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/touchscreen/mtouch.c | 200 +++++++++++++++++++++++++++++++++++++ 1 file changed, 200 insertions(+) create mode 100644 drivers/input/touchscreen/mtouch.c (limited to 'drivers/input/touchscreen/mtouch.c') diff --git a/drivers/input/touchscreen/mtouch.c b/drivers/input/touchscreen/mtouch.c new file mode 100644 index 000000000..cc2d206d2 --- /dev/null +++ b/drivers/input/touchscreen/mtouch.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MicroTouch (3M) serial touchscreen driver + * + * Copyright (c) 2004 Vojtech Pavlik + */ + + +/* + * 2005/02/19 Dan Streetman + * Copied elo.c and edited for MicroTouch protocol + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "MicroTouch serial touchscreen driver" + +MODULE_AUTHOR("Vojtech Pavlik "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80 +#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40 +#define MTOUCH_FORMAT_TABLET_LENGTH 5 +#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01 +#define MTOUCH_RESPONSE_END_BYTE 0x0d + +/* todo: check specs for max length of all responses */ +#define MTOUCH_MAX_LENGTH 16 + +#define MTOUCH_MIN_XC 0 +#define MTOUCH_MAX_XC 0x3fff +#define MTOUCH_MIN_YC 0 +#define MTOUCH_MAX_YC 0x3fff + +#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1]) +#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3]) +#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0]) + +/* + * Per-touchscreen data. + */ + +struct mtouch { + struct input_dev *dev; + struct serio *serio; + int idx; + unsigned char data[MTOUCH_MAX_LENGTH]; + char phys[32]; +}; + +static void mtouch_process_format_tablet(struct mtouch *mtouch) +{ + struct input_dev *dev = mtouch->dev; + + if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) { + input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data)); + input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data)); + input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data)); + input_sync(dev); + + mtouch->idx = 0; + } +} + +static void mtouch_process_response(struct mtouch *mtouch) +{ + if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) { + /* FIXME - process response */ + mtouch->idx = 0; + } else if (MTOUCH_MAX_LENGTH == mtouch->idx) { + printk(KERN_ERR "mtouch.c: too many response bytes\n"); + mtouch->idx = 0; + } +} + +static irqreturn_t mtouch_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct mtouch *mtouch = serio_get_drvdata(serio); + + mtouch->data[mtouch->idx] = data; + + if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0]) + mtouch_process_format_tablet(mtouch); + else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0]) + mtouch_process_response(mtouch); + else + printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]); + + return IRQ_HANDLED; +} + +/* + * mtouch_disconnect() is the opposite of mtouch_connect() + */ + +static void mtouch_disconnect(struct serio *serio) +{ + struct mtouch *mtouch = serio_get_drvdata(serio); + + input_get_device(mtouch->dev); + input_unregister_device(mtouch->dev); + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_put_device(mtouch->dev); + kfree(mtouch); +} + +/* + * mtouch_connect() is the routine that is called when someone adds a + * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as + * an input device. + */ + +static int mtouch_connect(struct serio *serio, struct serio_driver *drv) +{ + struct mtouch *mtouch; + struct input_dev *input_dev; + int err; + + mtouch = kzalloc_obj(*mtouch); + input_dev = input_allocate_device(); + if (!mtouch || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + mtouch->serio = serio; + mtouch->dev = input_dev; + scnprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys); + + input_dev->name = "MicroTouch Serial TouchScreen"; + input_dev->phys = mtouch->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_MICROTOUCH; + input_dev->id.product = 0; + input_dev->id.version = 0x0100; + input_dev->dev.parent = &serio->dev; + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0); + input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0); + + serio_set_drvdata(serio, mtouch); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(mtouch->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(mtouch); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id mtouch_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_MICROTOUCH, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, mtouch_serio_ids); + +static struct serio_driver mtouch_drv = { + .driver = { + .name = "mtouch", + }, + .description = DRIVER_DESC, + .id_table = mtouch_serio_ids, + .interrupt = mtouch_interrupt, + .connect = mtouch_connect, + .disconnect = mtouch_disconnect, +}; + +module_serio_driver(mtouch_drv); -- cgit v1.3.1