/*
 * Copyright 2008 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 * Copyright 2009 Jerome Glisse.
 *
 * 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: Dave Airlie
 *          Alex Deucher
 *          Jerome Glisse
 */

#include <linux/pci.h>
#include <linux/vmalloc.h>

#include <drm/radeon_drm.h>
#ifdef CONFIG_X86
#include <asm/set_memory.h>
#endif
#include "radeon.h"

/*
 * GART
 * The GART (Graphics Aperture Remapping Table) is an aperture
 * in the GPU's address space.  System pages can be mapped into
 * the aperture and look like contiguous pages from the GPU's
 * perspective.  A page table maps the pages in the aperture
 * to the actual backing pages in system memory.
 *
 * Radeon GPUs support both an internal GART, as described above,
 * and AGP.  AGP works similarly, but the GART table is configured
 * and maintained by the northbridge rather than the driver.
 * Radeon hw has a separate AGP aperture that is programmed to
 * point to the AGP aperture provided by the northbridge and the
 * requests are passed through to the northbridge aperture.
 * Both AGP and internal GART can be used at the same time, however
 * that is not currently supported by the driver.
 *
 * This file handles the common internal GART management.
 */

/*
 * Common GART table functions.
 */
/**
 * radeon_gart_table_ram_alloc - allocate system ram for gart page table
 *
 * @rdev: radeon_device pointer
 *
 * Allocate system memory for GART page table
 * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
 * gart table to be in system memory.
 * Returns 0 for success, -ENOMEM for failure.
 */
int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
{
        void *ptr;

        ptr = dma_alloc_coherent(&rdev->pdev->dev, rdev->gart.table_size,
                                 &rdev->gart.table_addr, GFP_KERNEL);
        if (ptr == NULL) {
                return -ENOMEM;
        }
#ifdef CONFIG_X86
        if (rdev->family == CHIP_RS400 || rdev->family == CHIP_RS480 ||
            rdev->family == CHIP_RS690 || rdev->family == CHIP_RS740) {
                set_memory_uc((unsigned long)ptr,
                              rdev->gart.table_size >> PAGE_SHIFT);
        }
#endif
        rdev->gart.ptr = ptr;
        return 0;
}

/**
 * radeon_gart_table_ram_free - free system ram for gart page table
 *
 * @rdev: radeon_device pointer
 *
 * Free system memory for GART page table
 * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
 * gart table to be in system memory.
 */
void radeon_gart_table_ram_free(struct radeon_device *rdev)
{
        if (rdev->gart.ptr == NULL) {
                return;
        }
#ifdef CONFIG_X86
        if (rdev->family == CHIP_RS400 || rdev->family == CHIP_RS480 ||
            rdev->family == CHIP_RS690 || rdev->family == CHIP_RS740) {
                set_memory_wb((unsigned long)rdev->gart.ptr,
                              rdev->gart.table_size >> PAGE_SHIFT);
        }
#endif
        dma_free_coherent(&rdev->pdev->dev, rdev->gart.table_size,
                          (void *)rdev->gart.ptr, rdev->gart.table_addr);
        rdev->gart.ptr = NULL;
        rdev->gart.table_addr = 0;
}

/**
 * radeon_gart_table_vram_alloc - allocate vram for gart page table
 *
 * @rdev: radeon_device pointer
 *
 * Allocate video memory for GART page table
 * (pcie r4xx, r5xx+).  These asics require the
 * gart table to be in video memory.
 * Returns 0 for success, error for failure.
 */
int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
{
        int r;

        if (rdev->gart.robj == NULL) {
                r = radeon_bo_create(rdev, rdev->gart.table_size,
                                     PAGE_SIZE, true, RADEON_GEM_DOMAIN_VRAM,
                                     0, NULL, NULL, &rdev->gart.robj);
                if (r) {
                        return r;
                }
        }
        return 0;
}

