/*
 * Copyright 2016 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: Christian König
 */

#include <linux/dma-mapping.h>
#include "amdgpu.h"
#include "amdgpu_vm.h"
#include "amdgpu_atomfirmware.h"
#include "atom.h"

struct amdgpu_vram_mgr {
        struct drm_mm mm;
        spinlock_t lock;
        atomic64_t usage;
        atomic64_t vis_usage;
};

/**
 * DOC: mem_info_vram_total
 *
 * The amdgpu driver provides a sysfs API for reporting current total VRAM
 * available on the device
 * The file mem_info_vram_total is used for this and returns the total
 * amount of VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vram_total_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = ddev->dev_private;

        return snprintf(buf, PAGE_SIZE, "%llu\n", adev->gmc.real_vram_size);
}

/**
 * DOC: mem_info_vis_vram_total
 *
 * The amdgpu driver provides a sysfs API for reporting current total
 * visible VRAM available on the device
 * The file mem_info_vis_vram_total is used for this and returns the total
 * amount of visible VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vis_vram_total_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = ddev->dev_private;

        return snprintf(buf, PAGE_SIZE, "%llu\n", adev->gmc.visible_vram_size);
}

/**
 * DOC: mem_info_vram_used
 *
 * The amdgpu driver provides a sysfs API for reporting current total VRAM
 * available on the device
 * The file mem_info_vram_used is used for this and returns the total
 * amount of currently used VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vram_used_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = ddev->dev_private;

        return snprintf(buf, PAGE_SIZE, "%llu\n",
                amdgpu_vram_mgr_usage(&adev->mman.bdev.man[TTM_PL_VRAM]));
}

/**
 * DOC: mem_info_vis_vram_used
 *
 * The amdgpu driver provides a sysfs API for reporting current total of
 * used visible VRAM
 * The file mem_info_vis_vram_used is used for this and returns the total
 * amount of currently used visible VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vis_vram_used_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = ddev->dev_private;

        return snprintf(buf, PAGE_SIZE, "%llu\n",
                amdgpu_vram_mgr_vis_usage(&adev->mman.bdev.man[TTM_PL_VRAM]));
}

static ssize_t amdgpu_mem_info_vram_vendor(struct device *dev,
                                                 struct device_attribute *attr,
                                                 char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = ddev->dev_private;

        switch (adev->gmc.vram_vendor) {
        case SAMSUNG:
                return snprintf(buf, PAGE_SIZE, "samsung\n");
        case INFINEON:
                return snprintf(buf, PAGE_SIZE, "infineon\n");
        case ELPIDA:
                return snprintf(buf, PAGE_SIZE, "elpida\n");
        case ETRON:
                return snprintf(buf, PAGE_SIZE, "etron\n");
        case NANYA:
                return snprintf(buf, PAGE_SIZE, "nanya\n");
        case HYNIX:
                return snprintf(buf, PAGE_SIZE, "hynix\n");
        case MOSEL:
                return snprintf(buf, PAGE_SIZE, "mosel\n");
        case WINBOND:
                return snprintf(buf, PAGE_SIZE, "winbond\n");
        case ESMT:
                return snprintf(buf, PAGE_SIZE, "esmt\n");
        case MICRON:
                return snprintf(buf, PAGE_SIZE, "micron\n");
        default:
                return snprintf(buf, PAGE_SIZE, "unknown\n");
        }
}

static DEVICE_ATTR(mem_info_vram_total, S_IRUGO,
                   amdgpu_mem_info_vram_total_show, NULL);
static DEVICE_ATTR(mem_info_vis_vram_total, S_IRUGO,
                   amdgpu_mem_info_vis_vram_total_show,NULL);
static DEVICE_ATTR(mem_info_vram_used, S_IRUGO,
                   amdgpu_mem_info_vram_used_show, NULL);
static DEVICE_ATTR(mem_info_vis_vram_used, S_IRUGO,
                   amdgpu_mem_info_vis_vram_used_show, NULL);
static DEVICE_ATTR(mem_info_vram_vendor, S_IRUGO,
                   amdgpu_mem_info_vram_vendor, NULL);

static const struct attribute *amdgpu_vram_mgr_attributes[] = {
        &dev_attr_mem_info_vram_total.attr,
        &dev_attr_mem_info_vis_vram_total.attr,
        &dev_attr_mem_info_vram_used.attr,
        &dev_attr_mem_info_vis_vram_used.attr,
        &dev_attr_mem_info_vram_vendor.attr,
        NULL
};

