/*
 * Tegra host1x Job
 *
 * Copyright (c) 2010-2015, NVIDIA Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/host1x.h>
#include <linux/kref.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <trace/events/host1x.h>

#include "channel.h"
#include "dev.h"
#include "job.h"
#include "syncpt.h"

#define HOST1X_WAIT_SYNCPT_OFFSET 0x8

struct host1x_job *host1x_job_alloc(struct host1x_channel *ch,
                                    u32 num_cmdbufs, u32 num_relocs,
                                    u32 num_waitchks)
{
        struct host1x_job *job = NULL;
        unsigned int num_unpins = num_cmdbufs + num_relocs;
        u64 total;
        void *mem;

        /* Check that we're not going to overflow */
        total = sizeof(struct host1x_job) +
                (u64)num_relocs * sizeof(struct host1x_reloc) +
                (u64)num_unpins * sizeof(struct host1x_job_unpin_data) +
                (u64)num_waitchks * sizeof(struct host1x_waitchk) +
                (u64)num_cmdbufs * sizeof(struct host1x_job_gather) +
                (u64)num_unpins * sizeof(dma_addr_t) +
                (u64)num_unpins * sizeof(u32 *);
        if (total > ULONG_MAX)
                return NULL;

        mem = job = kzalloc(total, GFP_KERNEL);
        if (!job)
                return NULL;

        kref_init(&job->ref);
        job->channel = ch;

        /* Redistribute memory to the structs  */
        mem += sizeof(struct host1x_job);
        job->relocarray = num_relocs ? mem : NULL;
        mem += num_relocs * sizeof(struct host1x_reloc);
        job->unpins = num_unpins ? mem : NULL;
        mem += num_unpins * sizeof(struct host1x_job_unpin_data);
        job->waitchk = num_waitchks ? mem : NULL;
        mem += num_waitchks * sizeof(struct host1x_waitchk);
        job->gathers = num_cmdbufs ? mem : NULL;
        mem += num_cmdbufs * sizeof(struct host1x_job_gather);
        job->addr_phys = num_unpins ? mem : NULL;

        job->reloc_addr_phys = job->addr_phys;
        job->gather_addr_phys = &job->addr_phys[num_relocs];

        return job;
}
EXPORT_SYMBOL(host1x_job_alloc);

struct host1x_job *host1x_job_get(struct host1x_job *job)
{
        kref_get(&job->ref);
        return job;
}
EXPORT_SYMBOL(host1x_job_get);

static void job_free(struct kref *ref)
{
        struct host1x_job *job = container_of(ref, struct host1x_job, ref);

        kfree(job);
}

void host1x_job_put(struct host1x_job *job)
{
        kref_put(&job->ref, job_free);
}
EXPORT_SYMBOL(host1x_job_put);

void host1x_job_add_gather(struct host1x_job *job, struct host1x_bo *bo,
                           u32 words, u32 offset)
{
        struct host1x_job_gather *cur_gather = &job->gathers[job->num_gathers];

        cur_gather->words = words;
        cur_gather->bo = bo;
        cur_gather->offset = offset;
        job->num_gathers++;
}
EXPORT_SYMBOL(host1x_job_add_gather);

/*
 * NULL an already satisfied WAIT_SYNCPT host method, by patching its
 * args in the command stream. The method data is changed to reference
 * a reserved (never given out or incr) HOST1X_SYNCPT_RESERVED syncpt
 * with a matching threshold value of 0, so is guaranteed to be popped
 * by the host HW.
 */
static void host1x_syncpt_patch_offset(struct host1x_syncpt *sp,
                                       struct host1x_bo *h, u32 offset)
{
        void *patch_addr = NULL;

        /* patch the wait */
        patch_addr = host1x_bo_kmap(h, offset >> PAGE_SHIFT);
        if (patch_addr) {
                host1x_syncpt_patch_wait(sp,
                                         patch_addr + (offset & ~PAGE_MASK));
                host1x_bo_kunmap(h, offset >> PAGE_SHIFT, patch_addr);
        } else
                pr_err("Could not map cmdbuf for wait check\n");
}

