// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright 2009-2015 VMware, Inc., Palo Alto, CA., USA
 *
 * 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, sub license, 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 (including the
 * next paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
 *
 **************************************************************************/

#include <drm/ttm/ttm_placement.h>

#include "vmwgfx_drv.h"
#include "vmwgfx_resource_priv.h"
#include "vmwgfx_binding.h"

struct vmw_shader {
        struct vmw_resource res;
        SVGA3dShaderType type;
        uint32_t size;
        uint8_t num_input_sig;
        uint8_t num_output_sig;
};

struct vmw_user_shader {
        struct ttm_base_object base;
        struct vmw_shader shader;
};

struct vmw_dx_shader {
        struct vmw_resource res;
        struct vmw_resource *ctx;
        struct vmw_resource *cotable;
        u32 id;
        bool committed;
        struct list_head cotable_head;
};

static void vmw_user_shader_free(struct vmw_resource *res);
static struct vmw_resource *
vmw_user_shader_base_to_res(struct ttm_base_object *base);

static int vmw_gb_shader_create(struct vmw_resource *res);
static int vmw_gb_shader_bind(struct vmw_resource *res,
                               struct ttm_validate_buffer *val_buf);
static int vmw_gb_shader_unbind(struct vmw_resource *res,
                                 bool readback,
                                 struct ttm_validate_buffer *val_buf);
static int vmw_gb_shader_destroy(struct vmw_resource *res);

static int vmw_dx_shader_create(struct vmw_resource *res);
static int vmw_dx_shader_bind(struct vmw_resource *res,
                               struct ttm_validate_buffer *val_buf);
static int vmw_dx_shader_unbind(struct vmw_resource *res,
                                 bool readback,
                                 struct ttm_validate_buffer *val_buf);
static void vmw_dx_shader_commit_notify(struct vmw_resource *res,
                                        enum vmw_cmdbuf_res_state state);
static bool vmw_shader_id_ok(u32 user_key, SVGA3dShaderType shader_type);
static u32 vmw_shader_key(u32 user_key, SVGA3dShaderType shader_type);

static const struct vmw_user_resource_conv user_shader_conv = {
        .object_type = VMW_RES_SHADER,
        .base_obj_to_res = vmw_user_shader_base_to_res,
        .res_free = vmw_user_shader_free
};

const struct vmw_user_resource_conv *user_shader_converter =
        &user_shader_conv;


static const struct vmw_res_func vmw_gb_shader_func = {
        .res_type = vmw_res_shader,
        .needs_backup = true,
        .may_evict = true,
        .prio = 3,
        .dirty_prio = 3,
        .type_name = "guest backed shaders",
        .backup_placement = &vmw_mob_placement,
        .create = vmw_gb_shader_create,
        .destroy = vmw_gb_shader_destroy,
        .bind = vmw_gb_shader_bind,
        .unbind = vmw_gb_shader_unbind
};

static const struct vmw_res_func vmw_dx_shader_func = {
        .res_type = vmw_res_shader,
        .needs_backup = true,
        .may_evict = true,
        .prio = 3,
        .dirty_prio = 3,
        .type_name = "dx shaders",
        .backup_placement = &vmw_mob_placement,
        .create = vmw_dx_shader_create,
        /*
         * The destroy callback is only called with a committed resource on
         * context destroy, in which case we destroy the cotable anyway,
         * so there's no need to destroy DX shaders separately.
         */
        .destroy = NULL,
        .bind = vmw_dx_shader_bind,
        .unbind = vmw_dx_shader_unbind,
        .commit_notify = vmw_dx_shader_commit_notify,
};

/*
 * Shader management:
 */

static inline struct vmw_shader *
vmw_res_to_shader(struct vmw_resource *res)
{
        return container_of(res, struct vmw_shader, res);
}

