/*
 * Copyright 2018 Advanced Micro Devices, Inc.
 * 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 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.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */

#include <linux/io-64-nonatomic-lo-hi.h>

#include "amdgpu.h"

/**
 * amdgpu_gmc_get_pde_for_bo - get the PDE for a BO
 *
 * @bo: the BO to get the PDE for
 * @level: the level in the PD hirarchy
 * @addr: resulting addr
 * @flags: resulting flags
 *
 * Get the address and flags to be used for a PDE (Page Directory Entry).
 */
void amdgpu_gmc_get_pde_for_bo(struct amdgpu_bo *bo, int level,
                               uint64_t *addr, uint64_t *flags)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        struct ttm_dma_tt *ttm;

        switch (bo->tbo.mem.mem_type) {
        case TTM_PL_TT:
                ttm = container_of(bo->tbo.ttm, struct ttm_dma_tt, ttm);
                *addr = ttm->dma_address[0];
                break;
        case TTM_PL_VRAM:
                *addr = amdgpu_bo_gpu_offset(bo);
                break;
        default:
                *addr = 0;
                break;
        }
        *flags = amdgpu_ttm_tt_pde_flags(bo->tbo.ttm, &bo->tbo.mem);
        amdgpu_gmc_get_vm_pde(adev, level, addr, flags);
}

/**
 * amdgpu_gmc_pd_addr - return the address of the root directory
 *
 */
uint64_t amdgpu_gmc_pd_addr(struct amdgpu_bo *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        uint64_t pd_addr;

        /* TODO: move that into ASIC specific code */
        if (adev->asic_type >= CHIP_VEGA10) {
                uint64_t flags = AMDGPU_PTE_VALID;

                amdgpu_gmc_get_pde_for_bo(bo, -1, &pd_addr, &flags);
                pd_addr |= flags;
        } else {
                pd_addr = amdgpu_bo_gpu_offset(bo);
        }
        return pd_addr;
}

/**
 * amdgpu_gmc_set_pte_pde - update the page tables using CPU
 *
 * @adev: amdgpu_device pointer
 * @cpu_pt_addr: cpu address of the page table
 * @gpu_page_idx: entry in the page table to update
 * @addr: dst addr to write into pte/pde
 * @flags: access flags
 *
 * Update the page tables using CPU.
 */
int amdgpu_gmc_set_pte_pde(struct amdgpu_device *adev, void *cpu_pt_addr,
                                uint32_t gpu_page_idx, uint64_t addr,
                                uint64_t flags)
{
        void __iomem *ptr = (void *)cpu_pt_addr;
        uint64_t value;

        /*
         * The following is for PTE only. GART does not have PDEs.
        */
        value = addr & 0x0000FFFFFFFFF000ULL;
        value |= flags;
        writeq(value, ptr + (gpu_page_idx * 8));
        return 0;
}

/**
 * amdgpu_gmc_agp_addr - return the address in the AGP address space
 *
 * @tbo: TTM BO which needs the address, must be in GTT domain
 *
 * Tries to figure out how to access the BO through the AGP aperture. Returns
 * AMDGPU_BO_INVALID_OFFSET if that is not possible.
 */
uint64_t amdgpu_gmc_agp_addr(struct ttm_buffer_object *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct ttm_dma_tt *ttm;

        if (bo->num_pages != 1 || bo->ttm->caching_state == tt_cached)
                return AMDGPU_BO_INVALID_OFFSET;

        ttm = container_of(bo->ttm, struct ttm_dma_tt, ttm);
        if (ttm->dma_address[0] + PAGE_SIZE >= adev->gmc.agp_size)
                return AMDGPU_BO_INVALID_OFFSET;

        return adev->gmc.agp_start + ttm->dma_address[0];
}

/**
 * amdgpu_gmc_vram_location - try to find VRAM location
 *
 * @adev: amdgpu device structure holding all necessary informations
 * @mc: memory controller structure holding memory informations
 * @base: base address at which to put VRAM
 *
 * Function will try to place VRAM at base address provided
 * as parameter.
 */
void amdgpu_gmc_vram_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc,
                              u64 base)
{
        uint64_t limit = (uint64_t)amdgpu_vram_limit << 20;

        mc->vram_start = base;
        mc->vram_end = mc->vram_start + mc->mc_vram_size - 1;
        if (limit && limit < mc->real_vram_size)
                mc->real_vram_size = limit;

        if (mc->xgmi.num_physical_nodes == 0) {
                mc->fb_start = mc->vram_start;
                mc->fb_end = mc->vram_end;
        }
        dev_info(adev->dev, "VRAM: %lluM 0x%016llX - 0x%016llX (%lluM used)\n",
                        mc->mc_vram_size >> 20, mc->vram_start,
                        mc->vram_end, mc->real_vram_size >> 20);
}

/**
 * amdgpu_gmc_gart_location - try to find GART location
 *
 * @adev: amdgpu device structure holding all necessary informations
 * @mc: memory controller structure holding memory informations
 *
 * Function will place try to place GART before or after VRAM.
 *
 * If GART size is bigger than space left then we ajust GART size.
 * Thus function will never fails.
 */
void amdgpu_gmc_gart_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
{
        const uint64_t four_gb = 0x100000000ULL;
        u64 size_af, size_bf;
        /*To avoid the hole, limit the max mc address to AMDGPU_GMC_HOLE_START*/
        u64 max_mc_address = min(adev->gmc.mc_mask, AMDGPU_GMC_HOLE_START - 1);

        mc->gart_size += adev->pm.smu_prv_buffer_size;

