// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright 2009-2023 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 "vmwgfx_bo.h"
#include "vmwgfx_drv.h"
#include <drm/ttm/ttm_placement.h>

static const struct ttm_place vram_placement_flags = {
        .fpfn = 0,
        .lpfn = 0,
        .mem_type = TTM_PL_VRAM,
        .flags = 0
};

static const struct ttm_place sys_placement_flags = {
        .fpfn = 0,
        .lpfn = 0,
        .mem_type = TTM_PL_SYSTEM,
        .flags = 0
};

struct ttm_placement vmw_vram_placement = {
        .num_placement = 1,
        .placement = &vram_placement_flags,
};

struct ttm_placement vmw_sys_placement = {
        .num_placement = 1,
        .placement = &sys_placement_flags,
};

const size_t vmw_tt_size = sizeof(struct vmw_ttm_tt);

/**
 * __vmw_piter_non_sg_next: Helper functions to advance
 * a struct vmw_piter iterator.
 *
 * @viter: Pointer to the iterator.
 *
 * These functions return false if past the end of the list,
 * true otherwise. Functions are selected depending on the current
 * DMA mapping mode.
 */
static bool __vmw_piter_non_sg_next(struct vmw_piter *viter)
{
        return ++(viter->i) < viter->num_pages;
}

static bool __vmw_piter_sg_next(struct vmw_piter *viter)
{
        bool ret = __vmw_piter_non_sg_next(viter);

        return __sg_page_iter_dma_next(&viter->iter) && ret;
}


static dma_addr_t __vmw_piter_dma_addr(struct vmw_piter *viter)
{
        return viter->addrs[viter->i];
}

static dma_addr_t __vmw_piter_sg_addr(struct vmw_piter *viter)
{
        return sg_page_iter_dma_address(&viter->iter);
}


/**
 * vmw_piter_start - Initialize a struct vmw_piter.
 *
 * @viter: Pointer to the iterator to initialize
 * @vsgt: Pointer to a struct vmw_sg_table to initialize from
 * @p_offset: Pointer offset used to update current array position
 *
 * Note that we're following the convention of __sg_page_iter_start, so that
 * the iterator doesn't point to a valid page after initialization; it has
 * to be advanced one step first.
 */
void vmw_piter_start(struct vmw_piter *viter, const struct vmw_sg_table *vsgt,
                     unsigned long p_offset)
{
        viter->i = p_offset - 1;
        viter->num_pages = vsgt->num_pages;
        viter->pages = vsgt->pages;
        switch (vsgt->mode) {
        case vmw_dma_alloc_coherent:
                viter->next = &__vmw_piter_non_sg_next;
                viter->dma_address = &__vmw_piter_dma_addr;
                viter->addrs = vsgt->addrs;
                break;
        case vmw_dma_map_populate:
        case vmw_dma_map_bind:
                viter->next = &__vmw_piter_sg_next;
                viter->dma_address = &__vmw_piter_sg_addr;
                __sg_page_iter_start(&viter->iter.base, vsgt->sgt->sgl,
                                     vsgt->sgt->orig_nents, p_offset);
                break;
        default:
                BUG();
        }
}

/**
 * vmw_ttm_unmap_from_dma - unmap  device addresses previsouly mapped for
 * TTM pages
 *
 * @vmw_tt: Pointer to a struct vmw_ttm_backend
 *
 * Used to free dma mappings previously mapped by vmw_ttm_map_for_dma.
 */
static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
{
        struct device *dev = vmw_tt->dev_priv->drm.dev;

        dma_unmap_sgtable(dev, &vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
        vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
}

/**
 * vmw_ttm_map_for_dma - map TTM pages to get device addresses
 *
 * @vmw_tt: Pointer to a struct vmw_ttm_backend
 *
 * This function is used to get device addresses from the kernel DMA layer.
 * However, it's violating the DMA API in that when this operation has been
 * performed, it's illegal for the CPU to write to the pages without first
 * unmapping the DMA mappings, or calling dma_sync_sg_for_cpu(). It is
 * therefore only legal to call this function if we know that the function
 * dma_sync_sg_for_cpu() is a NOP, and dma_sync_sg_for_device() is at most
 * a CPU write buffer flush.
 */
static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
{
        struct device *dev = vmw_tt->dev_priv->drm.dev;

        return dma_map_sgtable(dev, &vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
}

