask) : -EINVAL;
}

static ssize_t arm_ccn_pmu_cmp_mask_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));
        u64 *mask = arm_ccn_pmu_get_cmp_mask(ccn, attr->attr.name);
        int err = -EINVAL;

        if (mask)
                err = kstrtoull(buf, 0, mask);

        return err ? err : count;
}

#define CCN_CMP_MASK_ATTR(_name) \
        struct device_attribute arm_ccn_pmu_cmp_mask_attr_##_name = \
                        __ATTR(_name, S_IRUGO | S_IWUSR, \
                        arm_ccn_pmu_cmp_mask_show, arm_ccn_pmu_cmp_mask_store)

#define CCN_CMP_MASK_ATTR_RO(_name) \
        struct device_attribute arm_ccn_pmu_cmp_mask_attr_##_name = \
                        __ATTR(_name, S_IRUGO, arm_ccn_pmu_cmp_mask_show, NULL)

static CCN_CMP_MASK_ATTR(0l);
static CCN_CMP_MASK_ATTR(0h);
static CCN_CMP_MASK_ATTR(1l);
static CCN_CMP_MASK_ATTR(1h);
static CCN_CMP_MASK_ATTR(2l);
static CCN_CMP_MASK_ATTR(2h);
static CCN_CMP_MASK_ATTR(3l);
static CCN_CMP_MASK_ATTR(3h);
static CCN_CMP_MASK_ATTR(4l);
static CCN_CMP_MASK_ATTR(4h);
static CCN_CMP_MASK_ATTR(5l);
static CCN_CMP_MASK_ATTR(5h);
static CCN_CMP_MASK_ATTR(6l);
static CCN_CMP_MASK_ATTR(6h);
static CCN_CMP_MASK_ATTR(7l);
static CCN_CMP_MASK_ATTR(7h);
static CCN_CMP_MASK_ATTR_RO(8l);
static CCN_CMP_MASK_ATTR_RO(8h);
static CCN_CMP_MASK_ATTR_RO(9l);
static CCN_CMP_MASK_ATTR_RO(9h);
static CCN_CMP_MASK_ATTR_RO(al);
static CCN_CMP_MASK_ATTR_RO(ah);
static CCN_CMP_MASK_ATTR_RO(bl);
static CCN_CMP_MASK_ATTR_RO(bh);

static struct attribute *arm_ccn_pmu_cmp_mask_attrs[] = {
        &arm_ccn_pmu_cmp_mask_attr_0l.attr, &arm_ccn_pmu_cmp_mask_attr_0h.attr,
        &arm_ccn_pmu_cmp_mask_attr_1l.attr, &arm_ccn_pmu_cmp_mask_attr_1h.attr,
        &arm_ccn_pmu_cmp_mask_attr_2l.attr, &arm_ccn_pmu_cmp_mask_attr_2h.attr,
        &arm_ccn_pmu_cmp_mask_attr_3l.attr, &arm_ccn_pmu_cmp_mask_attr_3h.attr,
        &arm_ccn_pmu_cmp_mask_attr_4l.attr, &arm_ccn_pmu_cmp_mask_attr_4h.attr,
        &arm_ccn_pmu_cmp_mask_attr_5l.attr, &arm_ccn_pmu_cmp_mask_attr_5h.attr,
        &arm_ccn_pmu_cmp_mask_attr_6l.attr, &arm_ccn_pmu_cmp_mask_attr_6h.attr,
        &arm_ccn_pmu_cmp_mask_attr_7l.attr, &arm_ccn_pmu_cmp_mask_attr_7h.attr,
        &arm_ccn_pmu_cmp_mask_attr_8l.attr, &arm_ccn_pmu_cmp_mask_attr_8h.attr,
        &arm_ccn_pmu_cmp_mask_attr_9l.attr, &arm_ccn_pmu_cmp_mask_attr_9h.attr,
        &arm_ccn_pmu_cmp_mask_attr_al.attr, &arm_ccn_pmu_cmp_mask_attr_ah.attr,
        &arm_ccn_pmu_cmp_mask_attr_bl.attr, &arm_ccn_pmu_cmp_mask_attr_bh.attr,
        NULL
};

static struct attribute_group arm_ccn_pmu_cmp_mask_attr_group = {
        .name = "cmp_mask",
        .attrs = arm_ccn_pmu_cmp_mask_attrs,
};

static ssize_t arm_ccn_pmu_cpumask_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(dev_get_drvdata(dev));

        return cpumap_print_to_pagebuf(true, buf, &ccn->dt.cpu);
}

static struct device_attribute arm_ccn_pmu_cpumask_attr =
                __ATTR(cpumask, S_IRUGO, arm_ccn_pmu_cpumask_show, NULL);

static struct attribute *arm_ccn_pmu_cpumask_attrs[] = {
        &arm_ccn_pmu_cpumask_attr.attr,
        NULL,
};

static struct attribute_group arm_ccn_pmu_cpumask_attr_group = {
        .attrs = arm_ccn_pmu_cpumask_attrs,
};