/**
 * amdgpu_vram_mgr_init - init VRAM manager and DRM MM
 *
 * @man: TTM memory type manager
 * @p_size: maximum size of VRAM
 *
 * Allocate and initialize the VRAM manager.
 */
static int amdgpu_vram_mgr_init(struct ttm_mem_type_manager *man,
                                unsigned long p_size)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(man->bdev);
        struct amdgpu_vram_mgr *mgr;
        int ret;

        mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
        if (!mgr)
                return -ENOMEM;

        drm_mm_init(&mgr->mm, 0, p_size);
        spin_lock_init(&mgr->lock);
        man->priv = mgr;

        /* Add the two VRAM-related sysfs files */
        ret = sysfs_create_files(&adev->dev->kobj, amdgpu_vram_mgr_attributes);
        if (ret)
                DRM_ERROR("Failed to register sysfs\n");

        return 0;
}

/**
 * amdgpu_vram_mgr_fini - free and destroy VRAM manager
 *
 * @man: TTM memory type manager
 *
 * Destroy and free the VRAM manager, returns -EBUSY if ranges are still
 * allocated inside it.
 */
static int amdgpu_vram_mgr_fini(struct ttm_mem_type_manager *man)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(man->bdev);
        struct amdgpu_vram_mgr *mgr = man->priv;

        spin_lock(&mgr->lock);
        drm_mm_takedown(&mgr->mm);
        spin_unlock(&mgr->lock);
        kfree(mgr);
        man->priv = NULL;
        sysfs_remove_files(&adev->dev->kobj, amdgpu_vram_mgr_attributes);
        return 0;
}

/**
 * amdgpu_vram_mgr_vis_size - Calculate visible node size
 *
 * @adev: amdgpu device structure
 * @node: MM node structure
 *
 * Calculate how many bytes of the MM node are inside visible VRAM
 */
static u64 amdgpu_vram_mgr_vis_size(struct amdgpu_device *adev,
                                    struct drm_mm_node *node)
{
        uint64_t start = node->start << PAGE_SHIFT;
        uint64_t end = (node->size + node->start) << PAGE_SHIFT;

        if (start >= adev->gmc.visible_vram_size)
                return 0;

        return (end > adev->gmc.visible_vram_size ?
                adev->gmc.visible_vram_size : end) - start;
}

/**
 * amdgpu_vram_mgr_bo_visible_size - CPU visible BO size
 *
 * @bo: &amdgpu_bo buffer object (must be in VRAM)
 *
 * Returns:
 * How much of the given &amdgpu_bo buffer object lies in CPU visible VRAM.
 */
u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        struct ttm_mem_reg *mem = &bo->tbo.mem;
        struct drm_mm_node *nodes = mem->mm_node;
        unsigned pages = mem->num_pages;
        u64 usage;

        if (amdgpu_gmc_vram_full_visible(&adev->gmc))
                return amdgpu_bo_size(bo);

        if (mem->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT)
                return 0;

        for (usage = 0; nodes && pages; pages -= nodes->size, nodes++)
                usage += amdgpu_vram_mgr_vis_size(adev, nodes);

        return usage;
}

/**
 * amdgpu_vram_mgr_virt_start - update virtual start address
 *
 * @mem: ttm_mem_reg to update
 * @node: just allocated node
 *
 * Calculate a virtual BO start address to easily check if everything is CPU
 * accessible.
 */
static void amdgpu_vram_mgr_virt_start(struct ttm_mem_reg *mem,
                                       struct drm_mm_node *node)
{
        unsigned long start;

        start = node->start + node->size;
        if (start > mem->num_pages)
                start -= mem->num_pages;
        else
                start = 0;
        mem->start = max(mem->start, start);
}

/**
 * amdgpu_vram_mgr_new - allocate new ranges
 *
 * @man: TTM memory type manager
 * @tbo: TTM BO we need this range for
 * @place: placement flags and restrictions
 * @mem: the resulting mem object
 *
 * Allocate VRAM for the given BO.
 */
static int amdgpu_vram_mgr_new(struct ttm_mem_type_manager *man,
                               struct ttm_buffer_object *tbo,
                               const struct ttm_place *place,
                               struct ttm_mem_reg *mem)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(man->bdev);
        struct amdgpu_vram_mgr *mgr = man->priv;
        struct drm_mm *mm = &mgr->mm;
        struct drm_mm_node *nodes;
        enum drm_mm_insert_mode mode;
        unsigned long lpfn, num_nodes, pages_per_node, pages_left;
        uint64_t vis_usage = 0, mem_bytes, max_bytes;
        unsigned i;
        int r;

        lpfn = place->lpfn;
        if (!lpfn)
                lpfn = man->size;

        max_bytes = adev->gmc.mc_vram_size;
        if (tbo->type != ttm_bo_type_kernel)
                max_bytes -= AMDGPU_VM_RESERVED_VRAM;

