// SPDX-License-Identifier: GPL-2.0+
/* Copyright (C) 2014-2018 Broadcom */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/sched/signal.h>
#include <linux/uaccess.h>

#include <drm/drm_managed.h>
#include <drm/drm_print.h>

#include "v3d_drv.h"
#include "v3d_regs.h"
#include "v3d_trace.h"

static void
v3d_init_core(struct v3d_dev *v3d, int core)
{
        /* Set OVRTMUOUT, which means that the texture sampler uniform
         * configuration's tmu output type field is used, instead of
         * using the hardware default behavior based on the texture
         * type.  If you want the default behavior, you can still put
         * "2" in the indirect texture state's output_type field.
         */
        if (v3d->ver < V3D_GEN_41)
                V3D_CORE_WRITE(core, V3D_CTL_MISCCFG, V3D_MISCCFG_OVRTMUOUT);

        /* Whenever we flush the L2T cache, we always want to flush
         * the whole thing.
         */
        V3D_CORE_WRITE(core, V3D_CTL_L2TFLSTA, 0);
        V3D_CORE_WRITE(core, V3D_CTL_L2TFLEND, ~0);
}

/* Sets invariant state for the HW. */
static void
v3d_init_hw_state(struct v3d_dev *v3d)
{
        v3d_init_core(v3d, 0);
}

static void
v3d_idle_axi(struct v3d_dev *v3d, int core)
{
        V3D_CORE_WRITE(core, V3D_GMP_CFG(v3d->ver), V3D_GMP_CFG_STOP_REQ);

        if (wait_for((V3D_CORE_READ(core, V3D_GMP_STATUS(v3d->ver)) &
                      (V3D_GMP_STATUS_RD_COUNT_MASK |
                       V3D_GMP_STATUS_WR_COUNT_MASK |
                       V3D_GMP_STATUS_CFG_BUSY)) == 0, 100)) {
                drm_err(&v3d->drm, "Failed to wait for safe GMP shutdown\n");
        }
}

static void
v3d_idle_gca(struct v3d_dev *v3d)
{
        if (v3d->ver >= V3D_GEN_41)
                return;

        V3D_GCA_WRITE(V3D_GCA_SAFE_SHUTDOWN, V3D_GCA_SAFE_SHUTDOWN_EN);

        if (wait_for((V3D_GCA_READ(V3D_GCA_SAFE_SHUTDOWN_ACK) &
                      V3D_GCA_SAFE_SHUTDOWN_ACK_ACKED) ==
                     V3D_GCA_SAFE_SHUTDOWN_ACK_ACKED, 100)) {
                drm_err(&v3d->drm, "Failed to wait for safe GCA shutdown\n");
        }
}

static void
v3d_reset_by_bridge(struct v3d_dev *v3d)
{
        int version = V3D_BRIDGE_READ(V3D_TOP_GR_BRIDGE_REVISION);

        if (V3D_GET_FIELD(version, V3D_TOP_GR_BRIDGE_MAJOR) == 2) {
                V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_0,
                                 V3D_TOP_GR_BRIDGE_SW_INIT_0_V3D_CLK_108_SW_INIT);
                V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_0, 0);

                /* GFXH-1383: The SW_INIT may cause a stray write to address 0
                 * of the unit, so reset it to its power-on value here.
                 */
                V3D_WRITE(V3D_HUB_AXICFG, V3D_HUB_AXICFG_MAX_LEN_MASK);
        } else {
                WARN_ON_ONCE(V3D_GET_FIELD(version,
                                           V3D_TOP_GR_BRIDGE_MAJOR) != 7);
                V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_1,
                                 V3D_TOP_GR_BRIDGE_SW_INIT_1_V3D_CLK_108_SW_INIT);
                V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_1, 0);
        }
}

static void
v3d_reset_v3d(struct v3d_dev *v3d)
{
        if (v3d->reset)
                reset_control_reset(v3d->reset);
        else
                v3d_reset_by_bridge(v3d);

        v3d_init_hw_state(v3d);
}

void
v3d_reset_sms(struct v3d_dev *v3d)
{
        if (v3d->ver < V3D_GEN_71)
                return;

