Commit c569b369 authored by Loïc Molinari's avatar Loïc Molinari Committed by Boris Brezillon
Browse files

drm/panthor: Introduce huge tmpfs mountpoint option 



Introduce the 'panthor.transparent_hugepage' boolean module parameter
(false by default). When the parameter is set to true, a new tmpfs
mountpoint is created and mounted using the 'huge=within_size'
option. It's then used at GEM object creation instead of the default
'shm_mnt' mountpoint in order to enable Transparent Hugepage (THP) for
the object (without having to rely on a system wide parameter).

v3:
- use huge tmpfs mountpoint in drm_device

v4:
- fix builds with CONFIG_TRANSPARENT_HUGEPAGE=n
- clean up mountpoint creation error handling
- print negative error value

v5:
- use drm_gem_has_huge_tmp() helper
- get rid of CONFIG_TRANSPARENT_HUGEPAGE ifdefs

v9:
- replace drm_gem_has_huge_tmp() by drm_gem_get_huge_tmp()

v11:
- enable 'panthor.transparent_hugepage' by default

Signed-off-by: default avatarLoïc Molinari <loic.molinari@collabora.com>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Link: https://patch.msgid.link/20251205182231.194072-9-loic.molinari@collabora.com


Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
parent 7cdf69d9

drivers/gpu/drm/panthor/panthor_device.c

+3 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#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"
@@ -294,6 +295,8 @@ 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);

drivers/gpu/drm/panthor/panthor_drv.c

+7 −0
Original line number Diff line number Diff line
@@ -1559,6 +1559,7 @@ 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,

};
@@ -1627,6 +1628,12 @@ static const struct drm_driver panthor_drm_driver = { 
#endif

};



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

bool panthor_transparent_hugepage = true;

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 (true = default)");

#endif



static int panthor_probe(struct platform_device *pdev)

{

	struct panthor_device *ptdev;

drivers/gpu/drm/panthor/panthor_drv.h

0 → 100644
+9 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 or MIT */

/* Copyright 2025 Amazon.com, Inc. or its affiliates */



#ifndef __PANTHOR_DRV_H__

#define __PANTHOR_DRV_H__



extern bool panthor_transparent_hugepage;



#endif

drivers/gpu/drm/panthor/panthor_gem.c

+18 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0 or MIT

/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */

/* Copyright 2023 Collabora ltd. */

/* Copyright 2025 Amazon.com, Inc. or its affiliates */



#include <linux/cleanup.h>

#include <linux/dma-buf.h>
@@ -12,10 +13,27 @@ 
#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)

{

	int err;



	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&

	    !panthor_transparent_hugepage)

		return;



	err = drm_gem_huge_mnt_create(&ptdev->base, "within_size");

	if (drm_gem_get_huge_mnt(&ptdev->base))

		drm_info(&ptdev->base, "Using Transparent Hugepage\n");

	else if (err)

		drm_warn(&ptdev->base, "Can't use Transparent Hugepage (%d)\n",

			 err);

}



#ifdef CONFIG_DEBUG_FS

static void panthor_gem_debugfs_bo_init(struct panthor_gem_object *bo)

{

drivers/gpu/drm/panthor/panthor_gem.h

+2 −0
Original line number Diff line number Diff line
@@ -136,6 +136,8 @@ 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);



struct drm_gem_object *panthor_gem_create_object(struct drm_device *ddev, size_t size);



int