/*
 * 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/drm_auth.h>
#include "amdgpu.h"
#include "amdgpu_sched.h"
#include "amdgpu_ras.h"
#include <linux/nospec.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 amdgpu_ctx_priority_permit(struct drm_file *filp,
                                      enum drm_sched_priority priority)
{
        if (priority < 0 || priority >= DRM_SCHED_PRIORITY_COUNT)
                return -EINVAL;

        /* NORMAL and below are accessible by everyone */
        if (priority <= DRM_SCHED_PRIORITY_NORMAL)
                return 0;

        if (capable(CAP_SYS_NICE))
                return 0;

        if (drm_is_current_master(filp))
                return 0;

        return -EACCES;
}

static enum gfx_pipe_priority amdgpu_ctx_sched_prio_to_compute_prio(enum drm_sched_priority prio)
{
        switch (prio) {
        case DRM_SCHED_PRIORITY_HIGH:
        case DRM_SCHED_PRIORITY_KERNEL:
                return AMDGPU_GFX_PIPE_PRIO_HIGH;
        default:
                return AMDGPU_GFX_PIPE_PRIO_NORMAL;
        }
}

static unsigned int amdgpu_ctx_prio_sched_to_hw(struct amdgpu_device *adev,
                                                 enum drm_sched_priority prio,
                                                 u32 hw_ip)
{
        unsigned int hw_prio;

        hw_prio = (hw_ip == AMDGPU_HW_IP_COMPUTE) ?
                        amdgpu_ctx_sched_prio_to_compute_prio(prio) :
                        AMDGPU_RING_PRIO_DEFAULT;
        hw_ip = array_index_nospec(hw_ip, AMDGPU_HW_IP_NUM);
        if (adev->gpu_sched[hw_ip][hw_prio].num_scheds == 0)
                hw_prio = AMDGPU_RING_PRIO_DEFAULT;

        return hw_prio;
}

static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
                                   const u32 ring)
{
        struct amdgpu_device *adev = ctx->adev;
        struct amdgpu_ctx_entity *entity;
        struct drm_gpu_scheduler **scheds = NULL, *sched = NULL;
        unsigned num_scheds = 0;
        unsigned int hw_prio;
        enum drm_sched_priority priority;
        int r;

        entity = kzalloc(struct_size(entity, fences, amdgpu_sched_jobs),
                         GFP_KERNEL);
        if (!entity)
                return  -ENOMEM;

        entity->sequence = 1;
        priority = (ctx->override_priority == DRM_SCHED_PRIORITY_UNSET) ?
                                ctx->init_priority : ctx->override_priority;
        hw_prio = amdgpu_ctx_prio_sched_to_hw(adev, priority, hw_ip);

        hw_ip = array_index_nospec(hw_ip, AMDGPU_HW_IP_NUM);
        scheds = adev->gpu_sched[hw_ip][hw_prio].sched;
        num_scheds = adev->gpu_sched[hw_ip][hw_prio].num_scheds;

        /* disable load balance if the hw engine retains context among dependent jobs */
        if (hw_ip == AMDGPU_HW_IP_VCN_ENC ||
            hw_ip == AMDGPU_HW_IP_VCN_DEC ||
            hw_ip == AMDGPU_HW_IP_UVD_ENC ||
            hw_ip == AMDGPU_HW_IP_UVD) {
                sched = drm_sched_pick_best(scheds, num_scheds);
                scheds = &sched;
                num_scheds = 1;
        }

        r = drm_sched_entity_init(&entity->entity, priority, scheds, num_scheds,
                                  &ctx->guilty);
        if (r)
                goto error_free_entity;

        ctx->entities[hw_ip][ring] = entity;
        return 0;

error_free_entity:
        kfree(entity);

        return r;
}

static int amdgpu_ctx_init(struct amdgpu_device *adev,
                           enum drm_sched_priority priority,
                           struct drm_file *filp,
                           struct amdgpu_ctx *ctx)
{
        int r;

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

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

        ctx->adev = adev;

        kref_init(&ctx->refcount);
        spin_lock_init(&ctx->ring_lock);
        mutex_init(&ctx->lock);

        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;

        return 0;
}

static void amdgpu_ctx_fini_entity(struct amdgpu_ctx_entity *entity)
{

        int i;

        if (!entity)
                return;

        for (i = 0; i < amdgpu_sched_jobs; ++i)
                dma_fence_put(entity->fences[i]);

        kfree(entity);
}

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

        if (!adev)
                return;

        for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                for (j = 0; j < AMDGPU_MAX_ENTITY_NUM; ++j) {
                        amdgpu_ctx_fini_entity(ctx->entities[i][j]);
                        ctx->entities[i][j] = NULL;
                }
        }

        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)
{
        int r;

        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;
        }

        if (ctx->entities[hw_ip][ring] == NULL) {
                r = amdgpu_ctx_init_entity(ctx, hw_ip, ring);
                if (r)
                        return r;
        }