/*
 * Check driver supplied waitchk structs for syncpt thresholds
 * that have already been satisfied and NULL the comparison (to
 * avoid a wrap condition in the HW).
 */
static int do_waitchks(struct host1x_job *job, struct host1x *host,
                       struct host1x_job_gather *g)
{
        struct host1x_bo *patch = g->bo;
        int i;

        /* compare syncpt vs wait threshold */
        for (i = 0; i < job->num_waitchk; i++) {
                struct host1x_waitchk *wait = &job->waitchk[i];
                struct host1x_syncpt *sp =
                        host1x_syncpt_get(host, wait->syncpt_id);

                /* validate syncpt id */
                if (wait->syncpt_id > host1x_syncpt_nb_pts(host))
                        continue;

                /* skip all other gathers */
                if (patch != wait->bo)
                        continue;

                trace_host1x_syncpt_wait_check(wait->bo, wait->offset,
                                               wait->syncpt_id, wait->thresh,
                                               host1x_syncpt_read_min(sp));

                if (host1x_syncpt_is_expired(sp, wait->thresh)) {
                        dev_dbg(host->dev,
                                "drop WAIT id %u (%s) thresh 0x%x, min 0x%x\n",
                                wait->syncpt_id, sp->name, wait->thresh,
                                host1x_syncpt_read_min(sp));

                        host1x_syncpt_patch_offset(sp, patch,
                                                   g->offset + wait->offset);
                }

                wait->bo = NULL;
        }

        return 0;
}

static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
{
        unsigned int i;
        int err;

        job->num_unpins = 0;

        for (i = 0; i < job->num_relocs; i++) {
                struct host1x_reloc *reloc = &job->relocarray[i];
                struct sg_table *sgt;
                dma_addr_t phys_addr;

                reloc->target.bo = host1x_bo_get(reloc->target.bo);
                if (!reloc->target.bo) {
                        err = -EINVAL;
                        goto unpin;
                }

                phys_addr = host1x_bo_pin(reloc->target.bo, &sgt);

                job->addr_phys[job->num_unpins] = phys_addr;
                job->unpins[job->num_unpins].bo = reloc->target.bo;
                job->unpins[job->num_unpins].sgt = sgt;
                job->num_unpins++;
        }

        for (i = 0; i < job->num_gathers; i++) {
                struct host1x_job_gather *g = &job->gathers[i];
                size_t gather_size = 0;
                struct scatterlist *sg;
                struct sg_table *sgt;
                dma_addr_t phys_addr;
                unsigned long shift;
                struct iova *alloc;
                unsigned int j;

                g->bo = host1x_bo_get(g->bo);
                if (!g->bo) {
                        err = -EINVAL;
                        goto unpin;
                }

                phys_addr = host1x_bo_pin(g->bo, &sgt);

                if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) && host->domain) {
                        for_each_sg(sgt->sgl, sg, sgt->nents, j)
                                gather_size += sg->length;
                        gather_size = iova_align(&host->iova, gather_size);

                        shift = iova_shift(&host->iova);
                        alloc = alloc_iova(&host->iova, gather_size >> shift,
                                           host->iova_end >> shift, true);
                        if (!alloc) {
                                err = -ENOMEM;
                                goto unpin;
                        }

                        err = iommu_map_sg(host->domain,
                                        iova_dma_addr(&host->iova, alloc),
                                        sgt->sgl, sgt->nents, IOMMU_READ);
                        if (err == 0) {
                                __free_iova(&host->iova, alloc);
                                err = -EINVAL;
                                goto unpin;
                        }

                        job->addr_phys[job->num_unpins] =
                                iova_dma_addr(&host->iova, alloc);
                        job->unpins[job->num_unpins].size = gather_size;
                } else {
                        job->addr_phys[job->num_unpins] = phys_addr;
                }

                job->gather_addr_phys[i] = job->addr_phys[job->num_unpins];

                job->unpins[job->num_unpins].bo = g->bo;
                job->unpins[job->num_unpins].sgt = sgt;
                job->num_unpins++;
        }

        return 0;

unpin:
        host1x_job_unpin(job);
        return err;
}

static int do_relocs(struct host1x_job *job, struct host1x_job_gather *g)
{
        int i = 0;
        u32 last_page = ~0;
        void *cmdbuf_page_addr = NULL;
        struct host1x_bo *cmdbuf = g->bo;

