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/input/serio/maceps2.c | 204 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) create mode 100644 drivers/input/serio/maceps2.c (limited to 'drivers/input/serio/maceps2.c') diff --git a/drivers/input/serio/maceps2.c b/drivers/input/serio/maceps2.c new file mode 100644 index 000000000..fb41e7f5a --- /dev/null +++ b/drivers/input/serio/maceps2.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SGI O2 MACE PS2 controller driver for linux + * + * Copyright (C) 2002 Vivien Chappelier + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +MODULE_AUTHOR("Vivien Chappelier port_data)->port; + unsigned int timeout = MACE_PS2_TIMEOUT; + + do { + if (port->status & PS2_STATUS_TX_EMPTY) { + port->tx = val; + return 0; + } + udelay(50); + } while (timeout--); + + return -1; +} + +static irqreturn_t maceps2_interrupt(int irq, void *dev_id) +{ + struct serio *dev = dev_id; + struct mace_ps2port *port = ((struct maceps2_data *)dev->port_data)->port; + unsigned long byte; + + if (port->status & PS2_STATUS_RX_FULL) { + byte = port->rx; + serio_interrupt(dev, byte & 0xff, 0); + } + + return IRQ_HANDLED; +} + +static int maceps2_open(struct serio *dev) +{ + struct maceps2_data *data = (struct maceps2_data *)dev->port_data; + + if (request_irq(data->irq, maceps2_interrupt, 0, "PS2 port", dev)) { + printk(KERN_ERR "Could not allocate PS/2 IRQ\n"); + return -EBUSY; + } + + /* Reset port */ + data->port->control = PS2_CONTROL_TX_CLOCK_DISABLE | PS2_CONTROL_RESET; + udelay(100); + + /* Enable interrupts */ + data->port->control = PS2_CONTROL_RX_CLOCK_ENABLE | + PS2_CONTROL_TX_ENABLE | + PS2_CONTROL_RX_INT_ENABLE; + + return 0; +} + +static void maceps2_close(struct serio *dev) +{ + struct maceps2_data *data = (struct maceps2_data *)dev->port_data; + + data->port->control = PS2_CONTROL_TX_CLOCK_DISABLE | PS2_CONTROL_RESET; + udelay(100); + free_irq(data->irq, dev); +} + + +static struct serio *maceps2_allocate_port(int idx) +{ + struct serio *serio; + + serio = kzalloc_obj(*serio); + if (serio) { + serio->id.type = SERIO_8042; + serio->write = maceps2_write; + serio->open = maceps2_open; + serio->close = maceps2_close; + snprintf(serio->name, sizeof(serio->name), "MACE PS/2 port%d", idx); + snprintf(serio->phys, sizeof(serio->phys), "mace/serio%d", idx); + serio->port_data = &port_data[idx]; + serio->dev.parent = &maceps2_device->dev; + } + + return serio; +} + +static int maceps2_probe(struct platform_device *dev) +{ + maceps2_port[0] = maceps2_allocate_port(0); + maceps2_port[1] = maceps2_allocate_port(1); + if (!maceps2_port[0] || !maceps2_port[1]) { + kfree(maceps2_port[0]); + kfree(maceps2_port[1]); + return -ENOMEM; + } + + serio_register_port(maceps2_port[0]); + serio_register_port(maceps2_port[1]); + + return 0; +} + +static void maceps2_remove(struct platform_device *dev) +{ + serio_unregister_port(maceps2_port[0]); + serio_unregister_port(maceps2_port[1]); +} + +static struct platform_driver maceps2_driver = { + .driver = { + .name = "maceps2", + }, + .probe = maceps2_probe, + .remove = maceps2_remove, +}; + +static int __init maceps2_init(void) +{ + int error; + + error = platform_driver_register(&maceps2_driver); + if (error) + return error; + + maceps2_device = platform_device_alloc("maceps2", -1); + if (!maceps2_device) { + error = -ENOMEM; + goto err_unregister_driver; + } + + port_data[0].port = &mace->perif.ps2.keyb; + port_data[0].irq = MACEISA_KEYB_IRQ; + port_data[1].port = &mace->perif.ps2.mouse; + port_data[1].irq = MACEISA_MOUSE_IRQ; + + error = platform_device_add(maceps2_device); + if (error) + goto err_free_device; + + return 0; + + err_free_device: + platform_device_put(maceps2_device); + err_unregister_driver: + platform_driver_unregister(&maceps2_driver); + return error; +} + +static void __exit maceps2_exit(void) +{ + platform_device_unregister(maceps2_device); + platform_driver_unregister(&maceps2_driver); +} + +module_init(maceps2_init); +module_exit(maceps2_exit); -- cgit v1.3.1