Linaro-mm-sig

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3178 discussions

[PATCH -next v2] drm/amdgpu: use list_move instead of list_del/list_add in amdgpu_vm.c

by Baokun Li

Using list_move() instead of list_del() + list_add() in amdgpu_vm.c. Reported-by: Hulk Robot <hulkci(a)huawei.com> Signed-off-by: Baokun Li <libaokun1(a)huawei.com> --- V1->V2: CC mailist drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index 9e3ab3b6c105..684c13aae4d0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -2518,8 +2518,7 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device *adev, list_add(&after->list, &tmp->bo_va->invalids); } - list_del(&tmp->list); - list_add(&tmp->list, &removed); + list_move(&tmp->list, &removed); tmp = amdgpu_vm_it_iter_next(tmp, saddr, eaddr); }

4 years, 5 months

[PATCH -next v2] drm/ttm: use list_move instead of list_del/list_add in ttm_execbuf_util.c

by Baokun Li

Using list_move() instead of list_del() + list_add() in ttm_execbuf_util.c. Reported-by: Hulk Robot <hulkci(a)huawei.com> Signed-off-by: Baokun Li <libaokun1(a)huawei.com> --- V1->V2: CC mailist drivers/gpu/drm/ttm/ttm_execbuf_util.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c index 071c48d672c6..c50943888d04 100644 --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -95,8 +95,7 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, if (ret == -EALREADY && dups) { struct ttm_validate_buffer *safe = entry; entry = list_prev_entry(entry, head); - list_del(&safe->head); - list_add(&safe->head, dups); + list_move(&safe->head, dups); continue; } @@ -135,8 +134,7 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, /* move this item to the front of the list, * forces correct iteration of the loop without keeping track */ - list_del(&entry->head); - list_add(&entry->head, list); + list_move(&entry->head, list); } return 0;

4 years, 5 months

Re: [Linaro-mm-sig] [PATCH] dma-buf: fix build due to missing export

by Christian König

That was an already known issue and I've just pushed a patch to fix it. Christian. Am 05.06.21 um 02:20 schrieb Lucas De Marchi: > Commit 0c6b522abc2a ("dma-buf: cleanup dma-resv shared fence debugging a bit v2") > turned dma_resv_reset_shared_max() into a function when > CONFIG_DEBUG_MUTEXES is set, but forgot to export it. That resulted in a > broken build: > > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/vgem/vgem.ko] undefined! > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/i915/i915.ko] undefined! > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined! > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/ttm/ttm.ko] undefined! > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/drm.ko] undefined! > ERROR: modpost: "dma_resv_reset_shared_max" [drivers/gpu/drm/drm_vram_helper.ko] undefined! > make[1]: *** [scripts/Makefile.modpost:150: modules-only.symvers] Error 1 > > Fixes: 0c6b522abc2a ("dma-buf: cleanup dma-resv shared fence debugging a bit v2") > Cc: Christian König <christian.koenig(a)amd.com> > Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> > Cc: Sumit Semwal <sumit.semwal(a)linaro.org> > Cc: "Christian König" <christian.koenig(a)amd.com> > Cc: linux-media(a)vger.kernel.org > Cc: dri-devel(a)lists.freedesktop.org > Cc: linaro-mm-sig(a)lists.linaro.org > Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com> > --- > drivers/dma-buf/dma-resv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > index 3964df438505..6132ba631991 100644 > --- a/drivers/dma-buf/dma-resv.c > +++ b/drivers/dma-buf/dma-resv.c > @@ -226,6 +226,7 @@ void dma_resv_reset_shared_max(struct dma_resv *obj) > fence->shared_max = fence->shared_count; > } > } > +EXPORT_SYMBOL(dma_resv_reset_shared_max); > #endif > > /**

