// SPDX-License-Identifier: GPL-2.0 OR MIT
/* Copyright 2018-2019 Qiang Yu <yuq825@gmail.com> */

#include <linux/pid.h>
#include <linux/slab.h>

#include "lima_device.h"
#include "lima_ctx.h"

int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id)
{
        struct lima_ctx *ctx;
        int i, err;

        ctx = kzalloc_obj(*ctx);
        if (!ctx)
                return -ENOMEM;
        ctx->dev = dev;
        kref_init(&ctx->refcnt);

        for (i = 0; i < lima_pipe_num; i++) {
                err = lima_sched_context_init(dev->pipe + i, ctx->context + i);
                if (err)
                        goto err_out0;
        }

        err = xa_alloc(&mgr->handles, id, ctx, xa_limit_32b, GFP_KERNEL);
        if (err < 0)
                goto err_out0;

        ctx->pid = task_pid_nr(current);
        get_task_comm(ctx->pname, current);

        return 0;

err_out0:
        for (i--; i >= 0; i--)
                lima_sched_context_fini(dev->pipe + i, ctx->context + i);
        kfree(ctx);
        return err;
}

static void lima_ctx_do_release(struct kref *ref)
{
        struct lima_ctx *ctx = container_of(ref, struct lima_ctx, refcnt);
        int i;

        for (i = 0; i < lima_pipe_num; i++)
                lima_sched_context_fini(ctx->dev->pipe + i, ctx->context + i);
        kfree(ctx);
}

int lima_ctx_free(struct lima_ctx_mgr *mgr, u32 id)
{
        struct lima_ctx *ctx;
        int ret = 0;

        mutex_lock(&mgr->lock);
        ctx = xa_erase(&mgr->handles, id);
        if (ctx)
                kref_put(&ctx->refcnt, lima_ctx_do_release);
        else
                ret = -EINVAL;
        mutex_unlock(&mgr->lock);
        return ret;
}

struct lima_ctx *lima_ctx_get(struct lima_ctx_mgr *mgr, u32 id)
{
        struct lima_ctx *ctx;

        mutex_lock(&mgr->lock);
        ctx = xa_load(&mgr->handles, id);
        if (ctx)
                kref_get(&ctx->refcnt);
        mutex_unlock(&mgr->lock);
        return ctx;
}

void lima_ctx_put(struct lima_ctx *ctx)
{
        kref_put(&ctx->refcnt, lima_ctx_do_release);
}

void lima_ctx_mgr_init(struct lima_ctx_mgr *mgr)
{
        mutex_init(&mgr->lock);
        xa_init_flags(&mgr->handles, XA_FLAGS_ALLOC);
}

void lima_ctx_mgr_fini(struct lima_ctx_mgr *mgr)
{
        struct lima_ctx *ctx;
        unsigned long id;

        xa_for_each(&mgr->handles, id, ctx) {
                kref_put(&ctx->refcnt, lima_ctx_do_release);
        }

        xa_destroy(&mgr->handles);
        mutex_destroy(&mgr->lock);
}