/*
 * Copyright 2015 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 <bskeggs@redhat.com>
 */
#include <core/memory.h>
#include <core/mm.h>
#include <subdev/fb.h>
#include <subdev/instmem.h>

void
nvkm_memory_tags_put(struct nvkm_memory *memory, struct nvkm_device *device,
                     struct nvkm_tags **ptags)
{
        struct nvkm_fb *fb = device->fb;
        struct nvkm_tags *tags = *ptags;
        if (tags) {
                mutex_lock(&fb->tags.mutex);
                if (refcount_dec_and_test(&tags->refcount)) {
                        nvkm_mm_free(&fb->tags.mm, &tags->mn);
                        kfree(memory->tags);
                        memory->tags = NULL;
                }
                mutex_unlock(&fb->tags.mutex);
                *ptags = NULL;
        }
}

int
nvkm_memory_tags_get(struct nvkm_memory *memory, struct nvkm_device *device,
                     u32 nr, void (*clr)(struct nvkm_device *, u32, u32),
                     struct nvkm_tags **ptags)
{
        struct nvkm_fb *fb = device->fb;
        struct nvkm_tags *tags;

        mutex_lock(&fb->tags.mutex);
        if ((tags = memory->tags)) {
                /* If comptags exist for the memory, but a different amount
                 * than requested, the buffer is being mapped with settings
                 * that are incompatible with existing mappings.
                 */
                if (tags->mn && tags->mn->length != nr) {
                        mutex_unlock(&fb->tags.mutex);
                        return -EINVAL;
                }

                refcount_inc(&tags->refcount);
                mutex_unlock(&fb->tags.mutex);
                *ptags = tags;
                return 0;
        }

        if (!(tags = kmalloc_obj(*tags))) {
                mutex_unlock(&fb->tags.mutex);
                return -ENOMEM;
        }

        if (!nvkm_mm_head(&fb->tags.mm, 0, 1, nr, nr, 1, &tags->mn)) {
                if (clr)
                        clr(device, tags->mn->offset, tags->mn->length);
        } else {
                /* Failure to allocate HW comptags is not an error, the
                 * caller should fall back to an uncompressed map.
                 *
                 * As memory can be mapped in multiple places, we still
                 * need to track the allocation failure and ensure that
                 * any additional mappings remain uncompressed.
                 *
                 * This is handled by returning an empty nvkm_tags.
                 */
                tags->mn = NULL;
        }

        refcount_set(&tags->refcount, 1);
        *ptags = memory->tags = tags;
        mutex_unlock(&fb->tags.mutex);
        return 0;
}

void
nvkm_memory_ctor(const struct nvkm_memory_func *func,
                 struct nvkm_memory *memory)
{
        memory->func = func;
        kref_init(&memory->kref);
}

static void
nvkm_memory_del(struct kref *kref)
{
        struct nvkm_memory *memory = container_of(kref, typeof(*memory), kref);
        if (!WARN_ON(!memory->func)) {
                if (memory->func->dtor)
                        memory = memory->func->dtor(memory);
                kfree(memory);
        }
}

void
nvkm_memory_unref(struct nvkm_memory **pmemory)
{
        struct nvkm_memory *memory = *pmemory;
        if (memory) {
                kref_put(&memory->kref, nvkm_memory_del);
                *pmemory = NULL;
        }
}

struct nvkm_memory *
nvkm_memory_ref(struct nvkm_memory *memory)
{
        if (memory)
                kref_get(&memory->kref);
        return memory;
}

int
nvkm_memory_new(struct nvkm_device *device, enum nvkm_memory_target target,
                u64 size, u32 align, bool zero,
                struct nvkm_memory **pmemory)
{
        struct nvkm_instmem *imem = device->imem;
        struct nvkm_memory *memory;
        bool preserve = true;
        int ret;

        if (unlikely(!imem))
                return -ENOSYS;

        switch (target) {
        case NVKM_MEM_TARGET_INST_SR_LOST:
                preserve = false;
                break;
        case NVKM_MEM_TARGET_INST:
                break;
        default:
                return -ENOSYS;
        }

        ret = nvkm_instobj_new(imem, size, align, zero, preserve, &memory);
        if (ret)
                return ret;

        *pmemory = memory;
        return 0;
}