From 1c9f2c7606afe149800986182638f636646dd824 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 10 Jan 2024 08:28:16 -1000 Subject: kernfs: Rearrange kernfs_node fields to reduce its size on 64bit Moving .flags and .mode right below .hash makes kernfs_node smaller by 8 bytes on 64bit. To avoid creating a hole from 8 bytes alignment on 32bit archs, .priv is moved below so that there are two 32bit pointers after the 64bit .id field. v2: Updated to avoid size increase on 32bit noticed by Geert. Signed-off-by: Tejun Heo Cc: Geert Uytterhoeven Link: https://lore.kernel.org/r/ZZ7hwA18nfmFjYpj@slm.duckdns.org Signed-off-by: Greg Kroah-Hartman --- include/linux/kernfs.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 99aaa050ccb7..82e1ce79a70c 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -206,22 +206,22 @@ struct kernfs_node { const void *ns; /* namespace tag */ unsigned int hash; /* ns + name hash */ + unsigned short flags; + umode_t mode; + union { struct kernfs_elem_dir dir; struct kernfs_elem_symlink symlink; struct kernfs_elem_attr attr; }; - void *priv; - /* * 64bit unique ID. On 64bit ino setups, id is the ino. On 32bit, * the low 32bits are ino and upper generation. */ u64 id; - unsigned short flags; - umode_t mode; + void *priv; struct kernfs_iattrs *iattr; }; -- cgit v1.2.3 From 4207b556e62f0a8915afc5da4c5d5ad915a253a5 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 9 Jan 2024 11:48:04 -1000 Subject: kernfs: RCU protect kernfs_nodes and avoid kernfs_idr_lock in kernfs_find_and_get_node_by_id() The BPF helper bpf_cgroup_from_id() calls kernfs_find_and_get_node_by_id() which acquires kernfs_idr_lock, which is an non-raw non-IRQ-safe lock. This can lead to deadlocks as bpf_cgroup_from_id() can be called from any BPF programs including e.g. the ones that attach to functions which are holding the scheduler rq lock. Consider the following BPF program: SEC("fentry/__set_cpus_allowed_ptr_locked") int BPF_PROG(__set_cpus_allowed_ptr_locked, struct task_struct *p, struct affinity_context *affn_ctx, struct rq *rq, struct rq_flags *rf) { struct cgroup *cgrp = bpf_cgroup_from_id(p->cgroups->dfl_cgrp->kn->id); if (cgrp) { bpf_printk("%d[%s] in %s", p->pid, p->comm, cgrp->kn->name); bpf_cgroup_release(cgrp); } return 0; } __set_cpus_allowed_ptr_locked() is called with rq lock held and the above BPF program calls bpf_cgroup_from_id() within leading to the following lockdep warning: ===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.7.0-rc3-work-00053-g07124366a1d7-dirty #147 Not tainted ----------------------------------------------------- repro/1620 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff833b3688 (kernfs_idr_lock){+.+.}-{2:2}, at: kernfs_find_and_get_node_by_id+0x1e/0x70 and this task is already holding: ffff888237ced698 (&rq->__lock){-.-.}-{2:2}, at: task_rq_lock+0x4e/0xf0 which would create a new lock dependency: (&rq->__lock){-.-.}-{2:2} -> (kernfs_idr_lock){+.+.}-{2:2} ... Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(kernfs_idr_lock); local_irq_disable(); lock(&rq->__lock); lock(kernfs_idr_lock); lock(&rq->__lock); *** DEADLOCK *** ... Call Trace: dump_stack_lvl+0x55/0x70 dump_stack+0x10/0x20 __lock_acquire+0x781/0x2a40 lock_acquire+0xbf/0x1f0 _raw_spin_lock+0x2f/0x40 kernfs_find_and_get_node_by_id+0x1e/0x70 cgroup_get_from_id+0x21/0x240 bpf_cgroup_from_id+0xe/0x20 bpf_prog_98652316e9337a5a___set_cpus_allowed_ptr_locked+0x96/0x11a bpf_trampoline_6442545632+0x4f/0x1000 __set_cpus_allowed_ptr_locked+0x5/0x5a0 sched_setaffinity+0x1b3/0x290 __x64_sys_sched_setaffinity+0x4f/0x60 do_syscall_64+0x40/0xe0 entry_SYSCALL_64_after_hwframe+0x46/0x4e Let's fix it by protecting kernfs_node and kernfs_root with RCU and making kernfs_find_and_get_node_by_id() acquire rcu_read_lock() instead of kernfs_idr_lock. This adds an rcu_head to kernfs_node making it larger by 16 bytes on 64bit. Combined with the preceding rearrange patch, the net increase is 8 bytes. Signed-off-by: Tejun Heo Cc: Andrea Righi Cc: Geert Uytterhoeven Link: https://lore.kernel.org/r/20240109214828.252092-4-tj@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/dir.c | 31 ++++++++++++++++++++----------- fs/kernfs/kernfs-internal.h | 2 ++ include/linux/kernfs.h | 2 ++ 3 files changed, 24 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index bce1d7ac95ca..458519e416fe 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -529,6 +529,20 @@ void kernfs_get(struct kernfs_node *kn) } EXPORT_SYMBOL_GPL(kernfs_get); +static void kernfs_free_rcu(struct rcu_head *rcu) +{ + struct kernfs_node *kn = container_of(rcu, struct kernfs_node, rcu); + + kfree_const(kn->name); + + if (kn->iattr) { + simple_xattrs_free(&kn->iattr->xattrs, NULL); + kmem_cache_free(kernfs_iattrs_cache, kn->iattr); + } + + kmem_cache_free(kernfs_node_cache, kn); +} + /** * kernfs_put - put a reference count on a kernfs_node * @kn: the target kernfs_node @@ -557,16 +571,11 @@ void kernfs_put(struct kernfs_node *kn) if (kernfs_type(kn) == KERNFS_LINK) kernfs_put(kn->symlink.target_kn); - kfree_const(kn->name); - - if (kn->iattr) { - simple_xattrs_free(&kn->iattr->xattrs, NULL); - kmem_cache_free(kernfs_iattrs_cache, kn->iattr); - } spin_lock(&kernfs_idr_lock); idr_remove(&root->ino_idr, (u32)kernfs_ino(kn)); spin_unlock(&kernfs_idr_lock); - kmem_cache_free(kernfs_node_cache, kn); + + call_rcu(&kn->rcu, kernfs_free_rcu); kn = parent; if (kn) { @@ -575,7 +584,7 @@ void kernfs_put(struct kernfs_node *kn) } else { /* just released the root kn, free @root too */ idr_destroy(&root->ino_idr); - kfree(root); + kfree_rcu(root, rcu); } } EXPORT_SYMBOL_GPL(kernfs_put); @@ -715,7 +724,7 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, ino_t ino = kernfs_id_ino(id); u32 gen = kernfs_id_gen(id); - spin_lock(&kernfs_idr_lock); + rcu_read_lock(); kn = idr_find(&root->ino_idr, (u32)ino); if (!kn) @@ -739,10 +748,10 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, if (unlikely(!__kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) goto err_unlock; - spin_unlock(&kernfs_idr_lock); + rcu_read_unlock(); return kn; err_unlock: - spin_unlock(&kernfs_idr_lock); + rcu_read_unlock(); return NULL; } diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 237f2764b941..b42ee6547cdc 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -49,6 +49,8 @@ struct kernfs_root { struct rw_semaphore kernfs_rwsem; struct rw_semaphore kernfs_iattr_rwsem; struct rw_semaphore kernfs_supers_rwsem; + + struct rcu_head rcu; }; /* +1 to avoid triggering overflow warning when negating it */ diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 82e1ce79a70c..87c79d076d6d 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -223,6 +223,8 @@ struct kernfs_node { void *priv; struct kernfs_iattrs *iattr; + + struct rcu_head rcu; }; /* -- cgit v1.2.3 From 3a480d4bb5b1e1f09426223e68acaa90da32e384 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 5 Jan 2024 11:26:48 +0100 Subject: driver core: cpu: make cpu_subsys const Now that the driver core can properly handle constant struct bus_type, move the cpu_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/2024010548-crane-snooze-a871@gregkh Signed-off-by: Greg Kroah-Hartman --- drivers/base/cpu.c | 2 +- include/linux/cpu.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 47de0f140ba6..ac84854c85d7 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -366,7 +366,7 @@ static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env) } #endif -struct bus_type cpu_subsys = { +const struct bus_type cpu_subsys = { .name = "cpu", .dev_name = "cpu", .match = cpu_subsys_match, diff --git a/include/linux/cpu.h b/include/linux/cpu.h index dcb89c987164..0b993a140946 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -128,7 +128,7 @@ static inline void cpu_maps_update_done(void) static inline int add_cpu(unsigned int cpu) { return 0;} #endif /* CONFIG_SMP */ -extern struct bus_type cpu_subsys; +extern const struct bus_type cpu_subsys; extern int lockdep_is_cpus_held(void); -- cgit v1.2.3 From 2444a80c1cc2c4240f60f2162abef3797c1803de Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 14 Feb 2024 08:48:28 +0000 Subject: kobject: make uevent_seqnum atomic We will soon no longer acquire uevent_sock_mutex for most kobject_uevent_net_broadcast() calls, and also while calling uevent_net_broadcast(). Make uevent_seqnum an atomic64_t to get its own protection. This fixes a race while reading /sys/kernel/uevent_seqnum. Signed-off-by: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Christian Brauner Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20240214084829.684541-2-edumazet@google.com Signed-off-by: Greg Kroah-Hartman --- include/linux/kobject.h | 2 +- kernel/ksysfs.c | 2 +- lib/kobject_uevent.c | 17 +++++++++-------- 3 files changed, 11 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/include/linux/kobject.h b/include/linux/kobject.h index c30affcc43b4..c8219505a79f 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -38,7 +38,7 @@ extern char uevent_helper[]; #endif /* counter to tag the uevent, read only except for the kobject core */ -extern u64 uevent_seqnum; +extern atomic64_t uevent_seqnum; /* * The actions here must match the index to the string array diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 1d4bc493b2f4..32ae7fa74a9c 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -39,7 +39,7 @@ static struct kobj_attribute _name##_attr = __ATTR_RW(_name) static ssize_t uevent_seqnum_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return sysfs_emit(buf, "%llu\n", (unsigned long long)uevent_seqnum); + return sysfs_emit(buf, "%llu\n", (u64)atomic64_read(&uevent_seqnum)); } KERNEL_ATTR_RO(uevent_seqnum); diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index fb9a2f06dd1e..9cb1a7fdaeba 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -30,7 +30,7 @@ #include -u64 uevent_seqnum; +atomic64_t uevent_seqnum; #ifdef CONFIG_UEVENT_HELPER char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; #endif @@ -44,7 +44,7 @@ struct uevent_sock { static LIST_HEAD(uevent_sock_list); #endif -/* This lock protects uevent_seqnum and uevent_sock_list */ +/* This lock protects uevent_sock_list */ static DEFINE_MUTEX(uevent_sock_mutex); /* the strings here must match the enum in include/linux/kobject.h */ @@ -583,13 +583,13 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, break; } - mutex_lock(&uevent_sock_mutex); /* we will send an event, so request a new sequence number */ - retval = add_uevent_var(env, "SEQNUM=%llu", ++uevent_seqnum); - if (retval) { - mutex_unlock(&uevent_sock_mutex); + retval = add_uevent_var(env, "SEQNUM=%llu", + atomic64_inc_return(&uevent_seqnum)); + if (retval) goto exit; - } + + mutex_lock(&uevent_sock_mutex); retval = kobject_uevent_net_broadcast(kobj, env, action_string, devpath); mutex_unlock(&uevent_sock_mutex); @@ -688,7 +688,8 @@ static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb, int ret; /* bump and prepare sequence number */ - ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", ++uevent_seqnum); + ret = snprintf(buf, sizeof(buf), "SEQNUM=%llu", + atomic64_inc_return(&uevent_seqnum)); if (ret < 0 || (size_t)ret >= sizeof(buf)) return -ENOMEM; ret++; -- cgit v1.2.3 From d87c295f599cab2ab3b3df53a9098adba4a6002b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 30 Jan 2024 10:46:27 -0800 Subject: sysfs: Introduce a mechanism to hide static attribute_groups Add a mechanism for named attribute_groups to hide their directory at sysfs_update_group() time, or otherwise skip emitting the group directory when the group is first registered. It piggybacks on is_visible() in a similar manner as SYSFS_PREALLOC, i.e. special flags in the upper bits of the returned mode. To use it, specify a symbol prefix to DEFINE_SYSFS_GROUP_VISIBLE(), and then pass that same prefix to SYSFS_GROUP_VISIBLE() when assigning the @is_visible() callback: DEFINE_SYSFS_GROUP_VISIBLE($prefix) struct attribute_group $prefix_group = { .name = $name, .is_visible = SYSFS_GROUP_VISIBLE($prefix), }; SYSFS_GROUP_VISIBLE() expects a definition of $prefix_group_visible() and $prefix_attr_visible(), where $prefix_group_visible() just returns true / false and $prefix_attr_visible() behaves as normal. The motivation for this capability is to centralize PCI device authentication in the PCI core with a named sysfs group while keeping that group hidden for devices and platforms that do not meet the requirements. In a PCI topology, most devices will not support authentication, a small subset will support just PCI CMA (Component Measurement and Authentication), a smaller subset will support PCI CMA + PCIe IDE (Link Integrity and Encryption), and only next generation server hosts will start to include a platform TSM (TEE Security Manager). Without this capability the alternatives are: * Check if all attributes are invisible and if so, hide the directory. Beyond trouble getting this to work [1], this is an ABI change for scenarios if userspace happens to depend on group visibility absent any attributes. I.e. this new capability avoids regression since it does not retroactively apply to existing cases. * Publish an empty /sys/bus/pci/devices/$pdev/tsm/ directory for all PCI devices (i.e. for the case when TSM platform support is present, but device support is absent). Unfortunate that this will be a vestigial empty directory in the vast majority of cases. * Reintroduce usage of runtime calls to sysfs_{create,remove}_group() in the PCI core. Bjorn has already indicated that he does not want to see any growth of pci_sysfs_init() [2]. * Drop the named group and simulate a directory by prefixing all TSM-related attributes with "tsm_". Unfortunate to not use the naming capability of a sysfs group as intended. In comparison, there is a small potential for regression if for some reason an @is_visible() callback had dependencies on how many times it was called. Additionally, it is no longer an error to update a group that does not have its directory already present, and it is no longer a WARN() to remove a group that was never visible. Link: https://lore.kernel.org/all/2024012321-envious-procedure-4a58@gregkh/ [1] Link: https://lore.kernel.org/linux-pci/20231019200110.GA1410324@bhelgaas/ [2] Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/2024013028-deflator-flaring-ec62@gregkh Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/group.c | 45 ++++++++++++++++++++++++++++-------- include/linux/sysfs.h | 63 +++++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 87 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 138676463336..ccb275cdabcb 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -31,6 +31,17 @@ static void remove_files(struct kernfs_node *parent, kernfs_remove_by_name(parent, (*bin_attr)->attr.name); } +static umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj) +{ + if (grp->attrs && grp->is_visible) + return grp->is_visible(kobj, grp->attrs[0], 0); + + if (grp->bin_attrs && grp->is_bin_visible) + return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0); + + return 0; +} + static int create_files(struct kernfs_node *parent, struct kobject *kobj, kuid_t uid, kgid_t gid, const struct attribute_group *grp, int update) @@ -52,6 +63,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, kernfs_remove_by_name(parent, (*attr)->name); if (grp->is_visible) { mode = grp->is_visible(kobj, *attr, i); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } @@ -81,6 +93,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, (*bin_attr)->attr.name); if (grp->is_bin_visible) { mode = grp->is_bin_visible(kobj, *bin_attr, i); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } @@ -127,16 +140,31 @@ static int internal_create_group(struct kobject *kobj, int update, kobject_get_ownership(kobj, &uid, &gid); if (grp->name) { + umode_t mode = __first_visible(grp, kobj); + + if (mode & SYSFS_GROUP_INVISIBLE) + mode = 0; + else + mode = S_IRWXU | S_IRUGO | S_IXUGO; + if (update) { kn = kernfs_find_and_get(kobj->sd, grp->name); if (!kn) { - pr_warn("Can't update unknown attr grp name: %s/%s\n", - kobj->name, grp->name); - return -EINVAL; + pr_debug("attr grp %s/%s not created yet\n", + kobj->name, grp->name); + /* may have been invisible prior to this update */ + update = 0; + } else if (!mode) { + sysfs_remove_group(kobj, grp); + kernfs_put(kn); + return 0; } - } else { - kn = kernfs_create_dir_ns(kobj->sd, grp->name, - S_IRWXU | S_IRUGO | S_IXUGO, + } + + if (!update) { + if (!mode) + return 0; + kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode, uid, gid, kobj, NULL); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) @@ -279,9 +307,8 @@ void sysfs_remove_group(struct kobject *kobj, if (grp->name) { kn = kernfs_find_and_get(parent, grp->name); if (!kn) { - WARN(!kn, KERN_WARNING - "sysfs group '%s' not found for kobject '%s'\n", - grp->name, kobject_name(kobj)); + pr_debug("sysfs group '%s' not found for kobject '%s'\n", + grp->name, kobject_name(kobj)); return; } } else { diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index b717a70219f6..a42642b277dd 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -61,22 +61,32 @@ do { \ /** * struct attribute_group - data structure used to declare an attribute group. * @name: Optional: Attribute group name - * If specified, the attribute group will be created in - * a new subdirectory with this name. + * If specified, the attribute group will be created in a + * new subdirectory with this name. Additionally when a + * group is named, @is_visible and @is_bin_visible may + * return SYSFS_GROUP_INVISIBLE to control visibility of + * the directory itself. * @is_visible: Optional: Function to return permissions associated with an - * attribute of the group. Will be called repeatedly for each - * non-binary attribute in the group. Only read/write + * attribute of the group. Will be called repeatedly for + * each non-binary attribute in the group. Only read/write * permissions as well as SYSFS_PREALLOC are accepted. Must - * return 0 if an attribute is not visible. The returned value - * will replace static permissions defined in struct attribute. + * return 0 if an attribute is not visible. The returned + * value will replace static permissions defined in struct + * attribute. Use SYSFS_GROUP_VISIBLE() when assigning this + * callback to specify separate _group_visible() and + * _attr_visible() handlers. * @is_bin_visible: * Optional: Function to return permissions associated with a * binary attribute of the group. Will be called repeatedly * for each binary attribute in the group. Only read/write - * permissions as well as SYSFS_PREALLOC are accepted. Must - * return 0 if a binary attribute is not visible. The returned - * value will replace static permissions defined in - * struct bin_attribute. + * permissions as well as SYSFS_PREALLOC (and the + * visibility flags for named groups) are accepted. Must + * return 0 if a binary attribute is not visible. The + * returned value will replace static permissions defined + * in struct bin_attribute. If @is_visible is not set, Use + * SYSFS_GROUP_VISIBLE() when assigning this callback to + * specify separate _group_visible() and _attr_visible() + * handlers. * @attrs: Pointer to NULL terminated list of attributes. * @bin_attrs: Pointer to NULL terminated list of binary attributes. * Either attrs or bin_attrs or both must be provided. @@ -91,13 +101,42 @@ struct attribute_group { struct bin_attribute **bin_attrs; }; +#define SYSFS_PREALLOC 010000 +#define SYSFS_GROUP_INVISIBLE 020000 + +/* + * The first call to is_visible() in the create / update path may + * indicate visibility for the entire group + */ +#define DEFINE_SYSFS_GROUP_VISIBLE(name) \ + static inline umode_t sysfs_group_visible_##name( \ + struct kobject *kobj, struct attribute *attr, int n) \ + { \ + if (n == 0 && !name##_group_visible(kobj)) \ + return SYSFS_GROUP_INVISIBLE; \ + return name##_attr_visible(kobj, attr, n); \ + } + +/* + * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary + * attributes + */ +#define DEFINE_SYSFS_BIN_GROUP_VISIBLE(name) \ + static inline umode_t sysfs_group_visible_##name( \ + struct kobject *kobj, struct bin_attribute *attr, int n) \ + { \ + if (n == 0 && !name##_group_visible(kobj)) \ + return SYSFS_GROUP_INVISIBLE; \ + return name##_attr_visible(kobj, attr, n); \ + } + +#define SYSFS_GROUP_VISIBLE(fn) sysfs_group_visible_##fn + /* * Use these macros to make defining attributes easier. * See include/linux/device.h for examples.. */ -#define SYSFS_PREALLOC 010000 - #define __ATTR(_name, _mode, _show, _store) { \ .attr = {.name = __stringify(_name), \ .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ -- cgit v1.2.3 From aa3c88990f77bb9acb3d445337bc088031ac63f9 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 22 Feb 2024 12:41:00 -0800 Subject: sysfs: Document new "group visible" helpers Add documentation and examples for how to use DEFINE_SYSFS_GROUP_VISIBLE() and SYSFS_GROUP_VISIBLE(). Recall that the motivation for this work is that it is easier to reason about the lifetime of statically defined sysfs attributes that become visible at device_add() time rather than dynamically adding them later. DEFINE_SYSFS_GROUP_VISIBLE() tackles one of the reasons to opt for dynamically created attributes which did not have a facility for hiding empty directories. Signed-off-by: Dan Williams Link: https://lore.kernel.org/r/170863446065.1479840.10697164014098377292.