/**
 * vmw_ttm_map_dma - Make sure TTM pages are visible to the device
 *
 * @vmw_tt: Pointer to a struct vmw_ttm_tt
 *
 * Select the correct function for and make sure the TTM pages are
 * visible to the device. Allocate storage for the device mappings.
 * If a mapping has already been performed, indicated by the storage
 * pointer being non NULL, the function returns success.
 */
static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
{
        struct vmw_private *dev_priv = vmw_tt->dev_priv;
        struct vmw_sg_table *vsgt = &vmw_tt->vsgt;
        int ret = 0;

        if (vmw_tt->mapped)
                return 0;

        vsgt->mode = dev_priv->map_mode;
        vsgt->pages = vmw_tt->dma_ttm.pages;
        vsgt->num_pages = vmw_tt->dma_ttm.num_pages;
        vsgt->addrs = vmw_tt->dma_ttm.dma_address;
        vsgt->sgt = NULL;

        switch (dev_priv->map_mode) {
        case vmw_dma_map_bind:
        case vmw_dma_map_populate:
                if (vmw_tt->dma_ttm.page_flags  & TTM_TT_FLAG_EXTERNAL) {
                        vsgt->sgt = vmw_tt->dma_ttm.sg;
                } else {
                        vsgt->sgt = &vmw_tt->sgt;
                        ret = sg_alloc_table_from_pages_segment(&vmw_tt->sgt,
                                vsgt->pages, vsgt->num_pages, 0,
                                (unsigned long)vsgt->num_pages << PAGE_SHIFT,
                                dma_get_max_seg_size(dev_priv->drm.dev),
                                GFP_KERNEL);
                        if (ret)
                                goto out_sg_alloc_fail;
                }

                ret = vmw_ttm_map_for_dma(vmw_tt);
                if (unlikely(ret != 0))
                        goto out_map_fail;

                break;
        default:
                break;
        }

        vmw_tt->mapped = true;
        return 0;

out_map_fail:
        drm_warn(&dev_priv->drm, "VSG table map failed!");
        sg_free_table(vsgt->sgt);
        vsgt->sgt = NULL;
out_sg_alloc_fail:
        return ret;
}

/**
 * vmw_ttm_unmap_dma - Tear down any TTM page device mappings
 *
 * @vmw_tt: Pointer to a struct vmw_ttm_tt
 *
 * Tear down any previously set up device DMA mappings and free
 * any storage space allocated for them. If there are no mappings set up,
 * this function is a NOP.
 */
static void vmw_ttm_unmap_dma(struct vmw_ttm_tt *vmw_tt)
{
        struct vmw_private *dev_priv = vmw_tt->dev_priv;

        if (!vmw_tt->vsgt.sgt)
                return;

        switch (dev_priv->map_mode) {
        case vmw_dma_map_bind:
        case vmw_dma_map_populate:
                vmw_ttm_unmap_from_dma(vmw_tt);
                sg_free_table(vmw_tt->vsgt.sgt);
                vmw_tt->vsgt.sgt = NULL;
                break;
        default:
                break;
        }
        vmw_tt->mapped = false;
}

/**
 * vmw_bo_sg_table - Return a struct vmw_sg_table object for a
 * TTM buffer object
 *
 * @bo: Pointer to a struct ttm_buffer_object
 *
 * Returns a pointer to a struct vmw_sg_table object. The object should
 * not be freed after use.
 * Note that for the device addresses to be valid, the buffer object must
 * either be reserved or pinned.
 */
const struct vmw_sg_table *vmw_bo_sg_table(struct ttm_buffer_object *bo)
{
        struct vmw_ttm_tt *vmw_tt =
                container_of(bo->ttm, struct vmw_ttm_tt, dma_ttm);

        return &vmw_tt->vsgt;
}


static int vmw_ttm_bind(struct ttm_device *bdev,
                        struct ttm_tt *ttm, struct ttm_resource *bo_mem)
{
        struct vmw_ttm_tt *vmw_be =
                container_of(ttm, struct vmw_ttm_tt, dma_ttm);
        int ret = 0;

        if (!bo_mem)
                return -EINVAL;

        if (vmw_be->bound)
                return 0;

        ret = vmw_ttm_map_dma(vmw_be);
        if (unlikely(ret != 0))
                return ret;

        vmw_be->gmr_id = bo_mem->start;
        vmw_be->mem_type = bo_mem->mem_type;

        switch (bo_mem->mem_type) {
        case VMW_PL_GMR:
                ret = vmw_gmr_bind(vmw_be->dev_priv, &vmw_be->vsgt,
                                    ttm->num_pages, vmw_be->gmr_id);
                break;
        case VMW_PL_MOB:
                if (unlikely(vmw_be->mob == NULL)) {
                        vmw_be->mob =
                                vmw_mob_create(ttm->num_pages);
                        if (unlikely(vmw_be->mob == NULL))
                                return -ENOMEM;
                }