        /* pin & patch the relocs for one gather */
        for (i = 0; i < job->num_relocs; i++) {
                struct host1x_reloc *reloc = &job->relocarray[i];
                u32 reloc_addr = (job->reloc_addr_phys[i] +
                                  reloc->target.offset) >> reloc->shift;
                u32 *target;

                /* skip all other gathers */
                if (cmdbuf != reloc->cmdbuf.bo)
                        continue;

                if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) {
                        target = (u32 *)job->gather_copy_mapped +
                                        reloc->cmdbuf.offset / sizeof(u32) +
                                                g->offset / sizeof(u32);
                        goto patch_reloc;
                }

                if (last_page != reloc->cmdbuf.offset >> PAGE_SHIFT) {
                        if (cmdbuf_page_addr)
                                host1x_bo_kunmap(cmdbuf, last_page,
                                                 cmdbuf_page_addr);

                        cmdbuf_page_addr = host1x_bo_kmap(cmdbuf,
                                        reloc->cmdbuf.offset >> PAGE_SHIFT);
                        last_page = reloc->cmdbuf.offset >> PAGE_SHIFT;

                        if (unlikely(!cmdbuf_page_addr)) {
                                pr_err("Could not map cmdbuf for relocation\n");
                                return -ENOMEM;
                        }
                }

                target = cmdbuf_page_addr + (reloc->cmdbuf.offset & ~PAGE_MASK);
patch_reloc:
                *target = reloc_addr;
        }

        if (cmdbuf_page_addr)
                host1x_bo_kunmap(cmdbuf, last_page, cmdbuf_page_addr);

        return 0;
}

static bool check_reloc(struct host1x_reloc *reloc, struct host1x_bo *cmdbuf,
                        unsigned int offset)
{
        offset *= sizeof(u32);

        if (reloc->cmdbuf.bo != cmdbuf || reloc->cmdbuf.offset != offset)
                return false;

        /* relocation shift value validation isn't implemented yet */
        if (reloc->shift)
                return false;

        return true;
}

static bool check_wait(struct host1x_waitchk *wait, struct host1x_bo *cmdbuf,
                       unsigned int offset)
{
        offset *= sizeof(u32);

        if (wait->bo != cmdbuf || wait->offset != offset)
                return false;

        return true;
}

struct host1x_firewall {
        struct host1x_job *job;
        struct device *dev;

        unsigned int num_relocs;
        struct host1x_reloc *reloc;

        unsigned int num_waitchks;
        struct host1x_waitchk *waitchk;

        struct host1x_bo *cmdbuf;
        unsigned int offset;

        u32 words;
        u32 class;
        u32 reg;
        u32 mask;
        u32 count;
};

static int check_register(struct host1x_firewall *fw, unsigned long offset)
{
        if (!fw->job->is_addr_reg)
                return 0;

        if (fw->job->is_addr_reg(fw->dev, fw->class, offset)) {
                if (!fw->num_relocs)
                        return -EINVAL;

                if (!check_reloc(fw->reloc, fw->cmdbuf, fw->offset))
                        return -EINVAL;

                fw->num_relocs--;
                fw->reloc++;
        }

        if (offset == HOST1X_WAIT_SYNCPT_OFFSET) {
                if (fw->class != HOST1X_CLASS_HOST1X)
                        return -EINVAL;

                if (!fw->num_waitchks)
                        return -EINVAL;

                if (!check_wait(fw->waitchk, fw->cmdbuf, fw->offset))
                        return -EINVAL;

                fw->num_waitchks--;
                fw->waitchk++;
        }

        return 0;
}

static int check_class(struct host1x_firewall *fw, u32 class)
{
        if (!fw->job->is_valid_class) {
                if (fw->class != class)
                        return -EINVAL;
        } else {
                if (!fw->job->is_valid_class(fw->class))
                        return -EINVAL;
        }

        return 0;
}

static int check_mask(struct host1x_firewall *fw)
{
        u32 mask = fw->mask;
        u32 reg = fw->reg;
        int ret;

        while (mask) {
                if (fw->words == 0)
                        return -EINVAL;

                if (mask & 1) {
                        ret = check_register(fw, reg);
                        if (ret < 0)
                                return ret;

