From 16c243e99d335e1ef3059871897119affc98b493 Mon Sep 17 00:00:00 2001 From: Vivek Kasireddy Date: Wed, 9 Jun 2021 11:29:15 -0700 Subject: udmabuf: Add support for mapping hugepages (v4) If the VMM's (Qemu) memory backend is backed up by memfd + Hugepages (hugetlbfs and not THP), we have to first find the hugepage(s) where the Guest allocations are located and then extract the regular 4k sized subpages from them. v2: Ensure that the subpage and hugepage offsets are calculated correctly when the range of subpage allocations cuts across multiple hugepages. v3: Instead of repeatedly looking up the hugepage for each subpage, only do it when the subpage allocation crosses over into a different hugepage. (suggested by Gerd and DW) v4: Fix the following warning identified by checkpatch: CHECK:OPEN_ENDED_LINE: Lines should not end with a '(' Cc: Gerd Hoffmann Signed-off-by: Vivek Kasireddy Signed-off-by: Dongwon Kim Link: http://patchwork.freedesktop.org/patch/msgid/20210609182915.592743-1-vivek.kasireddy@intel.com [ kraxel: one more checkpatch format tweak ] Signed-off-by: Gerd Hoffmann --- drivers/dma-buf/udmabuf.c | 50 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 7 deletions(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index db732f71e59a..1a79ce899b0f 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -11,6 +11,7 @@ #include #include #include +#include static const u32 list_limit = 1024; /* udmabuf_create_list->count limit */ static const size_t size_limit_mb = 64; /* total dmabuf size, in megabytes */ @@ -160,10 +161,13 @@ static long udmabuf_create(struct miscdevice *device, { DEFINE_DMA_BUF_EXPORT_INFO(exp_info); struct file *memfd = NULL; + struct address_space *mapping = NULL; struct udmabuf *ubuf; struct dma_buf *buf; pgoff_t pgoff, pgcnt, pgidx, pgbuf = 0, pglimit; - struct page *page; + struct page *page, *hpage = NULL; + pgoff_t subpgoff, maxsubpgs; + struct hstate *hpstate; int seals, ret = -EINVAL; u32 i, flags; @@ -194,7 +198,8 @@ static long udmabuf_create(struct miscdevice *device, memfd = fget(list[i].memfd); if (!memfd) goto err; - if (!shmem_mapping(file_inode(memfd)->i_mapping)) + mapping = file_inode(memfd)->i_mapping; + if (!shmem_mapping(mapping) && !is_file_hugepages(memfd)) goto err; seals = memfd_fcntl(memfd, F_GET_SEALS, 0); if (seals == -EINVAL) @@ -205,17 +210,48 @@ static long udmabuf_create(struct miscdevice *device, goto err; pgoff = list[i].offset >> PAGE_SHIFT; pgcnt = list[i].size >> PAGE_SHIFT; + if (is_file_hugepages(memfd)) { + hpstate = hstate_file(memfd); + pgoff = list[i].offset >> huge_page_shift(hpstate); + subpgoff = (list[i].offset & + ~huge_page_mask(hpstate)) >> PAGE_SHIFT; + maxsubpgs = huge_page_size(hpstate) >> PAGE_SHIFT; + } for (pgidx = 0; pgidx < pgcnt; pgidx++) { - page = shmem_read_mapping_page( - file_inode(memfd)->i_mapping, pgoff + pgidx); - if (IS_ERR(page)) { - ret = PTR_ERR(page); - goto err; + if (is_file_hugepages(memfd)) { + if (!hpage) { + hpage = find_get_page_flags(mapping, pgoff, + FGP_ACCESSED); + if (IS_ERR(hpage)) { + ret = PTR_ERR(hpage); + goto err; + } + } + page = hpage + subpgoff; + get_page(page); + subpgoff++; + if (subpgoff == maxsubpgs) { + put_page(hpage); + hpage = NULL; + subpgoff = 0; + pgoff++; + } + } else { + page = shmem_read_mapping_page(mapping, + pgoff + pgidx); + if (IS_ERR(page)) { + ret = PTR_ERR(page); + goto err; + } } ubuf->pages[pgbuf++] = page; } fput(memfd); memfd = NULL; + if (hpage) { + put_page(hpage); + hpage = NULL; + } } exp_info.ops = &udmabuf_ops; -- cgit From 9c61e789546810ee63708568737cb990d2b86605 Mon Sep 17 00:00:00 2001 From: Christian König Date: Wed, 5 May 2021 11:40:54 +0200 Subject: dma-buf: some dma_fence_chain improvements MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The callback and the irq work are never used at the same time. Putting them into an union saves us 24 bytes and makes the structure only 120 bytes in size. Signed-off-by: Christian König Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210611120301.10595-2-christian.koenig@amd.com --- drivers/dma-buf/dma-fence-chain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index 7d129e68ac70..1b4cb3e5cec9 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -137,6 +137,7 @@ static void dma_fence_chain_cb(struct dma_fence *f, struct dma_fence_cb *cb) struct dma_fence_chain *chain; chain = container_of(cb, typeof(*chain), cb); + init_irq_work(&chain->work, dma_fence_chain_irq_work); irq_work_queue(&chain->work); dma_fence_put(f); } @@ -239,7 +240,6 @@ void dma_fence_chain_init(struct dma_fence_chain *chain, rcu_assign_pointer(chain->prev, prev); chain->fence = fence; chain->prev_seqno = 0; - init_irq_work(&chain->work, dma_fence_chain_irq_work); /* Try to reuse the context of the previous chain node. */ if (prev_chain && __dma_fence_is_later(seqno, prev->seqno, prev->ops)) { -- cgit From 440d0f12b52a920f4c78376b3ce7039ba59244c5 Mon Sep 17 00:00:00 2001 From: Christian König Date: Wed, 5 May 2021 13:38:12 +0200 Subject: dma-buf: add dma_fence_chain_alloc/free v3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a common allocation helper. Cleaning up the mix of kzalloc/kmalloc and some unused code in the selftest. v2: polish kernel doc a bit v3: polish kernel doc even a bit more Signed-off-by: Christian König Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210611120301.10595-3-christian.koenig@amd.com --- drivers/dma-buf/st-dma-fence-chain.