/*-
 * Copyright (c) 2013-2017, Mellanox Technologies, Ltd.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_rss.h"
#include "opt_ratelimit.h"

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <dev/mlx5/driver.h>
#include <dev/mlx5/mlx5_core/mlx5_core.h>

CTASSERT((uintptr_t)PAGE_MASK > (uintptr_t)PAGE_SIZE);

struct mlx5_pages_req {
        struct mlx5_core_dev *dev;
        u16     func_id;
        s32     npages;
        struct work_struct work;
};


enum {
        MAX_RECLAIM_TIME_MSECS  = 5000,
};

static void
mlx5_fwp_load_mem_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        struct mlx5_fw_page *fwp;
        uint8_t owned;

        fwp = (struct mlx5_fw_page *)arg;
        owned = MLX5_DMA_OWNED(fwp->dev);

        if (!owned)
                MLX5_DMA_LOCK(fwp->dev);

        if (error == 0) {
                KASSERT(nseg == 1, ("Number of segments is different from 1"));
                fwp->dma_addr = segs->ds_addr;
                fwp->load_done = MLX5_LOAD_ST_SUCCESS;
        } else {
                fwp->load_done = MLX5_LOAD_ST_FAILURE;
        }
        MLX5_DMA_DONE(fwp->dev);

        if (!owned)
                MLX5_DMA_UNLOCK(fwp->dev);
}

void
mlx5_fwp_flush(struct mlx5_fw_page *fwp)
{
        unsigned num = fwp->numpages;

        while (num--)
                bus_dmamap_sync(fwp[num].dev->cmd.dma_tag, fwp[num].dma_map, BUS_DMASYNC_PREWRITE);
}

void
mlx5_fwp_invalidate(struct mlx5_fw_page *fwp)
{
        unsigned num = fwp->numpages;

        while (num--) {
                bus_dmamap_sync(fwp[num].dev->cmd.dma_tag, fwp[num].dma_map, BUS_DMASYNC_POSTREAD);
                bus_dmamap_sync(fwp[num].dev->cmd.dma_tag, fwp[num].dma_map, BUS_DMASYNC_PREREAD);
        }
}

struct mlx5_fw_page *
mlx5_fwp_alloc(struct mlx5_core_dev *dev, gfp_t flags, unsigned num)
{
        struct mlx5_fw_page *fwp;
        unsigned x;
        int err;

        /* check for special case */
        if (num == 0) {
                fwp = kzalloc(sizeof(*fwp), flags);
                if (fwp != NULL)
                        fwp->dev = dev;
                return (fwp);
        }

        /* we need sleeping context for this function */
        if (flags & M_NOWAIT)
                return (NULL);

        fwp = kzalloc(sizeof(*fwp) * num, flags);

        /* serialize loading the DMA map(s) */
        sx_xlock(&dev->cmd.dma_sx);

        for (x = 0; x != num; x++) {
                /* store pointer to MLX5 core device */
                fwp[x].dev = dev;
                /* store number of pages left from the array */
                fwp[x].numpages = num - x;

                /* allocate memory */
                err = bus_dmamem_alloc(dev->cmd.dma_tag, &fwp[x].virt_addr,
                    BUS_DMA_WAITOK | BUS_DMA_COHERENT, &fwp[x].dma_map);
                if (err != 0)
                        goto failure;

                /* load memory into DMA */
                MLX5_DMA_LOCK(dev);
                (void) bus_dmamap_load(
                    dev->cmd.dma_tag, fwp[x].dma_map, fwp[x].virt_addr,
                    MLX5_ADAPTER_PAGE_SIZE, &mlx5_fwp_load_mem_cb,
                    fwp + x, BUS_DMA_WAITOK | BUS_DMA_COHERENT);

                while (fwp[x].load_done == MLX5_LOAD_ST_NONE)
                        MLX5_DMA_WAIT(dev);
                MLX5_DMA_UNLOCK(dev);

