/*
 * Copyright 2012 Tilera Corporation. All Rights Reserved.
 *
 *   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, version 2.
 *
 *   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, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

/*
 * Implementation of mpipe gxio calls.
 */

#include <linux/errno.h>
#include <linux/io.h>
#include <linux/module.h>

#include <gxio/iorpc_globals.h>
#include <gxio/iorpc_mpipe.h>
#include <gxio/iorpc_mpipe_info.h>
#include <gxio/kiorpc.h>
#include <gxio/mpipe.h>

/* HACK: Avoid pointless "shadow" warnings. */
#define link link_shadow

int gxio_mpipe_init(gxio_mpipe_context_t *context, unsigned int mpipe_index)
{
        char file[32];

        int fd;
        int i;

        snprintf(file, sizeof(file), "mpipe/%d/iorpc", mpipe_index);
        fd = hv_dev_open((HV_VirtAddr) file, 0);
        if (fd < 0) {
                if (fd >= GXIO_ERR_MIN && fd <= GXIO_ERR_MAX)
                        return fd;
                else
                        return -ENODEV;
        }

        context->fd = fd;

        /* Map in the MMIO space. */
        context->mmio_cfg_base = (void __force *)
                iorpc_ioremap(fd, HV_MPIPE_CONFIG_MMIO_OFFSET,
                              HV_MPIPE_CONFIG_MMIO_SIZE);
        if (context->mmio_cfg_base == NULL)
                goto cfg_failed;

        context->mmio_fast_base = (void __force *)
                iorpc_ioremap(fd, HV_MPIPE_FAST_MMIO_OFFSET,
                              HV_MPIPE_FAST_MMIO_SIZE);
        if (context->mmio_fast_base == NULL)
                goto fast_failed;

        /* Initialize the stacks. */
        for (i = 0; i < 8; i++)
                context->__stacks.stacks[i] = 255;

        return 0;

      fast_failed:
        iounmap((void __force __iomem *)(context->mmio_cfg_base));
      cfg_failed:
        hv_dev_close(context->fd);
        return -ENODEV;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_init);

int gxio_mpipe_destroy(gxio_mpipe_context_t *context)
{
        iounmap((void __force __iomem *)(context->mmio_cfg_base));
        iounmap((void __force __iomem *)(context->mmio_fast_base));
        return hv_dev_close(context->fd);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_destroy);

static int16_t gxio_mpipe_buffer_sizes[8] =
        { 128, 256, 512, 1024, 1664, 4096, 10368, 16384 };

gxio_mpipe_buffer_size_enum_t gxio_mpipe_buffer_size_to_buffer_size_enum(size_t
                                                                         size)
{
        int i;
        for (i = 0; i < 7; i++)
                if (size <= gxio_mpipe_buffer_sizes[i])
                        break;
        return i;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_buffer_size_to_buffer_size_enum);

size_t gxio_mpipe_buffer_size_enum_to_buffer_size(gxio_mpipe_buffer_size_enum_t
                                                  buffer_size_enum)
{
        if (buffer_size_enum > 7)
                buffer_size_enum = 7;

        return gxio_mpipe_buffer_sizes[buffer_size_enum];
}

EXPORT_SYMBOL_GPL(gxio_mpipe_buffer_size_enum_to_buffer_size);

size_t gxio_mpipe_calc_buffer_stack_bytes(unsigned long buffers)
{
        const int BUFFERS_PER_LINE = 12;

        /* Count the number of cachlines. */
        unsigned long lines =
                (buffers + BUFFERS_PER_LINE - 1) / BUFFERS_PER_LINE;

        /* Convert to bytes. */
        return lines * CHIP_L2_LINE_SIZE();
}

EXPORT_SYMBOL_GPL(gxio_mpipe_calc_buffer_stack_bytes);

int gxio_mpipe_init_buffer_stack(gxio_mpipe_context_t *context,
                                 unsigned int stack,
                                 gxio_mpipe_buffer_size_enum_t
                                 buffer_size_enum, void *mem, size_t mem_size,
                                 unsigned int mem_flags)
{
        int result;

        memset(mem, 0, mem_size);

        result = gxio_mpipe_init_buffer_stack_aux(context, mem, mem_size,
                                                  mem_flags, stack,
                                                  buffer_size_enum);
        if (result < 0)
                return result;