4 years, 5 months

[PATCH v5] dmabuf: Add the capability to expose DMA-BUF stats in sysfs

by Hridya Valsaraju

Overview ======== The patch adds DMA-BUF statistics to /sys/kernel/dmabuf/buffers. It allows statistics to be enabled for each DMA-BUF in sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS. The following stats will be exposed by the interface: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name /sys/kernel/dmabuf/buffers/<inode_number>/size /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter The inode_number is unique for each DMA-BUF and was added earlier [1] in order to allow userspace to track DMA-BUF usage across different processes. Use Cases ========= The interface provides a way to gather DMA-BUF per-buffer statistics from production devices. These statistics will be used to derive DMA-BUF per-exporter stats and per-device usage stats for Android Bug reports. The corresponding userspace changes can be found at [2]. Telemetry tools will also capture this information(along with other memory metrics) periodically as well as on important events like a foreground app kill (which might have been triggered by Low Memory Killer). It will also contribute to provide a snapshot of the system memory usage on other events such as OOM kills and Application Not Responding events. Background ========== Currently, there are two existing interfaces that provide information about DMA-BUFs. 1) /sys/kernel/debug/dma_buf/bufinfo debugfs is however unsuitable to be mounted in production systems and cannot be considered as an alternative to the sysfs interface being proposed. 2) proc/<pid>/fdinfo/<fd> The proc/<pid>/fdinfo/<fd> files expose information about DMA-BUF fds. However, the existing procfs interfaces can only provide information about the buffers for which processes hold fds or have the buffers mmapped into their address space. Since the procfs interfaces alone cannot provide a full picture of all DMA-BUFs in the system, there is the need for an alternate interface to provide this information on production systems. The patch contains the following major improvements over v1: 1) Each attachment is represented by its own directory to allow creating a symlink to the importing device and to also provide room for future expansion. 2) The number of distinct mappings of each attachment is exposed in a separate file. 3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers inorder to make the interface expandable in future. All of the improvements above are based on suggestions/feedback from Daniel Vetter and Christian König. A shell script that can be run on a classic Linux environment to read out the DMA-BUF statistics can be found at [3](suggested by John Stultz). [1]: https://lore.kernel.org/patchwork/patch/1088791/ [2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:… [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo… Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Hridya Valsaraju <hridya(a)google.com> Reported-by: kernel test robot <lkp(a)intel.com> --- Hi Daniel, I rewrote the commit message and added a new section to Documentation/driver-api/dma-buf.rst as per your suggestions. Please do take another look when you get a chance. Thanks again for the guidance. Regards, Hridya Change in v5: -Added a section on DMA-BUF statistics to Documentation/driver-api/dma-buf.rst. Organized the commit message to clearly state the need for the new interface and provide the background on why the existing means of DMA-BUF accounting will not suffice. Based on feedback from Daniel Vetter. Changes in v4: -Suppress uevents from kset creation to avoid waking up uevent listeners on DMA-BUF export/release. Changes in v3: -Fix a warning reported by the kernel test robot. Changes in v2: -Move statistics to /sys/kernel/dmabuf/buffers in oder to allow addition of other DMA-BUF-related sysfs stats in future. Based on feedback from Daniel Vetter. -Each attachment has its own directory to represent attached devices as symlinks and to introduce map_count as a separate file. Based on feedback from Daniel Vetter and Christian König. Thank you both! -Commit messages updated to point to userspace code in AOSP that will read the DMA-BUF sysfs stats. .../ABI/testing/sysfs-kernel-dmabuf-buffers | 52 +++ Documentation/driver-api/dma-buf.rst | 34 ++ drivers/dma-buf/Kconfig | 11 + drivers/dma-buf/Makefile | 1 + drivers/dma-buf/dma-buf-sysfs-stats.c | 300 ++++++++++++++++++ drivers/dma-buf/dma-buf-sysfs-stats.h | 62 ++++ drivers/dma-buf/dma-buf.c | 37 +++ include/linux/dma-buf.h | 20 ++ 8 files changed, 517 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.c create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.h diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers new file mode 100644 index 000000000000..a243984ed420 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers @@ -0,0 +1,52 @@ +What: /sys/kernel/dmabuf/buffers +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: The /sys/kernel/dmabuf/buffers directory contains a + snapshot of the internal state of every DMA-BUF. + /sys/kernel/dmabuf/buffers/<inode_number> will contain the + statistics for the DMA-BUF with the unique inode number + <inode_number> +Users: kernel memory tuning/debugging tools + +What: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and contains the name of the exporter of + the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/size +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and specifies the size of the DMA-BUF in + bytes. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This directory will contain subdirectories representing every + attachment of the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid> +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This directory will contain information on the attached device + and the number of current distinct device mappings. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and is a symlink to the attached device's + sysfs entry. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and contains a map_counter indicating the + number of distinct device mappings of the attachment. diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 7f37ec30d9fd..4027762a824a 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -106,6 +106,40 @@ Implicit Fence Poll Support .. kernel-doc:: drivers/dma-buf/dma-buf.c :doc: implicit fence polling +DMA-BUF statistics +~~~~~~~~~~~~~~~~~~ + +``/sys/kernel/debug/dma_buf/bufinfo`` provides an overview of every DMA-BUF in the +system. However, since debugfs is not safe to be mounted in production, +procfs and sysfs can be used to gather DMA-BUF statistics on production systems. + +The ``/proc/<pid>/fdinfo/<fd>`` files in procfs can be used to gather information +about DMA-BUF fds. Detailed documentation about the interface is present in +Documentation/filesystems/proc.rst. +Unfortunately, the existing procfs interfaces can only provide information about +the DMA-BUFs for which processes hold fds or have the buffers mmapped into their +address space. This necessitated the creation of the DMA-BUF sysfs statistics +interface to provide per-buffer information on production systems. + +The interface at ``/sys/kernel/dma-buf/buffers`` exposes information about +every DMA-BUF when ``CONFIG_DMABUF_SYSFS_STATS`` is enabled. + +The following stats are exposed by the interface: + +* ``/sys/kernel/dmabuf/buffers/<inode_number>/exporter_name`` +* ``/sys/kernel/dmabuf/buffers/<inode_number>/size`` +* ``/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device`` +* ``/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter`` + +The information in the interface can also be used to derive per-exporter and +per-device usage statistics. The data from the interface can be gathered +on error conditions or other important events to provide a snapshot of +DMA-BUF usage. It can also be collected periodically by telemetry to monitor +various metrics. + +Detailed documentation about the interface is present in +Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers + Kernel Functions and Structures Reference ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 4e16c71c24b7..9561e3d2d428 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -72,6 +72,17 @@ menuconfig DMABUF_HEAPS allows userspace to allocate dma-bufs that can be shared between drivers. +menuconfig DMABUF_SYSFS_STATS + bool "DMA-BUF sysfs statistics" + select DMA_SHARED_BUFFER + help + Choose this option to enable DMA-BUF sysfs statistics + in location /sys/kernel/dmabuf/buffers. + + /sys/kernel/dmabuf/buffers/<inode_number> will contain + statistics for the DMA-BUF with the unique inode number + <inode_number>. + source "drivers/dma-buf/heaps/Kconfig" endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 995e05f609ff..40d81f23cacf 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_DMABUF_HEAPS) += heaps/ obj-$(CONFIG_SYNC_FILE) += sync_file.o obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o obj-$(CONFIG_UDMABUF) += udmabuf.o +obj-$(CONFIG_DMABUF_SYSFS_STATS) += dma-buf-sysfs-stats.o dmabuf_selftests-y := \ selftest.o \ diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c new file mode 100644 index 000000000000..45717c8108c8 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -0,0 +1,300 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#include <linux/dma-buf.h> +#include <linux/dma-resv.h> +#include <linux/kobject.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "dma-buf-sysfs-stats.h" + +#define to_dma_buf_entry_from_kobj(x) container_of(x, struct dma_buf_sysfs_entry, kobj) + +struct dma_buf_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_stats_attr(x) container_of(x, struct dma_buf_stats_attribute, attr) + +static ssize_t dma_buf_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_stats_attribute *attribute; + struct dma_buf_sysfs_entry *sysfs_entry; + struct dma_buf *dmabuf; + + attribute = to_dma_buf_stats_attr(attr); + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + dmabuf = sysfs_entry->dmabuf; + + if (!dmabuf || !attribute->show) + return -EIO; + + return attribute->show(dmabuf, attribute, buf); +} + +static const struct sysfs_ops dma_buf_stats_sysfs_ops = { + .show = dma_buf_stats_attribute_show, +}; + +static ssize_t exporter_name_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", dmabuf->exp_name); +} + +static ssize_t size_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%zu\n", dmabuf->size); +} + +static struct dma_buf_stats_attribute exporter_name_attribute = + __ATTR_RO(exporter_name); +static struct dma_buf_stats_attribute size_attribute = __ATTR_RO(size); + +static struct attribute *dma_buf_stats_default_attrs[] = { + &exporter_name_attribute.attr, + &size_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_stats_default); + +static void dma_buf_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_ktype = { + .sysfs_ops = &dma_buf_stats_sysfs_ops, + .release = dma_buf_sysfs_release, + .default_groups = dma_buf_stats_default_groups, +}; + +#define to_dma_buf_attach_entry_from_kobj(x) container_of(x, struct dma_buf_attach_sysfs_entry, kobj) + +struct dma_buf_attach_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_attach_stats_attr(x) container_of(x, struct dma_buf_attach_stats_attribute, attr) + +static ssize_t