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c index 9525f7f56119..8ce1ea59d31b 100644 --- a/drivers/dma-buf/st-dma-fence-chain.c +++ b/drivers/dma-buf/st-dma-fence-chain.c @@ -58,28 +58,20 @@ static struct dma_fence *mock_fence(void) return &f->base; } -static inline struct mock_chain { - struct dma_fence_chain base; -} *to_mock_chain(struct dma_fence *f) { - return container_of(f, struct mock_chain, base.base); -} - static struct dma_fence *mock_chain(struct dma_fence *prev, struct dma_fence *fence, u64 seqno) { - struct mock_chain *f; + struct dma_fence_chain *f; - f = kmalloc(sizeof(*f), GFP_KERNEL); + f = dma_fence_chain_alloc(); if (!f) return NULL; - dma_fence_chain_init(&f->base, - dma_fence_get(prev), - dma_fence_get(fence), + dma_fence_chain_init(f, dma_fence_get(prev), dma_fence_get(fence), seqno); - return &f->base.base; + return &f->base; } static int sanitycheck(void *arg) -- cgit From bdb8d06dfefd666d5981d884b535b04105869fcc Mon Sep 17 00:00:00 2001 From: Hridya Valsaraju Date: Thu, 3 Jun 2021 14:47:51 -0700 Subject: dmabuf: Add the capability to expose DMA-BUF stats in sysfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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//exporter_name /sys/kernel/dmabuf/buffers//size /sys/kernel/dmabuf/buffers//attachments//device /sys/kernel/dmabuf/buffers//attachments//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//fdinfo/ The proc//fdinfo/ 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:open%20OR%20status:merged) [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Hridya Valsaraju Reported-by: kernel test robot Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210603214758.2955251-1-hridya@google.com --- drivers/dma-buf/Kconfig | 11 ++ drivers/dma-buf/Makefile | 1 + drivers/dma-buf/dma-buf-sysfs-stats.c | 337 ++++++++++++++++++++++++++++++++++ drivers/dma-buf/dma-buf-sysfs-stats.h | 62 +++++++ drivers/dma-buf/dma-buf.c | 37 ++++ 5 files changed, 448 insertions(+) create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.c create mode 100644 drivers/dma-buf/dma-buf-sysfs-stats.h (limited to 'drivers/dma-buf') 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/ will contain + statistics for the DMA-BUF with the unique 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..a2638e84199c --- /dev/null +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DMA-BUF sysfs statistics. + * + * Copyright (C) 2021 Google LLC. + */ + +#include +#include +#include +#include +#include +#include + +#include "dma-buf-sysfs-stats.h" + +#define to_dma_buf_entry_from_kobj(x) container_of(x, struct dma_buf_sysfs_entry, kobj) + +/** + * DOC: overview + * + * ``/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//fdinfo/`` 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//exporter_name`` + * * ``/sys/kernel/dmabuf/buffers//size`` + * * ``/sys/kernel/dmabuf/buffers//attachments//device`` + * * ``/sys/kernel/dmabuf/buffers//attachments//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. + */ + +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 511fe0d217a0..d0121402c58c 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -29,6 +29,8 @@ #include #include +#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 @@ err_unlock: 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)) { dmabuf->ops->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); @@ -1469,6 +1499,12 @@ 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); @@ -1484,5 +1520,6 @@ 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); -- cgit From 89bcadc8f94bd6e6361b5c803ec6f40132e8bace Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 21 Jun 2021 17:17:58 +0200 Subject: dma-buf: Document non-dynamic exporter expectations better MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Christian and me realized we have a pretty massive disconnect about different interpretations of what dma_resv is used for by different drivers. The discussion is much, much bigger than this change here, but this is an important one: Non-dynamic exporters must guarantee that the memory they return is ready for use. They cannot expect importers to wait for the exclusive fence. Only dynamic importers are required to obey the dma_resv fences strictly (and more patches are needed to define exactly what this means). Christian has patches to update nouvea, radeon and amdgpu. The only other driver using both ttm and supporting dma-buf export is qxl, which only uses synchronous ttm_bo_move. v2: To hammer this in document that dynamic importers _must_ wait for the exclusive fence after having called dma_buf_map_attachment. Reviewed-by: Christian König Cc: Christian König Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210621151758.2347474-1-daniel.vetter@ffwll.ch --- drivers/dma-buf/dma-buf.