                /* check for error */
                if (fwp[x].load_done != MLX5_LOAD_ST_SUCCESS) {
                        bus_dmamem_free(dev->cmd.dma_tag, fwp[x].virt_addr,
                            fwp[x].dma_map);
                        goto failure;
                }
        }
        sx_xunlock(&dev->cmd.dma_sx);
        return (fwp);

failure:
        while (x--) {
                bus_dmamap_unload(dev->cmd.dma_tag, fwp[x].dma_map);
                bus_dmamem_free(dev->cmd.dma_tag, fwp[x].virt_addr, fwp[x].dma_map);
        }
        sx_xunlock(&dev->cmd.dma_sx);
        kfree(fwp);
        return (NULL);
}

void
mlx5_fwp_free(struct mlx5_fw_page *fwp)
{
        struct mlx5_core_dev *dev;
        unsigned num;

        /* be NULL safe */
        if (fwp == NULL)
                return;

        /* check for special case */
        if (fwp->numpages == 0) {
                kfree(fwp);
                return;
        }

        num = fwp->numpages;
        dev = fwp->dev;

        while (num--) {
                bus_dmamap_unload(dev->cmd.dma_tag, fwp[num].dma_map);
                bus_dmamem_free(dev->cmd.dma_tag, fwp[num].virt_addr, fwp[num].dma_map);
        }

        kfree(fwp);
}

u64
mlx5_fwp_get_dma(struct mlx5_fw_page *fwp, size_t offset)
{
        size_t index = (offset / MLX5_ADAPTER_PAGE_SIZE);
        KASSERT(index < fwp->numpages, ("Invalid offset: %lld", (long long)offset));

        return ((fwp + index)->dma_addr + (offset % MLX5_ADAPTER_PAGE_SIZE));
}

void *
mlx5_fwp_get_virt(struct mlx5_fw_page *fwp, size_t offset)
{
        size_t index = (offset / MLX5_ADAPTER_PAGE_SIZE);
        KASSERT(index < fwp->numpages, ("Invalid offset: %lld", (long long)offset));

        return ((char *)(fwp + index)->virt_addr + (offset % MLX5_ADAPTER_PAGE_SIZE));
}

static int
mlx5_insert_fw_page_locked(struct mlx5_core_dev *dev, struct mlx5_fw_page *nfp)
{
        struct rb_root *root = &dev->priv.page_root;
        struct rb_node **new = &root->rb_node;
        struct rb_node *parent = NULL;
        struct mlx5_fw_page *tfp;

        while (*new) {
                parent = *new;
                tfp = rb_entry(parent, struct mlx5_fw_page, rb_node);
                if (tfp->dma_addr < nfp->dma_addr)
                        new = &parent->rb_left;
                else if (tfp->dma_addr > nfp->dma_addr)
                        new = &parent->rb_right;
                else
                        return (-EEXIST);
        }

        rb_link_node(&nfp->rb_node, parent, new);
        rb_insert_color(&nfp->rb_node, root);
        return (0);
}

static struct mlx5_fw_page *
mlx5_remove_fw_page_locked(struct mlx5_core_dev *dev, bus_addr_t addr)
{
        struct rb_root *root = &dev->priv.page_root;
        struct rb_node *tmp = root->rb_node;
        struct mlx5_fw_page *result = NULL;
        struct mlx5_fw_page *tfp;

        while (tmp) {
                tfp = rb_entry(tmp, struct mlx5_fw_page, rb_node);
                if (tfp->dma_addr < addr) {
                        tmp = tmp->rb_left;
                } else if (tfp->dma_addr > addr) {
                        tmp = tmp->rb_right;
                } else {
                        rb_erase(&tfp->rb_node, &dev->priv.page_root);
                        result = tfp;
                        break;
                }
        }
        return (result);
}

static int
alloc_4k(struct mlx5_core_dev *dev, u64 *addr, u16 func_id)
{
        struct mlx5_fw_page *fwp;
        int err;

        fwp = mlx5_fwp_alloc(dev, GFP_KERNEL, 1);
        if (fwp == NULL)
                return (-ENOMEM);

        fwp->func_id = func_id;

