/*
 * Copyright 2010 Red Hat 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: Ben Skeggs
 */
#include "priv.h"

#include <core/gpuobj.h>
#include <subdev/fb.h>

void
nvkm_vm_map_at(struct nvkm_vma *vma, u64 delta, struct nvkm_mem *node)
{
        struct nvkm_vm *vm = vma->vm;
        struct nvkm_mmu *mmu = vm->mmu;
        struct nvkm_mm_node *r;
        int big = vma->node->type != mmu->func->spg_shift;
        u32 offset = vma->node->offset + (delta >> 12);
        u32 bits = vma->node->type - 12;
        u32 pde  = (offset >> mmu->func->pgt_bits) - vm->fpde;
        u32 pte  = (offset & ((1 << mmu->func->pgt_bits) - 1)) >> bits;
        u32 max  = 1 << (mmu->func->pgt_bits - bits);
        u32 end, len;

        delta = 0;
        list_for_each_entry(r, &node->regions, rl_entry) {
                u64 phys = (u64)r->offset << 12;
                u32 num  = r->length >> bits;

                while (num) {
                        struct nvkm_memory *pgt = vm->pgt[pde].mem[big];

                        end = (pte + num);
                        if (unlikely(end >= max))
                                end = max;
                        len = end - pte;

                        mmu->func->map(vma, pgt, node, pte, len, phys, delta);

                        num -= len;
                        pte += len;
                        if (unlikely(end >= max)) {
                                phys += len << (bits + 12);
                                pde++;
                                pte = 0;
                        }

                        delta += (u64)len << vma->node->type;
                }
        }

        mmu->func->flush(vm);
}

static void
nvkm_vm_map_sg_table(struct nvkm_vma *vma, u64 delta, u64 length,
                     struct nvkm_mem *mem)
{
        struct nvkm_vm *vm = vma->vm;
        struct nvkm_mmu *mmu = vm->mmu;
        int big = vma->node->type != mmu->func->spg_shift;
        u32 offset = vma->node->offset + (delta >> 12);
        u32 bits = vma->node->type - 12;
        u32 num  = length >> vma->node->type;
        u32 pde  = (offset >> mmu->func->pgt_bits) - vm->fpde;
        u32 pte  = (offset & ((1 << mmu->func->pgt_bits) - 1)) >> bits;
        u32 max  = 1 << (mmu->func->pgt_bits - bits);
        unsigned m, sglen;
        u32 end, len;
        int i;
        struct scatterlist *sg;

        for_each_sg(mem->sg->sgl, sg, mem->sg->nents, i) {
                struct nvkm_memory *pgt = vm->pgt[pde].mem[big];
                sglen = sg_dma_len(sg) >> PAGE_SHIFT;

                end = pte + sglen;
                if (unlikely(end >= max))
                        end = max;
                len = end - pte;

                for (m = 0; m < len; m++) {
                        dma_addr_t addr = sg_dma_address(sg) + (m << PAGE_SHIFT);

                        mmu->func->map_sg(vma, pgt, mem, pte, 1, &addr);
                        num--;
                        pte++;

                        if (num == 0)
                                goto finish;
                }
                if (unlikely(end >= max)) {
                        pde++;
                        pte = 0;
                }
                if (m < sglen) {
                        for (; m < sglen; m++) {
                                dma_addr_t addr = sg_dma_address(sg) + (m << PAGE_SHIFT);

                                mmu->func->map_sg(vma, pgt, mem, pte, 1, &addr);
                                num--;
                                pte++;
                                if (num == 0)
                                        goto finish;
                        }
                }

        }
finish:
        mmu->func->flush(vm);
}

static void
nvkm_vm_map_sg(struct nvkm_vma *vma, u64 delta, u64 length,
               struct nvkm_mem *mem)
{
        struct nvkm_vm *vm = vma->vm;
        struct nvkm_mmu *mmu = vm->mmu;
        dma_addr_t *list = mem->pages;
        int big = vma->node->type != mmu->func->spg_shift;
        u32 offset = vma->node->offset + (delta >> 12);
        u32 bits = vma->node->type - 12;
        u32 num  = length >> vma->node->type;
        u32 pde  = (offset >> mmu->func->pgt_bits) - vm->fpde;
        u32 pte  = (offset & ((1 << mmu->func->pgt_bits) - 1)) >> bits;
        u32 max  = 1 << (mmu->func->pgt_bits - bits);
        u32 end, len;