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/sysfs.h | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index a42642b277dd..dabf7f4f3581 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -105,8 +105,42 @@ struct attribute_group { #define SYSFS_GROUP_INVISIBLE 020000 /* - * The first call to is_visible() in the create / update path may - * indicate visibility for the entire group + * DEFINE_SYSFS_GROUP_VISIBLE(name): + * A helper macro to pair with the assignment of ".is_visible = + * SYSFS_GROUP_VISIBLE(name)", that arranges for the directory + * associated with a named attribute_group to optionally be hidden. + * This allows for static declaration of attribute_groups, and the + * simplification of attribute visibility lifetime that implies, + * without polluting sysfs with empty attribute directories. + * Ex. + * + * static umode_t example_attr_visible(struct kobject *kobj, + * struct attribute *attr, int n) + * { + * if (example_attr_condition) + * return 0; + * else if (ro_attr_condition) + * return 0444; + * return a->mode; + * } + * + * static bool example_group_visible(struct kobject *kobj) + * { + * if (example_group_condition) + * return false; + * return true; + * } + * + * DEFINE_SYSFS_GROUP_VISIBLE(example); + * + * static struct attribute_group example_group = { + * .name = "example", + * .is_visible = SYSFS_GROUP_VISIBLE(example), + * .attrs = &example_attrs, + * }; + * + * Note that it expects _attr_visible and _group_visible to + * be defined. */ #define DEFINE_SYSFS_GROUP_VISIBLE(name) \ static inline umode_t sysfs_group_visible_##name( \ @@ -119,7 +153,9 @@ struct attribute_group { /* * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary - * attributes + * attributes. If an attribute_group defines both text and binary + * attributes, the group visibility is determined by the function + * specified to is_visible() not is_bin_visible() */ #define DEFINE_SYSFS_BIN_GROUP_VISIBLE(name) \ static inline umode_t sysfs_group_visible_##name( \ -- cgit v1.2.3 From 04edfa7fa059ba50d3236b55ba0ae23b1721e868 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 22 Feb 2024 12:41:06 -0800 Subject: sysfs: Introduce DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE() One of the first users of DEFINE_SYSFS_GROUP_VISIBLE() did this: static umode_t dp0_attr_visible(struct kobject *kobj, struct attribute *attr, int n) { struct sdw_slave *slave = dev_to_sdw_dev(kobj_to_dev(kobj)); if (slave->prop.dp0_prop) return attr->mode; return 0; } static bool dp0_group_visible(struct kobject *kobj) { struct sdw_slave *slave = dev_to_sdw_dev(kobj_to_dev(kobj)); if (slave->prop.dp0_prop) return true; return false; } DEFINE_SYSFS_GROUP_VISIBLE(dp0); ...i.e. the _group_visible() helper is identical to the _attr_visible() helper. Use the "simple" helper to reduce that to: static bool dp0_group_visible(struct kobject *kobj) { struct sdw_slave *slave = dev_to_sdw_dev(kobj_to_dev(kobj)); if (slave->prop.dp0_prop) return true; return false; } DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(dp0); Remove the need to specify per attribute visibility if the goal is to hide the entire group. Signed-off-by: Dan Williams Link: https://lore.kernel.org/r/170863446625.1479840.10593839479268727913.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/sysfs.h | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index dabf7f4f3581..326341c62385 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -140,7 +140,9 @@ struct attribute_group { * }; * * Note that it expects _attr_visible and _group_visible to - * be defined. + * be defined. For cases where individual attributes do not need + * separate visibility consideration, only entire group visibility at + * once, see DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(). */ #define DEFINE_SYSFS_GROUP_VISIBLE(name) \ static inline umode_t sysfs_group_visible_##name( \ @@ -151,6 +153,38 @@ struct attribute_group { return name##_attr_visible(kobj, attr, n); \ } +/* + * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name): + * A helper macro to pair with SYSFS_GROUP_VISIBLE() that like + * DEFINE_SYSFS_GROUP_VISIBLE() controls group visibility, but does + * not require the implementation of a per-attribute visibility + * callback. + * Ex. + * + * static bool example_group_visible(struct kobject *kobj) + * { + * if (example_group_condition) + * return false; + * return true; + * } + * + * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(example); + * + * static struct attribute_group example_group = { + * .name = "example", + * .is_visible = SYSFS_GROUP_VISIBLE(example), + * .attrs = &example_attrs, + * }; + */ +#define DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name) \ + static inline umode_t sysfs_group_visible_##name( \ + struct kobject *kobj, struct attribute *a, int n) \ + { \ + if (n == 0 && !name##_group_visible(kobj)) \ + return SYSFS_GROUP_INVISIBLE; \ + return a->mode; \ + } + /* * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary * attributes. If an attribute_group defines both text and binary @@ -166,6 +200,15 @@ struct attribute_group { return name##_attr_visible(kobj, attr, n); \ } +#define DEFINE_SIMPLE_SYSFS_BIN_GROUP_VISIBLE(name) \ + static inline umode_t sysfs_group_visible_##name( \ + struct kobject *kobj, struct bin_attribute *a, int n) \ + { \ + if (n == 0 && !name##_group_visible(kobj)) \ + return SYSFS_GROUP_INVISIBLE; \ + return a->mode; \ + } + #define SYSFS_GROUP_VISIBLE(fn) sysfs_group_visible_##fn /* -- cgit v1.2.3 From 8dde8fa0cc3edce73c050b9882d06c1a575f6402 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 17 Jan 2024 00:33:07 -0800 Subject: firmware_loader: introduce __free() cleanup hanler Define cleanup handler using facilities from linux/cleanup.h to simplify error handling in code using firmware loader. This will allow writing code like this: int driver_update_firmware(...) { const struct firmware *fw_entry __free(firmware) = NULL; int error; ... error = request_firmware(&fw_entry, fw_name, dev); if (error) { dev_err(dev, "failed to request firmware %s: %d", fw_name, error); return error; } error = check_firmware_valid(fw_entry); if (error) return error; guard(mutex)(&instance->lock); error = use_firmware(instance, fw); if (error) return error; return 0; } Signed-off-by: Dmitry Torokhov Acked-by: Luis Chamberalin Link: https://lore.kernel.org/r/ZaeQw7VXhnirX4pQ@google.com Signed-off-by: Greg Kroah-Hartman --- include/linux/firmware.