dma_buf_attach_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_attach_stats_attribute *attribute; + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + attribute = to_dma_buf_attach_stats_attr(attr); + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + + if (!attribute->show) + return -EIO; + + return attribute->show(sysfs_entry, attribute, buf); +} + +static const struct sysfs_ops dma_buf_attach_stats_sysfs_ops = { + .show = dma_buf_attach_stats_attribute_show, +}; + +static ssize_t map_counter_show(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%u\n", sysfs_entry->map_counter); +} + +static struct dma_buf_attach_stats_attribute map_counter_attribute = + __ATTR_RO(map_counter); + +static struct attribute *dma_buf_attach_stats_default_attrs[] = { + &map_counter_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_attach_stats_default); + +static void dma_buf_attach_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_attach_ktype = { + .sysfs_ops = &dma_buf_attach_stats_sysfs_ops, + .release = dma_buf_attach_sysfs_release, + .default_groups = dma_buf_attach_stats_default_groups, +}; + +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = attach->sysfs_entry; + if (!sysfs_entry) + return; + + sysfs_delete_link(&sysfs_entry->kobj, &attach->dev->kobj, "device"); + + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + int ret; + struct dma_buf *dmabuf; + + if (!attach) + return -EINVAL; + + dmabuf = attach->dmabuf; + + sysfs_entry = kzalloc(sizeof(struct dma_buf_attach_sysfs_entry), + GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dmabuf->sysfs_entry->attach_stats_kset; + + attach->sysfs_entry = sysfs_entry; + + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_attach_ktype, + NULL, "%u", uid); + if (ret) + goto kobj_err; + + ret = sysfs_create_link(&sysfs_entry->kobj, &attach->dev->kobj, + "device"); + if (ret) + goto link_err; + + return 0; + +link_err: + kobject_del(&sysfs_entry->kobj); +kobj_err: + kobject_put(&sysfs_entry->kobj); + attach->sysfs_entry = NULL; + + return ret; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = dmabuf->sysfs_entry; + if (!sysfs_entry) + return; + + kset_unregister(sysfs_entry->attach_stats_kset); + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + + +/* Statistics files do not need to send uevents. */ +static int dmabuf_sysfs_uevent_filter(struct kset *kset, struct kobject *kobj) +{ + return 0; +} + +static const struct kset_uevent_ops dmabuf_sysfs_no_uevent_ops = { + .filter = dmabuf_sysfs_uevent_filter, +}; + +static struct kset *dma_buf_stats_kset; +static struct kset *dma_buf_per_buffer_stats_kset; +int dma_buf_init_sysfs_statistics(void) +{ + dma_buf_stats_kset = kset_create_and_add("dmabuf", + &dmabuf_sysfs_no_uevent_ops, + kernel_kobj); + if (!dma_buf_stats_kset) + return -ENOMEM; + + dma_buf_per_buffer_stats_kset = kset_create_and_add("buffers", + &dmabuf_sysfs_no_uevent_ops, + &dma_buf_stats_kset->kobj); + if (!dma_buf_per_buffer_stats_kset) { + kset_unregister(dma_buf_stats_kset); + return -ENOMEM; + } + + return 0; +} + +void dma_buf_uninit_sysfs_statistics(void) +{ + kset_unregister(dma_buf_per_buffer_stats_kset); + kset_unregister(dma_buf_stats_kset); +} + +int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + int ret; + struct kset *attach_stats_kset; + + if (!dmabuf || !dmabuf->file) + return -EINVAL; + + if (!dmabuf->exp_name) { + pr_err("exporter name must not be empty if stats needed\n"); + return -EINVAL; + } + + sysfs_entry = kzalloc(sizeof(struct dma_buf_sysfs_entry), GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dma_buf_per_buffer_stats_kset; + sysfs_entry->dmabuf = dmabuf; + + dmabuf->sysfs_entry = sysfs_entry; + + /* create the directory for buffer stats */ + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_ktype, NULL, + "%lu", file_inode(dmabuf->file)->i_ino); + if (ret) + goto err_sysfs_dmabuf; + + /* create the directory for attachment stats */ + attach_stats_kset = kset_create_and_add("attachments", + &dmabuf_sysfs_no_uevent_ops, + &sysfs_entry->kobj); + if (!attach_stats_kset) { + ret = -ENOMEM; + goto err_sysfs_attach; + } + + sysfs_entry->attach_stats_kset = attach_stats_kset; + + return 0; + +err_sysfs_attach: + kobject_del(&sysfs_entry->kobj); +err_sysfs_dmabuf: + kobject_put(&sysfs_entry->kobj); + dmabuf->sysfs_entry = NULL; + return ret; +} diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h new file mode 100644 index 000000000000..5f4703249117 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#ifndef _DMA_BUF_SYSFS_STATS_H +#define _DMA_BUF_SYSFS_STATS_H + +#ifdef CONFIG_DMABUF_SYSFS_STATS + +int dma_buf_init_sysfs_statistics(void); +void dma_buf_uninit_sysfs_statistics(void); + +int dma_buf_stats_setup(struct dma_buf *dmabuf); +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid); +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) +{ + struct dma_buf_attach_sysfs_entry *entry = attach->sysfs_entry; + + entry->map_counter += delta; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf); +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach); +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *entry = dmabuf->sysfs_entry; + + return entry->attachment_uid++; +} +#else + +static inline int dma_buf_init_sysfs_statistics(void) +{ + return 0; +} + +static inline void dma_buf_uninit_sysfs_statistics(void) {} + +static inline int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + return 0; +} +static inline int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + return 0; +} + +static inline void dma_buf_stats_teardown(struct dma_buf *dmabuf) {} +static inline void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) {} +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) {} +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + return 0; +} +#endif +#endif // _DMA_BUF_SYSFS_STATS_H diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index f264b70c383e..184dd7acb1ed 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -29,6 +29,8 @@ #include <uapi/linux/dma-buf.h> #include <uapi/linux/magic.h> +#include "dma-buf-sysfs-stats.h" + static inline int is_dma_buf_file(struct file *); struct dma_buf_list { @@ -79,6 +81,7 @@ static void dma_buf_release(struct dentry *dentry) if (dmabuf->resv == (struct dma_resv *)&dmabuf[1]) dma_resv_fini(dmabuf->resv); + dma_buf_stats_teardown(dmabuf); module_put(dmabuf->owner); kfree(dmabuf->name); kfree(dmabuf); @@ -580,6 +583,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) file->f_mode |= FMODE_LSEEK; dmabuf->file = file; + ret = dma_buf_stats_setup(dmabuf); + if (ret) + goto err_sysfs; + mutex_init(&dmabuf->lock); INIT_LIST_HEAD(&dmabuf->attachments); @@ -589,6 +596,14 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return dmabuf; +err_sysfs: + /* + * Set file->f_path.dentry->d_fsdata to NULL so that when + * dma_buf_release() gets invoked by dentry_ops, it exits + * early before calling the release() dma_buf op. + */ + file->f_path.dentry->d_fsdata = NULL; + fput(file); err_dmabuf: kfree(dmabuf); err_module: @@ -723,6 +738,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, { struct dma_buf_attachment *attach; int ret; + unsigned int attach_uid; if (WARN_ON(!dmabuf || !dev)) return ERR_PTR(-EINVAL); @@ -748,8 +764,13 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, } dma_resv_lock(dmabuf->resv, NULL); list_add(&attach->node, &dmabuf->attachments); + attach_uid = dma_buf_update_attach_uid(dmabuf); dma_resv_unlock(dmabuf->resv); + ret = dma_buf_attach_stats_setup(attach, attach_uid); + if (ret) + goto err_sysfs; + /* When either the importer or the exporter can't handle dynamic * mappings we cache the mapping here to avoid issues with the * reservation object lock. @@ -776,6 +797,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dma_resv_unlock(attach->dmabuf->resv); attach->sgt = sgt; attach->dir = DMA_BIDIRECTIONAL; + dma_buf_update_attachment_map_count(attach, 1 /* delta */); } return attach; @@ -792,6 +814,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, if (dma_buf_is_dynamic(attach->dmabuf)) dma_resv_unlock(attach->dmabuf->resv); +err_sysfs: dma_buf_detach(dmabuf, attach); return ERR_PTR(ret); } @@ -841,6 +864,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dma_resv_lock(attach->dmabuf->resv, NULL); __unmap_dma_buf(attach, attach->sgt, attach->dir); + dma_buf_update_attachment_map_count(attach, -1 /* delta */); if (dma_buf_is_dynamic(attach->dmabuf)) { dma_buf_unpin(attach); @@ -854,6 +878,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); + dma_buf_attach_stats_teardown(attach); kfree(attach); } EXPORT_SYMBOL_GPL(dma_buf_detach); @@ -993,6 +1018,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } #endif /* CONFIG_DMA_API_DEBUG */ + if (!IS_ERR(sg_table)) + dma_buf_update_attachment_map_count(attach, 1 /* delta */); + return sg_table; } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); @@ -1030,6 +1058,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (dma_buf_is_dynamic(attach->dmabuf) && !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) dma_buf_unpin(attach); + + dma_buf_update_attachment_map_count(attach, -1 /* delta */); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); @@ -1480,6 +1510,12 @@ static inline void dma_buf_uninit_debugfs(void) static int __init dma_buf_init(void) { + int ret; + + ret = dma_buf_init_sysfs_statistics(); + if (ret) + return ret; + dma_buf_mnt = kern_mount(&dma_buf_fs_type); if (IS_ERR(dma_buf_mnt)) return PTR_ERR(dma_buf_mnt); @@ -1495,5 +1531,6 @@ static void __exit dma_buf_deinit(void) { dma_buf_uninit_debugfs(); kern_unmount(dma_buf_mnt); + dma_buf_uninit_sysfs_statistics(); } __exitcall(dma_buf_deinit); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index efdc56b9d95f..342585bd6dff 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -295,6 +295,9 @@ struct dma_buf_ops { * @poll: for userspace poll support * @cb_excl: for userspace poll support * @cb_shared: for userspace poll support + * @sysfs_entry: for exposing information about this buffer in sysfs. + * The attachment_uid member of @sysfs_entry is protected by dma_resv lock + * and is incremented on each attach. * * This represents a shared buffer, created by calling dma_buf_export(). The * userspace representation is a normal file descriptor, which can be created by @@ -330,6 +333,15 @@ struct dma_buf { __poll_t active; } cb_excl, cb_shared; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_sysfs_entry { + struct kobject kobj; + struct dma_buf *dmabuf; + unsigned int attachment_uid; + struct kset *attach_stats_kset; + } *sysfs_entry; +#endif }; /** @@ -379,6 +391,7 @@ struct dma_buf_attach_ops { * @importer_ops: importer operations for this attachment, if provided * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held. * @importer_priv: importer specific attachment data. + * @sysfs_entry: For exposing information about this attachment in sysfs. * * This structure holds the attachment information between the dma_buf buffer * and its user device(s). The list contains one attachment struct per device @@ -399,6 +412,13 @@ struct dma_buf_attachment { const struct dma_buf_attach_ops *importer_ops; void *importer_priv; void *priv; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_attach_sysfs_entry { + struct kobject kobj; + unsigned int map_counter; + } *sysfs_entry; +#endif }; /** -- 2.32.0.rc0.204.g9fa02ecfa5-goog