/**
 * vmw_res_to_dx_shader - typecast a struct vmw_resource to a
 * struct vmw_dx_shader
 *
 * @res: Pointer to the struct vmw_resource.
 */
static inline struct vmw_dx_shader *
vmw_res_to_dx_shader(struct vmw_resource *res)
{
        return container_of(res, struct vmw_dx_shader, res);
}

static void vmw_hw_shader_destroy(struct vmw_resource *res)
{
        if (likely(res->func->destroy))
                (void) res->func->destroy(res);
        else
                res->id = -1;
}


static int vmw_gb_shader_init(struct vmw_private *dev_priv,
                              struct vmw_resource *res,
                              uint32_t size,
                              uint64_t offset,
                              SVGA3dShaderType type,
                              uint8_t num_input_sig,
                              uint8_t num_output_sig,
                              struct vmw_buffer_object *byte_code,
                              void (*res_free) (struct vmw_resource *res))
{
        struct vmw_shader *shader = vmw_res_to_shader(res);
        int ret;

        ret = vmw_resource_init(dev_priv, res, true, res_free,
                                &vmw_gb_shader_func);

        if (unlikely(ret != 0)) {
                if (res_free)
                        res_free(res);
                else
                        kfree(res);
                return ret;
        }

        res->backup_size = size;
        if (byte_code) {
                res->backup = vmw_bo_reference(byte_code);
                res->backup_offset = offset;
        }
        shader->size = size;
        shader->type = type;
        shader->num_input_sig = num_input_sig;
        shader->num_output_sig = num_output_sig;

        res->hw_destroy = vmw_hw_shader_destroy;
        return 0;
}

/*
 * GB shader code:
 */

static int vmw_gb_shader_create(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct vmw_shader *shader = vmw_res_to_shader(res);
        int ret;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDefineGBShader body;
        } *cmd;

        if (likely(res->id != -1))
                return 0;

        ret = vmw_resource_alloc_id(res);
        if (unlikely(ret != 0)) {
                DRM_ERROR("Failed to allocate a shader id.\n");
                goto out_no_id;
        }

        if (unlikely(res->id >= VMWGFX_NUM_GB_SHADER)) {
                ret = -EBUSY;
                goto out_no_fifo;
        }

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL)) {
                ret = -ENOMEM;
                goto out_no_fifo;
        }

        cmd->header.id = SVGA_3D_CMD_DEFINE_GB_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.shid = res->id;
        cmd->body.type = shader->type;
        cmd->body.sizeInBytes = shader->size;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));
        vmw_fifo_resource_inc(dev_priv);

        return 0;

out_no_fifo:
        vmw_resource_release_id(res);
out_no_id:
        return ret;
}

static int vmw_gb_shader_bind(struct vmw_resource *res,
                              struct ttm_validate_buffer *val_buf)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdBindGBShader body;
        } *cmd;
        struct ttm_buffer_object *bo = val_buf->bo;

        BUG_ON(bo->resource->mem_type != VMW_PL_MOB);

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_BIND_GB_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.shid = res->id;
        cmd->body.mobid = bo->resource->start;
        cmd->body.offsetInBytes = res->backup_offset;
        res->backup_dirty = false;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        return 0;
}

static int vmw_gb_shader_unbind(struct vmw_resource *res,
                                bool readback,
                                struct ttm_validate_buffer *val_buf)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdBindGBShader body;
        } *cmd;
        struct vmw_fence_obj *fence;

        BUG_ON(res->backup->base.resource->mem_type != VMW_PL_MOB);

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_BIND_GB_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.shid = res->id;
        cmd->body.mobid = SVGA3D_INVALID_ID;
        cmd->body.offsetInBytes = 0;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        /*
         * Create a fence object and fence the backup buffer.
         */

        (void) vmw_execbuf_fence_commands(NULL, dev_priv,
                                          &fence, NULL);

        vmw_bo_fence_single(val_buf->bo, fence);

        if (likely(fence != NULL))
                vmw_fence_obj_unreference(&fence);

        return 0;
}

static int vmw_gb_shader_destroy(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDestroyGBShader body;
        } *cmd;

        if (likely(res->id == -1))
                return 0;

        mutex_lock(&dev_priv->binding_mutex);
        vmw_binding_res_list_scrub(&res->binding_head);