/**
 * radeon_gart_table_vram_pin - pin gart page table in vram
 *
 * @rdev: radeon_device pointer
 *
 * Pin the GART page table in vram so it will not be moved
 * by the memory manager (pcie r4xx, r5xx+).  These asics require the
 * gart table to be in video memory.
 * Returns 0 for success, error for failure.
 */
int radeon_gart_table_vram_pin(struct radeon_device *rdev)
{
        uint64_t gpu_addr;
        int r;

        r = radeon_bo_reserve(rdev->gart.robj, false);
        if (unlikely(r != 0))
                return r;
        r = radeon_bo_pin(rdev->gart.robj,
                                RADEON_GEM_DOMAIN_VRAM, &gpu_addr);
        if (r) {
                radeon_bo_unreserve(rdev->gart.robj);
                return r;
        }
        r = radeon_bo_kmap(rdev->gart.robj, &rdev->gart.ptr);
        if (r)
                radeon_bo_unpin(rdev->gart.robj);
        radeon_bo_unreserve(rdev->gart.robj);
        rdev->gart.table_addr = gpu_addr;

        if (!r) {
                int i;

                /* We might have dropped some GART table updates while it wasn't
                 * mapped, restore all entries
                 */
                for (i = 0; i < rdev->gart.num_gpu_pages; i++)
                        radeon_gart_set_page(rdev, i, rdev->gart.pages_entry[i]);
                mb();
                radeon_gart_tlb_flush(rdev);
        }

        return r;
}

/**
 * radeon_gart_table_vram_unpin - unpin gart page table in vram
 *
 * @rdev: radeon_device pointer
 *
 * Unpin the GART page table in vram (pcie r4xx, r5xx+).
 * These asics require the gart table to be in video memory.
 */
void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
{
        int r;

        if (rdev->gart.robj == NULL) {
                return;
        }
        r = radeon_bo_reserve(rdev->gart.robj, false);
        if (likely(r == 0)) {
                radeon_bo_kunmap(rdev->gart.robj);
                radeon_bo_unpin(rdev->gart.robj);
                radeon_bo_unreserve(rdev->gart.robj);
                rdev->gart.ptr = NULL;
        }
}

/**
 * radeon_gart_table_vram_free - free gart page table vram
 *
 * @rdev: radeon_device pointer
 *
 * Free the video memory used for the GART page table
 * (pcie r4xx, r5xx+).  These asics require the gart table to
 * be in video memory.
 */
void radeon_gart_table_vram_free(struct radeon_device *rdev)
{
        if (rdev->gart.robj == NULL) {
                return;
        }
        radeon_bo_unref(&rdev->gart.robj);
}

/*
 * Common gart functions.
 */
/**
 * radeon_gart_unbind - unbind pages from the gart page table
 *
 * @rdev: radeon_device pointer
 * @offset: offset into the GPU's gart aperture
 * @pages: number of pages to unbind
 *
 * Unbinds the requested pages from the gart page table and
 * replaces them with the dummy page (all asics).
 */
void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
                        int pages)
{
        unsigned t;
        unsigned p;
        int i, j;

        if (!rdev->gart.ready) {
                WARN(1, "trying to unbind memory from uninitialized GART !\n");
                return;
        }
        t = offset / RADEON_GPU_PAGE_SIZE;
        p = t / (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
        for (i = 0; i < pages; i++, p++) {
                if (rdev->gart.pages[p]) {
                        rdev->gart.pages[p] = NULL;
                        for (j = 0; j < (PAGE_SIZE / RADEON_GPU_PAGE_SIZE); j++, t++) {
                                rdev->gart.pages_entry[t] = rdev->dummy_page.entry;
                                if (rdev->gart.ptr) {
                                        radeon_gart_set_page(rdev, t,
                                                             rdev->dummy_page.entry);
                                }
                        }
                }
        }
        if (rdev->gart.ptr) {
                mb();
                radeon_gart_tlb_flush(rdev);
        }
}