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/firmware.h b/include/linux/firmware.h index 0311858b46ce..f026f8926d79 100644 --- a/include/linux/firmware.h +++ b/include/linux/firmware.h @@ -4,6 +4,7 @@ #include #include +#include #include #define FW_ACTION_NOUEVENT 0 @@ -198,4 +199,6 @@ static inline void firmware_upload_unregister(struct fw_upload *fw_upload) int firmware_request_cache(struct device *device, const char *name); +DEFINE_FREE(firmware, struct firmware *, release_firmware(_T)) + #endif -- cgit v1.2.3 From bbf6cfba49a117c502ec5df66d3ab3b485c113f8 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 1 Mar 2024 20:00:05 +0200 Subject: driver core: Drop unneeded 'extern' keyword in fwnode.h We do not use 'extern' keyword with functions. Remove the last one mistakenly added to fwnode.h. Reviewed-by: Sakari Ailus Acked-by: Saravana Kannan Acked-by: "Rafael J. Wysocki" Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240301180138.271590-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/fwnode.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 2a72f55d26eb..2d23a14857c7 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -209,9 +209,9 @@ static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode, fwnode->flags &= ~FWNODE_FLAG_INITIALIZED; } -extern bool fw_devlink_is_strict(void); int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup); void fwnode_links_purge(struct fwnode_handle *fwnode); void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode); +bool fw_devlink_is_strict(void); #endif -- cgit v1.2.3 From 1c4002aeab3c81afa8a00ae76b1ea38d066e9978 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 1 Mar 2024 20:00:06 +0200 Subject: driver core: Move fw_devlink stuff to where it belongs A few APIs, i.e. fwnode_is_ancestor_of(), fwnode_get_next_parent_dev(), and get_dev_from_fwnode(), that belong specifically to the fw_devlink APIs, may be static, but they are not. Resolve this mess by moving them to the driver/base/core where the all users are being resided and make static. No functional changes intended. Reviewed-by: Sakari Ailus Acked-by: "Rafael J. Wysocki" Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240301180138.271590-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ drivers/base/property.c | 56 ---------------------------------------------- include/linux/fwnode.h | 1 - include/linux/property.h | 2 -- 4 files changed, 58 insertions(+), 59 deletions(-) (limited to 'include') diff --git a/drivers/base/core.c b/drivers/base/core.c index 9828da9b933c..35ccd8bb2c9b 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1871,6 +1871,7 @@ static void fw_devlink_unblock_consumers(struct device *dev) device_links_write_unlock(); } +#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev) static bool fwnode_init_without_drv(struct fwnode_handle *fwnode) { @@ -1901,6 +1902,63 @@ static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode) return false; } +/** + * fwnode_is_ancestor_of - Test if @ancestor is ancestor of @child + * @ancestor: Firmware which is tested for being an ancestor + * @child: Firmware which is tested for being the child + * + * A node is considered an ancestor of itself too. + * + * Return: true if @ancestor is an ancestor of @child. Otherwise, returns false. + */ +static bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, + const struct fwnode_handle *child) +{ + struct fwnode_handle *parent; + + if (IS_ERR_OR_NULL(ancestor)) + return false; + + if (child == ancestor) + return true; + + fwnode_for_each_parent_node(child, parent) { + if (parent == ancestor) { + fwnode_handle_put(parent); + return true; + } + } + return false; +} + +/** + * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode + * @fwnode: firmware node + * + * Given a firmware node (@fwnode), this function finds its closest ancestor + * firmware node that has a corresponding struct device and returns that struct + * device. + * + * The caller is responsible for calling put_device() on the returned device + * pointer. + * + * Return: a pointer to the device of the @fwnode's closest ancestor. + */ +static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode) +{ + struct fwnode_handle *parent; + struct device *dev; + + fwnode_for_each_parent_node(fwnode, parent) { + dev = get_dev_from_fwnode(parent); + if (dev) { + fwnode_handle_put(parent); + return dev; + } + } + return NULL; +} + /** * __fw_devlink_relax_cycles - Relax and mark dependency cycles. * @con: Potential consumer device. diff --git a/drivers/base/property.c b/drivers/base/property.c index a1b01ab42052..afa1bf2b3c5a 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -699,34 +699,6 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(fwnode_get_next_parent); -/** - * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode - * @fwnode: firmware node - * - * Given a firmware node (@fwnode), this function finds its closest ancestor - * firmware node that has a corresponding struct device and returns that struct - * device. - * - * The caller is responsible for calling put_device() on the returned device - * pointer. - * - * Return: a pointer to