/*
 * Default poll period is 10ms, which is way over the top anyway,
 * as in the worst case scenario (an event every cycle), with 1GHz
 * clocked bus, the smallest, 32 bit counter will overflow in
 * more than 4s.
 */
static unsigned int arm_ccn_pmu_poll_period_us = 10000;
module_param_named(pmu_poll_period_us, arm_ccn_pmu_poll_period_us, uint,
                S_IRUGO | S_IWUSR);

static ktime_t arm_ccn_pmu_timer_period(void)
{
        return ns_to_ktime((u64)arm_ccn_pmu_poll_period_us * 1000);
}


static const struct attribute_group *arm_ccn_pmu_attr_groups[] = {
        &arm_ccn_pmu_events_attr_group,
        &arm_ccn_pmu_format_attr_group,
        &arm_ccn_pmu_cmp_mask_attr_group,
        &arm_ccn_pmu_cpumask_attr_group,
        NULL
};


static int arm_ccn_pmu_alloc_bit(unsigned long *bitmap, unsigned long size)
{
        int bit;

        do {
                bit = find_first_zero_bit(bitmap, size);
                if (bit >= size)
                        return -EAGAIN;
        } while (test_and_set_bit(bit, bitmap));

        return bit;
}

/* All RN-I and RN-D nodes have identical PMUs */
static int arm_ccn_pmu_type_eq(u32 a, u32 b)
{
        if (a == b)
                return 1;

        switch (a) {
        case CCN_TYPE_RNI_1P:
        case CCN_TYPE_RNI_2P:
        case CCN_TYPE_RNI_3P:
        case CCN_TYPE_RND_1P:
        case CCN_TYPE_RND_2P:
        case CCN_TYPE_RND_3P:
                switch (b) {
                case CCN_TYPE_RNI_1P:
                case CCN_TYPE_RNI_2P:
                case CCN_TYPE_RNI_3P:
                case CCN_TYPE_RND_1P:
                case CCN_TYPE_RND_2P:
                case CCN_TYPE_RND_3P:
                        return 1;
                }
                break;
        }

        return 0;
}

static int arm_ccn_pmu_event_alloc(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        u32 node_xp, type, event_id;
        struct arm_ccn_component *source;
        int bit;

        node_xp = CCN_CONFIG_NODE(event->attr.config);
        type = CCN_CONFIG_TYPE(event->attr.config);
        event_id = CCN_CONFIG_EVENT(event->attr.config);

        /* Allocate the cycle counter */
        if (type == CCN_TYPE_CYCLES) {
                if (test_and_set_bit(CCN_IDX_PMU_CYCLE_COUNTER,
                                ccn->dt.pmu_counters_mask))
                        return -EAGAIN;

                hw->idx = CCN_IDX_PMU_CYCLE_COUNTER;
                ccn->dt.pmu_counters[CCN_IDX_PMU_CYCLE_COUNTER].event = event;

                return 0;
        }

        /* Allocate an event counter */
        hw->idx = arm_ccn_pmu_alloc_bit(ccn->dt.pmu_counters_mask,
                        CCN_NUM_PMU_EVENT_COUNTERS);
        if (hw->idx < 0) {
                dev_dbg(ccn->dev, "No more counters available!\n");
                return -EAGAIN;
        }

        if (type == CCN_TYPE_XP)
                source = &ccn->xp[node_xp];
        else
                source = &ccn->node[node_xp];
        ccn->dt.pmu_counters[hw->idx].source = source;

        /* Allocate an event source or a watchpoint */
        if (type == CCN_TYPE_XP && event_id == CCN_EVENT_WATCHPOINT)
                bit = arm_ccn_pmu_alloc_bit(source->xp.dt_cmp_mask,
                                CCN_NUM_XP_WATCHPOINTS);
        else
                bit = arm_ccn_pmu_alloc_bit(source->pmu_events_mask,
                                CCN_NUM_PMU_EVENTS);
        if (bit < 0) {
                dev_dbg(ccn->dev, "No more event sources/watchpoints on node/XP %d!\n",
                                node_xp);
                clear_bit(hw->idx, ccn->dt.pmu_counters_mask);
                return -EAGAIN;
        }
        hw->config_base = bit;

        ccn->dt.pmu_counters[hw->idx].event = event;

        return 0;
}

static void arm_ccn_pmu_event_release(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;

        if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER) {
                clear_bit(CCN_IDX_PMU_CYCLE_COUNTER, ccn->dt.pmu_counters_mask);
        } else {
                struct arm_ccn_component *source =
                                ccn->dt.pmu_counters[hw->idx].source;

                if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP &&
                                CCN_CONFIG_EVENT(event->attr.config) ==
                                CCN_EVENT_WATCHPOINT)
                        clear_bit(hw->config_base, source->xp.dt_cmp_mask);
                else
                        clear_bit(hw->config_base, source->pmu_events_mask);
                clear_bit(hw->idx, ccn->dt.pmu_counters_mask);
        }

        ccn->dt.pmu_counters[hw->idx].source = NULL;
        ccn->dt.pmu_counters[hw->idx].event = NULL;
}

static int arm_ccn_pmu_event_init(struct perf_event *event)
{
        struct arm_ccn *ccn;
        struct hw_perf_event *hw = &event->hw;
        u32 node_xp, type, event_id;
        int valid;
        int i;
        struct perf_event *sibling;

        if (event->attr.type != event->pmu->type)
                return -ENOENT;

        ccn = pmu_to_arm_ccn(event->pmu);

        if (hw->sample_period) {
                dev_warn(ccn->dev, "Sampling not supported!\n");
                return -EOPNOTSUPP;
        }

        if (has_branch_stack(event) || event->attr.exclude_user ||
                        event->attr.exclude_kernel || event->attr.exclude_hv ||
                        event->attr.exclude_idle || event->attr.exclude_host ||
                        event->attr.exclude_guest) {
                dev_warn(ccn->dev, "Can't exclude execution levels!\n");
                return -EINVAL;
        }

        if (event->cpu < 0) {
                dev_warn(ccn->dev, "Can't provide per-task data!\n");
                return -EOPNOTSUPP;
        }
        /*
         * Many perf core operations (eg. events rotation) operate on a
         * single CPU context. This is obvious for CPU PMUs, where one
         * expects the same sets of events being observed on all CPUs,
         * but can lead to issues for off-core PMUs, like CCN, where each
         * event could be theoretically assigned to a different CPU. To
         * mitigate this, we enforce CPU assignment to one, selected
         * processor (the one described in the "cpumask" attribute).
         */
        event->cpu = cpumask_first(&ccn->dt.cpu);

        node_xp = CCN_CONFIG_NODE(event->attr.config);
        type = CCN_CONFIG_TYPE(event->attr.config);
        event_id = CCN_CONFIG_EVENT(event->attr.config);

