// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2014-2016 Freescale Semiconductor Inc.
 * Copyright 2016 NXP
 *
 */
#include <linux/types.h>
#include <linux/fsl/mc.h>
#include <soc/fsl/dpaa2-io.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

#include "dpio.h"
#include "qbman-portal.h"

struct dpaa2_io {
        struct dpaa2_io_desc dpio_desc;
        struct qbman_swp_desc swp_desc;
        struct qbman_swp *swp;
        struct list_head node;
        /* protect against multiple management commands */
        spinlock_t lock_mgmt_cmd;
        /* protect notifications list */
        spinlock_t lock_notifications;
        struct list_head notifications;
        struct device *dev;
};

struct dpaa2_io_store {
        unsigned int max;
        dma_addr_t paddr;
        struct dpaa2_dq *vaddr;
        void *alloced_addr;    /* unaligned value from kmalloc() */
        unsigned int idx;      /* position of the next-to-be-returned entry */
        struct qbman_swp *swp; /* portal used to issue VDQCR */
        struct device *dev;    /* device used for DMA mapping */
};

/* keep a per cpu array of DPIOs for fast access */
static struct dpaa2_io *dpio_by_cpu[NR_CPUS];
static struct list_head dpio_list = LIST_HEAD_INIT(dpio_list);
static DEFINE_SPINLOCK(dpio_list_lock);

static inline struct dpaa2_io *service_select_by_cpu(struct dpaa2_io *d,
                                                     int cpu)
{
        if (d)
                return d;

        if (cpu != DPAA2_IO_ANY_CPU && cpu >= num_possible_cpus())
                return NULL;

        /*
         * If cpu == -1, choose the current cpu, with no guarantees about
         * potentially being migrated away.
         */
        if (unlikely(cpu < 0))
                cpu = smp_processor_id();

        /* If a specific cpu was requested, pick it up immediately */
        return dpio_by_cpu[cpu];
}

static inline struct dpaa2_io *service_select(struct dpaa2_io *d)
{
        if (d)
                return d;

        spin_lock(&dpio_list_lock);
        d = list_entry(dpio_list.next, struct dpaa2_io, node);
        list_del(&d->node);
        list_add_tail(&d->node, &dpio_list);
        spin_unlock(&dpio_list_lock);

        return d;
}

/**
 * dpaa2_io_service_select() - return a dpaa2_io service affined to this cpu
 * @cpu: the cpu id
 *
 * Return the affine dpaa2_io service, or NULL if there is no service affined
 * to the specified cpu. If DPAA2_IO_ANY_CPU is used, return the next available
 * service.
 */
struct dpaa2_io *dpaa2_io_service_select(int cpu)
{
        if (cpu == DPAA2_IO_ANY_CPU)
                return service_select(NULL);

        return service_select_by_cpu(NULL, cpu);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_select);

/**
 * dpaa2_io_create() - create a dpaa2_io object.
 * @desc: the dpaa2_io descriptor
 * @dev: the actual DPIO device
 *
 * Activates a "struct dpaa2_io" corresponding to the given config of an actual
 * DPIO object.
 *
 * Return a valid dpaa2_io object for success, or NULL for failure.
 */
struct dpaa2_io *dpaa2_io_create(const struct dpaa2_io_desc *desc,
                                 struct device *dev)
{
        struct dpaa2_io *obj = kmalloc(sizeof(*obj), GFP_KERNEL);

        if (!obj)
                return NULL;

        /* check if CPU is out of range (-1 means any cpu) */
        if (desc->cpu != DPAA2_IO_ANY_CPU && desc->cpu >= num_possible_cpus()) {
                kfree(obj);
                return NULL;
        }

        obj->dpio_desc = *desc;
        obj->swp_desc.cena_bar = obj->dpio_desc.regs_cena;
        obj->swp_desc.cinh_bar = obj->dpio_desc.regs_cinh;
        obj->swp_desc.qman_version = obj->dpio_desc.qman_version;
        obj->swp = qbman_swp_init(&obj->swp_desc);

        if (!obj->swp) {
                kfree(obj);
                return NULL;
        }

        INIT_LIST_HEAD(&obj->node);
        spin_lock_init(&obj->lock_mgmt_cmd);
        spin_lock_init(&obj->lock_notifications);
        INIT_LIST_HEAD(&obj->notifications);