        MLX5_DMA_LOCK(dev);
        err = mlx5_insert_fw_page_locked(dev, fwp);
        MLX5_DMA_UNLOCK(dev);

        if (err != 0) {
                mlx5_fwp_free(fwp);
        } else {
                /* make sure cached data is cleaned */
                mlx5_fwp_invalidate(fwp);

                /* store DMA address */
                *addr = fwp->dma_addr;
        }
        return (err);
}

static void
free_4k(struct mlx5_core_dev *dev, u64 addr)
{
        struct mlx5_fw_page *fwp;

        MLX5_DMA_LOCK(dev);
        fwp = mlx5_remove_fw_page_locked(dev, addr);
        MLX5_DMA_UNLOCK(dev);

        if (fwp == NULL) {
                mlx5_core_warn(dev, "Cannot free 4K page at 0x%llx\n", (long long)addr);
                return;
        }
        mlx5_fwp_free(fwp);
}

static int mlx5_cmd_query_pages(struct mlx5_core_dev *dev, u16 *func_id,
                                s32 *npages, int boot)
{
        u32 in[MLX5_ST_SZ_DW(query_pages_in)] = {0};
        u32 out[MLX5_ST_SZ_DW(query_pages_out)] = {0};
        int err;

        MLX5_SET(query_pages_in, in, opcode, MLX5_CMD_OP_QUERY_PAGES);
        MLX5_SET(query_pages_in, in, op_mod, boot ?
                 MLX5_QUERY_PAGES_IN_OP_MOD_BOOT_PAGES :
                 MLX5_QUERY_PAGES_IN_OP_MOD_INIT_PAGES);

        err = mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
        if (err)
                return err;

        *npages = MLX5_GET(query_pages_out, out, num_pages);
        *func_id = MLX5_GET(query_pages_out, out, function_id);

        return 0;
}

static int give_pages(struct mlx5_core_dev *dev, u16 func_id, int npages,
                      int notify_fail)
{
        u32 out[MLX5_ST_SZ_DW(manage_pages_out)] = {0};
        int inlen = MLX5_ST_SZ_BYTES(manage_pages_in);
        u64 addr;
        int err;
        u32 *in, *nin;
        int i = 0;

        inlen += npages * MLX5_FLD_SZ_BYTES(manage_pages_in, pas[0]);
        in = mlx5_vzalloc(inlen);
        if (!in) {
                mlx5_core_warn(dev, "vzalloc failed %d\n", inlen);
                err = -ENOMEM;
                goto out_alloc;
        }

        for (i = 0; i < npages; i++) {
                err = alloc_4k(dev, &addr, func_id);
                if (err)
                        goto out_alloc;
                MLX5_ARRAY_SET64(manage_pages_in, in, pas, i, addr);
        }

        MLX5_SET(manage_pages_in, in, opcode, MLX5_CMD_OP_MANAGE_PAGES);
        MLX5_SET(manage_pages_in, in, op_mod, MLX5_PAGES_GIVE);
        MLX5_SET(manage_pages_in, in, function_id, func_id);
        MLX5_SET(manage_pages_in, in, input_num_entries, npages);

        err = mlx5_cmd_exec(dev, in, inlen, out, sizeof(out));
        if (err) {
                mlx5_core_warn(dev, "func_id 0x%x, npages %d, err %d\n",
                               func_id, npages, err);
                goto out_alloc;
        }
        dev->priv.fw_pages += npages;
        dev->priv.pages_per_func[func_id] += npages;

        mlx5_core_dbg(dev, "err %d\n", err);

        goto out_free;

out_alloc:
        if (notify_fail) {
                nin = mlx5_vzalloc(inlen);
                if (!nin)
                        goto out_4k;

                memset(&out, 0, sizeof(out));
                MLX5_SET(manage_pages_in, nin, opcode, MLX5_CMD_OP_MANAGE_PAGES);
                MLX5_SET(manage_pages_in, nin, op_mod, MLX5_PAGES_CANT_GIVE);
                MLX5_SET(manage_pages_in, nin, function_id, func_id);
                if (mlx5_cmd_exec(dev, nin, inlen, out, sizeof(out)))
                        mlx5_core_warn(dev, "page notify failed\n");
                kvfree(nin);
        }