4 years, 5 months

[PATCH v3 1/4] dma-buf: Require VM_PFNMAP vma for mmap

by Daniel Vetter

tldr; DMA buffers aren't normal memory, expecting that you can use them like that (like calling get_user_pages works, or that they're accounting like any other normal memory) cannot be guaranteed. Since some userspace only runs on integrated devices, where all buffers are actually all resident system memory, there's a huge temptation to assume that a struct page is always present and useable like for any more pagecache backed mmap. This has the potential to result in a uapi nightmare. To stop this gap require that DMA buffer mmaps are VM_PFNMAP, which blocks get_user_pages and all the other struct page based infrastructure for everyone. In spirit this is the uapi counterpart to the kernel-internal CONFIG_DMABUF_DEBUG. Motivated by a recent patch which wanted to swich the system dma-buf heap to vm_insert_page instead of vm_insert_pfn. v2: Jason brought up that we also want to guarantee that all ptes have the pte_special flag set, to catch fast get_user_pages (on architectures that support this). Allowing VM_MIXEDMAP (like VM_SPECIAL does) would still allow vm_insert_page, but limiting to VM_PFNMAP will catch that. >From auditing the various functions to insert pfn pte entires (vm_insert_pfn_prot, remap_pfn_range and all it's callers like dma_mmap_wc) it looks like VM_PFNMAP is already required anyway, so this should be the correct flag to check for. References: https://lore.kernel.org/lkml/CAKMK7uHi+mG0z0HUmNt13QCCvutuRVjpcR0NjRL12k-Wb… Acked-by: Christian König <christian.koenig(a)amd.com> Cc: Jason Gunthorpe <jgg(a)ziepe.ca> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: John Stultz <john.stultz(a)linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org -- Resending this so I can test the next two patches for vgem/shmem in intel-gfx-ci. Last round failed somehow, but I can't repro that at all locally here. No immediate plans to merge this patch here since ttm isn't addressed yet (and there we have the hugepte issue, for which I don't think we have a clear consensus yet). -Daniel --- drivers/dma-buf/dma-buf.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index eadd1eaa2fb5..dda583fb1f03 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -127,6 +127,7 @@ static struct file_system_type dma_buf_fs_type = { static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) { struct dma_buf *dmabuf; + int ret; if (!is_dma_buf_file(file)) return -EINVAL; @@ -142,7 +143,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) dmabuf->size >> PAGE_SHIFT) return -EINVAL; - return dmabuf->ops->mmap(dmabuf, vma); + ret = dmabuf->ops->mmap(dmabuf, vma); + + WARN_ON(!(vma->vm_flags & VM_PFNMAP)); + + return ret; } static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) @@ -1244,6 +1249,8 @@ EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, unsigned long pgoff) { + int ret; + if (WARN_ON(!dmabuf || !vma)) return -EINVAL; @@ -1264,7 +1271,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, vma_set_file(vma, dmabuf->file); vma->vm_pgoff = pgoff; - return dmabuf->ops->mmap(dmabuf, vma); + ret = dmabuf->ops->mmap(dmabuf, vma); + + WARN_ON(!(vma->vm_flags & VM_PFNMAP)); + + return ret; } EXPORT_SYMBOL_GPL(dma_buf_mmap); -- 2.31.0

4 years, 5 months

Re: [Linaro-mm-sig] [PATCH 03/11] drm/panfrost: Use xarray and helpers for depedency tracking

