From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- drivers/edac/debugfs.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 drivers/edac/debugfs.c (limited to 'drivers/edac/debugfs.c') diff --git a/drivers/edac/debugfs.c b/drivers/edac/debugfs.c new file mode 100644 index 000000000..8195fc9c9 --- /dev/null +++ b/drivers/edac/debugfs.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +#include "edac_module.h" + +static struct dentry *edac_debugfs; + +static ssize_t edac_fake_inject_write(struct file *file, + const char __user *data, + size_t count, loff_t *ppos) +{ + struct device *dev = file->private_data; + struct mem_ctl_info *mci = to_mci(dev); + static enum hw_event_mc_err_type type; + u16 errcount = mci->fake_inject_count; + + if (!errcount) + errcount = 1; + + type = mci->fake_inject_ue ? HW_EVENT_ERR_UNCORRECTED + : HW_EVENT_ERR_CORRECTED; + + printk(KERN_DEBUG + "Generating %d %s fake error%s to %d.%d.%d to test core handling. NOTE: this won't test the driver-specific decoding logic.\n", + errcount, + (type == HW_EVENT_ERR_UNCORRECTED) ? "UE" : "CE", + str_plural(errcount), + mci->fake_inject_layer[0], + mci->fake_inject_layer[1], + mci->fake_inject_layer[2] + ); + edac_mc_handle_error(type, mci, errcount, 0, 0, 0, + mci->fake_inject_layer[0], + mci->fake_inject_layer[1], + mci->fake_inject_layer[2], + "FAKE ERROR", "for EDAC testing only"); + + return count; +} + +static const struct file_operations debug_fake_inject_fops = { + .open = simple_open, + .write = edac_fake_inject_write, + .llseek = generic_file_llseek, +}; + +void __init edac_debugfs_init(void) +{ + edac_debugfs = debugfs_create_dir("edac", NULL); +} + +void edac_debugfs_exit(void) +{ + debugfs_remove_recursive(edac_debugfs); +} + +void edac_create_debugfs_nodes(struct mem_ctl_info *mci) +{ + struct dentry *parent; + char name[80]; + int i; + + parent = debugfs_create_dir(mci->dev.kobj.name, edac_debugfs); + + for (i = 0; i < mci->n_layers; i++) { + sprintf(name, "fake_inject_%s", + edac_layer_name[mci->layers[i].type]); + debugfs_create_u8(name, S_IRUGO | S_IWUSR, parent, + &mci->fake_inject_layer[i]); + } + + debugfs_create_bool("fake_inject_ue", S_IRUGO | S_IWUSR, parent, + &mci->fake_inject_ue); + + debugfs_create_u16("fake_inject_count", S_IRUGO | S_IWUSR, parent, + &mci->fake_inject_count); + + debugfs_create_file("fake_inject", S_IWUSR, parent, &mci->dev, + &debug_fake_inject_fops); + + mci->debugfs = parent; +} + +/* Create a toplevel dir under EDAC's debugfs hierarchy */ +struct dentry *edac_debugfs_create_dir(const char *dirname) +{ + if (!edac_debugfs) + return NULL; + + return debugfs_create_dir(dirname, edac_debugfs); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_dir); + +/* Create a toplevel dir under EDAC's debugfs hierarchy with parent @parent */ +struct dentry * +edac_debugfs_create_dir_at(const char *dirname, struct dentry *parent) +{ + return debugfs_create_dir(dirname, parent); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_dir_at); + +/* + * Create a file under EDAC's hierarchy or a sub-hierarchy: + * + * @name: file name + * @mode: file permissions + * @parent: parent dentry. If NULL, it becomes the toplevel EDAC dir + * @data: private data of caller + * @fops: file operations of this file + */ +struct dentry * +edac_debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, + void *data, const struct file_operations *fops) +{ + if (!parent) + parent = edac_debugfs; + + return debugfs_create_file(name, mode, parent, data, fops); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_file); + +/* Wrapper for debugfs_create_x8() */ +void edac_debugfs_create_x8(const char *name, umode_t mode, + struct dentry *parent, u8 *value) +{ + if (!parent) + parent = edac_debugfs; + + debugfs_create_x8(name, mode, parent, value); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_x8); + +/* Wrapper for debugfs_create_x16() */ +void edac_debugfs_create_x16(const char *name, umode_t mode, + struct dentry *parent, u16 *value) +{ + if (!parent) + parent = edac_debugfs; + + debugfs_create_x16(name, mode, parent, value); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_x16); + +/* Wrapper for debugfs_create_x32() */ +void edac_debugfs_create_x32(const char *name, umode_t mode, + struct dentry *parent, u32 *value) +{ + if (!parent) + parent = edac_debugfs; + + debugfs_create_x32(name, mode, parent, value); +} +EXPORT_SYMBOL_GPL(edac_debugfs_create_x32); -- cgit v1.3.1