/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * 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, sub license, 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 (including the
 * next paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */
/*
 * Copyright (c) 2013 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by Konstantin Belousov
 * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
 */

#include <sys/cdefs.h>
#include <dev/drm2/drmP.h>
#include <dev/drm2/ttm/ttm_module.h>
#include <dev/drm2/ttm/ttm_bo_driver.h>
#include <dev/drm2/ttm/ttm_placement.h>
#include <dev/drm2/ttm/ttm_page_alloc.h>

MALLOC_DEFINE(M_TTM_PD, "ttm_pd", "TTM Page Directories");

/**
 * Allocates storage for pointers to the pages that back the ttm.
 */
static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
{
        ttm->pages = malloc(ttm->num_pages * sizeof(void *),
            M_TTM_PD, M_WAITOK | M_ZERO);
}

static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
{
        ttm->ttm.pages = malloc(ttm->ttm.num_pages * sizeof(void *),
            M_TTM_PD, M_WAITOK | M_ZERO);
        ttm->dma_address = malloc(ttm->ttm.num_pages *
            sizeof(*ttm->dma_address), M_TTM_PD, M_WAITOK);
}

#if defined(__i386__) || defined(__amd64__)
static inline int ttm_tt_set_page_caching(vm_page_t p,
                                          enum ttm_caching_state c_old,
                                          enum ttm_caching_state c_new)
{

        /* XXXKIB our VM does not need this. */
#if 0
        if (c_old != tt_cached) {
                /* p isn't in the default caching state, set it to
                 * writeback first to free its current memtype. */
                pmap_page_set_memattr(p, VM_MEMATTR_WRITE_BACK);
        }
#endif

        if (c_new == tt_wc)
                pmap_page_set_memattr(p, VM_MEMATTR_WRITE_COMBINING);
        else if (c_new == tt_uncached)
                pmap_page_set_memattr(p, VM_MEMATTR_UNCACHEABLE);

        return (0);
}
#else
static inline int ttm_tt_set_page_caching(vm_page_t p,
                                          enum ttm_caching_state c_old,
                                          enum ttm_caching_state c_new)
{
        return 0;
}
#endif

/*
 * Change caching policy for the linear kernel map
 * for range of pages in a ttm.
 */

static int ttm_tt_set_caching(struct ttm_tt *ttm,
                              enum ttm_caching_state c_state)
{
        int i, j;
        vm_page_t cur_page;
        int ret;

        if (ttm->caching_state == c_state)
                return 0;

        if (ttm->state == tt_unpopulated) {
                /* Change caching but don't populate */
                ttm->caching_state = c_state;
                return 0;
        }

        if (ttm->caching_state == tt_cached)
                drm_clflush_pages(ttm->pages, ttm->num_pages);

        for (i = 0; i < ttm->num_pages; ++i) {
                cur_page = ttm->pages[i];
                if (likely(cur_page != NULL)) {
                        ret = ttm_tt_set_page_caching(cur_page,
                                                      ttm->caching_state,
                                                      c_state);
                        if (unlikely(ret != 0))
                                goto out_err;
                }
        }

        ttm->caching_state = c_state;

        return 0;

out_err:
        for (j = 0; j < i; ++j) {
                cur_page = ttm->pages[j];
                if (cur_page != NULL) {
                        (void)ttm_tt_set_page_caching(cur_page, c_state,
                                                      ttm->caching_state);
                }
        }

        return ret;
}

int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
{
        enum ttm_caching_state state;

        if (placement & TTM_PL_FLAG_WC)
                state = tt_wc;
        else if (placement & TTM_PL_FLAG_UNCACHED)
                state = tt_uncached;
        else
                state = tt_cached;

        return ttm_tt_set_caching(ttm, state);
}

void ttm_tt_destroy(struct ttm_tt *ttm)
{
        if (unlikely(ttm == NULL))
                return;

        if (ttm->state == tt_bound) {
                ttm_tt_unbind(ttm);
        }

        if (likely(ttm->pages != NULL)) {
                ttm->bdev->driver->ttm_tt_unpopulate(ttm);
        }

        if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP) &&
            ttm->swap_storage)
                vm_object_deallocate(ttm->swap_storage);

        ttm->swap_storage = NULL;
        ttm->func->destroy(ttm);
}

int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
                unsigned long size, uint32_t page_flags,
                vm_page_t dummy_read_page)
{
        ttm->bdev = bdev;
        ttm->glob = bdev->glob;
        ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
        ttm->caching_state = tt_cached;
        ttm->page_flags = page_flags;
        ttm->dummy_read_page = dummy_read_page;
        ttm->state = tt_unpopulated;
        ttm->swap_storage = NULL;

