On Mon, 29 Sep 2025 22:03:14 +0200 Loïc Molinari <[email protected]> wrote:
> Introduce the 'panthor.transparent_hugepage' boolean module parameter > (false by default). When the parameter is set to true, a new tmpfs > mount point is created and mounted using the 'huge=within_size' > option. It's then used at GEM object creation instead of the default > 'shm_mnt' mount point in order to enable Transparent Hugepage (THP) > for the object (without having to rely on a system wide parameter). > > Signed-off-by: Loïc Molinari <[email protected]> > --- > drivers/gpu/drm/panthor/panthor_device.c | 4 ++++ > drivers/gpu/drm/panthor/panthor_device.h | 3 +++ > drivers/gpu/drm/panthor/panthor_drv.c | 7 ++++++ > drivers/gpu/drm/panthor/panthor_drv.h | 11 +++++++++ > drivers/gpu/drm/panthor/panthor_gem.c | 30 +++++++++++++++++++++++- > drivers/gpu/drm/panthor/panthor_gem.h | 3 +++ > 6 files changed, 57 insertions(+), 1 deletion(-) > create mode 100644 drivers/gpu/drm/panthor/panthor_drv.h > > diff --git a/drivers/gpu/drm/panthor/panthor_device.c > b/drivers/gpu/drm/panthor/panthor_device.c > index 81df49880bd8..4f254b574287 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.c > +++ b/drivers/gpu/drm/panthor/panthor_device.c > @@ -17,6 +17,7 @@ > #include "panthor_devfreq.h" > #include "panthor_device.h" > #include "panthor_fw.h" > +#include "panthor_gem.h" > #include "panthor_gpu.h" > #include "panthor_hw.h" > #include "panthor_mmu.h" > @@ -98,6 +99,7 @@ void panthor_device_unplug(struct panthor_device *ptdev) > /* Now, try to cleanly shutdown the GPU before the device resources > * get reclaimed. > */ > + panthor_gem_fini(ptdev); > panthor_sched_unplug(ptdev); > panthor_fw_unplug(ptdev); > panthor_mmu_unplug(ptdev); > @@ -269,6 +271,8 @@ int panthor_device_init(struct panthor_device *ptdev) > if (ret) > goto err_unplug_fw; > > + panthor_gem_init(ptdev); > + > /* ~3 frames */ > pm_runtime_set_autosuspend_delay(ptdev->base.dev, 50); > pm_runtime_use_autosuspend(ptdev->base.dev); > diff --git a/drivers/gpu/drm/panthor/panthor_device.h > b/drivers/gpu/drm/panthor/panthor_device.h > index 4fc7cf2aeed5..54ca61567426 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.h > +++ b/drivers/gpu/drm/panthor/panthor_device.h > @@ -135,6 +135,9 @@ struct panthor_device { > /** @devfreq: Device frequency scaling management data. */ > struct panthor_devfreq *devfreq; > > + /** @huge_mnt: tmpfs mount point with Transparent Hugepage enabled. */ > + struct vfsmount *huge_mnt; Now that we have a helper to create a huge mountpoint, wouldn't it make sense to have this field in drm_device instead of having each driver add a huge_mnt field to their <driver>_device object. > + > /** @unplug: Device unplug related fields. */ > struct { > /** @lock: Lock used to serialize unplug operations. */ > diff --git a/drivers/gpu/drm/panthor/panthor_drv.c > b/drivers/gpu/drm/panthor/panthor_drv.c > index fdbe89ef7f43..a2be3b904ca2 100644 > --- a/drivers/gpu/drm/panthor/panthor_drv.c > +++ b/drivers/gpu/drm/panthor/panthor_drv.c > @@ -1556,6 +1556,7 @@ static const struct file_operations > panthor_drm_driver_fops = { > .read = drm_read, > .llseek = noop_llseek, > .mmap = panthor_mmap, > + .get_unmapped_area = drm_gem_get_unmapped_area, > .show_fdinfo = drm_show_fdinfo, > .fop_flags = FOP_UNSIGNED_OFFSET, > }; > @@ -1623,6 +1624,12 @@ static const struct drm_driver panthor_drm_driver = { > #endif > }; > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +bool panthor_transparent_hugepage; > +module_param_named(transparent_hugepage, panthor_transparent_hugepage, bool, > 0400); > +MODULE_PARM_DESC(transparent_hugepage, "Use a dedicated tmpfs mount point > with Transparent Hugepage enabled (false = default)"); > +#endif > + > static int panthor_probe(struct platform_device *pdev) > { > struct panthor_device *ptdev; > diff --git a/drivers/gpu/drm/panthor/panthor_drv.h > b/drivers/gpu/drm/panthor/panthor_drv.h > new file mode 100644 > index 000000000000..27fe9b6f77bd > --- /dev/null > +++ b/drivers/gpu/drm/panthor/panthor_drv.h > @@ -0,0 +1,11 @@ > +// SPDX-License-Identifier: GPL-2.0 or MIT > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > + > +#ifndef __PANTHOR_DRV_H__ > +#define __PANTHOR_DRV_H__ > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +extern bool panthor_transparent_hugepage; > +#endif > + > +#endif > diff --git a/drivers/gpu/drm/panthor/panthor_gem.c > b/drivers/gpu/drm/panthor/panthor_gem.c > index 156c7a0b62a2..16916e0b6d89 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.c > +++ b/drivers/gpu/drm/panthor/panthor_gem.c > @@ -1,6 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0 or MIT > /* Copyright 2019 Linaro, Ltd, Rob Herring <[email protected]> */ > /* Copyright 2023 Collabora ltd. */ > +/* Copyright 2025 Amazon.com, Inc. or its affiliates */ > > #include <linux/cleanup.h> > #include <linux/dma-buf.h> > @@ -11,10 +12,35 @@ > #include <drm/panthor_drm.h> > > #include "panthor_device.h" > +#include "panthor_drv.h" > #include "panthor_fw.h" > #include "panthor_gem.h" > #include "panthor_mmu.h" > > +void panthor_gem_init(struct panthor_device *ptdev) > +{ > + struct vfsmount *huge_mnt; > + > + if (!panthor_transparent_hugepage) > + return; > + > + huge_mnt = drm_gem_shmem_huge_mnt_create("within_size"); > + if (IS_ERR(huge_mnt)) { > + drm_warn(&ptdev->base, "Can't use Transparent Hugepage (%ld)\n", > + PTR_ERR(huge_mnt)); > + return; > + } > + > + ptdev->huge_mnt = huge_mnt; > + > + drm_info(&ptdev->base, "Using Transparent Hugepage\n"); > +} > + > +void panthor_gem_fini(struct panthor_device *ptdev) > +{ > + drm_gem_shmem_huge_mnt_free(ptdev->huge_mnt); > +} > + > #ifdef CONFIG_DEBUG_FS > static void panthor_gem_debugfs_bo_init(struct panthor_gem_object *bo) > { > @@ -270,10 +296,12 @@ panthor_gem_create_with_handle(struct drm_file *file, > u64 *size, u32 flags, u32 *handle) > { > int ret; > + struct panthor_device *ptdev = > + container_of(ddev, struct panthor_device, base); > struct drm_gem_shmem_object *shmem; > struct panthor_gem_object *bo; > > - shmem = drm_gem_shmem_create(ddev, *size); > + shmem = drm_gem_shmem_create_with_mnt(ddev, *size, ptdev->huge_mnt); > if (IS_ERR(shmem)) > return PTR_ERR(shmem); > > diff --git a/drivers/gpu/drm/panthor/panthor_gem.h > b/drivers/gpu/drm/panthor/panthor_gem.h > index 80c6e24112d0..6804b3912cc2 100644 > --- a/drivers/gpu/drm/panthor/panthor_gem.h > +++ b/drivers/gpu/drm/panthor/panthor_gem.h > @@ -136,6 +136,9 @@ struct panthor_gem_object *to_panthor_bo(struct > drm_gem_object *obj) > return container_of(to_drm_gem_shmem_obj(obj), struct > panthor_gem_object, base); > } > > +void panthor_gem_init(struct panthor_device *ptdev); > +void panthor_gem_fini(struct panthor_device *ptdev); > + > struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev, > size_t size); > > int
