/*
 * Copyright 2015 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: monk liu <monk.liu@amd.com>
 */

#include <drm/drmP.h>
#include <drm/drm_auth.h>
#include "amdgpu.h"
#include "amdgpu_sched.h"

#define to_amdgpu_ctx_entity(e) \
        container_of((e), struct amdgpu_ctx_entity, entity)

const unsigned int amdgpu_ctx_num_entities[AMDGPU_HW_IP_NUM] = {
        [AMDGPU_HW_IP_GFX]      =       1,
        [AMDGPU_HW_IP_COMPUTE]  =       4,
        [AMDGPU_HW_IP_DMA]      =       2,
        [AMDGPU_HW_IP_UVD]      =       1,
        [AMDGPU_HW_IP_VCE]      =       1,
        [AMDGPU_HW_IP_UVD_ENC]  =       1,
        [AMDGPU_HW_IP_VCN_DEC]  =       1,
        [AMDGPU_HW_IP_VCN_ENC]  =       1,
        [AMDGPU_HW_IP_VCN_JPEG] =       1,
};

static int amdgput_ctx_total_num_entities(void)
{
        unsigned i, num_entities = 0;

        for (i = 0; i < AMDGPU_HW_IP_NUM; ++i)
                num_entities += amdgpu_ctx_num_entities[i];

        return num_entities;
}

static int amdgpu_ctx_priority_permit(struct drm_file *filp,
                                      enum drm_sched_priority priority)
{
        /* NORMAL and below are accessible by everyone */
        if (priority <= DRM_SCHED_PRIORITY_NORMAL)
                return 0;

#if 0
        if (capable(CAP_SYS_NICE))
                return 0;
#endif

        if (drm_is_current_master(filp))
                return 0;

        return -EACCES;
}

static int amdgpu_ctx_init(struct amdgpu_device *adev,
                           enum drm_sched_priority priority,
                           struct drm_file *filp,
                           struct amdgpu_ctx *ctx)
{
        unsigned num_entities = amdgput_ctx_total_num_entities();
        unsigned i, j;
        int r;

        if (priority < 0 || priority >= DRM_SCHED_PRIORITY_MAX)
                return -EINVAL;

        r = amdgpu_ctx_priority_permit(filp, priority);
        if (r)
                return r;

        memset(ctx, 0, sizeof(*ctx));
        ctx->adev = adev;

        ctx->fences = kcalloc(amdgpu_sched_jobs * num_entities,
                              sizeof(struct dma_fence*), GFP_KERNEL);
        if (!ctx->fences)
                return -ENOMEM;

        ctx->entities[0] = kcalloc(num_entities,
                                   sizeof(struct amdgpu_ctx_entity),
                                   GFP_KERNEL);
        if (!ctx->entities[0]) {
                r = -ENOMEM;
                goto error_free_fences;
        }

        for (i = 0; i < num_entities; ++i) {
                struct amdgpu_ctx_entity *entity = &ctx->entities[0][i];

                entity->sequence = 1;
                entity->fences = &ctx->fences[amdgpu_sched_jobs * i];
        }
        for (i = 1; i < AMDGPU_HW_IP_NUM; ++i)
                ctx->entities[i] = ctx->entities[i - 1] +
                        amdgpu_ctx_num_entities[i - 1];

        kref_init(&ctx->refcount);
        lockinit(&ctx->ring_lock, "agcrl", 0, LK_CANRECURSE);
        lockinit(&ctx->lock, "agctxl", 0, LK_CANRECURSE);

        ctx->reset_counter = atomic_read(&adev->gpu_reset_counter);
        ctx->reset_counter_query = ctx->reset_counter;
        ctx->vram_lost_counter = atomic_read(&adev->vram_lost_counter);
        ctx->init_priority = priority;
        ctx->override_priority = DRM_SCHED_PRIORITY_UNSET;