out_4k:
        for (i--; i >= 0; i--)
                free_4k(dev, MLX5_GET64(manage_pages_in, in, pas[i]));
out_free:
        kvfree(in);
        return err;
}

static int reclaim_pages_cmd(struct mlx5_core_dev *dev,
                             u32 *in, int in_size, u32 *out, int out_size)
{
        struct mlx5_fw_page *fwp;
        struct rb_node *p;
        u32 func_id;
        u32 npages;
        u32 i = 0;

        if (dev->state != MLX5_DEVICE_STATE_INTERNAL_ERROR)
                return mlx5_cmd_exec(dev, in, in_size, out, out_size);

        /* No hard feelings, we want our pages back! */
        npages = MLX5_GET(manage_pages_in, in, input_num_entries);
        func_id = MLX5_GET(manage_pages_in, in, function_id);

        p = rb_first(&dev->priv.page_root);
        while (p && i < npages) {
                fwp = rb_entry(p, struct mlx5_fw_page, rb_node);
                p = rb_next(p);
                if (fwp->func_id != func_id)
                        continue;

                MLX5_ARRAY_SET64(manage_pages_out, out, pas, i, fwp->dma_addr);
                i++;
        }

        MLX5_SET(manage_pages_out, out, output_num_entries, i);
        return 0;
}

static int reclaim_pages(struct mlx5_core_dev *dev, u32 func_id, int npages,
                         int *nclaimed)
{
        int outlen = MLX5_ST_SZ_BYTES(manage_pages_out);
        u32 in[MLX5_ST_SZ_DW(manage_pages_in)] = {0};
        int num_claimed;
        u32 *out;
        int err;
        int i;

        if (nclaimed)
                *nclaimed = 0;

        outlen += npages * MLX5_FLD_SZ_BYTES(manage_pages_out, pas[0]);
        out = mlx5_vzalloc(outlen);
        if (!out)
                return -ENOMEM;

        MLX5_SET(manage_pages_in, in, opcode, MLX5_CMD_OP_MANAGE_PAGES);
        MLX5_SET(manage_pages_in, in, op_mod, MLX5_PAGES_TAKE);
        MLX5_SET(manage_pages_in, in, function_id, func_id);
        MLX5_SET(manage_pages_in, in, input_num_entries, npages);

        mlx5_core_dbg(dev, "npages %d, outlen %d\n", npages, outlen);
        err = reclaim_pages_cmd(dev, in, sizeof(in), out, outlen);
        if (err) {
                mlx5_core_err(dev, "failed reclaiming pages\n");
                goto out_free;
        }

        num_claimed = MLX5_GET(manage_pages_out, out, output_num_entries);
        if (nclaimed)
                *nclaimed = num_claimed;

        dev->priv.fw_pages -= num_claimed;
        dev->priv.pages_per_func[func_id] -= num_claimed;
        for (i = 0; i < num_claimed; i++)
                free_4k(dev, MLX5_GET64(manage_pages_out, out, pas[i]));

out_free:
        kvfree(out);
        return err;
}

static void pages_work_handler(struct work_struct *work)
{
        struct mlx5_pages_req *req = container_of(work, struct mlx5_pages_req, work);
        struct mlx5_core_dev *dev = req->dev;
        int err = 0;

        if (req->npages < 0)
                err = reclaim_pages(dev, req->func_id, -1 * req->npages, NULL);
        else if (req->npages > 0)
                err = give_pages(dev, req->func_id, req->npages, 1);

        if (err)
                mlx5_core_warn(dev, "%s fail %d\n",
                               req->npages < 0 ? "reclaim" : "give", err);

        kfree(req);
}

void mlx5_core_req_pages_handler(struct mlx5_core_dev *dev, u16 func_id,
                                 s32 npages)
{
        struct mlx5_pages_req *req;