        /* Save the stack. */
        context->__stacks.stacks[buffer_size_enum] = stack;

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_init_buffer_stack);

int gxio_mpipe_init_notif_ring(gxio_mpipe_context_t *context,
                               unsigned int ring,
                               void *mem, size_t mem_size,
                               unsigned int mem_flags)
{
        return gxio_mpipe_init_notif_ring_aux(context, mem, mem_size,
                                              mem_flags, ring);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_init_notif_ring);

int gxio_mpipe_init_notif_group_and_buckets(gxio_mpipe_context_t *context,
                                            unsigned int group,
                                            unsigned int ring,
                                            unsigned int num_rings,
                                            unsigned int bucket,
                                            unsigned int num_buckets,
                                            gxio_mpipe_bucket_mode_t mode)
{
        int i;
        int result;

        gxio_mpipe_bucket_info_t bucket_info = { {
                                                  .group = group,
                                                  .mode = mode,
                                                  }
        };

        gxio_mpipe_notif_group_bits_t bits = { {0} };

        for (i = 0; i < num_rings; i++)
                gxio_mpipe_notif_group_add_ring(&bits, ring + i);

        result = gxio_mpipe_init_notif_group(context, group, bits);
        if (result != 0)
                return result;

        for (i = 0; i < num_buckets; i++) {
                bucket_info.notifring = ring + (i % num_rings);

                result = gxio_mpipe_init_bucket(context, bucket + i,
                                                bucket_info);
                if (result != 0)
                        return result;
        }

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_init_notif_group_and_buckets);

int gxio_mpipe_init_edma_ring(gxio_mpipe_context_t *context,
                              unsigned int ring, unsigned int channel,
                              void *mem, size_t mem_size,
                              unsigned int mem_flags)
{
        memset(mem, 0, mem_size);

        return gxio_mpipe_init_edma_ring_aux(context, mem, mem_size, mem_flags,
                                             ring, channel);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_init_edma_ring);

void gxio_mpipe_rules_init(gxio_mpipe_rules_t *rules,
                           gxio_mpipe_context_t *context)
{
        rules->context = context;
        memset(&rules->list, 0, sizeof(rules->list));
}

EXPORT_SYMBOL_GPL(gxio_mpipe_rules_init);

int gxio_mpipe_rules_begin(gxio_mpipe_rules_t *rules,
                           unsigned int bucket, unsigned int num_buckets,
                           gxio_mpipe_rules_stacks_t *stacks)
{
        int i;
        int stack = 255;

        gxio_mpipe_rules_list_t *list = &rules->list;

        /* Current rule. */
        gxio_mpipe_rules_rule_t *rule =
                (gxio_mpipe_rules_rule_t *) (list->rules + list->head);

        unsigned int head = list->tail;

        /*
         * Align next rule properly.
         *Note that "dmacs_and_vlans" will also be aligned.
         */
        unsigned int pad = 0;
        while (((head + pad) % __alignof__(gxio_mpipe_rules_rule_t)) != 0)
                pad++;

        /*
         * Verify room.
         * ISSUE: Mark rules as broken on error?
         */
        if (head + pad + sizeof(*rule) >= sizeof(list->rules))
                return GXIO_MPIPE_ERR_RULES_FULL;

        /* Verify num_buckets is a power of 2. */
        if (__builtin_popcount(num_buckets) != 1)
                return GXIO_MPIPE_ERR_RULES_INVALID;

        /* Add padding to previous rule. */
        rule->size += pad;

        /* Start a new rule. */
        list->head = head + pad;

        rule = (gxio_mpipe_rules_rule_t *) (list->rules + list->head);

        /* Default some values. */
        rule->headroom = 2;
        rule->tailroom = 0;
        rule->capacity = 16384;

        /* Save the bucket info. */
        rule->bucket_mask = num_buckets - 1;
        rule->bucket_first = bucket;

        for (i = 8 - 1; i >= 0; i--) {
                int maybe =
                        stacks ? stacks->stacks[i] : rules->context->__stacks.
                        stacks[i];
                if (maybe != 255)
                        stack = maybe;
                rule->stacks.stacks[i] = stack;
        }

        if (stack == 255)
                return GXIO_MPIPE_ERR_RULES_INVALID;