the device of the @fwnode's closest ancestor. - */ -struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode) -{ - struct fwnode_handle *parent; - struct device *dev; - - fwnode_for_each_parent_node(fwnode, parent) { - dev = get_dev_from_fwnode(parent); - if (dev) { - fwnode_handle_put(parent); - return dev; - } - } - return NULL; -} - /** * fwnode_count_parents - Return the number of parents a node has * @fwnode: The node the parents of which are to be counted @@ -773,34 +745,6 @@ struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode, } EXPORT_SYMBOL_GPL(fwnode_get_nth_parent); -/** - * fwnode_is_ancestor_of - Test if @ancestor is ancestor of @child - * @ancestor: Firmware which is tested for being an ancestor - * @child: Firmware which is tested for being the child - * - * A node is considered an ancestor of itself too. - * - * Return: true if @ancestor is an ancestor of @child. Otherwise, returns false. - */ -bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child) -{ - struct fwnode_handle *parent; - - if (IS_ERR_OR_NULL(ancestor)) - return false; - - if (child == ancestor) - return true; - - fwnode_for_each_parent_node(child, parent) { - if (parent == ancestor) { - fwnode_handle_put(parent); - return true; - } - } - return false; -} - /** * fwnode_get_next_child_node - Return the next child node handle for a node * @fwnode: Firmware node to find the next child node for. diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 2d23a14857c7..416cbe72f0c7 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -187,7 +187,6 @@ struct fwnode_operations { if (fwnode_has_op(fwnode, op)) \ (fwnode)->ops->op(fwnode, ## __VA_ARGS__); \ } while (false) -#define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev) static inline void fwnode_init(struct fwnode_handle *fwnode, const struct fwnode_operations *ops) diff --git a/include/linux/property.h b/include/linux/property.h index e6516d0b7d52..284ff79ebf03 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -156,11 +156,9 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode); for (parent = fwnode_get_parent(fwnode); parent; \ parent = fwnode_get_next_parent(parent)) -struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwnode); unsigned int fwnode_count_parents(const struct fwnode_handle *fwn); struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn, unsigned int depth); -bool fwnode_is_ancestor_of(const struct fwnode_handle *ancestor, const struct fwnode_handle *child); struct fwnode_handle *fwnode_get_next_child_node( const struct fwnode_handle *fwnode, struct fwnode_handle *child); struct fwnode_handle *fwnode_get_next_available_child_node( -- cgit v1.2.3 From 420b104dd116cddd1615588a400b557bf4e436b4 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 1 Mar 2024 20:00:07 +0200 Subject: device property: Move enum dev_dma_attr to fwnode.h The struct fwnode_operations defines one of the callback to return enum dev_dma_attr. But this currently is defined in property.h. Move it to the correct location. Reviewed-by: Sakari Ailus Acked-by: "Rafael J. Wysocki" Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240301180138.271590-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/fwnode.h | 6 ++++++ include/linux/property.h | 6 ------ 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 416cbe72f0c7..4228c45d5ccc 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -14,6 +14,12 @@ #include #include +enum dev_dma_attr { + DEV_DMA_NOT_SUPPORTED, + DEV_DMA_NON_COHERENT, + DEV_DMA_COHERENT, +}; + struct fwnode_operations; struct device; diff --git a/include/linux/property.h b/include/linux/property.h index 284ff79ebf03..1f0135e24d00 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -27,12 +27,6 @@ enum dev_prop_type { DEV_PROP_REF, }; -enum dev_dma_attr { - DEV_DMA_NOT_SUPPORTED, - DEV_DMA_NON_COHERENT, - DEV_DMA_COHERENT, -}; - const struct fwnode_handle *__dev_fwnode_const(const struct device *dev); struct fwnode_handle *__dev_fwnode(struct device *dev); #define dev_fwnode(dev) \ -- cgit v1.2.3 From 4dc3d612ee5c3be2a4d1a73ab31bcfaaa850aa19 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 1 Mar 2024 20:00:08 +0200 Subject: device property: Don't use "proxy" headers Update header inclusions to follow IWYU (Include What You Use) principle. Reviewed-by: Sakari Ailus Acked-by: "Rafael J. Wysocki" Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240301180138.271590-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/property.c | 11 ++++++----- drivers/base/swnode.c | 13 ++++++++++++- include/linux/fwnode.h | 4 ++-- include/linux/property.h | 1 + 4 files changed, 21 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/drivers/base/property.c b/drivers/base/property.c index afa1bf2b3c5a..7324a704a9a1 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -7,15 +7,16 @@ * Mika Westerberg */ -#include +#include +#include #include -#include +#include #include -#include -#include -#include #include #include +#include +#include +#include struct fwnode_handle *__dev_fwnode(struct device *dev) { diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c index 36512fb75a20..eb6eb25b343b 100644 --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -6,10 +6,21 @@ * Author: Heikki Krogerus */ +#include #include -#include +#include +#include +#include +#include +#include +#include +#include #include #include +#include +#include +#include +#include #include "base.h" diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 4228c45d5ccc..80f3cd91b471 