        for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                struct amdgpu_ring *rings[AMDGPU_MAX_RINGS];
                struct drm_sched_rq *rqs[AMDGPU_MAX_RINGS];
                unsigned num_rings;

                switch (i) {
                case AMDGPU_HW_IP_GFX:
                        rings[0] = &adev->gfx.gfx_ring[0];
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_COMPUTE:
                        for (j = 0; j < adev->gfx.num_compute_rings; ++j)
                                rings[j] = &adev->gfx.compute_ring[j];
                        num_rings = adev->gfx.num_compute_rings;
                        break;
                case AMDGPU_HW_IP_DMA:
                        for (j = 0; j < adev->sdma.num_instances; ++j)
                                rings[j] = &adev->sdma.instance[j].ring;
                        num_rings = adev->sdma.num_instances;
                        break;
                case AMDGPU_HW_IP_UVD:
                        rings[0] = &adev->uvd.inst[0].ring;
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_VCE:
                        rings[0] = &adev->vce.ring[0];
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_UVD_ENC:
                        rings[0] = &adev->uvd.inst[0].ring_enc[0];
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_VCN_DEC:
                        rings[0] = &adev->vcn.ring_dec;
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_VCN_ENC:
                        rings[0] = &adev->vcn.ring_enc[0];
                        num_rings = 1;
                        break;
                case AMDGPU_HW_IP_VCN_JPEG:
                        rings[0] = &adev->vcn.ring_jpeg;
                        num_rings = 1;
                        break;
                }

                for (j = 0; j < num_rings; ++j)
                        rqs[j] = &rings[j]->sched.sched_rq[priority];

                for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j)
                        r = drm_sched_entity_init(&ctx->entities[i][j].entity,
                                                  rqs, num_rings, &ctx->guilty);
                if (r)
                        goto error_cleanup_entities;
        }

        return 0;

error_cleanup_entities:
        for (i = 0; i < num_entities; ++i)
                drm_sched_entity_destroy(&ctx->entities[0][i].entity);
        kfree(ctx->entities[0]);

error_free_fences:
        kfree(ctx->fences);
        ctx->fences = NULL;
        return r;
}

static void amdgpu_ctx_fini(struct kref *ref)
{
        struct amdgpu_ctx *ctx = container_of(ref, struct amdgpu_ctx, refcount);
        unsigned num_entities = amdgput_ctx_total_num_entities();
        struct amdgpu_device *adev = ctx->adev;
        unsigned i, j;

        if (!adev)
                return;

        for (i = 0; i < num_entities; ++i)
                for (j = 0; j < amdgpu_sched_jobs; ++j)
                        dma_fence_put(ctx->entities[0][i].fences[j]);
        kfree(ctx->fences);
        kfree(ctx->entities[0]);

        mutex_destroy(&ctx->lock);

        kfree(ctx);
}

int amdgpu_ctx_get_entity(struct amdgpu_ctx *ctx, u32 hw_ip, u32 instance,
                          u32 ring, struct drm_sched_entity **entity)
{
        if (hw_ip >= AMDGPU_HW_IP_NUM) {
                DRM_ERROR("unknown HW IP type: %d\n", hw_ip);
                return -EINVAL;
        }

        /* Right now all IPs have only one instance - multiple rings. */
        if (instance != 0) {
                DRM_DEBUG("invalid ip instance: %d\n", instance);
                return -EINVAL;
        }

        if (ring >= amdgpu_ctx_num_entities[hw_ip]) {
                DRM_DEBUG("invalid ring: %d %d\n", hw_ip, ring);
                return -EINVAL;
        }

        *entity = &ctx->entities[hw_ip][ring].entity;
        return 0;
}

static int amdgpu_ctx_alloc(struct amdgpu_device *adev,
                            struct amdgpu_fpriv *fpriv,
                            struct drm_file *filp,
                            enum drm_sched_priority priority,
                            uint32_t *id)
{
        struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
        struct amdgpu_ctx *ctx;
        int r;

        ctx = kmalloc(sizeof(*ctx), M_DRM, GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;

        mutex_lock(&mgr->lock);
        r = idr_alloc(&mgr->ctx_handles, ctx, 1, 0, GFP_KERNEL);
        if (r < 0) {
                mutex_unlock(&mgr->lock);
                kfree(ctx);
                return r;
        }