by Daniel Vetter

On Wed, Jun 02, 2021 at 03:06:50PM +0100, Steven Price wrote: > On 21/05/2021 10:09, Daniel Vetter wrote: > > More consistency and prep work for the next patch. > > > > Aside: I wonder whether we shouldn't just move this entire xarray > > business into the scheduler so that not everyone has to reinvent the > > same wheels. Cc'ing some scheduler people for this too. > > > > Cc: "Christian König" <christian.koenig(a)amd.com> > > Cc: Luben Tuikov <luben.tuikov(a)amd.com> > > Cc: Alex Deucher <alexander.deucher(a)amd.com> > > Cc: Lee Jones <lee.jones(a)linaro.org> > > Cc: Steven Price <steven.price(a)arm.com> > > Cc: Rob Herring <robh(a)kernel.org> > > Cc: Tomeu Vizoso <tomeu.vizoso(a)collabora.com> > > Cc: Alyssa Rosenzweig <alyssa.rosenzweig(a)collabora.com> > > Cc: Sumit Semwal <sumit.semwal(a)linaro.org> > > Cc: linux-media(a)vger.kernel.org > > Cc: linaro-mm-sig(a)lists.linaro.org > > Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> > > Two comments below, but otherwise looks like a nice cleanup. Thanks for taking a look. > > --- > > drivers/gpu/drm/panfrost/panfrost_drv.c | 41 ++++++++--------- > > drivers/gpu/drm/panfrost/panfrost_job.c | 61 ++++++++++--------------- > > drivers/gpu/drm/panfrost/panfrost_job.h | 8 ++-- > > 3 files changed, 46 insertions(+), 64 deletions(-) > > > > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c > > index ca07098a6141..7977b4752b5c 100644 > > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > > @@ -137,12 +137,6 @@ panfrost_lookup_bos(struct drm_device *dev, > > if (!job->bo_count) > > return 0; > > > > - job->implicit_fences = kvmalloc_array(job->bo_count, > > - sizeof(struct dma_fence *), > > - GFP_KERNEL | __GFP_ZERO); > > - if (!job->implicit_fences) > > - return -ENOMEM; > > - > > ret = drm_gem_objects_lookup(file_priv, > > (void __user *)(uintptr_t)args->bo_handles, > > job->bo_count, &job->bos); > > @@ -173,7 +167,7 @@ panfrost_lookup_bos(struct drm_device *dev, > > } > > > > /** > > - * panfrost_copy_in_sync() - Sets up job->in_fences[] with the sync objects > > + * panfrost_copy_in_sync() - Sets up job->deps with the sync objects > > * referenced by the job. > > * @dev: DRM device > > * @file_priv: DRM file for this fd > > @@ -193,22 +187,14 @@ panfrost_copy_in_sync(struct drm_device *dev, > > { > > u32 *handles; > > int ret = 0; > > - int i; > > + int i, in_fence_count; > > > > - job->in_fence_count = args->in_sync_count; > > + in_fence_count = args->in_sync_count; > > > > - if (!job->in_fence_count) > > + if (!in_fence_count) > > return 0; > > > > - job->in_fences = kvmalloc_array(job->in_fence_count, > > - sizeof(struct dma_fence *), > > - GFP_KERNEL | __GFP_ZERO); > > - if (!job->in_fences) { > > - DRM_DEBUG("Failed to allocate job in fences\n"); > > - return -ENOMEM; > > - } > > - > > - handles = kvmalloc_array(job->in_fence_count, sizeof(u32), GFP_KERNEL); > > + handles = kvmalloc_array(in_fence_count, sizeof(u32), GFP_KERNEL); > > if (!handles) { > > ret = -ENOMEM; > > DRM_DEBUG("Failed to allocate incoming syncobj handles\n"); > > @@ -217,16 +203,23 @@ panfrost_copy_in_sync(struct drm_device *dev, > > > > if (copy_from_user(handles, > > (void __user *)(uintptr_t)args->in_syncs, > > - job->in_fence_count * sizeof(u32))) { > > + in_fence_count * sizeof(u32))) { > > ret = -EFAULT; > > DRM_DEBUG("Failed to copy in syncobj handles\n"); > > goto fail; > > } > > > > - for (i = 0; i < job->in_fence_count; i++) { > > + for (i = 0; i < in_fence_count; i++) { > > + struct dma_fence *fence; > > + > > ret = drm_syncobj_find_fence(file_priv, handles[i], 0, 0, > > - &job->in_fences[i]); > > - if (ret == -EINVAL) > > + &fence); > > + if (ret) > > + goto fail; > > + > > + ret = drm_gem_fence_array_add(&job->deps, fence); > > + > > + if (ret) > > goto fail; > > } > > > > @@ -264,6 +257,8 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data, > > > > kref_init(&job->refcount); > > > > + xa_init_flags(&job->deps, XA_FLAGS_ALLOC); > > + > > job->pfdev = pfdev; > > job->jc = args->jc; > > job->requirements = args->requirements; > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > > index f5d39ee14ab5..707d912ff64a 100644 > > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > > @@ -196,14 +196,21 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js) > > job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START); > > } > > > > -static void panfrost_acquire_object_fences(struct drm_gem_object **bos, > > - int bo_count, > > - struct dma_fence **implicit_fences) > > +static int panfrost_acquire_object_fences(struct drm_gem_object **bos, > > + int bo_count, > > + struct xarray *deps) > > { > > - int i; > > + int i, ret; > > > > - for (i = 0; i < bo_count; i++) > > - implicit_fences[i] = dma_resv_get_excl_rcu(bos[i]->resv); > > + for (i = 0; i < bo_count; i++) { > > + struct dma_fence *fence = dma_resv_get_excl_rcu(bos[i]->resv); > > + > > + ret = drm_gem_fence_array_add(deps, fence); > > + if (ret) > > + return ret; > > + } > > + > > + return 0; > > } > > > > static void panfrost_attach_object_fences(struct drm_gem_object **bos, > > @@ -236,8 +243,10 @@ int panfrost_job_push(struct panfrost_job *job) > > > > kref_get(&job->refcount); /* put by scheduler job completion */ > > > > - panfrost_acquire_object_fences(job->bos, job->bo_count, > > - job->implicit_fences); > > + ret = panfrost_acquire_object_fences(job->bos, job->bo_count, > > + &job->deps); > > + if (ret) > > + goto unlock; > > I think this needs to move above the kref_get() otherwise we'll leak the > job on failure. Indeed, will fix for the next version. > > > > > drm_sched_entity_push_job(&job->base, entity); > > > > @@ -254,18 +263,15 @@ static void panfrost_job_cleanup(struct kref *ref) > > { > > struct panfrost_job *job = container_of(ref, struct panfrost_job, > > refcount); > > + struct dma_fence *fence; > > + unsigned long index; > > unsigned int i; > > > > - if (job->in_fences) { > > - for (i = 0; i < job->in_fence_count; i++) > > - dma_fence_put(job->in_fences[i]); > > - kvfree(job->in_fences); > > - } > > - if (job->implicit_fences) { > > - for (i = 0; i < job->bo_count; i++) > > - dma_fence_put(job->implicit_fences[i]); > > - kvfree(job->implicit_fences); > > + xa_for_each(&job->deps, index, fence) { > > + dma_fence_put(fence); > > } > > + xa_destroy(&job->deps); > > + > > dma_fence_put(job->done_fence); > > dma_fence_put(job->render_done_fence); > > > > @@ -308,26 +314,9 @@ static struct dma_fence *panfrost_job_dependency(struct drm_sched_job *sched_job > > struct drm_sched_entity *s_entity) > > { > > struct panfrost_job *job = to_panfrost_job(sched_job); > > - struct dma_fence *fence; > > - unsigned int i; > > > > - /* Explicit fences */ > > - for (i = 0; i < job->in_fence_count; i++) { > > - if (job->in_fences[i]) { > > - fence = job->in_fences[i]; > > - job->in_fences[i] = NULL; > > - return fence; > > - } > > - } > > - > > - /* Implicit fences, max. one per BO */ > > - for (i = 0; i < job->bo_count; i++) { > > - if (job->implicit_fences[i]) { > > - fence = job->implicit_fences[i]; > > - job->implicit_fences[i] = NULL; > > - return fence; > > - } > > - } > > + if (!xa_empty(&job->deps)) > > + return xa_erase(&job->deps, job->last_dep++); > > Rather than tracking last_dep separately this could be written using > xa_find(): > > if (xa_find(&job->deps, &i, ULONG_MAX, XA_PRESENT)) > return xa_erase(&job->deps, &i); I copypasted this from other drivers, imo consistency is better than looking pretty. I think eventually we should stuff this as optional helpers into drm/scheduler. Also yours walks the xa twice. -Daniel > > Steve > > > > > return NULL; > > } > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h > > index bbd3ba97ff67..82306a03b57e 100644 > > --- a/drivers/gpu/drm/panfrost/panfrost_job.h > > +++ b/drivers/gpu/drm/panfrost/panfrost_job.h > > @@ -19,9 +19,9 @@ struct panfrost_job { > > struct panfrost_device *pfdev; > > struct panfrost_file_priv *file_priv; > > > > - /* Optional fences userspace can pass in for the job to depend on. */ > > - struct dma_fence **in_fences; > > - u32 in_fence_count; > > + /* Contains both explicit and implicit fences */ > > + struct xarray deps; > > + unsigned long last_dep; > > > > /* Fence to be signaled by IRQ handler when the job is complete. */ > > struct dma_fence *done_fence; > > @@ -30,8 +30,6 @@ struct panfrost_job { > > __u32 requirements; > > __u32 flush_id; > > > > - /* Exclusive fences we have taken from the BOs to wait for */ > > - struct dma_fence **implicit_fences; > > struct panfrost_gem_mapping **mappings; > > struct drm_gem_object **bos; > > u32 bo_count; > > > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

4 years, 5 months

[RESEND 22/26] drm/vgem/vgem_drv: Standard comment blocks should not use kernel-doc format

by Lee Jones

Fixes the following W=1 kernel build warning(s): drivers/gpu/drm/vgem/vgem_drv.c:47: warning: expecting prototype for This is vgem, a (non-hardware(). Prototype was for DRIVER_NAME() instead Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: Adam Jackson <ajax(a)redhat.com> Cc: Ben Widawsky <ben(a)bwidawsk.net> Cc: dri-devel(a)lists.freedesktop.org Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Signed-off-by: Lee Jones <lee.jones(a)linaro.org> --- drivers/gpu/drm/vgem/vgem_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c index a0e75f1d5d016..bf38a7e319d14 100644 --- a/drivers/gpu/drm/vgem/vgem_drv.c +++ b/drivers/gpu/drm/vgem/vgem_drv.c @@ -25,7 +25,7 @@ * Ben Widawsky <ben(a)bwidawsk.net> */ -/** +/* * This is vgem, a (non-hardware-backed) GEM service. This is used by Mesa's * software renderer and the X server for efficient buffer sharing. */ -- 2.31.1