        /* For now only enable DQRR interrupts */
        qbman_swp_interrupt_set_trigger(obj->swp,
                                        QBMAN_SWP_INTERRUPT_DQRI);
        qbman_swp_interrupt_clear_status(obj->swp, 0xffffffff);
        if (obj->dpio_desc.receives_notifications)
                qbman_swp_push_set(obj->swp, 0, 1);

        spin_lock(&dpio_list_lock);
        list_add_tail(&obj->node, &dpio_list);
        if (desc->cpu >= 0 && !dpio_by_cpu[desc->cpu])
                dpio_by_cpu[desc->cpu] = obj;
        spin_unlock(&dpio_list_lock);

        obj->dev = dev;

        return obj;
}

/**
 * dpaa2_io_down() - release the dpaa2_io object.
 * @d: the dpaa2_io object to be released.
 *
 * The "struct dpaa2_io" type can represent an individual DPIO object (as
 * described by "struct dpaa2_io_desc") or an instance of a "DPIO service",
 * which can be used to group/encapsulate multiple DPIO objects. In all cases,
 * each handle obtained should be released using this function.
 */
void dpaa2_io_down(struct dpaa2_io *d)
{
        spin_lock(&dpio_list_lock);
        dpio_by_cpu[d->dpio_desc.cpu] = NULL;
        list_del(&d->node);
        spin_unlock(&dpio_list_lock);

        kfree(d);
}

#define DPAA_POLL_MAX 32

/**
 * dpaa2_io_irq() - ISR for DPIO interrupts
 *
 * @obj: the given DPIO object.
 *
 * Return IRQ_HANDLED for success or IRQ_NONE if there
 * were no pending interrupts.
 */
irqreturn_t dpaa2_io_irq(struct dpaa2_io *obj)
{
        const struct dpaa2_dq *dq;
        int max = 0;
        struct qbman_swp *swp;
        u32 status;

        swp = obj->swp;
        status = qbman_swp_interrupt_read_status(swp);
        if (!status)
                return IRQ_NONE;

        dq = qbman_swp_dqrr_next(swp);
        while (dq) {
                if (qbman_result_is_SCN(dq)) {
                        struct dpaa2_io_notification_ctx *ctx;
                        u64 q64;

                        q64 = qbman_result_SCN_ctx(dq);
                        ctx = (void *)(uintptr_t)q64;
                        ctx->cb(ctx);
                } else {
                        pr_crit("fsl-mc-dpio: Unrecognised/ignored DQRR entry\n");
                }
                qbman_swp_dqrr_consume(swp, dq);
                ++max;
                if (max > DPAA_POLL_MAX)
                        goto done;
                dq = qbman_swp_dqrr_next(swp);
        }
done:
        qbman_swp_interrupt_clear_status(swp, status);
        qbman_swp_interrupt_set_inhibit(swp, 0);
        return IRQ_HANDLED;
}

/**
 * dpaa2_io_get_cpu() - get the cpu associated with a given DPIO object
 *
 * @d: the given DPIO object.
 *
 * Return the cpu associated with the DPIO object
 */
int dpaa2_io_get_cpu(struct dpaa2_io *d)
{
        return d->dpio_desc.cpu;
}
EXPORT_SYMBOL(dpaa2_io_get_cpu);

/**
 * dpaa2_io_service_register() - Prepare for servicing of FQDAN or CDAN
 *                               notifications on the given DPIO service.
 * @d:   the given DPIO service.
 * @ctx: the notification context.
 * @dev: the device that requests the register
 *
 * The caller should make the MC command to attach a DPAA2 object to
 * a DPIO after this function completes successfully.  In that way:
 *    (a) The DPIO service is "ready" to handle a notification arrival
 *        (which might happen before the "attach" command to MC has
 *        returned control of execution back to the caller)
 *    (b) The DPIO service can provide back to the caller the 'dpio_id' and
 *        'qman64' parameters that it should pass along in the MC command
 *        in order for the object to be configured to produce the right
 *        notification fields to the DPIO service.
 *
 * Return 0 for success, or -ENODEV for failure.
 */
int dpaa2_io_service_register(struct dpaa2_io *d,
                              struct dpaa2_io_notification_ctx *ctx,
                              struct device *dev)
{
        struct device_link *link;
        unsigned long irqflags;

        d = service_select_by_cpu(d, ctx->desired_cpu);
        if (!d)
                return -ENODEV;

        link = device_link_add(dev, d->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
        if (!link)
                return -EINVAL;

        ctx->dpio_id = d->dpio_desc.dpio_id;
        ctx->qman64 = (u64)(uintptr_t)ctx;
        ctx->dpio_private = d;
        spin_lock_irqsave(&d->lock_notifications, irqflags);
        list_add(&ctx->node, &d->notifications);
        spin_unlock_irqrestore(&d->lock_notifications, irqflags);