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL)) {
                mutex_unlock(&dev_priv->binding_mutex);
                return -ENOMEM;
        }

        cmd->header.id = SVGA_3D_CMD_DESTROY_GB_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.shid = res->id;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));
        mutex_unlock(&dev_priv->binding_mutex);
        vmw_resource_release_id(res);
        vmw_fifo_resource_dec(dev_priv);

        return 0;
}

/*
 * DX shader code:
 */

/**
 * vmw_dx_shader_commit_notify - Notify that a shader operation has been
 * committed to hardware from a user-supplied command stream.
 *
 * @res: Pointer to the shader resource.
 * @state: Indicating whether a creation or removal has been committed.
 *
 */
static void vmw_dx_shader_commit_notify(struct vmw_resource *res,
                                        enum vmw_cmdbuf_res_state state)
{
        struct vmw_dx_shader *shader = vmw_res_to_dx_shader(res);
        struct vmw_private *dev_priv = res->dev_priv;

        if (state == VMW_CMDBUF_RES_ADD) {
                mutex_lock(&dev_priv->binding_mutex);
                vmw_cotable_add_resource(shader->cotable,
                                         &shader->cotable_head);
                shader->committed = true;
                res->id = shader->id;
                mutex_unlock(&dev_priv->binding_mutex);
        } else {
                mutex_lock(&dev_priv->binding_mutex);
                list_del_init(&shader->cotable_head);
                shader->committed = false;
                res->id = -1;
                mutex_unlock(&dev_priv->binding_mutex);
        }
}

/**
 * vmw_dx_shader_unscrub - Have the device reattach a MOB to a DX shader.
 *
 * @res: The shader resource
 *
 * This function reverts a scrub operation.
 */
static int vmw_dx_shader_unscrub(struct vmw_resource *res)
{
        struct vmw_dx_shader *shader = vmw_res_to_dx_shader(res);
        struct vmw_private *dev_priv = res->dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDXBindShader body;
        } *cmd;

        if (!list_empty(&shader->cotable_head) || !shader->committed)
                return 0;

        cmd = VMW_CMD_CTX_RESERVE(dev_priv, sizeof(*cmd), shader->ctx->id);
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_DX_BIND_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.cid = shader->ctx->id;
        cmd->body.shid = shader->id;
        cmd->body.mobid = res->backup->base.resource->start;
        cmd->body.offsetInBytes = res->backup_offset;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        vmw_cotable_add_resource(shader->cotable, &shader->cotable_head);

        return 0;
}

/**
 * vmw_dx_shader_create - The DX shader create callback
 *
 * @res: The DX shader resource
 *
 * The create callback is called as part of resource validation and
 * makes sure that we unscrub the shader if it's previously been scrubbed.
 */
static int vmw_dx_shader_create(struct vmw_resource *res)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct vmw_dx_shader *shader = vmw_res_to_dx_shader(res);
        int ret = 0;

        WARN_ON_ONCE(!shader->committed);

        if (vmw_resource_mob_attached(res)) {
                mutex_lock(&dev_priv->binding_mutex);
                ret = vmw_dx_shader_unscrub(res);
                mutex_unlock(&dev_priv->binding_mutex);
        }

        res->id = shader->id;
        return ret;
}

/**
 * vmw_dx_shader_bind - The DX shader bind callback
 *
 * @res: The DX shader resource
 * @val_buf: Pointer to the validate buffer.
 *
 */
static int vmw_dx_shader_bind(struct vmw_resource *res,
                              struct ttm_validate_buffer *val_buf)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct ttm_buffer_object *bo = val_buf->bo;