        /* Validate node/xp vs topology */
        switch (type) {
        case CCN_TYPE_MN:
                if (node_xp != ccn->mn_id) {
                        dev_warn(ccn->dev, "Invalid MN ID %d!\n", node_xp);
                        return -EINVAL;
                }
                break;
        case CCN_TYPE_XP:
                if (node_xp >= ccn->num_xps) {
                        dev_warn(ccn->dev, "Invalid XP ID %d!\n", node_xp);
                        return -EINVAL;
                }
                break;
        case CCN_TYPE_CYCLES:
                break;
        default:
                if (node_xp >= ccn->num_nodes) {
                        dev_warn(ccn->dev, "Invalid node ID %d!\n", node_xp);
                        return -EINVAL;
                }
                if (!arm_ccn_pmu_type_eq(type, ccn->node[node_xp].type)) {
                        dev_warn(ccn->dev, "Invalid type 0x%x for node %d!\n",
                                        type, node_xp);
                        return -EINVAL;
                }
                break;
        }

        /* Validate event ID vs available for the type */
        for (i = 0, valid = 0; i < ARRAY_SIZE(arm_ccn_pmu_events) && !valid;
                        i++) {
                struct arm_ccn_pmu_event *e = &arm_ccn_pmu_events[i];
                u32 port = CCN_CONFIG_PORT(event->attr.config);
                u32 vc = CCN_CONFIG_VC(event->attr.config);

                if (!arm_ccn_pmu_type_eq(type, e->type))
                        continue;
                if (event_id != e->event)
                        continue;
                if (e->num_ports && port >= e->num_ports) {
                        dev_warn(ccn->dev, "Invalid port %d for node/XP %d!\n",
                                        port, node_xp);
                        return -EINVAL;
                }
                if (e->num_vcs && vc >= e->num_vcs) {
                        dev_warn(ccn->dev, "Invalid vc %d for node/XP %d!\n",
                                        vc, node_xp);
                        return -EINVAL;
                }
                valid = 1;
        }
        if (!valid) {
                dev_warn(ccn->dev, "Invalid event 0x%x for node/XP %d!\n",
                                event_id, node_xp);
                return -EINVAL;
        }

        /* Watchpoint-based event for a node is actually set on XP */
        if (event_id == CCN_EVENT_WATCHPOINT && type != CCN_TYPE_XP) {
                u32 port;

                type = CCN_TYPE_XP;
                port = arm_ccn_node_to_xp_port(node_xp);
                node_xp = arm_ccn_node_to_xp(node_xp);

                arm_ccn_pmu_config_set(&event->attr.config,
                                node_xp, type, port);
        }

        /*
         * We must NOT create groups containing mixed PMUs, although software
         * events are acceptable (for example to create a CCN group
         * periodically read when a hrtimer aka cpu-clock leader triggers).
         */
        if (event->group_leader->pmu != event->pmu &&
                        !is_software_event(event->group_leader))
                return -EINVAL;

        list_for_each_entry(sibling, &event->group_leader->sibling_list,
                        group_entry)
                if (sibling->pmu != event->pmu &&
                                !is_software_event(sibling))
                        return -EINVAL;

        return 0;
}

static u64 arm_ccn_pmu_read_counter(struct arm_ccn *ccn, int idx)
{
        u64 res;

        if (idx == CCN_IDX_PMU_CYCLE_COUNTER) {
#ifdef readq
                res = readq(ccn->dt.base + CCN_DT_PMCCNTR);
#else
                /* 40 bit counter, can do snapshot and read in two parts */
                writel(0x1, ccn->dt.base + CCN_DT_PMSR_REQ);
                while (!(readl(ccn->dt.base + CCN_DT_PMSR) & 0x1))
                        ;
                writel(0x1, ccn->dt.base + CCN_DT_PMSR_CLR);
                res = readl(ccn->dt.base + CCN_DT_PMCCNTRSR + 4) & 0xff;
                res <<= 32;
                res |= readl(ccn->dt.base + CCN_DT_PMCCNTRSR);
#endif
        } else {
                res = readl(ccn->dt.base + CCN_DT_PMEVCNT(idx));
        }

        return res;
}

static void arm_ccn_pmu_event_update(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        u64 prev_count, new_count, mask;

        do {
                prev_count = local64_read(&hw->prev_count);
                new_count = arm_ccn_pmu_read_counter(ccn, hw->idx);
        } while (local64_xchg(&hw->prev_count, new_count) != prev_count);

        mask = (1LLU << (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER ? 40 : 32)) - 1;

        local64_add((new_count - prev_count) & mask, &event->count);
}

static void arm_ccn_pmu_xp_dt_config(struct perf_event *event, int enable)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        struct arm_ccn_component *xp;
        u32 val, dt_cfg;

