Unverified Commit eb8d395f authored by Maíra Canal's avatar Maíra Canal
Browse files

drm/v3d: Introduce gemfs 



Create a separate "tmpfs" kernel mount for V3D. This will allow us to
move away from the shmemfs `shm_mnt` and gives the flexibility to do
things like set our own mount options. Here, the interest is to use
"huge=", which should allow us to enable the use of THP for our
shmem-backed objects.

Signed-off-by: default avatarMaíra Canal <mcanal@igalia.com>
Reviewed-by: default avatarIago Toral Quiroga <itoral@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923141348.2422499-6-mcanal@igalia.com
parent 0992b254

drivers/gpu/drm/v3d/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -13,7 +13,8 @@ v3d-y := \ 
	v3d_trace_points.o \

	v3d_sched.o \

	v3d_sysfs.o \

	v3d_submit.o

	v3d_submit.o \

	v3d_gemfs.o



v3d-$(CONFIG_DEBUG_FS) += v3d_debugfs.o

drivers/gpu/drm/v3d/v3d_drv.h

+9 −0
Original line number Diff line number Diff line
@@ -137,6 +137,11 @@ struct v3d_dev { 
	struct drm_mm mm;

	spinlock_t mm_lock;



	/*

	 * tmpfs instance used for shmem backed objects

	 */

	struct vfsmount *gemfs;



	struct work_struct overflow_mem_work;



	struct v3d_bin_job *bin_job;
@@ -534,6 +539,10 @@ void v3d_reset(struct v3d_dev *v3d); 
void v3d_invalidate_caches(struct v3d_dev *v3d);

void v3d_clean_caches(struct v3d_dev *v3d);



/* v3d_gemfs.c */

void v3d_gemfs_init(struct v3d_dev *v3d);

void v3d_gemfs_fini(struct v3d_dev *v3d);



/* v3d_submit.c */

void v3d_job_cleanup(struct v3d_job *job);

void v3d_job_put(struct v3d_job *job);

drivers/gpu/drm/v3d/v3d_gem.c

+3 −0
Original line number Diff line number Diff line
@@ -288,6 +288,8 @@ v3d_gem_init(struct drm_device *dev) 
	v3d_init_hw_state(v3d);

	v3d_mmu_set_page_table(v3d);



	v3d_gemfs_init(v3d);



	ret = v3d_sched_init(v3d);

	if (ret) {

		drm_mm_takedown(&v3d->mm);
@@ -305,6 +307,7 @@ v3d_gem_destroy(struct drm_device *dev) 
	struct v3d_dev *v3d = to_v3d_dev(dev);



	v3d_sched_fini(v3d);

	v3d_gemfs_fini(v3d);



	/* Waiting for jobs to finish would need to be done before

	 * unregistering V3D.

drivers/gpu/drm/v3d/v3d_gemfs.c

0 → 100644
+46 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/* Copyright (C) 2024 Raspberry Pi */



#include <linux/fs.h>

#include <linux/mount.h>



#include "v3d_drv.h"



void v3d_gemfs_init(struct v3d_dev *v3d)

{

	char huge_opt[] = "huge=within_size";

	struct file_system_type *type;

	struct vfsmount *gemfs;



	/*

	 * By creating our own shmemfs mountpoint, we can pass in

	 * mount flags that better match our usecase. However, we

	 * only do so on platforms which benefit from it.

	 */

	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))

		goto err;



	type = get_fs_type("tmpfs");

	if (!type)

		goto err;



	gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name, huge_opt);

	if (IS_ERR(gemfs))

		goto err;



	v3d->gemfs = gemfs;

	drm_info(&v3d->drm, "Using Transparent Hugepages\n");



	return;



err:

	v3d->gemfs = NULL;

	drm_notice(&v3d->drm,

		   "Transparent Hugepage support is recommended for optimal performance on this platform!\n");

}



void v3d_gemfs_fini(struct v3d_dev *v3d)

{

	if (v3d->gemfs)

		kern_unmount(v3d->gemfs);

}