        req = kzalloc(sizeof(*req), GFP_ATOMIC);
        if (!req) {
                mlx5_core_warn(dev, "failed to allocate pages request\n");
                return;
        }

        req->dev = dev;
        req->func_id = func_id;
        req->npages = npages;
        INIT_WORK(&req->work, pages_work_handler);
        if (!queue_work(dev->priv.pg_wq, &req->work))
                mlx5_core_warn(dev, "failed to queue pages handler work\n");
}

int mlx5_satisfy_startup_pages(struct mlx5_core_dev *dev, int boot)
{
        u16 uninitialized_var(func_id);
        s32 uninitialized_var(npages);
        int err;

        err = mlx5_cmd_query_pages(dev, &func_id, &npages, boot);
        if (err)
                return err;

        mlx5_core_dbg(dev, "requested %d %s pages for func_id 0x%x\n",
                      npages, boot ? "boot" : "init", func_id);

        if (npages > 0)
                return give_pages(dev, func_id, npages, 0);
        else
                return 0;
}

enum {
        MLX5_BLKS_FOR_RECLAIM_PAGES = 12
};

s64 mlx5_wait_for_reclaim_vfs_pages(struct mlx5_core_dev *dev)
{
        unsigned long end = jiffies + msecs_to_jiffies(MAX_RECLAIM_TIME_MSECS);
        s64 prevpages = 0;
        s64 npages = 0;

        while (!time_after(jiffies, end)) {
                /* exclude own function, VFs only */
                npages = dev->priv.fw_pages - dev->priv.pages_per_func[0];
                if (!npages)
                        break;

                if (npages != prevpages)
                        end = end + msecs_to_jiffies(100);

                prevpages = npages;
                msleep(1);
        }

        if (npages)
                mlx5_core_warn(dev, "FW did not return all VFs pages, will cause to memory leak\n");

        return -npages;
}

static int optimal_reclaimed_pages(void)
{
        struct mlx5_cmd_prot_block *block;
        struct mlx5_cmd_layout *lay;
        int ret;

        ret = (sizeof(lay->out) + MLX5_BLKS_FOR_RECLAIM_PAGES * sizeof(block->data) -
               MLX5_ST_SZ_BYTES(manage_pages_out)) /
               MLX5_FLD_SZ_BYTES(manage_pages_out, pas[0]);

        return ret;
}

int mlx5_reclaim_startup_pages(struct mlx5_core_dev *dev)
{
        unsigned long end = jiffies + msecs_to_jiffies(MAX_RECLAIM_TIME_MSECS);
        struct mlx5_fw_page *fwp;
        struct rb_node *p;
        int nclaimed = 0;
        int err;

        do {
                p = rb_first(&dev->priv.page_root);
                if (p) {
                        fwp = rb_entry(p, struct mlx5_fw_page, rb_node);
                        err = reclaim_pages(dev, fwp->func_id,
                                            optimal_reclaimed_pages(),
                                            &nclaimed);
                        if (err) {
                                mlx5_core_warn(dev, "failed reclaiming pages (%d)\n",
                                               err);
                                return err;
                        }

                        if (nclaimed)
                                end = jiffies + msecs_to_jiffies(MAX_RECLAIM_TIME_MSECS);
                }
                if (time_after(jiffies, end)) {
                        mlx5_core_warn(dev, "FW did not return all pages. giving up...\n");
                        break;
                }
        } while (p);

        return 0;
}

void mlx5_pagealloc_init(struct mlx5_core_dev *dev)
{

        dev->priv.page_root = RB_ROOT;
}

void mlx5_pagealloc_cleanup(struct mlx5_core_dev *dev)
{
        /* nothing */
}

int mlx5_pagealloc_start(struct mlx5_core_dev *dev)
{
        dev->priv.pg_wq = create_singlethread_workqueue("mlx5_page_allocator");
        if (!dev->priv.pg_wq)
                return -ENOMEM;

        return 0;
}

void mlx5_pagealloc_stop(struct mlx5_core_dev *dev)
{
        destroy_workqueue(dev->priv.pg_wq);
}