        /* Nothing to do for cycle counter */
        if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER)
                return;

        if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP)
                xp = &ccn->xp[CCN_CONFIG_XP(event->attr.config)];
        else
                xp = &ccn->xp[arm_ccn_node_to_xp(
                                CCN_CONFIG_NODE(event->attr.config))];

        if (enable)
                dt_cfg = hw->event_base;
        else
                dt_cfg = CCN_XP_DT_CONFIG__DT_CFG__PASS_THROUGH;

        spin_lock(&ccn->dt.config_lock);

        val = readl(xp->base + CCN_XP_DT_CONFIG);
        val &= ~(CCN_XP_DT_CONFIG__DT_CFG__MASK <<
                        CCN_XP_DT_CONFIG__DT_CFG__SHIFT(hw->idx));
        val |= dt_cfg << CCN_XP_DT_CONFIG__DT_CFG__SHIFT(hw->idx);
        writel(val, xp->base + CCN_XP_DT_CONFIG);

        spin_unlock(&ccn->dt.config_lock);
}

static void arm_ccn_pmu_event_start(struct perf_event *event, int flags)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;

        local64_set(&event->hw.prev_count,
                        arm_ccn_pmu_read_counter(ccn, hw->idx));
        hw->state = 0;

        /* Set the DT bus input, engaging the counter */
        arm_ccn_pmu_xp_dt_config(event, 1);
}

static void arm_ccn_pmu_event_stop(struct perf_event *event, int flags)
{
        struct hw_perf_event *hw = &event->hw;

        /* Disable counting, setting the DT bus to pass-through mode */
        arm_ccn_pmu_xp_dt_config(event, 0);

        if (flags & PERF_EF_UPDATE)
                arm_ccn_pmu_event_update(event);

        hw->state |= PERF_HES_STOPPED;
}

static void arm_ccn_pmu_xp_watchpoint_config(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        struct arm_ccn_component *source =
                        ccn->dt.pmu_counters[hw->idx].source;
        unsigned long wp = hw->config_base;
        u32 val;
        u64 cmp_l = event->attr.config1;
        u64 cmp_h = event->attr.config2;
        u64 mask_l = ccn->dt.cmp_mask[CCN_CONFIG_MASK(event->attr.config)].l;
        u64 mask_h = ccn->dt.cmp_mask[CCN_CONFIG_MASK(event->attr.config)].h;

        hw->event_base = CCN_XP_DT_CONFIG__DT_CFG__WATCHPOINT(wp);

        /* Direction (RX/TX), device (port) & virtual channel */
        val = readl(source->base + CCN_XP_DT_INTERFACE_SEL);
        val &= ~(CCN_XP_DT_INTERFACE_SEL__DT_IO_SEL__MASK <<
                        CCN_XP_DT_INTERFACE_SEL__DT_IO_SEL__SHIFT(wp));
        val |= CCN_CONFIG_DIR(event->attr.config) <<
                        CCN_XP_DT_INTERFACE_SEL__DT_IO_SEL__SHIFT(wp);
        val &= ~(CCN_XP_DT_INTERFACE_SEL__DT_DEV_SEL__MASK <<
                        CCN_XP_DT_INTERFACE_SEL__DT_DEV_SEL__SHIFT(wp));
        val |= CCN_CONFIG_PORT(event->attr.config) <<
                        CCN_XP_DT_INTERFACE_SEL__DT_DEV_SEL__SHIFT(wp);
        val &= ~(CCN_XP_DT_INTERFACE_SEL__DT_VC_SEL__MASK <<
                        CCN_XP_DT_INTERFACE_SEL__DT_VC_SEL__SHIFT(wp));
        val |= CCN_CONFIG_VC(event->attr.config) <<
                        CCN_XP_DT_INTERFACE_SEL__DT_VC_SEL__SHIFT(wp);
        writel(val, source->base + CCN_XP_DT_INTERFACE_SEL);

        /* Comparison values */
        writel(cmp_l & 0xffffffff, source->base + CCN_XP_DT_CMP_VAL_L(wp));
        writel((cmp_l >> 32) & 0x7fffffff,
                        source->base + CCN_XP_DT_CMP_VAL_L(wp) + 4);
        writel(cmp_h & 0xffffffff, source->base + CCN_XP_DT_CMP_VAL_H(wp));
        writel((cmp_h >> 32) & 0x0fffffff,
                        source->base + CCN_XP_DT_CMP_VAL_H(wp) + 4);

        /* Mask */
        writel(mask_l & 0xffffffff, source->base + CCN_XP_DT_CMP_MASK_L(wp));
        writel((mask_l >> 32) & 0x7fffffff,
                        source->base + CCN_XP_DT_CMP_MASK_L(wp) + 4);
        writel(mask_h & 0xffffffff, source->base + CCN_XP_DT_CMP_MASK_H(wp));

        writel((mask_h >> 32) & 0x0fffffff,
                        source->base + CCN_XP_DT_CMP_MASK_H(wp) + 4);
}

static void arm_ccn_pmu_xp_event_config(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        struct arm_ccn_component *source =
                        ccn->dt.pmu_counters[hw->idx].source;
        u32 val, id;

        hw->event_base = CCN_XP_DT_CONFIG__DT_CFG__XP_PMU_EVENT(hw->config_base);

        id = (CCN_CONFIG_VC(event->attr.config) << 4) |
                        (CCN_CONFIG_BUS(event->attr.config) << 3) |
                        (CCN_CONFIG_EVENT(event->attr.config) << 0);