        BUG_ON(bo->resource->mem_type != VMW_PL_MOB);
        mutex_lock(&dev_priv->binding_mutex);
        vmw_dx_shader_unscrub(res);
        mutex_unlock(&dev_priv->binding_mutex);

        return 0;
}

/**
 * vmw_dx_shader_scrub - Have the device unbind a MOB from a DX shader.
 *
 * @res: The shader resource
 *
 * This function unbinds a MOB from the DX shader without requiring the
 * MOB dma_buffer to be reserved. The driver still considers the MOB bound.
 * However, once the driver eventually decides to unbind the MOB, it doesn't
 * need to access the context.
 */
static int vmw_dx_shader_scrub(struct vmw_resource *res)
{
        struct vmw_dx_shader *shader = vmw_res_to_dx_shader(res);
        struct vmw_private *dev_priv = res->dev_priv;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDXBindShader body;
        } *cmd;

        if (list_empty(&shader->cotable_head))
                return 0;

        WARN_ON_ONCE(!shader->committed);
        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_DX_BIND_SHADER;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.cid = shader->ctx->id;
        cmd->body.shid = res->id;
        cmd->body.mobid = SVGA3D_INVALID_ID;
        cmd->body.offsetInBytes = 0;
        vmw_cmd_commit(dev_priv, sizeof(*cmd));
        res->id = -1;
        list_del_init(&shader->cotable_head);

        return 0;
}

/**
 * vmw_dx_shader_unbind - The dx shader unbind callback.
 *
 * @res: The shader resource
 * @readback: Whether this is a readback unbind. Currently unused.
 * @val_buf: MOB buffer information.
 */
static int vmw_dx_shader_unbind(struct vmw_resource *res,
                                bool readback,
                                struct ttm_validate_buffer *val_buf)
{
        struct vmw_private *dev_priv = res->dev_priv;
        struct vmw_fence_obj *fence;
        int ret;

        BUG_ON(res->backup->base.resource->mem_type != VMW_PL_MOB);

        mutex_lock(&dev_priv->binding_mutex);
        ret = vmw_dx_shader_scrub(res);
        mutex_unlock(&dev_priv->binding_mutex);

        if (ret)
                return ret;

        (void) vmw_execbuf_fence_commands(NULL, dev_priv,
                                          &fence, NULL);
        vmw_bo_fence_single(val_buf->bo, fence);

        if (likely(fence != NULL))
                vmw_fence_obj_unreference(&fence);

        return 0;
}

/**
 * vmw_dx_shader_cotable_list_scrub - The cotable unbind_func callback for
 * DX shaders.
 *
 * @dev_priv: Pointer to device private structure.
 * @list: The list of cotable resources.
 * @readback: Whether the call was part of a readback unbind.
 *
 * Scrubs all shader MOBs so that any subsequent shader unbind or shader
 * destroy operation won't need to swap in the context.
 */
void vmw_dx_shader_cotable_list_scrub(struct vmw_private *dev_priv,
                                      struct list_head *list,
                                      bool readback)
{
        struct vmw_dx_shader *entry, *next;

        lockdep_assert_held_once(&dev_priv->binding_mutex);

        list_for_each_entry_safe(entry, next, list, cotable_head) {
                WARN_ON(vmw_dx_shader_scrub(&entry->res));
                if (!readback)
                        entry->committed = false;
        }
}

/**
 * vmw_dx_shader_res_free - The DX shader free callback
 *
 * @res: The shader resource
 *
 * Frees the DX shader resource.
 */
static void vmw_dx_shader_res_free(struct vmw_resource *res)
{
        struct vmw_dx_shader *shader = vmw_res_to_dx_shader(res);

        vmw_resource_unreference(&shader->cotable);
        kfree(shader);
}

/**
 * vmw_dx_shader_add - Add a shader resource as a command buffer managed
 * resource.
 *
 * @man: The command buffer resource manager.
 * @ctx: Pointer to the context resource.
 * @user_key: The id used for this shader.
 * @shader_type: The shader type.
 * @list: The list of staged command buffer managed resources.
 */
int vmw_dx_shader_add(struct vmw_cmdbuf_res_manager *man,
                      struct vmw_resource *ctx,
                      u32 user_key,
                      SVGA3dShaderType shader_type,
                      struct list_head *list)
{
        struct vmw_dx_shader *shader;
        struct vmw_resource *res;
        struct vmw_private *dev_priv = ctx->dev_priv;
        int ret;