        V3D_SMS_WRITE(V3D_SMS_REE_CS, V3D_SET_FIELD(0x4, V3D_SMS_STATE));

        if (wait_for(!(V3D_GET_FIELD(V3D_SMS_READ(V3D_SMS_REE_CS),
                                     V3D_SMS_STATE) == V3D_SMS_ISOLATING_FOR_RESET) &&
                     !(V3D_GET_FIELD(V3D_SMS_READ(V3D_SMS_REE_CS),
                                     V3D_SMS_STATE) == V3D_SMS_RESETTING), 100)) {
                drm_err(&v3d->drm, "Failed to wait for SMS reset\n");
        }
}

void
v3d_reset(struct v3d_dev *v3d)
{
        struct drm_device *dev = &v3d->drm;

        drm_err(dev, "Resetting GPU for hang.\n");
        drm_err(dev, "V3D_ERR_STAT: 0x%08x\n", V3D_CORE_READ(0, V3D_ERR_STAT));

        trace_v3d_reset_begin(dev);

        /* XXX: only needed for safe powerdown, not reset. */
        if (false)
                v3d_idle_axi(v3d, 0);

        v3d_irq_disable(v3d);

        v3d_idle_gca(v3d);
        v3d_reset_sms(v3d);
        v3d_reset_v3d(v3d);

        v3d_mmu_set_page_table(v3d);
        v3d_irq_reset(v3d);

        v3d_perfmon_stop(v3d, v3d->active_perfmon, false);

        trace_v3d_reset_end(dev);
}

static void
v3d_flush_l3(struct v3d_dev *v3d)
{
        if (v3d->ver < V3D_GEN_41) {
                u32 gca_ctrl = V3D_GCA_READ(V3D_GCA_CACHE_CTRL);

                V3D_GCA_WRITE(V3D_GCA_CACHE_CTRL,
                              gca_ctrl | V3D_GCA_CACHE_CTRL_FLUSH);

                if (v3d->ver < V3D_GEN_33) {
                        V3D_GCA_WRITE(V3D_GCA_CACHE_CTRL,
                                      gca_ctrl & ~V3D_GCA_CACHE_CTRL_FLUSH);
                }
        }
}

/* Invalidates the (read-only) L2C cache.  This was the L2 cache for
 * uniforms and instructions on V3D 3.2.
 */
static void
v3d_invalidate_l2c(struct v3d_dev *v3d, int core)
{
        if (v3d->ver >= V3D_GEN_33)
                return;

        V3D_CORE_WRITE(core, V3D_CTL_L2CACTL,
                       V3D_L2CACTL_L2CCLR |
                       V3D_L2CACTL_L2CENA);
}

/* Invalidates texture L2 cachelines */
static void
v3d_flush_l2t(struct v3d_dev *v3d, int core)
{
        /* While there is a busy bit (V3D_L2TCACTL_L2TFLS), we don't
         * need to wait for completion before dispatching the job --
         * L2T accesses will be stalled until the flush has completed.
         * However, we do need to make sure we don't try to trigger a
         * new flush while the L2_CLEAN queue is trying to
         * synchronously clean after a job.
         */
        mutex_lock(&v3d->cache_clean_lock);
        V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL,
                       V3D_L2TCACTL_L2TFLS |
                       V3D_SET_FIELD(V3D_L2TCACTL_FLM_FLUSH, V3D_L2TCACTL_FLM));
        mutex_unlock(&v3d->cache_clean_lock);
}

/* Cleans texture L1 and L2 cachelines (writing back dirty data).
 *
 * For cleaning, which happens from the CACHE_CLEAN queue after CSD has
 * executed, we need to make sure that the clean is done before
 * signaling job completion.  So, we synchronously wait before
 * returning, and we make sure that L2 invalidates don't happen in the
 * meantime to confuse our are-we-done checks.
 */
void
v3d_clean_caches(struct v3d_dev *v3d)
{
        struct drm_device *dev = &v3d->drm;
        int core = 0;

        trace_v3d_cache_clean_begin(dev);

        V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL, V3D_L2TCACTL_TMUWCF);
        if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) &
                       V3D_L2TCACTL_TMUWCF), 100)) {
                drm_err(dev, "Timeout waiting for TMU write combiner flush\n");
        }

        mutex_lock(&v3d->cache_clean_lock);
        V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL,
                       V3D_L2TCACTL_L2TFLS |
                       V3D_SET_FIELD(V3D_L2TCACTL_FLM_CLEAN, V3D_L2TCACTL_FLM));

        if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) &
                       V3D_L2TCACTL_L2TFLS), 100)) {
                drm_err(dev, "Timeout waiting for L2T clean\n");
        }

        mutex_unlock(&v3d->cache_clean_lock);