                        fw->words--;
                        fw->offset++;
                }
                mask >>= 1;
                reg++;
        }

        return 0;
}

static int check_incr(struct host1x_firewall *fw)
{
        u32 count = fw->count;
        u32 reg = fw->reg;
        int ret;

        while (count) {
                if (fw->words == 0)
                        return -EINVAL;

                ret = check_register(fw, reg);
                if (ret < 0)
                        return ret;

                reg++;
                fw->words--;
                fw->offset++;
                count--;
        }

        return 0;
}

static int check_nonincr(struct host1x_firewall *fw)
{
        u32 count = fw->count;
        int ret;

        while (count) {
                if (fw->words == 0)
                        return -EINVAL;

                ret = check_register(fw, fw->reg);
                if (ret < 0)
                        return ret;

                fw->words--;
                fw->offset++;
                count--;
        }

        return 0;
}

static int validate(struct host1x_firewall *fw, struct host1x_job_gather *g)
{
        u32 *cmdbuf_base = (u32 *)fw->job->gather_copy_mapped +
                (g->offset / sizeof(u32));
        u32 job_class = fw->class;
        int err = 0;

        fw->words = g->words;
        fw->cmdbuf = g->bo;
        fw->offset = 0;

        while (fw->words && !err) {
                u32 word = cmdbuf_base[fw->offset];
                u32 opcode = (word & 0xf0000000) >> 28;

                fw->mask = 0;
                fw->reg = 0;
                fw->count = 0;
                fw->words--;
                fw->offset++;

                switch (opcode) {
                case 0:
                        fw->class = word >> 6 & 0x3ff;
                        fw->mask = word & 0x3f;
                        fw->reg = word >> 16 & 0xfff;
                        err = check_class(fw, job_class);
                        if (!err)
                                err = check_mask(fw);
                        if (err)
                                goto out;
                        break;
                case 1:
                        fw->reg = word >> 16 & 0xfff;
                        fw->count = word & 0xffff;
                        err = check_incr(fw);
                        if (err)
                                goto out;
                        break;

                case 2:
                        fw->reg = word >> 16 & 0xfff;
                        fw->count = word & 0xffff;
                        err = check_nonincr(fw);
                        if (err)
                                goto out;
                        break;

                case 3:
                        fw->mask = word & 0xffff;
                        fw->reg = word >> 16 & 0xfff;
                        err = check_mask(fw);
                        if (err)
                                goto out;
                        break;
                case 4:
                case 14:
                        break;
                default:
                        err = -EINVAL;
                        break;
                }
        }

out:
        return err;
}

static inline int copy_gathers(struct host1x_job *job, struct device *dev)
{
        struct host1x_firewall fw;
        size_t size = 0;
        size_t offset = 0;
        int i;

        fw.job = job;
        fw.dev = dev;
        fw.reloc = job->relocarray;
        fw.num_relocs = job->num_relocs;
        fw.waitchk = job->waitchk;
        fw.num_waitchks = job->num_waitchk;
        fw.class = job->class;

        for (i = 0; i < job->num_gathers; i++) {
                struct host1x_job_gather *g = &job->gathers[i];

                size += g->words * sizeof(u32);
        }

        /*
         * Try a non-blocking allocation from a higher priority pools first,
         * as awaiting for the allocation here is a major performance hit.
         */
        job->gather_copy_mapped = dma_alloc_wc(dev, size, &job->gather_copy,
                                               GFP_NOWAIT);

        /* the higher priority allocation failed, try the generic-blocking */
        if (!job->gather_copy_mapped)
                job->gather_copy_mapped = dma_alloc_wc(dev, size,
                                                       &job->gather_copy,
                                                       GFP_KERNEL);
        if (!job->gather_copy_mapped)
                return -ENOMEM;

        job->gather_copy_size = size;

        for (i = 0; i < job->num_gathers; i++) {
                struct host1x_job_gather *g = &job->gathers[i];
                void *gather;