        /* bail out quickly if there's likely not enough VRAM for this BO */
        mem_bytes = (u64)mem->num_pages << PAGE_SHIFT;
        if (atomic64_add_return(mem_bytes, &mgr->usage) > max_bytes) {
                atomic64_sub(mem_bytes, &mgr->usage);
                mem->mm_node = NULL;
                return 0;
        }

        if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
                pages_per_node = ~0ul;
                num_nodes = 1;
        } else {
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                pages_per_node = HPAGE_PMD_NR;
#else
                /* default to 2MB */
                pages_per_node = (2UL << (20UL - PAGE_SHIFT));
#endif
                pages_per_node = max((uint32_t)pages_per_node, mem->page_alignment);
                num_nodes = DIV_ROUND_UP(mem->num_pages, pages_per_node);
        }

        nodes = kvmalloc_array((uint32_t)num_nodes, sizeof(*nodes),
                               GFP_KERNEL | __GFP_ZERO);
        if (!nodes) {
                atomic64_sub(mem_bytes, &mgr->usage);
                return -ENOMEM;
        }

        mode = DRM_MM_INSERT_BEST;
        if (place->flags & TTM_PL_FLAG_TOPDOWN)
                mode = DRM_MM_INSERT_HIGH;

        mem->start = 0;
        pages_left = mem->num_pages;

        spin_lock(&mgr->lock);
        for (i = 0; pages_left >= pages_per_node; ++i) {
                unsigned long pages = rounddown_pow_of_two(pages_left);

                r = drm_mm_insert_node_in_range(mm, &nodes[i], pages,
                                                pages_per_node, 0,
                                                place->fpfn, lpfn,
                                                mode);
                if (unlikely(r))
                        break;

                vis_usage += amdgpu_vram_mgr_vis_size(adev, &nodes[i]);
                amdgpu_vram_mgr_virt_start(mem, &nodes[i]);
                pages_left -= pages;
        }

        for (; pages_left; ++i) {
                unsigned long pages = min(pages_left, pages_per_node);
                uint32_t alignment = mem->page_alignment;

                if (pages == pages_per_node)
                        alignment = pages_per_node;

                r = drm_mm_insert_node_in_range(mm, &nodes[i],
                                                pages, alignment, 0,
                                                place->fpfn, lpfn,
                                                mode);
                if (unlikely(r))
                        goto error;

                vis_usage += amdgpu_vram_mgr_vis_size(adev, &nodes[i]);
                amdgpu_vram_mgr_virt_start(mem, &nodes[i]);
                pages_left -= pages;
        }
        spin_unlock(&mgr->lock);

        atomic64_add(vis_usage, &mgr->vis_usage);

        mem->mm_node = nodes;

        return 0;

error:
        while (i--)
                drm_mm_remove_node(&nodes[i]);
        spin_unlock(&mgr->lock);
        atomic64_sub(mem->num_pages << PAGE_SHIFT, &mgr->usage);

        kvfree(nodes);
        return r == -ENOSPC ? 0 : r;
}

/**
 * amdgpu_vram_mgr_del - free ranges
 *
 * @man: TTM memory type manager
 * @tbo: TTM BO we need this range for
 * @place: placement flags and restrictions
 * @mem: TTM memory object
 *
 * Free the allocated VRAM again.
 */
static void amdgpu_vram_mgr_del(struct ttm_mem_type_manager *man,
                                struct ttm_mem_reg *mem)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(man->bdev);
        struct amdgpu_vram_mgr *mgr = man->priv;
        struct drm_mm_node *nodes = mem->mm_node;
        uint64_t usage = 0, vis_usage = 0;
        unsigned pages = mem->num_pages;

        if (!mem->mm_node)
                return;

        spin_lock(&mgr->lock);
        while (pages) {
                pages -= nodes->size;
                drm_mm_remove_node(nodes);
                usage += nodes->size << PAGE_SHIFT;
                vis_usage += amdgpu_vram_mgr_vis_size(adev, nodes);
                ++nodes;
        }
        spin_unlock(&mgr->lock);

        atomic64_sub(usage, &mgr->usage);
        atomic64_sub(vis_usage, &mgr->vis_usage);

        kvfree(mem->mm_node);
        mem->mm_node = NULL;
}

/**
 * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
 *
 * @adev: amdgpu device pointer
 * @mem: TTM memory object
 * @dev: the other device
 * @dir: dma direction
 * @sgt: resulting sg table
 *
 * Allocate and fill a sg table from a VRAM allocation.
 */
int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
                              struct ttm_mem_reg *mem,
                              struct device *dev,
                              enum dma_data_direction dir,
                              struct sg_table **sgt)
{
        struct drm_mm_node *node;
        struct scatterlist *sg;
        int num_entries = 0;
        unsigned int pages;
        int i, r;