        *id = (uint32_t)r;
        r = amdgpu_ctx_init(adev, priority, filp, ctx);
        if (r) {
                idr_remove(&mgr->ctx_handles, *id);
                *id = 0;
                kfree(ctx);
        }
        mutex_unlock(&mgr->lock);
        return r;
}

static void amdgpu_ctx_do_release(struct kref *ref)
{
        struct amdgpu_ctx *ctx;
        unsigned num_entities;
        u32 i;

        ctx = container_of(ref, struct amdgpu_ctx, refcount);

        num_entities = 0;
        for (i = 0; i < AMDGPU_HW_IP_NUM; i++)
                num_entities += amdgpu_ctx_num_entities[i];

        for (i = 0; i < num_entities; i++)
                drm_sched_entity_destroy(&ctx->entities[0][i].entity);

        amdgpu_ctx_fini(ref);
}

static int amdgpu_ctx_free(struct amdgpu_fpriv *fpriv, uint32_t id)
{
        struct amdgpu_ctx_mgr *mgr = &fpriv->ctx_mgr;
        struct amdgpu_ctx *ctx;

        mutex_lock(&mgr->lock);
        ctx = idr_remove(&mgr->ctx_handles, id);
        if (ctx)
                kref_put(&ctx->refcount, amdgpu_ctx_do_release);
        mutex_unlock(&mgr->lock);
        return ctx ? 0 : -EINVAL;
}

static int amdgpu_ctx_query(struct amdgpu_device *adev,
                            struct amdgpu_fpriv *fpriv, uint32_t id,
                            union drm_amdgpu_ctx_out *out)
{
        struct amdgpu_ctx *ctx;
        struct amdgpu_ctx_mgr *mgr;
        unsigned reset_counter;

        if (!fpriv)
                return -EINVAL;

        mgr = &fpriv->ctx_mgr;
        mutex_lock(&mgr->lock);
        ctx = idr_find(&mgr->ctx_handles, id);
        if (!ctx) {
                mutex_unlock(&mgr->lock);
                return -EINVAL;
        }

        /* TODO: these two are always zero */
        out->state.flags = 0x0;
        out->state.hangs = 0x0;

        /* determine if a GPU reset has occured since the last call */
        reset_counter = atomic_read(&adev->gpu_reset_counter);
        /* TODO: this should ideally return NO, GUILTY, or INNOCENT. */
        if (ctx->reset_counter_query == reset_counter)
                out->state.reset_status = AMDGPU_CTX_NO_RESET;
        else
                out->state.reset_status = AMDGPU_CTX_UNKNOWN_RESET;
        ctx->reset_counter_query = reset_counter;

        mutex_unlock(&mgr->lock);
        return 0;
}

static int amdgpu_ctx_query2(struct amdgpu_device *adev,
        struct amdgpu_fpriv *fpriv, uint32_t id,
        union drm_amdgpu_ctx_out *out)
{
        struct amdgpu_ctx *ctx;
        struct amdgpu_ctx_mgr *mgr;

        if (!fpriv)
                return -EINVAL;

        mgr = &fpriv->ctx_mgr;
        mutex_lock(&mgr->lock);
        ctx = idr_find(&mgr->ctx_handles, id);
        if (!ctx) {
                mutex_unlock(&mgr->lock);
                return -EINVAL;
        }

        out->state.flags = 0x0;
        out->state.hangs = 0x0;

        if (ctx->reset_counter != atomic_read(&adev->gpu_reset_counter))
                out->state.flags |= AMDGPU_CTX_QUERY2_FLAGS_RESET;