                ret = vmw_mob_bind(vmw_be->dev_priv, vmw_be->mob,
                                    &vmw_be->vsgt, ttm->num_pages,
                                    vmw_be->gmr_id);
                break;
        case VMW_PL_SYSTEM:
                /* Nothing to be done for a system bind */
                break;
        default:
                BUG();
        }
        vmw_be->bound = true;
        return ret;
}

static void vmw_ttm_unbind(struct ttm_device *bdev,
                           struct ttm_tt *ttm)
{
        struct vmw_ttm_tt *vmw_be =
                container_of(ttm, struct vmw_ttm_tt, dma_ttm);

        if (!vmw_be->bound)
                return;

        switch (vmw_be->mem_type) {
        case VMW_PL_GMR:
                vmw_gmr_unbind(vmw_be->dev_priv, vmw_be->gmr_id);
                break;
        case VMW_PL_MOB:
                vmw_mob_unbind(vmw_be->dev_priv, vmw_be->mob);
                break;
        case VMW_PL_SYSTEM:
                break;
        default:
                BUG();
        }

        if (vmw_be->dev_priv->map_mode == vmw_dma_map_bind)
                vmw_ttm_unmap_dma(vmw_be);
        vmw_be->bound = false;
}


static void vmw_ttm_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
{
        struct vmw_ttm_tt *vmw_be =
                container_of(ttm, struct vmw_ttm_tt, dma_ttm);

        vmw_ttm_unmap_dma(vmw_be);
        ttm_tt_fini(ttm);
        if (vmw_be->mob)
                vmw_mob_destroy(vmw_be->mob);

        kfree(vmw_be);
}


static int vmw_ttm_populate(struct ttm_device *bdev,
                            struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
        bool external = (ttm->page_flags & TTM_TT_FLAG_EXTERNAL) != 0;

        if (ttm_tt_is_populated(ttm))
                return 0;

        if (external && ttm->sg)
                return  drm_prime_sg_to_dma_addr_array(ttm->sg,
                                                       ttm->dma_address,
                                                       ttm->num_pages);

        return ttm_pool_alloc(&bdev->pool, ttm, ctx);
}

static void vmw_ttm_unpopulate(struct ttm_device *bdev,
                               struct ttm_tt *ttm)
{
        struct vmw_ttm_tt *vmw_tt = container_of(ttm, struct vmw_ttm_tt,
                                                 dma_ttm);
        bool external = (ttm->page_flags & TTM_TT_FLAG_EXTERNAL) != 0;

        if (external)
                return;

        vmw_ttm_unbind(bdev, ttm);

        if (vmw_tt->mob) {
                vmw_mob_destroy(vmw_tt->mob);
                vmw_tt->mob = NULL;
        }

        vmw_ttm_unmap_dma(vmw_tt);

        ttm_pool_free(&bdev->pool, ttm);
}

static struct ttm_tt *vmw_ttm_tt_create(struct ttm_buffer_object *bo,
                                        uint32_t page_flags)
{
        struct vmw_ttm_tt *vmw_be;
        int ret;
        bool external = bo->type == ttm_bo_type_sg;

        vmw_be = kzalloc_obj(*vmw_be);
        if (!vmw_be)
                return NULL;

        vmw_be->dev_priv = vmw_priv_from_ttm(bo->bdev);
        vmw_be->mob = NULL;

        if (external)
                page_flags |= TTM_TT_FLAG_EXTERNAL | TTM_TT_FLAG_EXTERNAL_MAPPABLE;

        if (vmw_be->dev_priv->map_mode == vmw_dma_alloc_coherent || external)
                ret = ttm_sg_tt_init(&vmw_be->dma_ttm, bo, page_flags,
                                     ttm_cached);
        else
                ret = ttm_tt_init(&vmw_be->dma_ttm, bo, page_flags,
                                  ttm_cached, 0);
        if (unlikely(ret != 0))
                goto out_no_init;

        return &vmw_be->dma_ttm;
out_no_init:
        kfree(vmw_be);
        return NULL;
}

static void vmw_evict_flags(struct ttm_buffer_object *bo,
                     struct ttm_placement *placement)
{
        *placement = vmw_sys_placement;
}

static int vmw_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem)
{
        struct vmw_private *dev_priv = vmw_priv_from_ttm(bdev);

        switch (mem->mem_type) {
        case TTM_PL_SYSTEM:
        case VMW_PL_SYSTEM:
        case VMW_PL_GMR:
        case VMW_PL_MOB:
                return 0;
        case TTM_PL_VRAM:
                mem->bus.offset = (mem->start << PAGE_SHIFT) +
                        dev_priv->vram_start;
                mem->bus.is_iomem = true;
                mem->bus.caching = ttm_cached;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