        val = readl(source->base + CCN_XP_PMU_EVENT_SEL);
        val &= ~(CCN_XP_PMU_EVENT_SEL__ID__MASK <<
                        CCN_XP_PMU_EVENT_SEL__ID__SHIFT(hw->config_base));
        val |= id << CCN_XP_PMU_EVENT_SEL__ID__SHIFT(hw->config_base);
        writel(val, source->base + CCN_XP_PMU_EVENT_SEL);
}

static void arm_ccn_pmu_node_event_config(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        struct arm_ccn_component *source =
                        ccn->dt.pmu_counters[hw->idx].source;
        u32 type = CCN_CONFIG_TYPE(event->attr.config);
        u32 val, port;

        port = arm_ccn_node_to_xp_port(CCN_CONFIG_NODE(event->attr.config));
        hw->event_base = CCN_XP_DT_CONFIG__DT_CFG__DEVICE_PMU_EVENT(port,
                        hw->config_base);

        /* These *_event_sel regs should be identical, but let's make sure... */
        BUILD_BUG_ON(CCN_HNF_PMU_EVENT_SEL != CCN_SBAS_PMU_EVENT_SEL);
        BUILD_BUG_ON(CCN_SBAS_PMU_EVENT_SEL != CCN_RNI_PMU_EVENT_SEL);
        BUILD_BUG_ON(CCN_HNF_PMU_EVENT_SEL__ID__SHIFT(1) !=
                        CCN_SBAS_PMU_EVENT_SEL__ID__SHIFT(1));
        BUILD_BUG_ON(CCN_SBAS_PMU_EVENT_SEL__ID__SHIFT(1) !=
                        CCN_RNI_PMU_EVENT_SEL__ID__SHIFT(1));
        BUILD_BUG_ON(CCN_HNF_PMU_EVENT_SEL__ID__MASK !=
                        CCN_SBAS_PMU_EVENT_SEL__ID__MASK);
        BUILD_BUG_ON(CCN_SBAS_PMU_EVENT_SEL__ID__MASK !=
                        CCN_RNI_PMU_EVENT_SEL__ID__MASK);
        if (WARN_ON(type != CCN_TYPE_HNF && type != CCN_TYPE_SBAS &&
                        !arm_ccn_pmu_type_eq(type, CCN_TYPE_RNI_3P)))
                return;

        /* Set the event id for the pre-allocated counter */
        val = readl(source->base + CCN_HNF_PMU_EVENT_SEL);
        val &= ~(CCN_HNF_PMU_EVENT_SEL__ID__MASK <<
                CCN_HNF_PMU_EVENT_SEL__ID__SHIFT(hw->config_base));
        val |= CCN_CONFIG_EVENT(event->attr.config) <<
                CCN_HNF_PMU_EVENT_SEL__ID__SHIFT(hw->config_base);
        writel(val, source->base + CCN_HNF_PMU_EVENT_SEL);
}

static void arm_ccn_pmu_event_config(struct perf_event *event)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);
        struct hw_perf_event *hw = &event->hw;
        u32 xp, offset, val;

        /* Cycle counter requires no setup */
        if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER)
                return;

        if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP)
                xp = CCN_CONFIG_XP(event->attr.config);
        else
                xp = arm_ccn_node_to_xp(CCN_CONFIG_NODE(event->attr.config));

        spin_lock(&ccn->dt.config_lock);

        /* Set the DT bus "distance" register */
        offset = (hw->idx / 4) * 4;
        val = readl(ccn->dt.base + CCN_DT_ACTIVE_DSM + offset);
        val &= ~(CCN_DT_ACTIVE_DSM__DSM_ID__MASK <<
                        CCN_DT_ACTIVE_DSM__DSM_ID__SHIFT(hw->idx % 4));
        val |= xp << CCN_DT_ACTIVE_DSM__DSM_ID__SHIFT(hw->idx % 4);
        writel(val, ccn->dt.base + CCN_DT_ACTIVE_DSM + offset);

        if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP) {
                if (CCN_CONFIG_EVENT(event->attr.config) ==
                                CCN_EVENT_WATCHPOINT)
                        arm_ccn_pmu_xp_watchpoint_config(event);
                else
                        arm_ccn_pmu_xp_event_config(event);
        } else {
                arm_ccn_pmu_node_event_config(event);
        }

        spin_unlock(&ccn->dt.config_lock);
}

static int arm_ccn_pmu_active_counters(struct arm_ccn *ccn)
{
        return bitmap_weight(ccn->dt.pmu_counters_mask,
                             CCN_NUM_PMU_EVENT_COUNTERS + 1);
}

static int arm_ccn_pmu_event_add(struct perf_event *event, int flags)
{
        int err;
        struct hw_perf_event *hw = &event->hw;
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);

        err = arm_ccn_pmu_event_alloc(event);
        if (err)
                return err;