                /* Copy the gather */
                gather = host1x_bo_mmap(g->bo);
                memcpy(job->gather_copy_mapped + offset, gather + g->offset,
                       g->words * sizeof(u32));
                host1x_bo_munmap(g->bo, gather);

                /* Store the location in the buffer */
                g->base = job->gather_copy;
                g->offset = offset;

                /* Validate the job */
                if (validate(&fw, g))
                        return -EINVAL;

                offset += g->words * sizeof(u32);
        }

        /* No relocs and waitchks should remain at this point */
        if (fw.num_relocs || fw.num_waitchks)
                return -EINVAL;

        return 0;
}

int host1x_job_pin(struct host1x_job *job, struct device *dev)
{
        int err;
        unsigned int i, j;
        struct host1x *host = dev_get_drvdata(dev->parent);
        DECLARE_BITMAP(waitchk_mask, host1x_syncpt_nb_pts(host));

        bitmap_zero(waitchk_mask, host1x_syncpt_nb_pts(host));
        for (i = 0; i < job->num_waitchk; i++) {
                u32 syncpt_id = job->waitchk[i].syncpt_id;

                if (syncpt_id < host1x_syncpt_nb_pts(host))
                        set_bit(syncpt_id, waitchk_mask);
        }

        /* get current syncpt values for waitchk */
        for_each_set_bit(i, waitchk_mask, host1x_syncpt_nb_pts(host))
                host1x_syncpt_load(host->syncpt + i);

        /* pin memory */
        err = pin_job(host, job);
        if (err)
                goto out;

        if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) {
                err = copy_gathers(job, dev);
                if (err)
                        goto out;
        }

        /* patch gathers */
        for (i = 0; i < job->num_gathers; i++) {
                struct host1x_job_gather *g = &job->gathers[i];

                /* process each gather mem only once */
                if (g->handled)
                        continue;

                /* copy_gathers() sets gathers base if firewall is enabled */
                if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL))
                        g->base = job->gather_addr_phys[i];

                for (j = i + 1; j < job->num_gathers; j++) {
                        if (job->gathers[j].bo == g->bo) {
                                job->gathers[j].handled = true;
                                job->gathers[j].base = g->base;
                        }
                }

                err = do_relocs(job, g);
                if (err)
                        break;

                err = do_waitchks(job, host, g);
                if (err)
                        break;
        }

out:
        if (err)
                host1x_job_unpin(job);
        wmb();

        return err;
}
EXPORT_SYMBOL(host1x_job_pin);

void host1x_job_unpin(struct host1x_job *job)
{
        struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
        unsigned int i;

        for (i = 0; i < job->num_unpins; i++) {
                struct host1x_job_unpin_data *unpin = &job->unpins[i];

                if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) && host->domain) {
                        iommu_unmap(host->domain, job->addr_phys[i],
                                    unpin->size);
                        free_iova(&host->iova,
                                iova_pfn(&host->iova, job->addr_phys[i]));
                }

                host1x_bo_unpin(unpin->bo, unpin->sgt);
                host1x_bo_put(unpin->bo);
        }

        job->num_unpins = 0;

        if (job->gather_copy_size)
                dma_free_wc(job->channel->dev, job->gather_copy_size,
                            job->gather_copy_mapped, job->gather_copy);
}
EXPORT_SYMBOL(host1x_job_unpin);

/*
 * Debug routine used to dump job entries
 */
void host1x_job_dump(struct device *dev, struct host1x_job *job)
{
        dev_dbg(dev, "    SYNCPT_ID   %d\n", job->syncpt_id);
        dev_dbg(dev, "    SYNCPT_VAL  %d\n", job->syncpt_end);
        dev_dbg(dev, "    FIRST_GET   0x%x\n", job->first_get);
        dev_dbg(dev, "    TIMEOUT     %d\n", job->timeout);
        dev_dbg(dev, "    NUM_SLOTS   %d\n", job->num_slots);
        dev_dbg(dev, "    NUM_HANDLES %d\n", job->num_unpins);
}