/*
 * Copyright 2017 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.
 */
#define nvkm_mem(p) container_of((p), struct nvkm_mem, memory)
#include "mem.h"

#include <core/memory.h>

#include <nvif/if000a.h>
#include <nvif/unpack.h>

struct nvkm_mem {
        struct nvkm_memory memory;
        enum nvkm_memory_target target;
        struct nvkm_mmu *mmu;
        u64 pages;
        struct page **mem;
        union {
                struct scatterlist *sgl;
                dma_addr_t *dma;
        };
};

static enum nvkm_memory_target
nvkm_mem_target(struct nvkm_memory *memory)
{
        return nvkm_mem(memory)->target;
}

static u8
nvkm_mem_page(struct nvkm_memory *memory)
{
        return PAGE_SHIFT;
}

static u64
nvkm_mem_addr(struct nvkm_memory *memory)
{
        struct nvkm_mem *mem = nvkm_mem(memory);
        if (mem->pages == 1 && mem->mem)
                return mem->dma[0];
        return ~0ULL;
}

static u64
nvkm_mem_size(struct nvkm_memory *memory)
{
        return nvkm_mem(memory)->pages << PAGE_SHIFT;
}

static int
nvkm_mem_map_dma(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *vmm,
                 struct nvkm_vma *vma, void *argv, u32 argc)
{
        struct nvkm_mem *mem = nvkm_mem(memory);
        struct nvkm_vmm_map map = {
                .memory = &mem->memory,
                .offset = offset,
                .dma = mem->dma,
        };
        return nvkm_vmm_map(vmm, vma, argv, argc, &map);
}

static void *
nvkm_mem_dtor(struct nvkm_memory *memory)
{
        struct nvkm_mem *mem = nvkm_mem(memory);
        if (mem->mem) {
                while (mem->pages--) {
                        dma_unmap_page(mem->mmu->subdev.device->dev,
                                       mem->dma[mem->pages], PAGE_SIZE,
                                       DMA_BIDIRECTIONAL);
                        __free_page(mem->mem[mem->pages]);
                }
                kvfree(mem->dma);
                kvfree(mem->mem);
        }
        return mem;
}

static const struct nvkm_memory_func
nvkm_mem_dma = {
        .dtor = nvkm_mem_dtor,
        .target = nvkm_mem_target,
        .page = nvkm_mem_page,
        .addr = nvkm_mem_addr,
        .size = nvkm_mem_size,
        .map = nvkm_mem_map_dma,
};

static int
nvkm_mem_map_sgl(struct nvkm_memory *memory, u64 offset, struct nvkm_vmm *vmm,
                 struct nvkm_vma *vma, void *argv, u32 argc)
{
        struct nvkm_mem *mem = nvkm_mem(memory);
        struct nvkm_vmm_map map = {
                .memory = &mem->memory,
                .offset = offset,
                .sgl = mem->sgl,
        };
        return nvkm_vmm_map(vmm, vma, argv, argc, &map);
}

static const struct nvkm_memory_func
nvkm_mem_sgl = {
        .dtor = nvkm_mem_dtor,
        .target = nvkm_mem_target,
        .page = nvkm_mem_page,
        .addr = nvkm_mem_addr,
        .size = nvkm_mem_size,
        .map = nvkm_mem_map_sgl,
};

int
nvkm_mem_map_host(struct nvkm_memory *memory, void **pmap)
{
        struct nvkm_mem *mem = nvkm_mem(memory);
        if (mem->mem) {
                *pmap = vmap(mem->mem, mem->pages, VM_MAP, PAGE_KERNEL);
                return *pmap ? 0 : -EFAULT;
        }
        return -EINVAL;
}

static int
nvkm_mem_new_host(struct nvkm_mmu *mmu, int type, u8 page, u64 size,
                  void *argv, u32 argc, struct nvkm_memory **pmemory)
{
        struct device *dev = mmu->subdev.device->dev;
        union {
                struct nvif_mem_ram_vn vn;
                struct nvif_mem_ram_v0 v0;
        } *args = argv;
        int ret = -ENOSYS;
        enum nvkm_memory_target target;
        struct nvkm_mem *mem;
        gfp_t gfp = GFP_USER | __GFP_ZERO;

        if ( (mmu->type[type].type & NVKM_MEM_COHERENT) &&
            !(mmu->type[type].type & NVKM_MEM_UNCACHED))
                target = NVKM_MEM_TARGET_HOST;
        else
                target = NVKM_MEM_TARGET_NCOH;

        if (page != PAGE_SHIFT)
                return -EINVAL;

        if (!(mem = kzalloc(sizeof(*mem), GFP_KERNEL)))
                return -ENOMEM;
        mem->target = target;
        mem->mmu = mmu;
        *pmemory = &mem->memory;

        if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
                if (args->v0.dma) {
                        nvkm_memory_ctor(&nvkm_mem_dma, &mem->memory);
                        mem->dma = args->v0.dma;
                } else {
                        nvkm_memory_ctor(&nvkm_mem_sgl, &mem->memory);
                        mem->sgl = args->v0.sgl;
                }

                if (!IS_ALIGNED(size, PAGE_SIZE))
                        return -EINVAL;
                mem->pages = size >> PAGE_SHIFT;
                return 0;
        } else
        if ( (ret = nvif_unvers(ret, &argv, &argc, args->vn))) {
                kfree(mem);
                return ret;
        }

        nvkm_memory_ctor(&nvkm_mem_dma, &mem->memory);
        size = ALIGN(size, PAGE_SIZE) >> PAGE_SHIFT;

        if (!(mem->mem = kvmalloc_array(size, sizeof(*mem->mem), GFP_KERNEL)))
                return -ENOMEM;
        if (!(mem->dma = kvmalloc_array(size, sizeof(*mem->dma), GFP_KERNEL)))
                return -ENOMEM;

        if (mmu->dma_bits > 32)
                gfp |= GFP_HIGHUSER;
        else
                gfp |= GFP_DMA32;

        for (mem->pages = 0; size; size--, mem->pages++) {
                struct page *p = alloc_page(gfp);
                if (!p)
                        return -ENOMEM;

                mem->dma[mem->pages] = dma_map_page(mmu->subdev.device->dev,
                                                    p, 0, PAGE_SIZE,
                                                    DMA_BIDIRECTIONAL);
                if (dma_mapping_error(dev, mem->dma[mem->pages])) {
                        __free_page(p);
                        return -ENOMEM;
                }

                mem->mem[mem->pages] = p;
        }

        return 0;
}

int
nvkm_mem_new_type(struct nvkm_mmu *mmu, int type, u8 page, u64 size,
                  void *argv, u32 argc, struct nvkm_memory **pmemory)
{
        struct nvkm_memory *memory = NULL;
        int ret;

        if (mmu->type[type].type & NVKM_MEM_VRAM) {
                ret = mmu->func->mem.vram(mmu, type, page, size,
                                          argv, argc, &memory);
        } else {
                ret = nvkm_mem_new_host(mmu, type, page, size,
                                        argv, argc, &memory);
        }

        if (ret)
                nvkm_memory_unref(&memory);
        *pmemory = memory;
        return ret;
}