        while (num) {
                struct nvkm_memory *pgt = vm->pgt[pde].mem[big];

                end = (pte + num);
                if (unlikely(end >= max))
                        end = max;
                len = end - pte;

                mmu->func->map_sg(vma, pgt, mem, pte, len, list);

                num  -= len;
                pte  += len;
                list += len;
                if (unlikely(end >= max)) {
                        pde++;
                        pte = 0;
                }
        }

        mmu->func->flush(vm);
}

void
nvkm_vm_map(struct nvkm_vma *vma, struct nvkm_mem *node)
{
        if (node->sg)
                nvkm_vm_map_sg_table(vma, 0, node->size << 12, node);
        else
        if (node->pages)
                nvkm_vm_map_sg(vma, 0, node->size << 12, node);
        else
                nvkm_vm_map_at(vma, 0, node);
}

void
nvkm_vm_unmap_at(struct nvkm_vma *vma, u64 delta, u64 length)
{
        struct nvkm_vm *vm = vma->vm;
        struct nvkm_mmu *mmu = vm->mmu;
        int big = vma->node->type != mmu->func->spg_shift;
        u32 offset = vma->node->offset + (delta >> 12);
        u32 bits = vma->node->type - 12;
        u32 num  = length >> vma->node->type;
        u32 pde  = (offset >> mmu->func->pgt_bits) - vm->fpde;
        u32 pte  = (offset & ((1 << mmu->func->pgt_bits) - 1)) >> bits;
        u32 max  = 1 << (mmu->func->pgt_bits - bits);
        u32 end, len;

        while (num) {
                struct nvkm_memory *pgt = vm->pgt[pde].mem[big];

                end = (pte + num);
                if (unlikely(end >= max))
                        end = max;
                len = end - pte;

                mmu->func->unmap(vma, pgt, pte, len);

                num -= len;
                pte += len;
                if (unlikely(end >= max)) {
                        pde++;
                        pte = 0;
                }
        }

        mmu->func->flush(vm);
}

void
nvkm_vm_unmap(struct nvkm_vma *vma)
{
        nvkm_vm_unmap_at(vma, 0, (u64)vma->node->length << 12);
}

static void
nvkm_vm_unmap_pgt(struct nvkm_vm *vm, int big, u32 fpde, u32 lpde)
{
        struct nvkm_mmu *mmu = vm->mmu;
        struct nvkm_vm_pgd *vpgd;
        struct nvkm_vm_pgt *vpgt;
        struct nvkm_memory *pgt;
        u32 pde;

        for (pde = fpde; pde <= lpde; pde++) {
                vpgt = &vm->pgt[pde - vm->fpde];
                if (--vpgt->refcount[big])
                        continue;

                pgt = vpgt->mem[big];
                vpgt->mem[big] = NULL;

                list_for_each_entry(vpgd, &vm->pgd_list, head) {
                        mmu->func->map_pgt(vpgd->obj, pde, vpgt->mem);
                }

                nvkm_memory_del(&pgt);
        }
}

static int
nvkm_vm_map_pgt(struct nvkm_vm *vm, u32 pde, u32 type)
{
        struct nvkm_mmu *mmu = vm->mmu;
        struct nvkm_vm_pgt *vpgt = &vm->pgt[pde - vm->fpde];
        struct nvkm_vm_pgd *vpgd;
        int big = (type != mmu->func->spg_shift);
        u32 pgt_size;
        int ret;

        pgt_size  = (1 << (mmu->func->pgt_bits + 12)) >> type;
        pgt_size *= 8;

        ret = nvkm_memory_new(mmu->subdev.device, NVKM_MEM_TARGET_INST,
                              pgt_size, 0x1000, true, &vpgt->mem[big]);
        if (unlikely(ret))
                return ret;

        list_for_each_entry(vpgd, &vm->pgd_list, head) {
                mmu->func->map_pgt(vpgd->obj, pde, vpgt->mem);
        }

        vpgt->refcount[big]++;
        return 0;
}

int
nvkm_vm_get(struct nvkm_vm *vm, u64 size, u32 page_shift, u32 access,
            struct nvkm_vma *vma)
{
        struct nvkm_mmu *mmu = vm->mmu;
        u32 align = (1 << page_shift) >> 12;
        u32 msize = size >> 12;
        u32 fpde, lpde, pde;
        int ret;