4 years, 5 months

[RESEND 12/26] drm/msm/msm_gem: Demote kernel-doc abuses

by Lee Jones

Fixes the following W=1 kernel build warning(s): drivers/gpu/drm/msm/msm_gem.c:364: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst drivers/gpu/drm/msm/msm_gem.c:763: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst Cc: Rob Clark <robdclark(a)gmail.com> Cc: Sean Paul <sean(a)poorly.run> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-arm-msm(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: freedreno(a)lists.freedesktop.org Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Signed-off-by: Lee Jones <lee.jones(a)linaro.org> --- drivers/gpu/drm/msm/msm_gem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 56df86e5f7400..15434deb19334 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -372,7 +372,7 @@ static void del_vma(struct msm_gem_vma *vma) kfree(vma); } -/** +/* * If close is true, this also closes the VMA (releasing the allocated * iova range) in addition to removing the iommu mapping. In the eviction * case (!close), we keep the iova allocated, but only remove the iommu @@ -773,7 +773,7 @@ void msm_gem_purge(struct drm_gem_object *obj) 0, (loff_t)-1); } -/** +/* * Unpin the backing pages and make them available to be swapped out. */ void msm_gem_evict(struct drm_gem_object *obj) -- 2.31.1

4 years, 5 months

[PATCH v3] amdgpu: remove unreachable code

by Jiapeng Chong

In the function amdgpu_uvd_cs_msg(), every branch in the switch statement will have a return, so the code below the switch statement will not be executed. Eliminate the follow smatch warning: drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c:845 amdgpu_uvd_cs_msg() warn: ignoring unreachable code. Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- Changes in v2: -For the follow advice: https://lore.kernel.org/patchwork/patch/1435968/ drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c index c6dbc08..35f6874 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c @@ -829,9 +829,8 @@ static int amdgpu_uvd_cs_msg(struct amdgpu_uvd_cs_ctx *ctx, default: DRM_ERROR("Illegal UVD message type (%d)!\n", msg_type); - return -EINVAL; } - BUG(); + return -EINVAL; } -- 1.8.3.1

