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    Subject[PATCH v18 26/26] drm/panfrost: Switch to generic memory shrinker
    Date
    Replace Panfrost's custom memory shrinker with a common drm-shmem
    memory shrinker.

    Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
    ---
    drivers/gpu/drm/panfrost/Makefile | 1 -
    drivers/gpu/drm/panfrost/panfrost_device.h | 4 -
    drivers/gpu/drm/panfrost/panfrost_drv.c | 27 ++--
    drivers/gpu/drm/panfrost/panfrost_gem.c | 34 +++--
    drivers/gpu/drm/panfrost/panfrost_gem.h | 9 --
    .../gpu/drm/panfrost/panfrost_gem_shrinker.c | 129 ------------------
    drivers/gpu/drm/panfrost/panfrost_job.c | 18 ++-
    drivers/gpu/drm/panfrost/panfrost_mmu.c | 18 ++-
    include/drm/drm_gem_shmem_helper.h | 7 -
    9 files changed, 66 insertions(+), 181 deletions(-)
    delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c

    diff --git a/drivers/gpu/drm/panfrost/Makefile b/drivers/gpu/drm/panfrost/Makefile
    index 2c01c1e7523e..f2cb1ab0a32d 100644
    --- a/drivers/gpu/drm/panfrost/Makefile
    +++ b/drivers/gpu/drm/panfrost/Makefile
    @@ -5,7 +5,6 @@ panfrost-y := \
    panfrost_device.o \
    panfrost_devfreq.o \
    panfrost_gem.o \
    - panfrost_gem_shrinker.o \
    panfrost_gpu.o \
    panfrost_job.o \
    panfrost_mmu.o \
    diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
    index 1e85656dc2f7..2b24a0d4f85e 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_device.h
    +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
    @@ -117,10 +117,6 @@ struct panfrost_device {
    atomic_t pending;
    } reset;

    - struct mutex shrinker_lock;
    - struct list_head shrinker_list;
    - struct shrinker shrinker;
    -
    struct panfrost_devfreq pfdevfreq;

    struct {
    diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
    index 7f2aba96d5b9..ef520d2cc1d2 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
    +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
    @@ -171,7 +171,6 @@ panfrost_lookup_bos(struct drm_device *dev,
    break;
    }

    - atomic_inc(&bo->gpu_usecount);
    job->mappings[i] = mapping;
    }

    @@ -397,7 +396,6 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
    {
    struct panfrost_file_priv *priv = file_priv->driver_priv;
    struct drm_panfrost_madvise *args = data;
    - struct panfrost_device *pfdev = dev->dev_private;
    struct drm_gem_object *gem_obj;
    struct panfrost_gem_object *bo;
    int ret = 0;
    @@ -410,11 +408,15 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,

    bo = to_panfrost_bo(gem_obj);

    + if (bo->is_heap) {
    + args->retained = 1;
    + goto out_put_object;
    + }
    +
    ret = dma_resv_lock_interruptible(bo->base.base.resv, NULL);
    if (ret)
    goto out_put_object;

    - mutex_lock(&pfdev->shrinker_lock);
    mutex_lock(&bo->mappings.lock);
    if (args->madv == PANFROST_MADV_DONTNEED) {
    struct panfrost_gem_mapping *first;
    @@ -440,17 +442,8 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,

    args->retained = drm_gem_shmem_madvise_locked(&bo->base, args->madv);

    - if (args->retained) {
    - if (args->madv == PANFROST_MADV_DONTNEED)
    - list_move_tail(&bo->base.madv_list,
    - &pfdev->shrinker_list);
    - else if (args->madv == PANFROST_MADV_WILLNEED)
    - list_del_init(&bo->base.madv_list);
    - }
    -
    out_unlock_mappings:
    mutex_unlock(&bo->mappings.lock);
    - mutex_unlock(&pfdev->shrinker_lock);
    dma_resv_unlock(bo->base.base.resv);
    out_put_object:
    drm_gem_object_put(gem_obj);
    @@ -635,9 +628,6 @@ static int panfrost_probe(struct platform_device *pdev)
    ddev->dev_private = pfdev;
    pfdev->ddev = ddev;