        if (!vmw_shader_id_ok(user_key, shader_type))
                return -EINVAL;

        shader = kmalloc(sizeof(*shader), GFP_KERNEL);
        if (!shader) {
                return -ENOMEM;
        }

        res = &shader->res;
        shader->ctx = ctx;
        shader->cotable = vmw_resource_reference
                (vmw_context_cotable(ctx, SVGA_COTABLE_DXSHADER));
        shader->id = user_key;
        shader->committed = false;
        INIT_LIST_HEAD(&shader->cotable_head);
        ret = vmw_resource_init(dev_priv, res, true,
                                vmw_dx_shader_res_free, &vmw_dx_shader_func);
        if (ret)
                goto out_resource_init;

        /*
         * The user_key name-space is not per shader type for DX shaders,
         * so when hashing, use a single zero shader type.
         */
        ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_shader,
                                 vmw_shader_key(user_key, 0),
                                 res, list);
        if (ret)
                goto out_resource_init;

        res->id = shader->id;
        res->hw_destroy = vmw_hw_shader_destroy;

out_resource_init:
        vmw_resource_unreference(&res);

        return ret;
}



/*
 * User-space shader management:
 */

static struct vmw_resource *
vmw_user_shader_base_to_res(struct ttm_base_object *base)
{
        return &(container_of(base, struct vmw_user_shader, base)->
                 shader.res);
}

static void vmw_user_shader_free(struct vmw_resource *res)
{
        struct vmw_user_shader *ushader =
                container_of(res, struct vmw_user_shader, shader.res);

        ttm_base_object_kfree(ushader, base);
}

static void vmw_shader_free(struct vmw_resource *res)
{
        struct vmw_shader *shader = vmw_res_to_shader(res);

        kfree(shader);
}

/*
 * This function is called when user space has no more references on the
 * base object. It releases the base-object's reference on the resource object.
 */

static void vmw_user_shader_base_release(struct ttm_base_object **p_base)
{
        struct ttm_base_object *base = *p_base;
        struct vmw_resource *res = vmw_user_shader_base_to_res(base);

        *p_base = NULL;
        vmw_resource_unreference(&res);
}

int vmw_shader_destroy_ioctl(struct drm_device *dev, void *data,
                              struct drm_file *file_priv)
{
        struct drm_vmw_shader_arg *arg = (struct drm_vmw_shader_arg *)data;
        struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;

        return ttm_ref_object_base_unref(tfile, arg->handle);
}

static int vmw_user_shader_alloc(struct vmw_private *dev_priv,
                                 struct vmw_buffer_object *buffer,
                                 size_t shader_size,
                                 size_t offset,
                                 SVGA3dShaderType shader_type,
                                 uint8_t num_input_sig,
                                 uint8_t num_output_sig,
                                 struct ttm_object_file *tfile,
                                 u32 *handle)
{
        struct vmw_user_shader *ushader;
        struct vmw_resource *res, *tmp;
        int ret;

        ushader = kzalloc(sizeof(*ushader), GFP_KERNEL);
        if (unlikely(!ushader)) {
                ret = -ENOMEM;
                goto out;
        }

        res = &ushader->shader.res;
        ushader->base.shareable = false;
        ushader->base.tfile = NULL;

        /*
         * From here on, the destructor takes over resource freeing.
         */

        ret = vmw_gb_shader_init(dev_priv, res, shader_size,
                                 offset, shader_type, num_input_sig,
                                 num_output_sig, buffer,
                                 vmw_user_shader_free);
        if (unlikely(ret != 0))
                goto out;

        tmp = vmw_resource_reference(res);
        ret = ttm_base_object_init(tfile, &ushader->base, false,
                                   VMW_RES_SHADER,
                                   &vmw_user_shader_base_release);

        if (unlikely(ret != 0)) {
                vmw_resource_unreference(&tmp);
                goto out_err;
        }