        mutex_lock(&vm->mutex);
        ret = nvkm_mm_head(&vm->mm, 0, page_shift, msize, msize, align,
                           &vma->node);
        if (unlikely(ret != 0)) {
                mutex_unlock(&vm->mutex);
                return ret;
        }

        fpde = (vma->node->offset >> mmu->func->pgt_bits);
        lpde = (vma->node->offset + vma->node->length - 1) >> mmu->func->pgt_bits;

        for (pde = fpde; pde <= lpde; pde++) {
                struct nvkm_vm_pgt *vpgt = &vm->pgt[pde - vm->fpde];
                int big = (vma->node->type != mmu->func->spg_shift);

                if (likely(vpgt->refcount[big])) {
                        vpgt->refcount[big]++;
                        continue;
                }

                ret = nvkm_vm_map_pgt(vm, pde, vma->node->type);
                if (ret) {
                        if (pde != fpde)
                                nvkm_vm_unmap_pgt(vm, big, fpde, pde - 1);
                        nvkm_mm_free(&vm->mm, &vma->node);
                        mutex_unlock(&vm->mutex);
                        return ret;
                }
        }
        mutex_unlock(&vm->mutex);

        vma->vm = NULL;
        nvkm_vm_ref(vm, &vma->vm, NULL);
        vma->offset = (u64)vma->node->offset << 12;
        vma->access = access;
        return 0;
}

void
nvkm_vm_put(struct nvkm_vma *vma)
{
        struct nvkm_mmu *mmu;
        struct nvkm_vm *vm;
        u32 fpde, lpde;

        if (unlikely(vma->node == NULL))
                return;
        vm = vma->vm;
        mmu = vm->mmu;

        fpde = (vma->node->offset >> mmu->func->pgt_bits);
        lpde = (vma->node->offset + vma->node->length - 1) >> mmu->func->pgt_bits;

        mutex_lock(&vm->mutex);
        nvkm_vm_unmap_pgt(vm, vma->node->type != mmu->func->spg_shift, fpde, lpde);
        nvkm_mm_free(&vm->mm, &vma->node);
        mutex_unlock(&vm->mutex);

        nvkm_vm_ref(NULL, &vma->vm, NULL);
}

int
nvkm_vm_boot(struct nvkm_vm *vm, u64 size)
{
        struct nvkm_mmu *mmu = vm->mmu;
        struct nvkm_memory *pgt;
        int ret;

        ret = nvkm_memory_new(mmu->subdev.device, NVKM_MEM_TARGET_INST,
                              (size >> mmu->func->spg_shift) * 8, 0x1000, true, &pgt);
        if (ret == 0) {
                vm->pgt[0].refcount[0] = 1;
                vm->pgt[0].mem[0] = pgt;
                nvkm_memory_boot(pgt, vm);
        }

        return ret;
}

int
nvkm_vm_create(struct nvkm_mmu *mmu, u64 offset, u64 length, u64 mm_offset,
               u32 block, struct lock_class_key *key, struct nvkm_vm **pvm)
{
        static struct lock_class_key _key;
        struct nvkm_vm *vm;
        u64 mm_length = (offset + length) - mm_offset;
        int ret;

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

        __mutex_init(&vm->mutex, "&vm->mutex", key ? key : &_key);
        INIT_LIST_HEAD(&vm->pgd_list);
        vm->mmu = mmu;
        kref_init(&vm->refcount);
        vm->fpde = offset >> (mmu->func->pgt_bits + 12);
        vm->lpde = (offset + length - 1) >> (mmu->func->pgt_bits + 12);

        vm->pgt  = vzalloc((vm->lpde - vm->fpde + 1) * sizeof(*vm->pgt));
        if (!vm->pgt) {
                kfree(vm);
                return -ENOMEM;
        }

        ret = nvkm_mm_init(&vm->mm, mm_offset >> 12, mm_length >> 12,
                           block >> 12);
        if (ret) {
                vfree(vm->pgt);
                kfree(vm);
                return ret;
        }