/**
 * radeon_gart_bind - bind pages into the gart page table
 *
 * @rdev: radeon_device pointer
 * @offset: offset into the GPU's gart aperture
 * @pages: number of pages to bind
 * @pagelist: pages to bind
 * @dma_addr: DMA addresses of pages
 * @flags: RADEON_GART_PAGE_* flags
 *
 * Binds the requested pages to the gart page table
 * (all asics).
 * Returns 0 for success, -EINVAL for failure.
 */
int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
                     int pages, struct page **pagelist, dma_addr_t *dma_addr,
                     uint32_t flags)
{
        unsigned t;
        unsigned p;
        uint64_t page_base, page_entry;
        int i, j;

        if (!rdev->gart.ready) {
                WARN(1, "trying to bind memory to uninitialized GART !\n");
                return -EINVAL;
        }
        t = offset / RADEON_GPU_PAGE_SIZE;
        p = t / (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);

        for (i = 0; i < pages; i++, p++) {
                rdev->gart.pages[p] = pagelist ? pagelist[i] :
                        rdev->dummy_page.page;
                page_base = dma_addr[i];
                for (j = 0; j < (PAGE_SIZE / RADEON_GPU_PAGE_SIZE); j++, t++) {
                        page_entry = radeon_gart_get_page_entry(page_base, flags);
                        rdev->gart.pages_entry[t] = page_entry;
                        if (rdev->gart.ptr) {
                                radeon_gart_set_page(rdev, t, page_entry);
                        }
                        page_base += RADEON_GPU_PAGE_SIZE;
                }
        }
        if (rdev->gart.ptr) {
                mb();
                radeon_gart_tlb_flush(rdev);
        }
        return 0;
}

/**
 * radeon_gart_init - init the driver info for managing the gart
 *
 * @rdev: radeon_device pointer
 *
 * Allocate the dummy page and init the gart driver info (all asics).
 * Returns 0 for success, error for failure.
 */
int radeon_gart_init(struct radeon_device *rdev)
{
        int r, i;

        if (rdev->gart.pages) {
                return 0;
        }
        /* We need PAGE_SIZE >= RADEON_GPU_PAGE_SIZE */
        if (PAGE_SIZE < RADEON_GPU_PAGE_SIZE) {
                DRM_ERROR("Page size is smaller than GPU page size!\n");
                return -EINVAL;
        }
        r = radeon_dummy_page_init(rdev);
        if (r)
                return r;
        /* Compute table size */
        rdev->gart.num_cpu_pages = rdev->mc.gtt_size / PAGE_SIZE;
        rdev->gart.num_gpu_pages = rdev->mc.gtt_size / RADEON_GPU_PAGE_SIZE;
        DRM_INFO("GART: num cpu pages %u, num gpu pages %u\n",
                 rdev->gart.num_cpu_pages, rdev->gart.num_gpu_pages);
        /* Allocate pages table */
        rdev->gart.pages = vzalloc(array_size(sizeof(void *),
                                   rdev->gart.num_cpu_pages));
        if (rdev->gart.pages == NULL) {
                radeon_gart_fini(rdev);
                return -ENOMEM;
        }
        rdev->gart.pages_entry = vmalloc(array_size(sizeof(uint64_t),
                                                    rdev->gart.num_gpu_pages));
        if (rdev->gart.pages_entry == NULL) {
                radeon_gart_fini(rdev);
                return -ENOMEM;
        }
        /* set GART entry to point to the dummy page by default */
        for (i = 0; i < rdev->gart.num_gpu_pages; i++)
                rdev->gart.pages_entry[i] = rdev->dummy_page.entry;
        return 0;
}

/**
 * radeon_gart_fini - tear down the driver info for managing the gart
 *
 * @rdev: radeon_device pointer
 *
 * Tear down the gart driver info and free the dummy page (all asics).
 */
void radeon_gart_fini(struct radeon_device *rdev)
{
        if (rdev->gart.ready) {
                /* unbind pages */
                radeon_gart_unbind(rdev, 0, rdev->gart.num_cpu_pages);
        }
        rdev->gart.ready = false;
        vfree(rdev->gart.pages);
        vfree(rdev->gart.pages_entry);
        rdev->gart.pages = NULL;
        rdev->gart.pages_entry = NULL;

        radeon_dummy_page_fini(rdev);
}