        /* Enable the generation of CDAN notifications */
        if (ctx->is_cdan)
                return qbman_swp_CDAN_set_context_enable(d->swp,
                                                         (u16)ctx->id,
                                                         ctx->qman64);
        return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_register);

/**
 * dpaa2_io_service_deregister - The opposite of 'register'.
 * @service: the given DPIO service.
 * @ctx: the notification context.
 * @dev: the device that requests to be deregistered
 *
 * This function should be called only after sending the MC command to
 * to detach the notification-producing device from the DPIO.
 */
void dpaa2_io_service_deregister(struct dpaa2_io *service,
                                 struct dpaa2_io_notification_ctx *ctx,
                                 struct device *dev)
{
        struct dpaa2_io *d = ctx->dpio_private;
        unsigned long irqflags;

        if (ctx->is_cdan)
                qbman_swp_CDAN_disable(d->swp, (u16)ctx->id);

        spin_lock_irqsave(&d->lock_notifications, irqflags);
        list_del(&ctx->node);
        spin_unlock_irqrestore(&d->lock_notifications, irqflags);

        if (dev)
                device_link_remove(dev, d->dev);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_deregister);

/**
 * dpaa2_io_service_rearm() - Rearm the notification for the given DPIO service.
 * @d: the given DPIO service.
 * @ctx: the notification context.
 *
 * Once a FQDAN/CDAN has been produced, the corresponding FQ/channel is
 * considered "disarmed". Ie. the user can issue pull dequeue operations on that
 * traffic source for as long as it likes. Eventually it may wish to "rearm"
 * that source to allow it to produce another FQDAN/CDAN, that's what this
 * function achieves.
 *
 * Return 0 for success.
 */
int dpaa2_io_service_rearm(struct dpaa2_io *d,
                           struct dpaa2_io_notification_ctx *ctx)
{
        unsigned long irqflags;
        int err;

        d = service_select_by_cpu(d, ctx->desired_cpu);
        if (!unlikely(d))
                return -ENODEV;

        spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
        if (ctx->is_cdan)
                err = qbman_swp_CDAN_enable(d->swp, (u16)ctx->id);
        else
                err = qbman_swp_fq_schedule(d->swp, ctx->id);
        spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);

        return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_rearm);

/**
 * dpaa2_io_service_pull_fq() - pull dequeue functions from a fq.
 * @d: the given DPIO service.
 * @fqid: the given frame queue id.
 * @s: the dpaa2_io_store object for the result.
 *
 * Return 0 for success, or error code for failure.
 */
int dpaa2_io_service_pull_fq(struct dpaa2_io *d, u32 fqid,
                             struct dpaa2_io_store *s)
{
        struct qbman_pull_desc pd;
        int err;

        qbman_pull_desc_clear(&pd);
        qbman_pull_desc_set_storage(&pd, s->vaddr, s->paddr, 1);
        qbman_pull_desc_set_numframes(&pd, (u8)s->max);
        qbman_pull_desc_set_fq(&pd, fqid);

        d = service_select(d);
        if (!d)
                return -ENODEV;
        s->swp = d->swp;
        err = qbman_swp_pull(d->swp, &pd);
        if (err)
                s->swp = NULL;

        return err;
}
EXPORT_SYMBOL(dpaa2_io_service_pull_fq);

/**
 * dpaa2_io_service_pull_channel() - pull dequeue functions from a channel.
 * @d: the given DPIO service.
 * @channelid: the given channel id.
 * @s: the dpaa2_io_store object for the result.
 *
 * Return 0 for success, or error code for failure.
 */
int dpaa2_io_service_pull_channel(struct dpaa2_io *d, u32 channelid,
                                  struct dpaa2_io_store *s)
{
        struct qbman_pull_desc pd;
        int err;

        qbman_pull_desc_clear(&pd);
        qbman_pull_desc_set_storage(&pd, s->vaddr, s->paddr, 1);
        qbman_pull_desc_set_numframes(&pd, (u8)s->max);
        qbman_pull_desc_set_channel(&pd, channelid, qbman_pull_type_prio);

        d = service_select(d);
        if (!d)
                return -ENODEV;

        s->swp = d->swp;
        err = qbman_swp_pull(d->swp, &pd);
        if (err)
                s->swp = NULL;

        return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_pull_channel);