4 years, 5 months

[PATCH v4] dmabuf: Add the capability to expose DMA-BUF stats in sysfs

by Hridya Valsaraju

This patch allows statistics to be enabled for each DMA-BUF in sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS. The following stats will be exposed by the interface: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name /sys/kernel/dmabuf/buffers/<inode_number>/size /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter The inode_number is unique for each DMA-BUF and was added earlier [1] in order to allow userspace to track DMA-BUF usage across different processes. Currently, this information is exposed in /sys/kernel/debug/dma_buf/bufinfo. However, since debugfs is considered unsafe to be mounted in production, it is being duplicated in sysfs. Procfs also uses the proc/<pid>/fdinfo/<fd> file to expose some information about DMA-BUF fds. However, the existing procfs interfaces can only provide information about the buffers for which processes hold fds or have the buffers mmapped into their address space. The sysfs interface also exposes attachment statistics for each buffer. This information will be used to derive DMA-BUF per-exporter stats and per-device usage stats for Android Bug reports. The corresponding userspace changes can be found at [2]. Telemetry tools will also capture this information(along with other memory metrics) periodically as well as on important events like a foreground app kill (which might have been triggered by Low Memory Killer). It will also contribute to provide a snapshot of the system memory usage on other events such as OOM kills and Application Not Responding events. A shell script that can be run on a classic Linux environment to read out the DMA-BUF statistics can be found at [3](suggested by John Stultz). The patch contains the following major improvements over v1: 1) Each attachment is represented by its own directory to allow creating a symlink to the importing device and to also provide room for future expansion. 2) The number of distinct mappings of each attachment is exposed in a separate file. 3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers inorder to make the interface expandable in future. All of the improvements above are based on suggestions/feedback from Daniel Vetter and Christian König. [1]: https://lore.kernel.org/patchwork/patch/1088791/ [2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:… [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo… Signed-off-by: Hridya Valsaraju <hridya(a)google.com> Reported-by: kernel test robot <lkp(a)intel.com> --- Hi Daniel, I am sending the latest version of the DMA-BUF sysfs statistics patch to the list again as per your suggestion to restart the discussion on it :) Please do take a look and let me know your thoughts, thank you! Regards, Hridya Changes in v4: -Suppress uevents from kset creation to avoid waking up uevent listeners on DMA-BUF export/release. Changes in v3: -Fix a warning reported by the kernel test robot. Changes in v2: -Move statistics to /sys/kernel/dmabuf/buffers in oder to allow addition of other DMA-BUF-related sysfs stats in future. Based on feedback from Daniel Vetter. -Each attachment has its own directory to represent attaching devices as symlinks and to introduce map_count as a separate file. Based on feedback from Daniel Vetter and Christian König. Thank you both! -Commit messages updated to point to userspace code in AOSP that will read the DMA-BUF sysfs stats. .../ABI/testing/sysfs-kernel-dmabuf-buffers | 52 +++ drivers/dma-buf/Kconfig | 11 + drivers/dma-buf/Makefile | 1 + drivers/dma-buf/dma-buf-sysfs-stats.c | 300 ++++++++++++++++++ drivers/dma-buf/dma-buf-sysfs-stats.h | 62 ++++ drivers/dma-buf/dma-buf.c | 37 +++ include/linux/dma-buf.h | 20 ++ 7 files changed, 483 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.c create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.h diff --git a/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers new file mode 100644 index 000000000000..73a8c372b0f2 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-dmabuf-buffers @@ -0,0 +1,52 @@ +What: /sys/kernel/dmabuf/buffers +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: The /sys/kernel/dmabuf/buffers directory contains a + snapshot of the internal state of every DMA-BUF. + /sys/kernel/dmabuf/buffers/<inode_number> will contain the + statistics for the DMA-BUF with the unique inode number + <inode_number> +Users: kernel memory tuning/debugging tools + +What: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and contains the name of the exporter of + the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/size +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and specifies the size of the DMA-BUF in + bytes. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This directory will contain subdirectories representing every + attachment of the DMA-BUF. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid> +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This directory will contain information on the attaching device + and the number of current distinct device mappings. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/device +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and is a symlink to the attaching devices's + sysfs entry. + +What: /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attachment_uid>/map_counter +Date: May 2021 +KernelVersion: v5.13 +Contact: Hridya Valsaraju <hridya(a)google.com> +Description: This file is read-only and contains a map_counter indicating the + number of distinct device mappings of the attachment. diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 4e16c71c24b7..9561e3d2d428 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -72,6 +72,17 @@ menuconfig DMABUF_HEAPS allows userspace to allocate dma-bufs that can be shared between drivers. +menuconfig DMABUF_SYSFS_STATS + bool "DMA-BUF sysfs statistics" + select DMA_SHARED_BUFFER + help + Choose this option to enable DMA-BUF sysfs statistics + in location /sys/kernel/dmabuf/buffers. + + /sys/kernel/dmabuf/buffers/<inode_number> will contain + statistics for the DMA-BUF with the unique inode number + <inode_number>. + source "drivers/dma-buf/heaps/Kconfig" endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 995e05f609ff..40d81f23cacf 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_DMABUF_HEAPS) += heaps/ obj-$(CONFIG_SYNC_FILE) += sync_file.o obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o obj-$(CONFIG_UDMABUF) += udmabuf.o +obj-$(CONFIG_DMABUF_SYSFS_STATS) += dma-buf-sysfs-stats.o dmabuf_selftests-y := \ selftest.o \ diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c new file mode 100644 index 000000000000..45717c8108c8 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -0,0 +1,300 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#include <linux/dma-buf.h> +#include <linux/dma-resv.h> +#include <linux/kobject.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "dma-buf-sysfs-stats.h" + +#define to_dma_buf_entry_from_kobj(x) container_of(x, struct dma_buf_sysfs_entry, kobj) + +struct dma_buf_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_stats_attr(x) container_of(x, struct dma_buf_stats_attribute, attr) + +static ssize_t dma_buf_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_stats_attribute *attribute; + struct dma_buf_sysfs_entry *sysfs_entry; + struct dma_buf *dmabuf; + + attribute = to_dma_buf_stats_attr(attr); + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + dmabuf = sysfs_entry->dmabuf; + + if (!dmabuf || !attribute->show) + return -EIO; + + return attribute->show(dmabuf, attribute, buf); +} + +static const struct sysfs_ops dma_buf_stats_sysfs_ops = { + .show = dma_buf_stats_attribute_show, +}; + +static ssize_t exporter_name_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", dmabuf->exp_name); +} + +static ssize_t size_show(struct dma_buf *dmabuf, + struct dma_buf_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%zu\n", dmabuf->size); +} + +static struct dma_buf_stats_attribute exporter_name_attribute = + __ATTR_RO(exporter_name); +static struct dma_buf_stats_attribute size_attribute = __ATTR_RO(size); + +static struct attribute *dma_buf_stats_default_attrs[] = { + &exporter_name_attribute.attr, + &size_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_stats_default); + +static void dma_buf_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_ktype = { + .sysfs_ops = &dma_buf_stats_sysfs_ops, + .release = dma_buf_sysfs_release, + .default_groups = dma_buf_stats_default_groups, +}; + +#define to_dma_buf_attach_entry_from_kobj(x) container_of(x, struct dma_buf_attach_sysfs_entry, kobj) + +struct dma_buf_attach_stats_attribute { + struct attribute attr; + ssize_t (*show)(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, char *buf); +}; +#define to_dma_buf_attach_stats_attr(x) container_of(x, struct dma_buf_attach_stats_attribute, attr) + +static ssize_t dma_buf_attach_stats_attribute_show(struct kobject *kobj, + struct attribute *attr, + char *buf) +{ + struct dma_buf_attach_stats_attribute *attribute; + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + attribute = to_dma_buf_attach_stats_attr(attr); + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + + if (!attribute->show) + return -EIO; + + return attribute->show(sysfs_entry, attribute, buf); +} + +static const struct sysfs_ops dma_buf_attach_stats_sysfs_ops = { + .show = dma_buf_attach_stats_attribute_show, +}; + +static ssize_t map_counter_show(struct dma_buf_attach_sysfs_entry *sysfs_entry, + struct dma_buf_attach_stats_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%u\n", sysfs_entry->map_counter); +} + +static struct dma_buf_attach_stats_attribute map_counter_attribute = + __ATTR_RO(map_counter); + +static struct attribute *dma_buf_attach_stats_default_attrs[] = { + &map_counter_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dma_buf_attach_stats_default); + +static void dma_buf_attach_sysfs_release(struct kobject *kobj) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = to_dma_buf_attach_entry_from_kobj(kobj); + kfree(sysfs_entry); +} + +static struct kobj_type dma_buf_attach_ktype = { + .sysfs_ops = &dma_buf_attach_stats_sysfs_ops, + .release = dma_buf_attach_sysfs_release, + .default_groups = dma_buf_attach_stats_default_groups, +}; + +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + + sysfs_entry = attach->sysfs_entry; + if (!sysfs_entry) + return; + + sysfs_delete_link(&sysfs_entry->kobj, &attach->dev->kobj, "device"); + + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + struct dma_buf_attach_sysfs_entry *sysfs_entry; + int ret; + struct dma_buf *dmabuf; + + if (!attach) + return -EINVAL; + + dmabuf = attach->dmabuf; + + sysfs_entry = kzalloc(sizeof(struct dma_buf_attach_sysfs_entry), + GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dmabuf->sysfs_entry->attach_stats_kset; + + attach->sysfs_entry = sysfs_entry; + + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_attach_ktype, + NULL, "%u", uid); + if (ret) + goto kobj_err; + + ret = sysfs_create_link(&sysfs_entry->kobj, &attach->dev->kobj, + "device"); + if (ret) + goto link_err; + + return 0; + +link_err: + kobject_del(&sysfs_entry->kobj); +kobj_err: + kobject_put(&sysfs_entry->kobj); + attach->sysfs_entry = NULL; + + return ret; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + + sysfs_entry = dmabuf->sysfs_entry; + if (!sysfs_entry) + return; + + kset_unregister(sysfs_entry->attach_stats_kset); + kobject_del(&sysfs_entry->kobj); + kobject_put(&sysfs_entry->kobj); +} + + +/* Statistics files do not need to send uevents. */ +static int dmabuf_sysfs_uevent_filter(struct kset *kset, struct kobject *kobj) +{ + return 0; +} + +static const struct kset_uevent_ops dmabuf_sysfs_no_uevent_ops = { + .filter = dmabuf_sysfs_uevent_filter, +}; + +static struct kset *dma_buf_stats_kset; +static struct kset *dma_buf_per_buffer_stats_kset; +int dma_buf_init_sysfs_statistics(void) +{ + dma_buf_stats_kset = kset_create_and_add("dmabuf", + &dmabuf_sysfs_no_uevent_ops, + kernel_kobj); + if (!dma_buf_stats_kset) + return -ENOMEM; + + dma_buf_per_buffer_stats_kset = kset_create_and_add("buffers", + &dmabuf_sysfs_no_uevent_ops, + &dma_buf_stats_kset->kobj); + if (!dma_buf_per_buffer_stats_kset) { + kset_unregister(dma_buf_stats_kset); + return -ENOMEM; + } + + return 0; +} + +void dma_buf_uninit_sysfs_statistics(void) +{ + kset_unregister(dma_buf_per_buffer_stats_kset); + kset_unregister(dma_buf_stats_kset); +} + +int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *sysfs_entry; + int ret; + struct kset *attach_stats_kset; + + if (!dmabuf || !dmabuf->file) + return -EINVAL; + + if (!dmabuf->exp_name) { + pr_err("exporter name must not be empty if stats needed\n"); + return -EINVAL; + } + + sysfs_entry = kzalloc(sizeof(struct dma_buf_sysfs_entry), GFP_KERNEL); + if (!sysfs_entry) + return -ENOMEM; + + sysfs_entry->kobj.kset = dma_buf_per_buffer_stats_kset; + sysfs_entry->dmabuf = dmabuf; + + dmabuf->sysfs_entry = sysfs_entry; + + /* create the directory for buffer stats */ + ret = kobject_init_and_add(&sysfs_entry->kobj, &dma_buf_ktype, NULL, + "%lu", file_inode(dmabuf->file)->i_ino); + if (ret) + goto err_sysfs_dmabuf; + + /* create the directory for attachment stats */ + attach_stats_kset = kset_create_and_add("attachments", + &dmabuf_sysfs_no_uevent_ops, + &sysfs_entry->kobj); + if (!attach_stats_kset) { + ret = -ENOMEM; + goto err_sysfs_attach; + } + + sysfs_entry->attach_stats_kset = attach_stats_kset; + + return 0; + +err_sysfs_attach: + kobject_del(&sysfs_entry->kobj); +err_sysfs_dmabuf: + kobject_put(&sysfs_entry->kobj); + dmabuf->sysfs_entry = NULL; + return ret; +} diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.h b/drivers/dma-buf/dma-buf-sysfs-stats.h new file mode 100644 index 000000000000..5f4703249117 --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#ifndef _DMA_BUF_SYSFS_STATS_H +#define _DMA_BUF_SYSFS_STATS_H + +#ifdef CONFIG_DMABUF_SYSFS_STATS + +int dma_buf_init_sysfs_statistics(void); +void dma_buf_uninit_sysfs_statistics(void); + +int dma_buf_stats_setup(struct dma_buf *dmabuf); +int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid); +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) +{ + struct dma_buf_attach_sysfs_entry *entry = attach->sysfs_entry; + + entry->map_counter += delta; +} +void dma_buf_stats_teardown(struct dma_buf *dmabuf); +void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach); +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + struct dma_buf_sysfs_entry *entry = dmabuf->sysfs_entry; + + return entry->attachment_uid++; +} +#else + +static inline int dma_buf_init_sysfs_statistics(void) +{ + return 0; +} + +static inline void dma_buf_uninit_sysfs_statistics(void) {} + +static inline int dma_buf_stats_setup(struct dma_buf *dmabuf) +{ + return 0; +} +static inline int dma_buf_attach_stats_setup(struct dma_buf_attachment *attach, + unsigned int uid) +{ + return 0; +} + +static inline void dma_buf_stats_teardown(struct dma_buf *dmabuf) {} +static inline void dma_buf_attach_stats_teardown(struct dma_buf_attachment *attach) {} +static inline void dma_buf_update_attachment_map_count(struct dma_buf_attachment *attach, + int delta) {} +static inline unsigned int dma_buf_update_attach_uid(struct dma_buf *dmabuf) +{ + return 0; +} +#endif +#endif // _DMA_BUF_SYSFS_STATS_H diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index f264b70c383e..184dd7acb1ed 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -29,6 +29,8 @@ #include <uapi/linux/dma-buf.h> #include <uapi/linux/magic.h> +#include "dma-buf-sysfs-stats.h" + static inline int is_dma_buf_file(struct file *); struct dma_buf_list { @@ -79,6 +81,7 @@ static void dma_buf_release(struct dentry *dentry) if (dmabuf->resv == (struct dma_resv *)&dmabuf[1]) dma_resv_fini(dmabuf->resv); + dma_buf_stats_teardown(dmabuf); module_put(dmabuf->owner); kfree(dmabuf->name); kfree(dmabuf); @@ -580,6 +583,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) file->f_mode |= FMODE_LSEEK; dmabuf->file = file; + ret = dma_buf_stats_setup(dmabuf); + if (ret) + goto err_sysfs; + mutex_init(&dmabuf->lock); INIT_LIST_HEAD(&dmabuf->attachments); @@ -589,6 +596,14 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return dmabuf; +err_sysfs: + /* + * Set file->f_path.dentry->d_fsdata to NULL so that when + * dma_buf_release() gets invoked by dentry_ops, it exits + * early before calling the release() dma_buf op. + */ + file->f_path.dentry->d_fsdata = NULL; + fput(file); err_dmabuf: kfree(dmabuf); err_module: @@ -723,6 +738,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, { struct dma_buf_attachment *attach; int ret; + unsigned int attach_uid; if (WARN_ON(!dmabuf || !dev)) return ERR_PTR(-EINVAL); @@ -748,8 +764,13 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, } dma_resv_lock(dmabuf->resv, NULL); list_add(&attach->node, &dmabuf->attachments); + attach_uid = dma_buf_update_attach_uid(dmabuf); dma_resv_unlock(dmabuf->resv); + ret = dma_buf_attach_stats_setup(attach, attach_uid); + if (ret) + goto err_sysfs; + /* When either the importer or the exporter can't handle dynamic * mappings we cache the mapping here to avoid issues with the * reservation object lock. @@ -776,6 +797,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dma_resv_unlock(attach->dmabuf->resv); attach->sgt = sgt; attach->dir = DMA_BIDIRECTIONAL; + dma_buf_update_attachment_map_count(attach, 1 /* delta */); } return attach; @@ -792,6 +814,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, if (dma_buf_is_dynamic(attach->dmabuf)) dma_resv_unlock(attach->dmabuf->resv); +err_sysfs: dma_buf_detach(dmabuf, attach); return ERR_PTR(ret); } @@ -841,6 +864,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dma_resv_lock(attach->dmabuf->resv, NULL); __unmap_dma_buf(attach, attach->sgt, attach->dir); + dma_buf_update_attachment_map_count(attach, -1 /* delta */); if (dma_buf_is_dynamic(attach->dmabuf)) { dma_buf_unpin(attach); @@ -854,6 +878,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); + dma_buf_attach_stats_teardown(attach); kfree(attach); } EXPORT_SYMBOL_GPL(dma_buf_detach); @@ -993,6 +1018,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } #endif /* CONFIG_DMA_API_DEBUG */ + if (!IS_ERR(sg_table)) + dma_buf_update_attachment_map_count(attach, 1 /* delta */); + return sg_table; } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); @@ -1030,6 +1058,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (dma_buf_is_dynamic(attach->dmabuf) && !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) dma_buf_unpin(attach); + + dma_buf_update_attachment_map_count(attach, -1 /* delta */); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); @@ -1480,6 +1510,12 @@ static inline void dma_buf_uninit_debugfs(void) static int __init dma_buf_init(void) { + int ret; + + ret = dma_buf_init_sysfs_statistics(); + if (ret) + return ret; + dma_buf_mnt = kern_mount(&dma_buf_fs_type); if (IS_ERR(dma_buf_mnt)) return PTR_ERR(dma_buf_mnt); @@ -1495,5 +1531,6 @@ static void __exit dma_buf_deinit(void) { dma_buf_uninit_debugfs(); kern_unmount(dma_buf_mnt); + dma_buf_uninit_sysfs_statistics(); } __exitcall(dma_buf_deinit); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index efdc56b9d95f..342585bd6dff 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -295,6 +295,9 @@ struct dma_buf_ops { * @poll: for userspace poll support * @cb_excl: for userspace poll support * @cb_shared: for userspace poll support + * @sysfs_entry: for exposing information about this buffer in sysfs. + * The attachment_uid member of @sysfs_entry is protected by dma_resv lock + * and is incremented on each attach. * * This represents a shared buffer, created by calling dma_buf_export(). The * userspace representation is a normal file descriptor, which can be created by @@ -330,6 +333,15 @@ struct dma_buf { __poll_t active; } cb_excl, cb_shared; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_sysfs_entry { + struct kobject kobj; + struct dma_buf *dmabuf; + unsigned int attachment_uid; + struct kset *attach_stats_kset; + } *sysfs_entry; +#endif }; /** @@ -379,6 +391,7 @@ struct dma_buf_attach_ops { * @importer_ops: importer operations for this attachment, if provided * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held. * @importer_priv: importer specific attachment data. + * @sysfs_entry: For exposing information about this attachment in sysfs. * * This structure holds the attachment information between the dma_buf buffer * and its user device(s). The list contains one attachment struct per device @@ -399,6 +412,13 @@ struct dma_buf_attachment { const struct dma_buf_attach_ops *importer_ops; void *importer_priv; void *priv; +#ifdef CONFIG_DMABUF_SYSFS_STATS + /* for sysfs stats */ + struct dma_buf_attach_sysfs_entry { + struct kobject kobj; + unsigned int map_counter; + } *sysfs_entry; +#endif }; /** -- 2.31.1.818.g46aad6cb9e-goog

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