    - mutex_init(&pfdev->shrinker_lock);
    - INIT_LIST_HEAD(&pfdev->shrinker_list);
    -
    err = panfrost_device_init(pfdev);
    if (err) {
    if (err != -EPROBE_DEFER)
    @@ -659,10 +649,14 @@ static int panfrost_probe(struct platform_device *pdev)
    if (err < 0)
    goto err_out1;

    - panfrost_gem_shrinker_init(ddev);
    + err = drmm_gem_shmem_init(ddev);
    + if (err < 0)
    + goto err_out2;

    return 0;

    +err_out2:
    + drm_dev_unregister(ddev);
    err_out1:
    pm_runtime_disable(pfdev->dev);
    panfrost_device_fini(pfdev);
    @@ -678,7 +672,6 @@ static void panfrost_remove(struct platform_device *pdev)
    struct drm_device *ddev = pfdev->ddev;

    drm_dev_unregister(ddev);
    - panfrost_gem_shrinker_cleanup(ddev);

    pm_runtime_get_sync(pfdev->dev);
    pm_runtime_disable(pfdev->dev);
    diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
    index bb9d43cf7c3c..a6128e32f303 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
    +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
    @@ -19,16 +19,6 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
    struct panfrost_gem_object *bo = to_panfrost_bo(obj);
    struct panfrost_device *pfdev = obj->dev->dev_private;

    - /*
    - * Make sure the BO is no longer inserted in the shrinker list before
    - * taking care of the destruction itself. If we don't do that we have a
    - * race condition between this function and what's done in
    - * panfrost_gem_shrinker_scan().
    - */
    - mutex_lock(&pfdev->shrinker_lock);
    - list_del_init(&bo->base.madv_list);
    - mutex_unlock(&pfdev->shrinker_lock);
    -
    /*
    * If we still have mappings attached to the BO, there's a problem in
    * our refcounting.
    @@ -94,7 +84,11 @@ static void panfrost_gem_mapping_release(struct kref *kref)

    mapping = container_of(kref, struct panfrost_gem_mapping, refcount);

    + /* shrinker that may purge mapping at the same time */
    + dma_resv_lock(mapping->obj->base.base.resv, NULL);
    panfrost_gem_teardown_mapping(mapping);
    + dma_resv_unlock(mapping->obj->base.base.resv);
    +
    drm_gem_object_put(&mapping->obj->base.base);
    panfrost_mmu_ctx_put(mapping->mmu);
    kfree(mapping);
    @@ -228,6 +222,25 @@ static size_t panfrost_gem_rss(struct drm_gem_object *obj)
    return 0;
    }

    +static int panfrost_shmem_evict(struct drm_gem_object *obj)
    +{
    + struct panfrost_gem_object *bo = to_panfrost_bo(obj);
    +
    + if (!drm_gem_shmem_is_purgeable(&bo->base))
    + return -EBUSY;
    +
    + if (!mutex_trylock(&bo->mappings.lock))
    + return -EBUSY;
    +
    + panfrost_gem_teardown_mappings_locked(bo);
    +
    + drm_gem_shmem_purge_locked(&bo->base);
    +
    + mutex_unlock(&bo->mappings.lock);
    +
    + return 0;
    +}
    +
    static const struct drm_gem_object_funcs panfrost_gem_funcs = {
    .free = panfrost_gem_free_object,
    .open = panfrost_gem_open,
    @@ -242,6 +255,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
    .status = panfrost_gem_status,
    .rss = panfrost_gem_rss,
    .vm_ops = &drm_gem_shmem_vm_ops,
    + .evict = panfrost_shmem_evict,
    };

    /**
    diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
    index 13c0a8149c3a..8ddc2d310d29 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
    +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
    @@ -30,12 +30,6 @@ struct panfrost_gem_object {
    struct mutex lock;
    } mappings;