        /*
         * Pin the timer, so that the overflows are handled by the chosen
         * event->cpu (this is the same one as presented in "cpumask"
         * attribute).
         */
        if (!ccn->irq && arm_ccn_pmu_active_counters(ccn) == 1)
                hrtimer_start(&ccn->dt.hrtimer, arm_ccn_pmu_timer_period(),
                              HRTIMER_MODE_REL_PINNED);

        arm_ccn_pmu_event_config(event);

        hw->state = PERF_HES_STOPPED;

        if (flags & PERF_EF_START)
                arm_ccn_pmu_event_start(event, PERF_EF_UPDATE);

        return 0;
}

static void arm_ccn_pmu_event_del(struct perf_event *event, int flags)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(event->pmu);

        arm_ccn_pmu_event_stop(event, PERF_EF_UPDATE);

        arm_ccn_pmu_event_release(event);

        if (!ccn->irq && arm_ccn_pmu_active_counters(ccn) == 0)
                hrtimer_cancel(&ccn->dt.hrtimer);
}

static void arm_ccn_pmu_event_read(struct perf_event *event)
{
        arm_ccn_pmu_event_update(event);
}

static void arm_ccn_pmu_enable(struct pmu *pmu)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(pmu);

        u32 val = readl(ccn->dt.base + CCN_DT_PMCR);
        val |= CCN_DT_PMCR__PMU_EN;
        writel(val, ccn->dt.base + CCN_DT_PMCR);
}

static void arm_ccn_pmu_disable(struct pmu *pmu)
{
        struct arm_ccn *ccn = pmu_to_arm_ccn(pmu);

        u32 val = readl(ccn->dt.base + CCN_DT_PMCR);
        val &= ~CCN_DT_PMCR__PMU_EN;
        writel(val, ccn->dt.base + CCN_DT_PMCR);
}

static irqreturn_t arm_ccn_pmu_overflow_handler(struct arm_ccn_dt *dt)
{
        u32 pmovsr = readl(dt->base + CCN_DT_PMOVSR);
        int idx;

        if (!pmovsr)
                return IRQ_NONE;

        writel(pmovsr, dt->base + CCN_DT_PMOVSR_CLR);

        BUILD_BUG_ON(CCN_IDX_PMU_CYCLE_COUNTER != CCN_NUM_PMU_EVENT_COUNTERS);

        for (idx = 0; idx < CCN_NUM_PMU_EVENT_COUNTERS + 1; idx++) {
                struct perf_event *event = dt->pmu_counters[idx].event;
                int overflowed = pmovsr & BIT(idx);

                WARN_ON_ONCE(overflowed && !event &&
                                idx != CCN_IDX_PMU_CYCLE_COUNTER);

                if (!event || !overflowed)
                        continue;

                arm_ccn_pmu_event_update(event);
        }

        return IRQ_HANDLED;
}

static enum hrtimer_restart arm_ccn_pmu_timer_handler(struct hrtimer *hrtimer)
{
        struct arm_ccn_dt *dt = container_of(hrtimer, struct arm_ccn_dt,
                        hrtimer);
        unsigned long flags;

        local_irq_save(flags);
        arm_ccn_pmu_overflow_handler(dt);
        local_irq_restore(flags);

        hrtimer_forward_now(hrtimer, arm_ccn_pmu_timer_period());
        return HRTIMER_RESTART;
}


static int arm_ccn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
{
        struct arm_ccn_dt *dt = hlist_entry_safe(node, struct arm_ccn_dt, node);
        struct arm_ccn *ccn = container_of(dt, struct arm_ccn, dt);
        unsigned int target;

        if (!cpumask_test_and_clear_cpu(cpu, &dt->cpu))
                return 0;
        target = cpumask_any_but(cpu_online_mask, cpu);
        if (target >= nr_cpu_ids)
                return 0;
        perf_pmu_migrate_context(&dt->pmu, cpu, target);
        cpumask_set_cpu(target, &dt->cpu);
        if (ccn->irq)
                WARN_ON(irq_set_affinity_hint(ccn->irq, &dt->cpu) != 0);
        return 0;
}

static DEFINE_IDA(arm_ccn_pmu_ida);

static int arm_ccn_pmu_init(struct arm_ccn *ccn)
{
        int i;
        char *name;
        int err;

        /* Initialize DT subsystem */
        ccn->dt.base = ccn->base + CCN_REGION_SIZE;
        spin_lock_init(&ccn->dt.config_lock);
        writel(CCN_DT_PMOVSR_CLR__MASK, ccn->dt.base + CCN_DT_PMOVSR_CLR);
        writel(CCN_DT_CTL__DT_EN, ccn->dt.base + CCN_DT_CTL);
        writel(CCN_DT_PMCR__OVFL_INTR_EN | CCN_DT_PMCR__PMU_EN,
                        ccn->dt.base + CCN_DT_PMCR);
        writel(0x1, ccn->dt.base + CCN_DT_PMSR_CLR);
        for (i = 0; i < ccn->num_xps; i++) {
                writel(0, ccn->xp[i].base + CCN_XP_DT_CONFIG);
                writel((CCN_XP_DT_CONTROL__WP_ARM_SEL__ALWAYS <<
                                CCN_XP_DT_CONTROL__WP_ARM_SEL__SHIFT(0)) |
                                (CCN_XP_DT_CONTROL__WP_ARM_SEL__ALWAYS <<
                                CCN_XP_DT_CONTROL__WP_ARM_SEL__SHIFT(1)) |
                                CCN_XP_DT_CONTROL__DT_ENABLE,
                                ccn->xp[i].base + CCN_XP_DT_CONTROL);
        }
        ccn->dt.cmp_mask[CCN_IDX_MASK_ANY].l = ~0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_ANY].h = ~0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_EXACT].l = 0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_EXACT].h = 0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_ORDER].l = ~0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_ORDER].h = ~(0x1 << 15);
        ccn->dt.cmp_mask[CCN_IDX_MASK_OPCODE].l = ~0;
        ccn->dt.cmp_mask[CCN_IDX_MASK_OPCODE].h = ~(0x1f << 9);