/**
 * dpaa2_io_service_enqueue_fq() - Enqueue a frame to a frame queue.
 * @d: the given DPIO service.
 * @fqid: the given frame queue id.
 * @fd: the frame descriptor which is enqueued.
 *
 * Return 0 for successful enqueue, -EBUSY if the enqueue ring is not ready,
 * or -ENODEV if there is no dpio service.
 */
int dpaa2_io_service_enqueue_fq(struct dpaa2_io *d,
                                u32 fqid,
                                const struct dpaa2_fd *fd)
{
        struct qbman_eq_desc ed;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        qbman_eq_desc_clear(&ed);
        qbman_eq_desc_set_no_orp(&ed, 0);
        qbman_eq_desc_set_fq(&ed, fqid);

        return qbman_swp_enqueue(d->swp, &ed, fd);
}
EXPORT_SYMBOL(dpaa2_io_service_enqueue_fq);

/**
 * dpaa2_io_service_enqueue_qd() - Enqueue a frame to a QD.
 * @d: the given DPIO service.
 * @qdid: the given queuing destination id.
 * @prio: the given queuing priority.
 * @qdbin: the given queuing destination bin.
 * @fd: the frame descriptor which is enqueued.
 *
 * Return 0 for successful enqueue, or -EBUSY if the enqueue ring is not ready,
 * or -ENODEV if there is no dpio service.
 */
int dpaa2_io_service_enqueue_qd(struct dpaa2_io *d,
                                u32 qdid, u8 prio, u16 qdbin,
                                const struct dpaa2_fd *fd)
{
        struct qbman_eq_desc ed;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        qbman_eq_desc_clear(&ed);
        qbman_eq_desc_set_no_orp(&ed, 0);
        qbman_eq_desc_set_qd(&ed, qdid, qdbin, prio);

        return qbman_swp_enqueue(d->swp, &ed, fd);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_enqueue_qd);

/**
 * dpaa2_io_service_release() - Release buffers to a buffer pool.
 * @d: the given DPIO object.
 * @bpid: the buffer pool id.
 * @buffers: the buffers to be released.
 * @num_buffers: the number of the buffers to be released.
 *
 * Return 0 for success, and negative error code for failure.
 */
int dpaa2_io_service_release(struct dpaa2_io *d,
                             u16 bpid,
                             const u64 *buffers,
                             unsigned int num_buffers)
{
        struct qbman_release_desc rd;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        qbman_release_desc_clear(&rd);
        qbman_release_desc_set_bpid(&rd, bpid);

        return qbman_swp_release(d->swp, &rd, buffers, num_buffers);
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_release);

/**
 * dpaa2_io_service_acquire() - Acquire buffers from a buffer pool.
 * @d: the given DPIO object.
 * @bpid: the buffer pool id.
 * @buffers: the buffer addresses for acquired buffers.
 * @num_buffers: the expected number of the buffers to acquire.
 *
 * Return a negative error code if the command failed, otherwise it returns
 * the number of buffers acquired, which may be less than the number requested.
 * Eg. if the buffer pool is empty, this will return zero.
 */
int dpaa2_io_service_acquire(struct dpaa2_io *d,
                             u16 bpid,
                             u64 *buffers,
                             unsigned int num_buffers)
{
        unsigned long irqflags;
        int err;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
        err = qbman_swp_acquire(d->swp, bpid, buffers, num_buffers);
        spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);

        return err;
}
EXPORT_SYMBOL_GPL(dpaa2_io_service_acquire);

/*
 * 'Stores' are reusable memory blocks for holding dequeue results, and to
 * assist with parsing those results.
 */

/**
 * dpaa2_io_store_create() - Create the dma memory storage for dequeue result.
 * @max_frames: the maximum number of dequeued result for frames, must be <= 16.
 * @dev:        the device to allow mapping/unmapping the DMAable region.
 *
 * The size of the storage is "max_frames*sizeof(struct dpaa2_dq)".
 * The 'dpaa2_io_store' returned is a DPIO service managed object.
 *
 * Return pointer to dpaa2_io_store struct for successfully created storage
 * memory, or NULL on error.
 */
struct dpaa2_io_store *dpaa2_io_store_create(unsigned int max_frames,
                                             struct device *dev)
{
        struct dpaa2_io_store *ret;
        size_t size;

        if (!max_frames || (max_frames > 16))
                return NULL;

        ret = kmalloc(sizeof(*ret), GFP_KERNEL);
        if (!ret)
                return NULL;

        ret->max = max_frames;
        size = max_frames * sizeof(struct dpaa2_dq) + 64;
        ret->alloced_addr = kzalloc(size, GFP_KERNEL);
        if (!ret->alloced_addr) {
                kfree(ret);
                return NULL;
        }

        ret->vaddr = PTR_ALIGN(ret->alloced_addr, 64);
        ret->paddr = dma_map_single(dev, ret->vaddr,
                                    sizeof(struct dpaa2_dq) * max_frames,
                                    DMA_FROM_DEVICE);
        if (dma_mapping_error(dev, ret->paddr)) {
                kfree(ret->alloced_addr);
                kfree(ret);
                return NULL;
        }

        ret->idx = 0;
        ret->dev = dev;

        return ret;
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_create);