    - /*
    - * Count the number of jobs referencing this BO so we don't let the
    - * shrinker reclaim this object prematurely.
    - */
    - atomic_t gpu_usecount;
    -
    /*
    * Object chunk size currently mapped onto physical memory
    */
    @@ -86,7 +80,4 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
    void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping);
    void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);

    -void panfrost_gem_shrinker_init(struct drm_device *dev);
    -void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
    -
    #endif /* __PANFROST_GEM_H__ */
    diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
    deleted file mode 100644
    index 1aa94fff7072..000000000000
    --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
    +++ /dev/null
    @@ -1,129 +0,0 @@
    -// SPDX-License-Identifier: GPL-2.0
    -/* Copyright (C) 2019 Arm Ltd.
    - *
    - * Based on msm_gem_freedreno.c:
    - * Copyright (C) 2016 Red Hat
    - * Author: Rob Clark <robdclark@gmail.com>
    - */
    -
    -#include <linux/list.h>
    -
    -#include <drm/drm_device.h>
    -#include <drm/drm_gem_shmem_helper.h>
    -
    -#include "panfrost_device.h"
    -#include "panfrost_gem.h"
    -#include "panfrost_mmu.h"
    -
    -static bool panfrost_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
    -{
    - return (shmem->madv > 0) &&
    - !refcount_read(&shmem->pages_pin_count) && shmem->sgt &&
    - !shmem->base.dma_buf && !shmem->base.import_attach;
    -}
    -
    -static unsigned long
    -panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
    -{
    - struct panfrost_device *pfdev =
    - container_of(shrinker, struct panfrost_device, shrinker);
    - struct drm_gem_shmem_object *shmem;
    - unsigned long count = 0;
    -
    - if (!mutex_trylock(&pfdev->shrinker_lock))
    - return 0;
    -
    - list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) {
    - if (panfrost_gem_shmem_is_purgeable(shmem))
    - count += shmem->base.size >> PAGE_SHIFT;
    - }
    -
    - mutex_unlock(&pfdev->shrinker_lock);
    -
    - return count;
    -}
    -
    -static bool panfrost_gem_purge(struct drm_gem_object *obj)
    -{
    - struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
    - struct panfrost_gem_object *bo = to_panfrost_bo(obj);
    - bool ret = false;
    -
    - if (atomic_read(&bo->gpu_usecount))
    - return false;
    -
    - if (!mutex_trylock(&bo->mappings.lock))
    - return false;
    -
    - if (!dma_resv_trylock(shmem->base.resv))
    - goto unlock_mappings;
    -
    - panfrost_gem_teardown_mappings_locked(bo);
    - drm_gem_shmem_purge_locked(&bo->base);
    - ret = true;
    -
    - dma_resv_unlock(shmem->base.resv);
    -
    -unlock_mappings:
    - mutex_unlock(&bo->mappings.lock);
    - return ret;
    -}
    -
    -static unsigned long
    -panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
    -{
    - struct panfrost_device *pfdev =
    - container_of(shrinker, struct panfrost_device, shrinker);
    - struct drm_gem_shmem_object *shmem, *tmp;
    - unsigned long freed = 0;
    -
    - if (!mutex_trylock(&pfdev->shrinker_lock))
    - return SHRINK_STOP;
    -
    - list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) {
    - if (freed >= sc->nr_to_scan)
    - break;
    - if (drm_gem_shmem_is_purgeable(shmem) &&
    - panfrost_gem_purge(&shmem->base)) {
    - freed += shmem->base.size >> PAGE_SHIFT;
    - list_del_init(&shmem->madv_list);
    - }
    - }
    -
    - mutex_unlock(&pfdev->shrinker_lock);
    -
    - if (freed > 0)
    - pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);
    -
    - return freed;
    -}
    -
    -/**
    - * panfrost_gem_shrinker_init - Initialize panfrost shrinker
    - * @dev: DRM device
    - *
    - * This function registers and sets up the panfrost shrinker.
    - */
    -void panfrost_gem_shrinker_init(struct drm_device *dev)
    -{
    - struct panfrost_device *pfdev = dev->dev_private;
    - pfdev->shrinker.count_objects = panfrost_gem_shrinker_count;
    - pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan;
    - pfdev->shrinker.seeks = DEFAULT_SEEKS;
    - WARN_ON(register_shrinker(&pfdev->shrinker, "drm-panfrost"));
    -}
    -
    -/**
    - * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker
    - * @dev: DRM device
    - *
    - * This function unregisters the panfrost shrinker.
    - */
    -void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
    -{
    - struct panfrost_device *pfdev = dev->dev_private;
    -
    - if (pfdev->shrinker.nr_deferred) {
    - unregister_shrinker(&pfdev->shrinker);
    - }
    -}
    diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
    index fb16de2d0420..da6be590557f 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_job.c
    +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
    @@ -289,6 +289,19 @@ static void panfrost_attach_object_fences(struct drm_gem_object **bos,
    dma_resv_add_fence(bos[i]->resv, fence, DMA_RESV_USAGE_WRITE);
    }