        trace_v3d_cache_clean_end(dev);
}

/* Invalidates the slice caches.  These are read-only caches. */
static void
v3d_invalidate_slices(struct v3d_dev *v3d, int core)
{
        V3D_CORE_WRITE(core, V3D_CTL_SLCACTL,
                       V3D_SET_FIELD(0xf, V3D_SLCACTL_TVCCS) |
                       V3D_SET_FIELD(0xf, V3D_SLCACTL_TDCCS) |
                       V3D_SET_FIELD(0xf, V3D_SLCACTL_UCC) |
                       V3D_SET_FIELD(0xf, V3D_SLCACTL_ICC));
}

void
v3d_invalidate_caches(struct v3d_dev *v3d)
{
        /* Invalidate the caches from the outside in.  That way if
         * another CL's concurrent use of nearby memory were to pull
         * an invalidated cacheline back in, we wouldn't leave stale
         * data in the inner cache.
         */
        v3d_flush_l3(v3d);
        v3d_invalidate_l2c(v3d, 0);
        v3d_flush_l2t(v3d, 0);
        v3d_invalidate_slices(v3d, 0);
}

static void
v3d_huge_mnt_init(struct v3d_dev *v3d)
{
        int err = 0;

        if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && super_pages)
                err = drm_gem_huge_mnt_create(&v3d->drm, "within_size");

        if (drm_gem_get_huge_mnt(&v3d->drm))
                drm_info(&v3d->drm, "Using Transparent Hugepages\n");
        else if (err)
                drm_warn(&v3d->drm, "Can't use Transparent Hugepages (%d)\n",
                         err);
        else
                drm_notice(&v3d->drm,
                           "Transparent Hugepage support is recommended for optimal performance on this platform!\n");
}

int
v3d_gem_init(struct drm_device *dev)
{
        struct v3d_dev *v3d = to_v3d_dev(dev);
        u32 pt_size = 4096 * 1024;
        int ret, i;

        for (i = 0; i < V3D_MAX_QUEUES; i++) {
                struct v3d_queue_state *queue = &v3d->queue[i];

                queue->fence_context = dma_fence_context_alloc(1);
                memset(&queue->stats, 0, sizeof(queue->stats));
                seqcount_init(&queue->stats.lock);

                spin_lock_init(&queue->queue_lock);
                spin_lock_init(&queue->fence_lock);
        }

        spin_lock_init(&v3d->mm_lock);
        ret = drmm_mutex_init(dev, &v3d->bo_lock);
        if (ret)
                return ret;
        ret = drmm_mutex_init(dev, &v3d->reset_lock);
        if (ret)
                return ret;
        ret = drmm_mutex_init(dev, &v3d->sched_lock);
        if (ret)
                return ret;
        ret = drmm_mutex_init(dev, &v3d->cache_clean_lock);
        if (ret)
                return ret;

        /* Note: We don't allocate address 0.  Various bits of HW
         * treat 0 as special, such as the occlusion query counters
         * where 0 means "disabled".
         */
        drm_mm_init(&v3d->mm, 1, pt_size / sizeof(u32) - 1);

        v3d->pt = dma_alloc_wc(v3d->drm.dev, pt_size,
                               &v3d->pt_paddr,
                               GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
        if (!v3d->pt) {
                drm_mm_takedown(&v3d->mm);
                dev_err(v3d->drm.dev,
                        "Failed to allocate page tables. Please ensure you have DMA enabled.\n");
                return -ENOMEM;
        }

        v3d_init_hw_state(v3d);
        v3d_mmu_set_page_table(v3d);

        v3d_huge_mnt_init(v3d);

        ret = v3d_sched_init(v3d);
        if (ret) {
                drm_mm_takedown(&v3d->mm);
                dma_free_coherent(v3d->drm.dev, pt_size, (void *)v3d->pt,
                                  v3d->pt_paddr);
                return ret;
        }

        return 0;
}

void
v3d_gem_destroy(struct drm_device *dev)
{
        struct v3d_dev *v3d = to_v3d_dev(dev);
        enum v3d_queue q;

        v3d_sched_fini(v3d);

        /* Waiting for jobs to finish would need to be done before
         * unregistering V3D.
         */
        for (q = 0; q < V3D_MAX_QUEUES; q++)
                WARN_ON(v3d->queue[q].active_job);

        drm_mm_takedown(&v3d->mm);

        dma_free_coherent(v3d->drm.dev, 4096 * 1024, (void *)v3d->pt,
                          v3d->pt_paddr);
}