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index d0121402c58c..510b42771974 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -951,6 +951,9 @@ EXPORT_SYMBOL_GPL(dma_buf_unpin); * the underlying backing storage is pinned for as long as a mapping exists, * therefore users/importers should not hold onto a mapping for undue amounts of * time. + * + * Important: Dynamic importers must wait for the exclusive fence of the struct + * dma_resv attached to the DMA-BUF first. */ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, enum dma_data_direction direction) -- cgit From 2e717a55982affbf424b1ac2bf751201e3f4b19e Mon Sep 17 00:00:00 2001 From: Dongwon Kim Date: Fri, 11 Jun 2021 14:21:07 -0700 Subject: udmabuf: configurable list_limit and size_limit_mb Default list_limit and size_limit_mb are not big enough to cover all possible use cases. For example, list_limit could be well over its default, 1024 if only one or several pages are chained in all individual list entries when creating dmabuf backed by >4MB buffer. list_limit and size_limit_mb are now defined as module parameters so that those can be optionally configured by root with proper values to remove these constraints. Cc: Gerd Hoffmann Signed-off-by: Dongwon Kim Link: http://patchwork.freedesktop.org/patch/msgid/20210611212107.9876-1-dongwon.kim@intel.com Signed-off-by: Gerd Hoffmann --- drivers/dma-buf/udmabuf.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 1a79ce899b0f..8df761a10251 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -13,8 +13,13 @@ #include #include -static const u32 list_limit = 1024; /* udmabuf_create_list->count limit */ -static const size_t size_limit_mb = 64; /* total dmabuf size, in megabytes */ +static int list_limit = 1024; +module_param(list_limit, int, 0644); +MODULE_PARM_DESC(list_limit, "udmabuf_create_list->count limit. Default is 1024."); + +static int size_limit_mb = 64; +module_param(size_limit_mb, int, 0644); +MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is 64."); struct udmabuf { pgoff_t pagecount; -- cgit From 9d38814d1e346ea37a51cbf31f4424c9d059459e Mon Sep 17 00:00:00 2001 From: Christian König Date: Sun, 6 Jun 2021 11:46:33 +0200 Subject: dma-buf: fix dma_resv_test_signaled test_all handling v2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As the name implies if testing all fences is requested we should indeed test all fences and not skip the exclusive one because we see shared ones. v2: fix logic once more Signed-off-by: Christian König Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210702111642.17259-3-christian.koenig@amd.com --- drivers/dma-buf/dma-resv.c | 33 ++++++++++++--------------------- 1 file changed, 12 insertions(+), 21 deletions(-) (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index f26c71747d43..e744fd87c63c 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -615,25 +615,21 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence) */ bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all) { - unsigned int seq, shared_count; + struct dma_fence *fence; + unsigned int seq; int ret; rcu_read_lock(); retry: ret = true; - shared_count = 0; seq = read_seqcount_begin(&obj->seq); if (test_all) { struct dma_resv_list *fobj = dma_resv_shared_list(obj); - unsigned int i; - - if (fobj) - shared_count = fobj->shared_count; + unsigned int i, shared_count; + shared_count = fobj ? fobj->shared_count : 0; for (i = 0; i < shared_count; ++i) { - struct dma_fence *fence; - fence = rcu_dereference(fobj->shared[i]); ret = dma_resv_test_signaled_single(fence); if (ret < 0) @@ -641,24 +637,19 @@ retry: else if (!ret) break; } - - if (read_seqcount_retry(&obj->seq, seq)) - goto retry; } - if (!shared_count) { - struct dma_fence *fence_excl = dma_resv_excl_fence(obj); - - if (fence_excl) { - ret = dma_resv_test_signaled_single(fence_excl); - if (ret < 0) - goto retry; + fence = dma_resv_excl_fence(obj); + if (ret && fence) { + ret = dma_resv_test_signaled_single(fence); + if (ret < 0) + goto retry; - if (read_seqcount_retry(&obj->seq, seq)) - goto retry; - } } + if (read_seqcount_retry(&obj->seq, seq)) + goto retry; + rcu_read_unlock(); return ret; } -- cgit