        *pvm = vm;

        return 0;
}

int
nvkm_vm_new(struct nvkm_device *device, u64 offset, u64 length, u64 mm_offset,
            struct lock_class_key *key, struct nvkm_vm **pvm)
{
        struct nvkm_mmu *mmu = device->mmu;
        if (!mmu->func->create)
                return -EINVAL;
        return mmu->func->create(mmu, offset, length, mm_offset, key, pvm);
}

static int
nvkm_vm_link(struct nvkm_vm *vm, struct nvkm_gpuobj *pgd)
{
        struct nvkm_mmu *mmu = vm->mmu;
        struct nvkm_vm_pgd *vpgd;
        int i;

        if (!pgd)
                return 0;

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

        vpgd->obj = pgd;

        mutex_lock(&vm->mutex);
        for (i = vm->fpde; i <= vm->lpde; i++)
                mmu->func->map_pgt(pgd, i, vm->pgt[i - vm->fpde].mem);
        list_add(&vpgd->head, &vm->pgd_list);
        mutex_unlock(&vm->mutex);
        return 0;
}

static void
nvkm_vm_unlink(struct nvkm_vm *vm, struct nvkm_gpuobj *mpgd)
{
        struct nvkm_vm_pgd *vpgd, *tmp;

        if (!mpgd)
                return;

        mutex_lock(&vm->mutex);
        list_for_each_entry_safe(vpgd, tmp, &vm->pgd_list, head) {
                if (vpgd->obj == mpgd) {
                        list_del(&vpgd->head);
                        kfree(vpgd);
                        break;
                }
        }
        mutex_unlock(&vm->mutex);
}

static void
nvkm_vm_del(struct kref *kref)
{
        struct nvkm_vm *vm = container_of(kref, typeof(*vm), refcount);
        struct nvkm_vm_pgd *vpgd, *tmp;

        list_for_each_entry_safe(vpgd, tmp, &vm->pgd_list, head) {
                nvkm_vm_unlink(vm, vpgd->obj);
        }

        nvkm_mm_fini(&vm->mm);
        vfree(vm->pgt);
        kfree(vm);
}

int
nvkm_vm_ref(struct nvkm_vm *ref, struct nvkm_vm **ptr, struct nvkm_gpuobj *pgd)
{
        if (ref) {
                int ret = nvkm_vm_link(ref, pgd);
                if (ret)
                        return ret;

                kref_get(&ref->refcount);
        }

        if (*ptr) {
                nvkm_vm_unlink(*ptr, pgd);
                kref_put(&(*ptr)->refcount, nvkm_vm_del);
        }

        *ptr = ref;
        return 0;
}

static int
nvkm_mmu_oneinit(struct nvkm_subdev *subdev)
{
        struct nvkm_mmu *mmu = nvkm_mmu(subdev);
        if (mmu->func->oneinit)
                return mmu->func->oneinit(mmu);
        return 0;
}

static int
nvkm_mmu_init(struct nvkm_subdev *subdev)
{
        struct nvkm_mmu *mmu = nvkm_mmu(subdev);
        if (mmu->func->init)
                mmu->func->init(mmu);
        return 0;
}

static void *
nvkm_mmu_dtor(struct nvkm_subdev *subdev)
{
        struct nvkm_mmu *mmu = nvkm_mmu(subdev);
        if (mmu->func->dtor)
                return mmu->func->dtor(mmu);
        return mmu;
}

static const struct nvkm_subdev_func
nvkm_mmu = {
        .dtor = nvkm_mmu_dtor,
        .oneinit = nvkm_mmu_oneinit,
        .init = nvkm_mmu_init,
};

void
nvkm_mmu_ctor(const struct nvkm_mmu_func *func, struct nvkm_device *device,
              int index, struct nvkm_mmu *mmu)
{
        nvkm_subdev_ctor(&nvkm_mmu, device, index, 0, &mmu->subdev);
        mmu->func = func;
        mmu->limit = func->limit;
        mmu->dma_bits = func->dma_bits;
        mmu->lpg_shift = func->lpg_shift;
}

int
nvkm_mmu_new_(const struct nvkm_mmu_func *func, struct nvkm_device *device,
              int index, struct nvkm_mmu **pmmu)
{
        if (!(*pmmu = kzalloc(sizeof(**pmmu), GFP_KERNEL)))
                return -ENOMEM;
        nvkm_mmu_ctor(func, device, index, *pmmu);
        return 0;
}