        if (handle)
                *handle = ushader->base.handle;
out_err:
        vmw_resource_unreference(&res);
out:
        return ret;
}


static struct vmw_resource *vmw_shader_alloc(struct vmw_private *dev_priv,
                                             struct vmw_buffer_object *buffer,
                                             size_t shader_size,
                                             size_t offset,
                                             SVGA3dShaderType shader_type)
{
        struct vmw_shader *shader;
        struct vmw_resource *res;
        int ret;

        shader = kzalloc(sizeof(*shader), GFP_KERNEL);
        if (unlikely(!shader)) {
                ret = -ENOMEM;
                goto out_err;
        }

        res = &shader->res;

        /*
         * From here on, the destructor takes over resource freeing.
         */
        ret = vmw_gb_shader_init(dev_priv, res, shader_size,
                                 offset, shader_type, 0, 0, buffer,
                                 vmw_shader_free);

out_err:
        return ret ? ERR_PTR(ret) : res;
}


static int vmw_shader_define(struct drm_device *dev, struct drm_file *file_priv,
                             enum drm_vmw_shader_type shader_type_drm,
                             u32 buffer_handle, size_t size, size_t offset,
                             uint8_t num_input_sig, uint8_t num_output_sig,
                             uint32_t *shader_handle)
{
        struct vmw_private *dev_priv = vmw_priv(dev);
        struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
        struct vmw_buffer_object *buffer = NULL;
        SVGA3dShaderType shader_type;
        int ret;

        if (buffer_handle != SVGA3D_INVALID_ID) {
                ret = vmw_user_bo_lookup(file_priv, buffer_handle, &buffer);
                if (unlikely(ret != 0)) {
                        VMW_DEBUG_USER("Couldn't find buffer for shader creation.\n");
                        return ret;
                }

                if ((u64)buffer->base.base.size < (u64)size + (u64)offset) {
                        VMW_DEBUG_USER("Illegal buffer- or shader size.\n");
                        ret = -EINVAL;
                        goto out_bad_arg;
                }
        }

        switch (shader_type_drm) {
        case drm_vmw_shader_type_vs:
                shader_type = SVGA3D_SHADERTYPE_VS;
                break;
        case drm_vmw_shader_type_ps:
                shader_type = SVGA3D_SHADERTYPE_PS;
                break;
        default:
                VMW_DEBUG_USER("Illegal shader type.\n");
                ret = -EINVAL;
                goto out_bad_arg;
        }

        ret = vmw_user_shader_alloc(dev_priv, buffer, size, offset,
                                    shader_type, num_input_sig,
                                    num_output_sig, tfile, shader_handle);
out_bad_arg:
        vmw_bo_unreference(&buffer);
        return ret;
}

/**
 * vmw_shader_id_ok - Check whether a compat shader user key and
 * shader type are within valid bounds.
 *
 * @user_key: User space id of the shader.
 * @shader_type: Shader type.
 *
 * Returns true if valid false if not.
 */
static bool vmw_shader_id_ok(u32 user_key, SVGA3dShaderType shader_type)
{
        return user_key <= ((1 << 20) - 1) && (unsigned) shader_type < 16;
}

/**
 * vmw_shader_key - Compute a hash key suitable for a compat shader.
 *
 * @user_key: User space id of the shader.
 * @shader_type: Shader type.
 *
 * Returns a hash key suitable for a command buffer managed resource
 * manager hash table.
 */
static u32 vmw_shader_key(u32 user_key, SVGA3dShaderType shader_type)
{
        return user_key | (shader_type << 20);
}

/**
 * vmw_shader_remove - Stage a compat shader for removal.
 *
 * @man: Pointer to the compat shader manager identifying the shader namespace.
 * @user_key: The key that is used to identify the shader. The key is
 * unique to the shader type.
 * @shader_type: Shader type.
 * @list: Caller's list of staged command buffer resource actions.
 */
int vmw_shader_remove(struct vmw_cmdbuf_res_manager *man,
                      u32 user_key, SVGA3dShaderType shader_type,
                      struct list_head *list)
{
        struct vmw_resource *dummy;

        if (!vmw_shader_id_ok(user_key, shader_type))
                return -EINVAL;

        return vmw_cmdbuf_res_remove(man, vmw_cmdbuf_res_shader,
                                     vmw_shader_key(user_key, shader_type),
                                     list, &dummy);
}