/**
 * dpaa2_io_store_destroy() - Frees the dma memory storage for dequeue
 *                            result.
 * @s: the storage memory to be destroyed.
 */
void dpaa2_io_store_destroy(struct dpaa2_io_store *s)
{
        dma_unmap_single(s->dev, s->paddr, sizeof(struct dpaa2_dq) * s->max,
                         DMA_FROM_DEVICE);
        kfree(s->alloced_addr);
        kfree(s);
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_destroy);

/**
 * dpaa2_io_store_next() - Determine when the next dequeue result is available.
 * @s: the dpaa2_io_store object.
 * @is_last: indicate whether this is the last frame in the pull command.
 *
 * When an object driver performs dequeues to a dpaa2_io_store, this function
 * can be used to determine when the next frame result is available. Once
 * this function returns non-NULL, a subsequent call to it will try to find
 * the next dequeue result.
 *
 * Note that if a pull-dequeue has a NULL result because the target FQ/channel
 * was empty, then this function will also return NULL (rather than expecting
 * the caller to always check for this. As such, "is_last" can be used to
 * differentiate between "end-of-empty-dequeue" and "still-waiting".
 *
 * Return dequeue result for a valid dequeue result, or NULL for empty dequeue.
 */
struct dpaa2_dq *dpaa2_io_store_next(struct dpaa2_io_store *s, int *is_last)
{
        int match;
        struct dpaa2_dq *ret = &s->vaddr[s->idx];

        match = qbman_result_has_new_result(s->swp, ret);
        if (!match) {
                *is_last = 0;
                return NULL;
        }

        s->idx++;

        if (dpaa2_dq_is_pull_complete(ret)) {
                *is_last = 1;
                s->idx = 0;
                /*
                 * If we get an empty dequeue result to terminate a zero-results
                 * vdqcr, return NULL to the caller rather than expecting him to
                 * check non-NULL results every time.
                 */
                if (!(dpaa2_dq_flags(ret) & DPAA2_DQ_STAT_VALIDFRAME))
                        ret = NULL;
        } else {
                prefetch(&s->vaddr[s->idx]);
                *is_last = 0;
        }

        return ret;
}
EXPORT_SYMBOL_GPL(dpaa2_io_store_next);

/**
 * dpaa2_io_query_fq_count() - Get the frame and byte count for a given fq.
 * @d: the given DPIO object.
 * @fqid: the id of frame queue to be queried.
 * @fcnt: the queried frame count.
 * @bcnt: the queried byte count.
 *
 * Knowing the FQ count at run-time can be useful in debugging situations.
 * The instantaneous frame- and byte-count are hereby returned.
 *
 * Return 0 for a successful query, and negative error code if query fails.
 */
int dpaa2_io_query_fq_count(struct dpaa2_io *d, u32 fqid,
                            u32 *fcnt, u32 *bcnt)
{
        struct qbman_fq_query_np_rslt state;
        struct qbman_swp *swp;
        unsigned long irqflags;
        int ret;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        swp = d->swp;
        spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
        ret = qbman_fq_query_state(swp, fqid, &state);
        spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);
        if (ret)
                return ret;
        *fcnt = qbman_fq_state_frame_count(&state);
        *bcnt = qbman_fq_state_byte_count(&state);

        return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_query_fq_count);

/**
 * dpaa2_io_query_bp_count() - Query the number of buffers currently in a
 * buffer pool.
 * @d: the given DPIO object.
 * @bpid: the index of buffer pool to be queried.
 * @num: the queried number of buffers in the buffer pool.
 *
 * Return 0 for a successful query, and negative error code if query fails.
 */
int dpaa2_io_query_bp_count(struct dpaa2_io *d, u16 bpid, u32 *num)
{
        struct qbman_bp_query_rslt state;
        struct qbman_swp *swp;
        unsigned long irqflags;
        int ret;

        d = service_select(d);
        if (!d)
                return -ENODEV;

        swp = d->swp;
        spin_lock_irqsave(&d->lock_mgmt_cmd, irqflags);
        ret = qbman_bp_query(swp, bpid, &state);
        spin_unlock_irqrestore(&d->lock_mgmt_cmd, irqflags);
        if (ret)
                return ret;
        *num = qbman_bp_info_num_free_bufs(&state);
        return 0;
}
EXPORT_SYMBOL_GPL(dpaa2_io_query_bp_count);