        if (ctx->vram_lost_counter != atomic_read(&adev->vram_lost_counter))
                out->state.flags |= AMDGPU_CTX_QUERY2_FLAGS_VRAMLOST;

        if (atomic_read(&ctx->guilty))
                out->state.flags |= AMDGPU_CTX_QUERY2_FLAGS_GUILTY;

        mutex_unlock(&mgr->lock);
        return 0;
}

int amdgpu_ctx_ioctl(struct drm_device *dev, void *data,
                     struct drm_file *filp)
{
        int r;
        uint32_t id;
        enum drm_sched_priority priority;

        union drm_amdgpu_ctx *args = data;
        struct amdgpu_device *adev = dev->dev_private;
        struct amdgpu_fpriv *fpriv = filp->driver_priv;

        r = 0;
        id = args->in.ctx_id;
        priority = amdgpu_to_sched_priority(args->in.priority);

        /* For backwards compatibility reasons, we need to accept
         * ioctls with garbage in the priority field */
        if (priority == DRM_SCHED_PRIORITY_INVALID)
                priority = DRM_SCHED_PRIORITY_NORMAL;

        switch (args->in.op) {
        case AMDGPU_CTX_OP_ALLOC_CTX:
                r = amdgpu_ctx_alloc(adev, fpriv, filp, priority, &id);
                args->out.alloc.ctx_id = id;
                break;
        case AMDGPU_CTX_OP_FREE_CTX:
                r = amdgpu_ctx_free(fpriv, id);
                break;
        case AMDGPU_CTX_OP_QUERY_STATE:
                r = amdgpu_ctx_query(adev, fpriv, id, &args->out);
                break;
        case AMDGPU_CTX_OP_QUERY_STATE2:
                r = amdgpu_ctx_query2(adev, fpriv, id, &args->out);
                break;
        default:
                return -EINVAL;
        }

        return r;
}

struct amdgpu_ctx *amdgpu_ctx_get(struct amdgpu_fpriv *fpriv, uint32_t id)
{
        struct amdgpu_ctx *ctx;
        struct amdgpu_ctx_mgr *mgr;

        if (!fpriv)
                return NULL;

        mgr = &fpriv->ctx_mgr;

        mutex_lock(&mgr->lock);
        ctx = idr_find(&mgr->ctx_handles, id);
        if (ctx)
                kref_get(&ctx->refcount);
        mutex_unlock(&mgr->lock);
        return ctx;
}

int amdgpu_ctx_put(struct amdgpu_ctx *ctx)
{
        if (ctx == NULL)
                return -EINVAL;

        kref_put(&ctx->refcount, amdgpu_ctx_do_release);
        return 0;
}

void amdgpu_ctx_add_fence(struct amdgpu_ctx *ctx,
                          struct drm_sched_entity *entity,
                          struct dma_fence *fence, uint64_t* handle)
{
        struct amdgpu_ctx_entity *centity = to_amdgpu_ctx_entity(entity);
        uint64_t seq = centity->sequence;
        struct dma_fence *other = NULL;
        unsigned idx = 0;

        idx = seq & (amdgpu_sched_jobs - 1);
        other = centity->fences[idx];
        if (other)
                BUG_ON(!dma_fence_is_signaled(other));

        dma_fence_get(fence);

        lockmgr(&ctx->ring_lock, LK_EXCLUSIVE);
        centity->fences[idx] = fence;
        centity->sequence++;
        lockmgr(&ctx->ring_lock, LK_RELEASE);

        dma_fence_put(other);
        if (handle)
                *handle = seq;
}

struct dma_fence *amdgpu_ctx_get_fence(struct amdgpu_ctx *ctx,
                                       struct drm_sched_entity *entity,
                                       uint64_t seq)
{
        struct amdgpu_ctx_entity *centity = to_amdgpu_ctx_entity(entity);
        struct dma_fence *fence;

        lockmgr(&ctx->ring_lock, LK_EXCLUSIVE);

        if (seq == ~0ull)
                seq = centity->sequence - 1;