        /* Get a convenient /sys/event_source/devices/ name */
        ccn->dt.id = ida_simple_get(&arm_ccn_pmu_ida, 0, 0, GFP_KERNEL);
        if (ccn->dt.id == 0) {
                name = "ccn";
        } else {
                int len = snprintf(NULL, 0, "ccn_%d", ccn->dt.id);

                name = devm_kzalloc(ccn->dev, len + 1, GFP_KERNEL);
                snprintf(name, len + 1, "ccn_%d", ccn->dt.id);
        }

        /* Perf driver registration */
        ccn->dt.pmu = (struct pmu) {
                .attr_groups = arm_ccn_pmu_attr_groups,
                .task_ctx_nr = perf_invalid_context,
                .event_init = arm_ccn_pmu_event_init,
                .add = arm_ccn_pmu_event_add,
                .del = arm_ccn_pmu_event_del,
                .start = arm_ccn_pmu_event_start,
                .stop = arm_ccn_pmu_event_stop,
                .read = arm_ccn_pmu_event_read,
                .pmu_enable = arm_ccn_pmu_enable,
                .pmu_disable = arm_ccn_pmu_disable,
        };

        /* No overflow interrupt? Have to use a timer instead. */
        if (!ccn->irq) {
                dev_info(ccn->dev, "No access to interrupts, using timer.\n");
                hrtimer_init(&ccn->dt.hrtimer, CLOCK_MONOTONIC,
                                HRTIMER_MODE_REL);
                ccn->dt.hrtimer.function = arm_ccn_pmu_timer_handler;
        }

        /* Pick one CPU which we will use to collect data from CCN... */
        cpumask_set_cpu(smp_processor_id(), &ccn->dt.cpu);

        /* Also make sure that the overflow interrupt is handled by this CPU */
        if (ccn->irq) {
                err = irq_set_affinity_hint(ccn->irq, &ccn->dt.cpu);
                if (err) {
                        dev_err(ccn->dev, "Failed to set interrupt affinity!\n");
                        goto error_set_affinity;
                }
        }

        err = perf_pmu_register(&ccn->dt.pmu, name, -1);
        if (err)
                goto error_pmu_register;

        cpuhp_state_add_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
                                         &ccn->dt.node);
        return 0;

error_pmu_register:
error_set_affinity:
        ida_simple_remove(&arm_ccn_pmu_ida, ccn->dt.id);
        for (i = 0; i < ccn->num_xps; i++)
                writel(0, ccn->xp[i].base + CCN_XP_DT_CONTROL);
        writel(0, ccn->dt.base + CCN_DT_PMCR);
        return err;
}

static void arm_ccn_pmu_cleanup(struct arm_ccn *ccn)
{
        int i;

        cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_CCN_ONLINE,
                                            &ccn->dt.node);
        if (ccn->irq)
                irq_set_affinity_hint(ccn->irq, NULL);
        for (i = 0; i < ccn->num_xps; i++)
                writel(0, ccn->xp[i].base + CCN_XP_DT_CONTROL);
        writel(0, ccn->dt.base + CCN_DT_PMCR);
        perf_pmu_unregister(&ccn->dt.pmu);
        ida_simple_remove(&arm_ccn_pmu_ida, ccn->dt.id);
}

static int arm_ccn_for_each_valid_region(struct arm_ccn *ccn,
                int (*callback)(struct arm_ccn *ccn, int region,
                void __iomem *base, u32 type, u32 id))
{
        int region;

        for (region = 0; region < CCN_NUM_REGIONS; region++) {
                u32 val, type, id;
                void __iomem *base;
                int err;

                val = readl(ccn->base + CCN_MN_OLY_COMP_LIST_63_0 +
                                4 * (region / 32));
                if (!(val & (1 << (region % 32))))
                        continue;

                base = ccn->base + region * CCN_REGION_SIZE;
                val = readl(base + CCN_ALL_OLY_ID);
                type = (val >> CCN_ALL_OLY_ID__OLY_ID__SHIFT) &
                                CCN_ALL_OLY_ID__OLY_ID__MASK;
                id = (val >> CCN_ALL_OLY_ID__NODE_ID__SHIFT) &
                                CCN_ALL_OLY_ID__NODE_ID__MASK;

                err = callback(ccn, region, base, type, id);
                if (err)
                        return err;
        }

        return 0;
}

static int arm_ccn_get_nodes_num(struct arm_ccn *ccn, int region,
                void __iomem *base, u32 type, u32 id)
{

        if (type == CCN_TYPE_XP && id >= ccn->num_xps)
                ccn->num_xps = id + 1;
        else if (id >= ccn->num_nodes)
                ccn->num_nodes = id + 1;

        return 0;
}

static int arm_ccn_init_nodes(struct arm_ccn *ccn, int region,
                void __iomem *base, u32 type, u32 id)
{
        struct arm_ccn_component *component;

        dev_dbg(ccn->dev, "Region %d: id=%u, type=0x%02x\n", region, id, type);

        switch (type) {
        case CCN_TYPE_MN:
                ccn->mn_id = id;
                return 0;
        case CCN_TYPE_DT:
                return 0;
        case CCN_TYPE_XP:
                component = &ccn->xp[id];
                break;
        case CCN_TYPE_SBSX:
                ccn->sbsx_present = 1;
                component = &ccn->node[id];
                break;
        case CCN_TYPE_SBAS:
                ccn->sbas_present = 1;
                /* Fall-through */
        default:
                component = &ccn->node[id];
                break;
        }

        component->base = base;
        component->type = type;

        return 0;
}


static irqreturn_t arm_ccn_error_handler(struct arm_ccn *ccn,
                const u32 *err_sig_val)
{
        /* This should be really handled by firmware... */
        dev_err(ccn->dev, "Error reported in %08x%08x%08x%08x%08x%08x.\n",
                        err_sig_val[5], err_sig_val[4], err_sig_val[3],
                        err_sig_val[2], err_sig_val[1], err_sig_val[0]);
        dev_err(ccn->dev, "Disabling interrupt generation for all errors.\n");
        writel(CCN_MN_ERRINT_STATUS__ALL_ERRORS__DISABLE,
                        ccn->base + CCN_MN_ERRINT_STATUS);

        return IRQ_HANDLED;
}


static irqreturn_t arm_ccn_irq_handler(int irq, void *dev_id)
{
        irqreturn_t res = IRQ_NONE;
        struct arm_ccn *ccn = dev_id;
        u32 err_sig_val[6];
        u32 err_or;
        int i;