    +static int panfrost_objects_prepare(struct drm_gem_object **bos, int bo_count)
    +{
    + struct panfrost_gem_object *bo;
    + int ret = 0;
    +
    + while (!ret && bo_count--) {
    + bo = to_panfrost_bo(bos[bo_count]);
    + ret = bo->base.madv ? -ENOMEM : 0;
    + }
    +
    + return ret;
    +}
    +
    int panfrost_job_push(struct panfrost_job *job)
    {
    struct panfrost_device *pfdev = job->pfdev;
    @@ -300,6 +313,10 @@ int panfrost_job_push(struct panfrost_job *job)
    if (ret)
    return ret;

    + ret = panfrost_objects_prepare(job->bos, job->bo_count);
    + if (ret)
    + goto unlock;
    +
    mutex_lock(&pfdev->sched_lock);
    drm_sched_job_arm(&job->base);

    @@ -341,7 +358,6 @@ static void panfrost_job_cleanup(struct kref *ref)
    if (!job->mappings[i])
    break;

    - atomic_dec(&job->mappings[i]->obj->gpu_usecount);
    panfrost_gem_mapping_put(job->mappings[i]);
    }
    kvfree(job->mappings);
    diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
    index ac145a98377b..01cd97011ea5 100644
    --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
    +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
    @@ -326,6 +326,7 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
    struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
    struct sg_table *sgt;
    int prot = IOMMU_READ | IOMMU_WRITE;
    + int ret = 0;

    if (WARN_ON(mapping->active))
    return 0;
    @@ -333,15 +334,26 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
    if (bo->noexec)
    prot |= IOMMU_NOEXEC;

    + if (!obj->import_attach) {
    + ret = drm_gem_shmem_pin(shmem);
    + if (ret)
    + return ret;
    + }
    +
    sgt = drm_gem_shmem_get_pages_sgt(shmem);
    - if (WARN_ON(IS_ERR(sgt)))
    - return PTR_ERR(sgt);
    + if (WARN_ON(IS_ERR(sgt))) {
    + ret = PTR_ERR(sgt);
    + goto unpin;
    + }

    mmu_map_sg(pfdev, mapping->mmu, mapping->mmnode.start << PAGE_SHIFT,
    prot, sgt);
    mapping->active = true;
    +unpin:
    + if (!obj->import_attach)
    + drm_gem_shmem_unpin(shmem);

    - return 0;
    + return ret;
    }

    void panfrost_mmu_unmap(struct panfrost_gem_mapping *mapping)
    diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
    index 6ac77c2082ed..2a506074da46 100644
    --- a/include/drm/drm_gem_shmem_helper.h
    +++ b/include/drm/drm_gem_shmem_helper.h
    @@ -61,13 +61,6 @@ struct drm_gem_shmem_object {
    */
    int madv;

    - /**
    - * @madv_list: List entry for madvise tracking
    - *
    - * Typically used by drivers to track purgeable objects
    - */
    - struct list_head madv_list;
    -
    /**
    * @sgt: Scatter/gather table for imported PRIME buffers
    */
    --
    2.41.0
    \
     
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      Last update: 2023-10-30 00:24    [W:4.797 / U:0.020 seconds]
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