        ttm_tt_alloc_page_directory(ttm);
        if (!ttm->pages) {
                ttm_tt_destroy(ttm);
                printf("Failed allocating page table\n");
                return -ENOMEM;
        }
        return 0;
}

void ttm_tt_fini(struct ttm_tt *ttm)
{
        free(ttm->pages, M_TTM_PD);
        ttm->pages = NULL;
}

int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
                unsigned long size, uint32_t page_flags,
                vm_page_t dummy_read_page)
{
        struct ttm_tt *ttm = &ttm_dma->ttm;

        ttm->bdev = bdev;
        ttm->glob = bdev->glob;
        ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
        ttm->caching_state = tt_cached;
        ttm->page_flags = page_flags;
        ttm->dummy_read_page = dummy_read_page;
        ttm->state = tt_unpopulated;
        ttm->swap_storage = NULL;

        INIT_LIST_HEAD(&ttm_dma->pages_list);
        ttm_dma_tt_alloc_page_directory(ttm_dma);
        if (!ttm->pages || !ttm_dma->dma_address) {
                ttm_tt_destroy(ttm);
                printf("Failed allocating page table\n");
                return -ENOMEM;
        }
        return 0;
}

void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma)
{
        struct ttm_tt *ttm = &ttm_dma->ttm;

        free(ttm->pages, M_TTM_PD);
        ttm->pages = NULL;
        free(ttm_dma->dma_address, M_TTM_PD);
        ttm_dma->dma_address = NULL;
}

void ttm_tt_unbind(struct ttm_tt *ttm)
{
        int ret __diagused;

        if (ttm->state == tt_bound) {
                ret = ttm->func->unbind(ttm);
                MPASS(ret == 0);
                ttm->state = tt_unbound;
        }
}

int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
{
        int ret = 0;

        if (!ttm)
                return -EINVAL;

        if (ttm->state == tt_bound)
                return 0;

        ret = ttm->bdev->driver->ttm_tt_populate(ttm);
        if (ret)
                return ret;

        ret = ttm->func->bind(ttm, bo_mem);
        if (unlikely(ret != 0))
                return ret;

        ttm->state = tt_bound;

        return 0;
}

int ttm_tt_swapin(struct ttm_tt *ttm)
{
        vm_object_t obj;
        vm_page_t from_page, to_page;
        int i, ret, rv;

        obj = ttm->swap_storage;

        vm_object_pip_add(obj, 1);
        for (i = 0; i < ttm->num_pages; ++i) {
                rv = vm_page_grab_valid_unlocked(&from_page, obj, i,
                    VM_ALLOC_NORMAL | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY);
                if (rv != VM_PAGER_OK) {
                        ret = -EIO;
                        goto err_ret;
                }
                to_page = ttm->pages[i];
                if (unlikely(to_page == NULL)) {
                        vm_page_sunbusy(from_page);
                        ret = -ENOMEM;
                        goto err_ret;
                }
                pmap_copy_page(from_page, to_page);
                vm_page_sunbusy(from_page);
        }
        vm_object_pip_wakeup(obj);

        if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
                vm_object_deallocate(obj);
        ttm->swap_storage = NULL;
        ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
        return (0);

err_ret:
        vm_object_pip_wakeup(obj);
        return (ret);
}

int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
{
        vm_object_t obj;
        vm_page_t from_page, to_page;
        int i;

        MPASS(ttm->state == tt_unbound || ttm->state == tt_unpopulated);
        MPASS(ttm->caching_state == tt_cached);

        if (persistent_swap_storage == NULL) {
                obj = vm_pager_allocate(OBJT_SWAP, NULL,
                    IDX_TO_OFF(ttm->num_pages), VM_PROT_DEFAULT, 0,
                    curthread->td_ucred);
                if (obj == NULL) {
                        printf("[TTM] Failed allocating swap storage\n");
                        return (-ENOMEM);
                }
        } else
                obj = persistent_swap_storage;

        VM_OBJECT_WLOCK(obj);
        vm_object_pip_add(obj, 1);
        for (i = 0; i < ttm->num_pages; ++i) {
                from_page = ttm->pages[i];
                if (unlikely(from_page == NULL))
                        continue;
                to_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL);
                pmap_copy_page(from_page, to_page);
                vm_page_valid(to_page);
                vm_page_dirty(to_page);
                vm_page_xunbusy(to_page);
        }
        vm_object_pip_wakeup(obj);
        VM_OBJECT_WUNLOCK(obj);

        ttm->bdev->driver->ttm_tt_unpopulate(ttm);
        ttm->swap_storage = obj;
        ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
        if (persistent_swap_storage != NULL)
                ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;
        return (0);
}