        *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), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;

        mutex_lock(&mgr->lock);
        r = idr_alloc(&mgr->ctx_handles, ctx, 1, AMDGPU_VM_MAX_NUM_CTX, 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;
        u32 i, j;

        ctx = container_of(ref, struct amdgpu_ctx, refcount);
        for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j) {
                        if (!ctx->entities[i][j])
                                continue;

                        drm_sched_entity_destroy(&ctx->entities[i][j]->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;
        unsigned long ras_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;
        }

        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;

        /*query ue count*/
        ras_counter = amdgpu_ras_query_error_count(adev, false);
        /*ras counter is monotonic increasing*/
        if (ras_counter != ctx->ras_counter_ue) {
                out->state.flags |= AMDGPU_CTX_QUERY2_FLAGS_RAS_UE;
                ctx->ras_counter_ue = ras_counter;
        }

        /*query ce count*/
        ras_counter = amdgpu_ras_query_error_count(adev, true);
        if (ras_counter != ctx->ras_counter_ce) {
                out->state.flags |= AMDGPU_CTX_QUERY2_FLAGS_RAS_CE;
                ctx->ras_counter_ce = ras_counter;
        }

        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 = drm_to_adev(dev);
        struct amdgpu_fpriv *fpriv = filp->driver_priv;

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

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

        spin_lock(&ctx->ring_lock);
        centity->fences[idx] = fence;
        centity->sequence++;
        spin_unlock(&ctx->ring_lock);

        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;

        spin_lock(&ctx->ring_lock);

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

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


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

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

        return fence;
}

static void amdgpu_ctx_set_entity_priority(struct amdgpu_ctx *ctx,
                                            struct amdgpu_ctx_entity *aentity,
                                            int hw_ip,
                                            enum drm_sched_priority priority)
{
        struct amdgpu_device *adev = ctx->adev;
        unsigned int hw_prio;
        struct drm_gpu_scheduler **scheds = NULL;
        unsigned num_scheds;

        /* set sw priority */
        drm_sched_entity_set_priority(&aentity->entity, priority);

        /* set hw priority */
        if (hw_ip == AMDGPU_HW_IP_COMPUTE) {
                hw_prio = amdgpu_ctx_prio_sched_to_hw(adev, priority,
                                                      AMDGPU_HW_IP_COMPUTE);
                hw_prio = array_index_nospec(hw_prio, AMDGPU_RING_PRIO_MAX);
                scheds = adev->gpu_sched[hw_ip][hw_prio].sched;
                num_scheds = adev->gpu_sched[hw_ip][hw_prio].num_scheds;
                drm_sched_entity_modify_sched(&aentity->entity, scheds,
                                              num_scheds);
        }
}

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

        ctx->override_priority = priority;

        ctx_prio = (ctx->override_priority == DRM_SCHED_PRIORITY_UNSET) ?
                        ctx->init_priority : ctx->override_priority;
        for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j) {
                        if (!ctx->entities[i][j])
                                continue;

                        amdgpu_ctx_set_entity_priority(ctx, ctx->entities[i][j],
                                                       i, 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);
        struct dma_fence *other;
        unsigned idx;
        long r;

        spin_lock(&ctx->ring_lock);
        idx = centity->sequence & (amdgpu_sched_jobs - 1);
        other = dma_fence_get(centity->fences[idx]);
        spin_unlock(&ctx->ring_lock);

        if (!other)
                return 0;

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

        dma_fence_put(other);
        return r;
}

void amdgpu_ctx_mgr_init(struct amdgpu_ctx_mgr *mgr)
{
        mutex_init(&mgr->lock);
        idr_init(&mgr->ctx_handles);
}

long amdgpu_ctx_mgr_entity_flush(struct amdgpu_ctx_mgr *mgr, long timeout)
{
        struct amdgpu_ctx *ctx;
        struct idr *idp;
        uint32_t id, i, j;

        idp = &mgr->ctx_handles;

        mutex_lock(&mgr->lock);
        idr_for_each_entry(idp, ctx, id) {
                for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                        for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j) {
                                struct drm_sched_entity *entity;

                                if (!ctx->entities[i][j])
                                        continue;

                                entity = &ctx->entities[i][j]->entity;
                                timeout = drm_sched_entity_flush(entity, timeout);
                        }
                }
        }
        mutex_unlock(&mgr->lock);
        return timeout;
}

void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr)
{
        struct amdgpu_ctx *ctx;
        struct idr *idp;
        uint32_t id, i, j;

        idp = &mgr->ctx_handles;

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

                for (i = 0; i < AMDGPU_HW_IP_NUM; ++i) {
                        for (j = 0; j < amdgpu_ctx_num_entities[i]; ++j) {
                                struct drm_sched_entity *entity;

                                if (!ctx->entities[i][j])
                                        continue;

                                entity = &ctx->entities[i][j]->entity;
                                drm_sched_entity_fini(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);
}