        /* NOTE: Only entries at the end of the array can be 255. */
        for (i = 8 - 1; i > 0; i--) {
                if (rule->stacks.stacks[i] == 255) {
                        rule->stacks.stacks[i] = stack;
                        rule->capacity =
                                gxio_mpipe_buffer_size_enum_to_buffer_size(i -
                                                                           1);
                }
        }

        rule->size = sizeof(*rule);
        list->tail = list->head + rule->size;

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_rules_begin);

int gxio_mpipe_rules_add_channel(gxio_mpipe_rules_t *rules,
                                 unsigned int channel)
{
        gxio_mpipe_rules_list_t *list = &rules->list;

        gxio_mpipe_rules_rule_t *rule =
                (gxio_mpipe_rules_rule_t *) (list->rules + list->head);

        /* Verify channel. */
        if (channel >= 32)
                return GXIO_MPIPE_ERR_RULES_INVALID;

        /* Verify begun. */
        if (list->tail == 0)
                return GXIO_MPIPE_ERR_RULES_EMPTY;

        rule->channel_bits |= (1UL << channel);

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_rules_add_channel);

int gxio_mpipe_rules_set_headroom(gxio_mpipe_rules_t *rules, uint8_t headroom)
{
        gxio_mpipe_rules_list_t *list = &rules->list;

        gxio_mpipe_rules_rule_t *rule =
                (gxio_mpipe_rules_rule_t *) (list->rules + list->head);

        /* Verify begun. */
        if (list->tail == 0)
                return GXIO_MPIPE_ERR_RULES_EMPTY;

        rule->headroom = headroom;

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_rules_set_headroom);

int gxio_mpipe_rules_commit(gxio_mpipe_rules_t *rules)
{
        gxio_mpipe_rules_list_t *list = &rules->list;
        unsigned int size =
                offsetof(gxio_mpipe_rules_list_t, rules) + list->tail;
        return gxio_mpipe_commit_rules(rules->context, list, size);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_rules_commit);

int gxio_mpipe_iqueue_init(gxio_mpipe_iqueue_t *iqueue,
                           gxio_mpipe_context_t *context,
                           unsigned int ring,
                           void *mem, size_t mem_size, unsigned int mem_flags)
{
        /* The init call below will verify that "mem_size" is legal. */
        unsigned int num_entries = mem_size / sizeof(gxio_mpipe_idesc_t);

        iqueue->context = context;
        iqueue->idescs = (gxio_mpipe_idesc_t *)mem;
        iqueue->ring = ring;
        iqueue->num_entries = num_entries;
        iqueue->mask_num_entries = num_entries - 1;
        iqueue->log2_num_entries = __builtin_ctz(num_entries);
        iqueue->head = 1;
#ifdef __BIG_ENDIAN__
        iqueue->swapped = 0;
#endif

        /* Initialize the "tail". */
        __gxio_mmio_write(mem, iqueue->head);

        return gxio_mpipe_init_notif_ring(context, ring, mem, mem_size,
                                          mem_flags);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_iqueue_init);

int gxio_mpipe_equeue_init(gxio_mpipe_equeue_t *equeue,
                           gxio_mpipe_context_t *context,
                           unsigned int edma_ring_id,
                           unsigned int channel,
                           void *mem, unsigned int mem_size,
                           unsigned int mem_flags)
{
        /* The init call below will verify that "mem_size" is legal. */
        unsigned int num_entries = mem_size / sizeof(gxio_mpipe_edesc_t);

        /* Offset used to read number of completed commands. */
        MPIPE_EDMA_POST_REGION_ADDR_t offset;

        int result = gxio_mpipe_init_edma_ring(context, edma_ring_id, channel,
                                               mem, mem_size, mem_flags);
        if (result < 0)
                return result;

        memset(equeue, 0, sizeof(*equeue));

        offset.word = 0;
        offset.region =
                MPIPE_MMIO_ADDR__REGION_VAL_EDMA -
                MPIPE_MMIO_ADDR__REGION_VAL_IDMA;
        offset.ring = edma_ring_id;