        /* VCE doesn't like it when BOs cross a 4GB segment, so align
         * the GART base on a 4GB boundary as well.
         */
        size_bf = mc->fb_start;
        size_af = max_mc_address + 1 - ALIGN(mc->fb_end + 1, four_gb);

        if (mc->gart_size > max(size_bf, size_af)) {
                dev_warn(adev->dev, "limiting GART\n");
                mc->gart_size = max(size_bf, size_af);
        }

        if ((size_bf >= mc->gart_size && size_bf < size_af) ||
            (size_af < mc->gart_size))
                mc->gart_start = 0;
        else
                mc->gart_start = max_mc_address - mc->gart_size + 1;

        mc->gart_start &= ~(four_gb - 1);
        mc->gart_end = mc->gart_start + mc->gart_size - 1;
        dev_info(adev->dev, "GART: %lluM 0x%016llX - 0x%016llX\n",
                        mc->gart_size >> 20, mc->gart_start, mc->gart_end);
}

/**
 * amdgpu_gmc_agp_location - try to find AGP location
 * @adev: amdgpu device structure holding all necessary informations
 * @mc: memory controller structure holding memory informations
 *
 * Function will place try to find a place for the AGP BAR in the MC address
 * space.
 *
 * AGP BAR will be assigned the largest available hole in the address space.
 * Should be called after VRAM and GART locations are setup.
 */
void amdgpu_gmc_agp_location(struct amdgpu_device *adev, struct amdgpu_gmc *mc)
{
        const uint64_t sixteen_gb = 1ULL << 34;
        const uint64_t sixteen_gb_mask = ~(sixteen_gb - 1);
        u64 size_af, size_bf;

        if (amdgpu_sriov_vf(adev)) {
                mc->agp_start = 0xffffffff;
                mc->agp_end = 0x0;
                mc->agp_size = 0;

                return;
        }

        if (mc->fb_start > mc->gart_start) {
                size_bf = (mc->fb_start & sixteen_gb_mask) -
                        ALIGN(mc->gart_end + 1, sixteen_gb);
                size_af = mc->mc_mask + 1 - ALIGN(mc->fb_end + 1, sixteen_gb);
        } else {
                size_bf = mc->fb_start & sixteen_gb_mask;
                size_af = (mc->gart_start & sixteen_gb_mask) -
                        ALIGN(mc->fb_end + 1, sixteen_gb);
        }

        if (size_bf > size_af) {
                mc->agp_start = (mc->fb_start - size_bf) & sixteen_gb_mask;
                mc->agp_size = size_bf;
        } else {
                mc->agp_start = ALIGN(mc->fb_end + 1, sixteen_gb);
                mc->agp_size = size_af;
        }

        mc->agp_end = mc->agp_start + mc->agp_size - 1;
        dev_info(adev->dev, "AGP: %lluM 0x%016llX - 0x%016llX\n",
                        mc->agp_size >> 20, mc->agp_start, mc->agp_end);
}

/**
 * amdgpu_gmc_filter_faults - filter VM faults
 *
 * @adev: amdgpu device structure
 * @addr: address of the VM fault
 * @pasid: PASID of the process causing the fault
 * @timestamp: timestamp of the fault
 *
 * Returns:
 * True if the fault was filtered and should not be processed further.
 * False if the fault is a new one and needs to be handled.
 */
bool amdgpu_gmc_filter_faults(struct amdgpu_device *adev, uint64_t addr,
                              uint16_t pasid, uint64_t timestamp)
{
        struct amdgpu_gmc *gmc = &adev->gmc;

        uint64_t stamp, key = addr << 4 | pasid;
        struct amdgpu_gmc_fault *fault;
        uint32_t hash;

        /* If we don't have space left in the ring buffer return immediately */
        stamp = max(timestamp, AMDGPU_GMC_FAULT_TIMEOUT + 1) -
                AMDGPU_GMC_FAULT_TIMEOUT;
        if (gmc->fault_ring[gmc->last_fault].timestamp >= stamp)
                return true;

        /* Try to find the fault in the hash */
        hash = hash_64(key, AMDGPU_GMC_FAULT_HASH_ORDER);
        fault = &gmc->fault_ring[gmc->fault_hash[hash].idx];
        while (fault->timestamp >= stamp) {
                uint64_t tmp;

                if (fault->key == key)
                        return true;

                tmp = fault->timestamp;
                fault = &gmc->fault_ring[fault->next];

                /* Check if the entry was reused */
                if (fault->timestamp >= tmp)
                        break;
        }

        /* Add the fault to the ring */
        fault = &gmc->fault_ring[gmc->last_fault];
        fault->key = key;
        fault->timestamp = timestamp;

        /* And update the hash */
        fault->next = gmc->fault_hash[hash].idx;
        gmc->fault_hash[hash].idx = gmc->last_fault++;
        return false;
}