        /* PMU overflow is a special case */
        err_or = err_sig_val[0] = readl(ccn->base + CCN_MN_ERR_SIG_VAL_63_0);
        if (err_or & CCN_MN_ERR_SIG_VAL_63_0__DT) {
                err_or &= ~CCN_MN_ERR_SIG_VAL_63_0__DT;
                res = arm_ccn_pmu_overflow_handler(&ccn->dt);
        }

        /* Have to read all err_sig_vals to clear them */
        for (i = 1; i < ARRAY_SIZE(err_sig_val); i++) {
                err_sig_val[i] = readl(ccn->base +
                                CCN_MN_ERR_SIG_VAL_63_0 + i * 4);
                err_or |= err_sig_val[i];
        }
        if (err_or)
                res |= arm_ccn_error_handler(ccn, err_sig_val);

        if (res != IRQ_NONE)
                writel(CCN_MN_ERRINT_STATUS__INTREQ__DESSERT,
                                ccn->base + CCN_MN_ERRINT_STATUS);

        return res;
}


static int arm_ccn_probe(struct platform_device *pdev)
{
        struct arm_ccn *ccn;
        struct resource *res;
        unsigned int irq;
        int err;

        ccn = devm_kzalloc(&pdev->dev, sizeof(*ccn), GFP_KERNEL);
        if (!ccn)
                return -ENOMEM;
        ccn->dev = &pdev->dev;
        platform_set_drvdata(pdev, ccn);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -EINVAL;

        if (!devm_request_mem_region(ccn->dev, res->start,
                        resource_size(res), pdev->name))
                return -EBUSY;

        ccn->base = devm_ioremap(ccn->dev, res->start,
                                resource_size(res));
        if (!ccn->base)
                return -EFAULT;

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (!res)
                return -EINVAL;
        irq = res->start;

        /* Check if we can use the interrupt */
        writel(CCN_MN_ERRINT_STATUS__PMU_EVENTS__DISABLE,
                        ccn->base + CCN_MN_ERRINT_STATUS);
        if (readl(ccn->base + CCN_MN_ERRINT_STATUS) &
                        CCN_MN_ERRINT_STATUS__PMU_EVENTS__DISABLED) {
                /* Can set 'disable' bits, so can acknowledge interrupts */
                writel(CCN_MN_ERRINT_STATUS__PMU_EVENTS__ENABLE,
                                ccn->base + CCN_MN_ERRINT_STATUS);
                err = devm_request_irq(ccn->dev, irq, arm_ccn_irq_handler,
                                       IRQF_NOBALANCING | IRQF_NO_THREAD,
                                       dev_name(ccn->dev), ccn);
                if (err)
                        return err;

                ccn->irq = irq;
        }


        /* Build topology */

        err = arm_ccn_for_each_valid_region(ccn, arm_ccn_get_nodes_num);
        if (err)
                return err;

        ccn->node = devm_kzalloc(ccn->dev, sizeof(*ccn->node) * ccn->num_nodes,
                GFP_KERNEL);
        ccn->xp = devm_kzalloc(ccn->dev, sizeof(*ccn->node) * ccn->num_xps,
                GFP_KERNEL);
        if (!ccn->node || !ccn->xp)
                return -ENOMEM;

        err = arm_ccn_for_each_valid_region(ccn, arm_ccn_init_nodes);
        if (err)
                return err;

        return arm_ccn_pmu_init(ccn);
}

static int arm_ccn_remove(struct platform_device *pdev)
{
        struct arm_ccn *ccn = platform_get_drvdata(pdev);

        arm_ccn_pmu_cleanup(ccn);

        return 0;
}

static const struct of_device_id arm_ccn_match[] = {
        { .compatible = "arm,ccn-504", },
        {},
};

static struct platform_driver arm_ccn_driver = {
        .driver = {
                .name = "arm-ccn",
                .of_match_table = arm_ccn_match,
        },
        .probe = arm_ccn_probe,
        .remove = arm_ccn_remove,
};

static int __init arm_ccn_init(void)
{
        int i, ret;

        ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCN_ONLINE,
                                      "AP_PERF_ARM_CCN_ONLINE", NULL,
                                      arm_ccn_pmu_offline_cpu);
        if (ret)
                return ret;

        for (i = 0; i < ARRAY_SIZE(arm_ccn_pmu_events); i++)
                arm_ccn_pmu_events_attrs[i] = &arm_ccn_pmu_events[i].attr.attr;

        return platform_driver_register(&arm_ccn_driver);
}

static void __exit arm_ccn_exit(void)
{
        cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CCN_ONLINE);
        platform_driver_unregister(&arm_ccn_driver);
}

module_init(arm_ccn_init);
module_exit(arm_ccn_exit);

MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
MODULE_LICENSE("GPL");