        *sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
        if (!*sgt)
                return -ENOMEM;

        for (pages = mem->num_pages, node = mem->mm_node;
             pages; pages -= node->size, ++node)
                ++num_entries;

        r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
        if (r)
                goto error_free;

        for_each_sg((*sgt)->sgl, sg, num_entries, i)
                sg->length = 0;

        node = mem->mm_node;
        for_each_sg((*sgt)->sgl, sg, num_entries, i) {
                phys_addr_t phys = (node->start << PAGE_SHIFT) +
                        adev->gmc.aper_base;
                size_t size = node->size << PAGE_SHIFT;
                dma_addr_t addr;

                ++node;
                addr = dma_map_resource(dev, phys, size, dir,
                                        DMA_ATTR_SKIP_CPU_SYNC);
                r = dma_mapping_error(dev, addr);
                if (r)
                        goto error_unmap;

                sg_set_page(sg, NULL, size, 0);
                sg_dma_address(sg) = addr;
                sg_dma_len(sg) = size;
        }
        return 0;

error_unmap:
        for_each_sg((*sgt)->sgl, sg, num_entries, i) {
                if (!sg->length)
                        continue;

                dma_unmap_resource(dev, sg->dma_address,
                                   sg->length, dir,
                                   DMA_ATTR_SKIP_CPU_SYNC);
        }
        sg_free_table(*sgt);

error_free:
        kfree(*sgt);
        return r;
}

/**
 * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
 *
 * @adev: amdgpu device pointer
 * @sgt: sg table to free
 *
 * Free a previously allocate sg table.
 */
void amdgpu_vram_mgr_free_sgt(struct amdgpu_device *adev,
                              struct device *dev,
                              enum dma_data_direction dir,
                              struct sg_table *sgt)
{
        struct scatterlist *sg;
        int i;

        for_each_sg(sgt->sgl, sg, sgt->nents, i)
                dma_unmap_resource(dev, sg->dma_address,
                                   sg->length, dir,
                                   DMA_ATTR_SKIP_CPU_SYNC);
        sg_free_table(sgt);
        kfree(sgt);
}

/**
 * amdgpu_vram_mgr_usage - how many bytes are used in this domain
 *
 * @man: TTM memory type manager
 *
 * Returns how many bytes are used in this domain.
 */
uint64_t amdgpu_vram_mgr_usage(struct ttm_mem_type_manager *man)
{
        struct amdgpu_vram_mgr *mgr = man->priv;

        return atomic64_read(&mgr->usage);
}

/**
 * amdgpu_vram_mgr_vis_usage - how many bytes are used in the visible part
 *
 * @man: TTM memory type manager
 *
 * Returns how many bytes are used in the visible part of VRAM
 */
uint64_t amdgpu_vram_mgr_vis_usage(struct ttm_mem_type_manager *man)
{
        struct amdgpu_vram_mgr *mgr = man->priv;

        return atomic64_read(&mgr->vis_usage);
}

/**
 * amdgpu_vram_mgr_debug - dump VRAM table
 *
 * @man: TTM memory type manager
 * @printer: DRM printer to use
 *
 * Dump the table content using printk.
 */
static void amdgpu_vram_mgr_debug(struct ttm_mem_type_manager *man,
                                  struct drm_printer *printer)
{
        struct amdgpu_vram_mgr *mgr = man->priv;

        spin_lock(&mgr->lock);
        drm_mm_print(&mgr->mm, printer);
        spin_unlock(&mgr->lock);

        drm_printf(printer, "man size:%llu pages, ram usage:%lluMB, vis usage:%lluMB\n",
                   man->size, amdgpu_vram_mgr_usage(man) >> 20,
                   amdgpu_vram_mgr_vis_usage(man) >> 20);
}

const struct ttm_mem_type_manager_func amdgpu_vram_mgr_func = {
        .init           = amdgpu_vram_mgr_init,
        .takedown       = amdgpu_vram_mgr_fini,
        .get_node       = amdgpu_vram_mgr_new,
        .put_node       = amdgpu_vram_mgr_del,
        .debug          = amdgpu_vram_mgr_debug
};