/**
 * vmw_move_notify - TTM move_notify_callback
 *
 * @bo: The TTM buffer object about to move.
 * @old_mem: The old memory where we move from
 * @new_mem: The struct ttm_resource indicating to what memory
 *       region the move is taking place.
 *
 * Calls move_notify for all subsystems needing it.
 * (currently only resources).
 */
static void vmw_move_notify(struct ttm_buffer_object *bo,
                            struct ttm_resource *old_mem,
                            struct ttm_resource *new_mem)
{
        vmw_bo_move_notify(bo, new_mem);
        vmw_query_move_notify(bo, old_mem, new_mem);
}


/**
 * vmw_swap_notify - TTM move_notify_callback
 *
 * @bo: The TTM buffer object about to be swapped out.
 */
static void vmw_swap_notify(struct ttm_buffer_object *bo)
{
        vmw_bo_swap_notify(bo);
        (void) ttm_bo_wait(bo, false, false);
}

static bool vmw_memtype_is_system(uint32_t mem_type)
{
        return mem_type == TTM_PL_SYSTEM || mem_type == VMW_PL_SYSTEM;
}

static int vmw_move(struct ttm_buffer_object *bo,
                    bool evict,
                    struct ttm_operation_ctx *ctx,
                    struct ttm_resource *new_mem,
                    struct ttm_place *hop)
{
        struct ttm_resource_manager *new_man;
        struct ttm_resource_manager *old_man = NULL;
        int ret = 0;

        new_man = ttm_manager_type(bo->bdev, new_mem->mem_type);
        if (bo->resource)
                old_man = ttm_manager_type(bo->bdev, bo->resource->mem_type);

        if (new_man->use_tt && !vmw_memtype_is_system(new_mem->mem_type)) {
                ret = vmw_ttm_bind(bo->bdev, bo->ttm, new_mem);
                if (ret)
                        return ret;
        }

        if (!bo->resource || (bo->resource->mem_type == TTM_PL_SYSTEM &&
                              bo->ttm == NULL)) {
                ttm_bo_move_null(bo, new_mem);
                return 0;
        }

        vmw_move_notify(bo, bo->resource, new_mem);

        if (old_man && old_man->use_tt && new_man->use_tt) {
                if (vmw_memtype_is_system(bo->resource->mem_type)) {
                        ttm_bo_move_null(bo, new_mem);
                        return 0;
                }
                ret = ttm_bo_wait_ctx(bo, ctx);
                if (ret)
                        goto fail;

                vmw_ttm_unbind(bo->bdev, bo->ttm);
                ttm_resource_free(bo, &bo->resource);
                ttm_bo_assign_mem(bo, new_mem);
                return 0;
        } else {
                ret = ttm_bo_move_memcpy(bo, ctx, new_mem);
                if (ret)
                        goto fail;
        }
        return 0;
fail:
        vmw_move_notify(bo, new_mem, bo->resource);
        return ret;
}

struct ttm_device_funcs vmw_bo_driver = {
        .ttm_tt_create = &vmw_ttm_tt_create,
        .ttm_tt_populate = &vmw_ttm_populate,
        .ttm_tt_unpopulate = &vmw_ttm_unpopulate,
        .ttm_tt_destroy = &vmw_ttm_destroy,
        .eviction_valuable = ttm_bo_eviction_valuable,
        .evict_flags = vmw_evict_flags,
        .move = vmw_move,
        .swap_notify = vmw_swap_notify,
        .io_mem_reserve = &vmw_ttm_io_mem_reserve,
};

int vmw_bo_create_and_populate(struct vmw_private *dev_priv,
                               size_t bo_size, u32 domain,
                               struct vmw_bo **bo_p)
{
        struct ttm_operation_ctx ctx = {
                .interruptible = false,
                .no_wait_gpu = false
        };
        struct vmw_bo *vbo;
        int ret;
        struct vmw_bo_params bo_params = {
                .domain = domain,
                .busy_domain = domain,
                .bo_type = ttm_bo_type_kernel,
                .size = bo_size,
                .pin = true,
                .keep_resv = true,
        };

        ret = vmw_bo_create(dev_priv, &bo_params, &vbo);
        if (unlikely(ret != 0))
                return ret;

        ret = vmw_ttm_populate(vbo->tbo.bdev, vbo->tbo.ttm, &ctx);
        if (likely(ret == 0)) {
                struct vmw_ttm_tt *vmw_tt =
                        container_of(vbo->tbo.ttm, struct vmw_ttm_tt, dma_ttm);
                ret = vmw_ttm_map_dma(vmw_tt);
        }

        ttm_bo_unreserve(&vbo->tbo);

        if (likely(ret == 0))
                *bo_p = vbo;
        return ret;
}