        if (seq >= centity->sequence) {
                lockmgr(&ctx->ring_lock, LK_RELEASE);
                return ERR_PTR(-EINVAL);
        }


        if (seq + amdgpu_sched_jobs < centity->sequence) {
                lockmgr(&ctx->ring_lock, LK_RELEASE);
                return NULL;
        }

        fence = dma_fence_get(centity->fences[seq & (amdgpu_sched_jobs - 1)]);
        lockmgr(&ctx->ring_lock, LK_RELEASE);

        return fence;
}

void amdgpu_ctx_priority_override(struct amdgpu_ctx *ctx,
                                  enum drm_sched_priority priority)
{
        unsigned num_entities = amdgput_ctx_total_num_entities();
        enum drm_sched_priority ctx_prio;
        unsigned i;

        ctx->override_priority = priority;

        ctx_prio = (ctx->override_priority == DRM_SCHED_PRIORITY_UNSET) ?
                        ctx->init_priority : ctx->override_priority;

        for (i = 0; i < num_entities; i++) {
                struct drm_sched_entity *entity = &ctx->entities[0][i].entity;

                drm_sched_entity_set_priority(entity, ctx_prio);
        }
}

int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx,
                               struct drm_sched_entity *entity)
{
        struct amdgpu_ctx_entity *centity = to_amdgpu_ctx_entity(entity);
        unsigned idx = centity->sequence & (amdgpu_sched_jobs - 1);
        struct dma_fence *other = centity->fences[idx];

        if (other) {
                signed long r;
                r = dma_fence_wait(other, true);
                if (r < 0) {
                        if (r != -ERESTARTSYS)
                                DRM_ERROR("Error (%ld) waiting for fence!\n", r);

                        return r;
                }
        }

        return 0;
}

void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr)
{
        lockinit(&mgr->lock, "agml", 0, LK_CANRECURSE);
        idr_init(&mgr->ctx_handles);
}

void amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr)
{
        unsigned num_entities = amdgput_ctx_total_num_entities();
        struct amdgpu_ctx *ctx;
        struct idr *idp;
        uint32_t id, i;
        long max_wait = MAX_WAIT_SCHED_ENTITY_Q_EMPTY;

        idp = &mgr->ctx_handles;

        mutex_lock(&mgr->lock);
        idr_for_each_entry(idp, ctx, id) {

                if (!ctx->adev) {
                        mutex_unlock(&mgr->lock);
                        return;
                }

                for (i = 0; i < num_entities; i++) {
                        struct drm_sched_entity *entity;

                        entity = &ctx->entities[0][i].entity;
                        max_wait = drm_sched_entity_flush(entity, max_wait);
                }
        }
        mutex_unlock(&mgr->lock);
}

void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr)
{
        unsigned num_entities = amdgput_ctx_total_num_entities();
        struct amdgpu_ctx *ctx;
        struct idr *idp;
        uint32_t id, i;

        idp = &mgr->ctx_handles;

        idr_for_each_entry(idp, ctx, id) {

                if (!ctx->adev)
                        return;

                if (kref_read(&ctx->refcount) != 1) {
                        DRM_ERROR("ctx %p is still alive\n", ctx);
                        continue;
                }

                for (i = 0; i < num_entities; i++)
                        drm_sched_entity_fini(&ctx->entities[0][i].entity);
        }
}

void amdgpu_ctx_mgr_fini(struct amdgpu_ctx_mgr *mgr)
{
        struct amdgpu_ctx *ctx;
        struct idr *idp;
        uint32_t id;

        amdgpu_ctx_mgr_entity_fini(mgr);

        idp = &mgr->ctx_handles;

        idr_for_each_entry(idp, ctx, id) {
                if (kref_put(&ctx->refcount, amdgpu_ctx_fini) != 1)
                        DRM_ERROR("ctx %p is still alive\n", ctx);
        }

        idr_destroy(&mgr->ctx_handles);
        mutex_destroy(&mgr->lock);
}