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -9,10 +9,10 @@ #ifndef _LINUX_FWNODE_H_ #define _LINUX_FWNODE_H_ -#include -#include #include #include +#include +#include enum dev_dma_attr { DEV_DMA_NOT_SUPPORTED, diff --git a/include/linux/property.h b/include/linux/property.h index 1f0135e24d00..3a1045eb786c 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -11,6 +11,7 @@ #define _LINUX_PROPERTY_H_ #include +#include #include #include #include -- cgit v1.2.3 From 75cde56a5b504d07a64ce0e3f8c7410df70308a3 Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Mon, 4 Mar 2024 21:04:54 -0800 Subject: driver core: Adds flags param to fwnode_link_add() Allow the callers to set fwnode link flags when adding fwnode links. Signed-off-by: Saravana Kannan Acked-by: "Rafael J. Wysocki" Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/20240305050458.1400667-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 5 +++-- drivers/firmware/efi/sysfb_efi.c | 2 +- drivers/of/property.c | 2 +- include/linux/fwnode.h | 3 ++- 4 files changed, 7 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/drivers/base/core.c b/drivers/base/core.c index 35ccd8bb2c9b..83a6f429bddb 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -92,12 +92,13 @@ static int __fwnode_link_add(struct fwnode_handle *con, return 0; } -int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) +int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup, + u8 flags) { int ret; mutex_lock(&fwnode_link_lock); - ret = __fwnode_link_add(con, sup, 0); + ret = __fwnode_link_add(con, sup, flags); mutex_unlock(&fwnode_link_lock); return ret; } diff --git a/drivers/firmware/efi/sysfb_efi.c b/drivers/firmware/efi/sysfb_efi.c index 456d0e5eaf78..cc807ed35aed 100644 --- a/drivers/firmware/efi/sysfb_efi.c +++ b/drivers/firmware/efi/sysfb_efi.c @@ -336,7 +336,7 @@ static int efifb_add_links(struct fwnode_handle *fwnode) if (!sup_np) return 0; - fwnode_link_add(fwnode, of_fwnode_handle(sup_np)); + fwnode_link_add(fwnode, of_fwnode_handle(sup_np), 0); of_node_put(sup_np); return 0; diff --git a/drivers/of/property.c b/drivers/of/property.c index b71267c6667c..bce849f21ae2 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1085,7 +1085,7 @@ static void of_link_to_phandle(struct device_node *con_np, tmp_np = of_get_next_parent(tmp_np); } - fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np)); + fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np), 0); } /** diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 80f3cd91b471..70d9c40269b9 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -214,7 +214,8 @@ static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode, fwnode->flags &= ~FWNODE_FLAG_INITIALIZED; } -int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup); +int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup, + u8 flags); void fwnode_links_purge(struct fwnode_handle *fwnode); void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode); bool fw_devlink_is_strict(void); -- cgit v1.2.3 From b7e1241d8f77ed64404a5e4450f43a319310fc91 Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Mon, 4 Mar 2024 21:04:55 -0800 Subject: driver core: Add FWLINK_FLAG_IGNORE to completely ignore a fwnode link A fwnode link between specific supplier-consumer fwnodes can be added multiple times for multiple reasons. If that dependency doesn't exist, deleting the fwnode link once doesn't guarantee that it won't get created again. So, add FWLINK_FLAG_IGNORE flag to mark a fwnode link as one that needs to be completely ignored. Since a fwnode link's flags is an OR of all the flags passed to all the fwnode_link_add() calls to create that specific fwnode link, the FWLINK_FLAG_IGNORE flag is preserved and can be used to mark a fwnode link as on that need to be completely ignored until it is deleted. Signed-off-by: Saravana Kannan Acked-by: "Rafael J. Wysocki" Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/20240305050458.1400667-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 9 ++++++++- include/linux/fwnode.h | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/base/core.c b/drivers/base/core.c index 83a6f429bddb..b93f3c5716ae 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1012,7 +1012,8 @@ static struct fwnode_handle *fwnode_links_check_suppliers( return NULL; list_for_each_entry(link, &fwnode->suppliers, c_hook) - if (!(link->flags & FWLINK_FLAG_CYCLE)) + if (!(link->flags & + (FWLINK_FLAG_CYCLE | FWLINK_FLAG_IGNORE))) return link->supplier; return NULL; @@ -2021,6 +2022,9 @@ static bool __fw_devlink_relax_cycles(struct device *con, } list_for_each_entry(link, &sup_handle->suppliers, c_hook) { + if (link->flags & FWLINK_FLAG_IGNORE) + continue; + if (__fw_devlink_relax_cycles(con, link->supplier)) { __fwnode_link_cycle(link); ret = true; @@ -2099,6 +2103,9 @@ static int fw_devlink_create_devlink(struct device *con, int ret = 0; u32 flags; + if (link->flags & FWLINK_FLAG_IGNORE) + return 0; + if (con->fwnode == link->consumer) flags = fw_devlink_get_flags(link->flags); else diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 70d9c40269b9..0d79070c5a70 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -59,8 +59,10 @@ struct fwnode_handle { * fwnode link flags * * CYCLE: The fwnode link is part of a cycle. Don't defer probe. + * IGNORE: Completely ignore this link, even during cycle detection. */ #define FWLINK_FLAG_CYCLE BIT(0) +#define FWLINK_FLAG_IGNORE BIT(1) struct fwnode_link { struct fwnode_handle *supplier; -- cgit v1.2.3