/**
 * vmw_compat_shader_add - Create a compat shader and stage it for addition
 * as a command buffer managed resource.
 *
 * @dev_priv: Pointer to device private structure.
 * @man: Pointer to the compat shader manager identifying the shader namespace.
 * @user_key: The key that is used to identify the shader. The key is
 * unique to the shader type.
 * @bytecode: Pointer to the bytecode of the shader.
 * @shader_type: Shader type.
 * @size: Command size.
 * @list: Caller's list of staged command buffer resource actions.
 *
 */
int vmw_compat_shader_add(struct vmw_private *dev_priv,
                          struct vmw_cmdbuf_res_manager *man,
                          u32 user_key, const void *bytecode,
                          SVGA3dShaderType shader_type,
                          size_t size,
                          struct list_head *list)
{
        struct ttm_operation_ctx ctx = { false, true };
        struct vmw_buffer_object *buf;
        struct ttm_bo_kmap_obj map;
        bool is_iomem;
        int ret;
        struct vmw_resource *res;

        if (!vmw_shader_id_ok(user_key, shader_type))
                return -EINVAL;

        ret = vmw_bo_create(dev_priv, size, &vmw_sys_placement,
                            true, true, vmw_bo_bo_free, &buf);
        if (unlikely(ret != 0))
                goto out;

        ret = ttm_bo_reserve(&buf->base, false, true, NULL);
        if (unlikely(ret != 0))
                goto no_reserve;

        /* Map and copy shader bytecode. */
        ret = ttm_bo_kmap(&buf->base, 0, PFN_UP(size), &map);
        if (unlikely(ret != 0)) {
                ttm_bo_unreserve(&buf->base);
                goto no_reserve;
        }

        memcpy(ttm_kmap_obj_virtual(&map, &is_iomem), bytecode, size);
        WARN_ON(is_iomem);

        ttm_bo_kunmap(&map);
        ret = ttm_bo_validate(&buf->base, &vmw_sys_placement, &ctx);
        WARN_ON(ret != 0);
        ttm_bo_unreserve(&buf->base);

        res = vmw_shader_alloc(dev_priv, buf, size, 0, shader_type);
        if (unlikely(ret != 0))
                goto no_reserve;

        ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_shader,
                                 vmw_shader_key(user_key, shader_type),
                                 res, list);
        vmw_resource_unreference(&res);
no_reserve:
        vmw_bo_unreference(&buf);
out:
        return ret;
}

/**
 * vmw_shader_lookup - Look up a compat shader
 *
 * @man: Pointer to the command buffer managed resource manager identifying
 * the shader namespace.
 * @user_key: The user space id of the shader.
 * @shader_type: The shader type.
 *
 * Returns a refcounted pointer to a struct vmw_resource if the shader was
 * found. An error pointer otherwise.
 */
struct vmw_resource *
vmw_shader_lookup(struct vmw_cmdbuf_res_manager *man,
                  u32 user_key,
                  SVGA3dShaderType shader_type)
{
        if (!vmw_shader_id_ok(user_key, shader_type))
                return ERR_PTR(-EINVAL);

        return vmw_cmdbuf_res_lookup(man, vmw_cmdbuf_res_shader,
                                     vmw_shader_key(user_key, shader_type));
}

int vmw_shader_define_ioctl(struct drm_device *dev, void *data,
                             struct drm_file *file_priv)
{
        struct drm_vmw_shader_create_arg *arg =
                (struct drm_vmw_shader_create_arg *)data;

        return vmw_shader_define(dev, file_priv, arg->shader_type,
                                 arg->buffer_handle,
                                 arg->size, arg->offset,
                                 0, 0,
                                 &arg->shader_handle);
}