        __gxio_dma_queue_init(&equeue->dma_queue,
                              context->mmio_fast_base + offset.word,
                              num_entries);
        equeue->edescs = mem;
        equeue->mask_num_entries = num_entries - 1;
        equeue->log2_num_entries = __builtin_ctz(num_entries);

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_equeue_init);

int gxio_mpipe_set_timestamp(gxio_mpipe_context_t *context,
                             const struct timespec *ts)
{
        cycles_t cycles = get_cycles();
        return gxio_mpipe_set_timestamp_aux(context, (uint64_t)ts->tv_sec,
                                            (uint64_t)ts->tv_nsec,
                                            (uint64_t)cycles);
}

int gxio_mpipe_get_timestamp(gxio_mpipe_context_t *context,
                             struct timespec *ts)
{
        int ret;
        cycles_t cycles_prev, cycles_now, clock_rate;
        cycles_prev = get_cycles();
        ret = gxio_mpipe_get_timestamp_aux(context, (uint64_t *)&ts->tv_sec,
                                           (uint64_t *)&ts->tv_nsec,
                                           (uint64_t *)&cycles_now);
        if (ret < 0) {
                return ret;
        }

        clock_rate = get_clock_rate();
        ts->tv_nsec -= (cycles_now - cycles_prev) * 1000000000LL / clock_rate;
        if (ts->tv_nsec < 0) {
                ts->tv_nsec += 1000000000LL;
                ts->tv_sec -= 1;
        }
        return ret;
}

int gxio_mpipe_adjust_timestamp(gxio_mpipe_context_t *context, int64_t delta)
{
        return gxio_mpipe_adjust_timestamp_aux(context, delta);
}

/* Get our internal context used for link name access.  This context is
 *  special in that it is not associated with an mPIPE service domain.
 */
static gxio_mpipe_context_t *_gxio_get_link_context(void)
{
        static gxio_mpipe_context_t context;
        static gxio_mpipe_context_t *contextp;
        static int tried_open = 0;
        static DEFINE_MUTEX(mutex);

        mutex_lock(&mutex);

        if (!tried_open) {
                int i = 0;
                tried_open = 1;

                /*
                 * "4" here is the maximum possible number of mPIPE shims; it's
                 * an exaggeration but we shouldn't ever go beyond 2 anyway.
                 */
                for (i = 0; i < 4; i++) {
                        char file[80];

                        snprintf(file, sizeof(file), "mpipe/%d/iorpc_info", i);
                        context.fd = hv_dev_open((HV_VirtAddr) file, 0);
                        if (context.fd < 0)
                                continue;

                        contextp = &context;
                        break;
                }
        }

        mutex_unlock(&mutex);

        return contextp;
}

int gxio_mpipe_link_enumerate_mac(int idx, char *link_name, uint8_t *link_mac)
{
        int rv;
        _gxio_mpipe_link_name_t name;
        _gxio_mpipe_link_mac_t mac;

        gxio_mpipe_context_t *context = _gxio_get_link_context();
        if (!context)
                return GXIO_ERR_NO_DEVICE;

        rv = gxio_mpipe_info_enumerate_aux(context, idx, &name, &mac);
        if (rv >= 0) {
                strncpy(link_name, name.name, sizeof(name.name));
                memcpy(link_mac, mac.mac, sizeof(mac.mac));
        }

        return rv;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_link_enumerate_mac);

int gxio_mpipe_link_open(gxio_mpipe_link_t *link,
                         gxio_mpipe_context_t *context, const char *link_name,
                         unsigned int flags)
{
        _gxio_mpipe_link_name_t name;
        int rv;

        strncpy(name.name, link_name, sizeof(name.name));
        name.name[GXIO_MPIPE_LINK_NAME_LEN - 1] = '\0';

        rv = gxio_mpipe_link_open_aux(context, name, flags);
        if (rv < 0)
                return rv;

        link->context = context;
        link->channel = rv >> 8;
        link->mac = rv & 0xFF;

        return 0;
}

EXPORT_SYMBOL_GPL(gxio_mpipe_link_open);

int gxio_mpipe_link_close(gxio_mpipe_link_t *link)
{
        return gxio_mpipe_link_close_aux(link->context, link->mac);
}

EXPORT_SYMBOL_GPL(gxio_mpipe_link_close);