ccw_device_s..._timeout_key(9)

ccw_device_s..._timeout_key(9) 💅

okay so welcome to the Kernel API Manual, bestie — this page is literally about ccw_device_start_timeout_key(9), and it's giving timed I/O main character energy ✨. It starts a s390 channel program with timeout and key, no cap.

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🌸 NAME 🌸

ccw_device_start_timeout_key — start a s390 channel program with timeout and key.

✨ SYNOPSIS ✨

int ccw_device_start_timeout_key (struct ccw_device *cdev , struct ccw1
       *cpa , unsigned long intparm , __u8 lpm , __u8 key , unsigned long flags
       , int expires );

🎀 ARGUMENTS 🎀

• cdev — target ccw device.
• cpa — logical start address of channel program.
• intparm — user specific interruption parameter; it will be presented back to cdev's interrupt handler. It lets a device driver associate the interrupt with a particular I/O request.
• lpm — defines the channel path to be used for a specific I/O request. A value of 0 will make cio use the opm.
• key — storage key to be used for the I/O.
• flags — additional flags; defines the action to be performed for I/O processing.
• expires — timeout value in jiffies.

💖 DESCRIPTION 💖

Start a S/390 channel program. When the interrupt arrives, the IRQ handler is called, either immediately, delayed (dev-end missing, or sense required) or never (no IRQ handler registered). This function notifies the device driver if the channel program has not completed during the time specified by expires.

If a timeout occurs, the channel program is terminated via xsch, hsch or csch, and the device's interrupt handler will be called with an irb containing ERR_PTR(-ETIMEDOUT). The interruption handler will echo back the intparm specified here, unless another interruption parameter is specified by a subsequent invocation of ccw_device_halt or ccw_device_clear.

🔥 RETURN 🔥

• 0 — if the operation was successful.
• -EBUSY — if the device is busy, or status pending.
• -EACCES — if no path specified in lpm is operational.
• -ENODEV — if the device is not operational.

😭 CONTEXT 😭

Interrupts disabled 😴, ccw device lock held 🔒.

🫶 SEE ALSO 🫶

• Kernel file: ./drivers/s390/cio/device_ops.c
• The whole reference squad: ccw_device_set_options_mask(9), ccw_device_set_options(9), ccw_device_clear_options(9), ccw_device_is_pathgroup(9), ccw_device_is_multipath(9), ccw_device_clear(9), ccw_device_start_key(9), ccw_device_start(9), ccw_device_start_timeout(9), ccw_device_halt(9), ccw_device_resume(9), ccw_device_get_ciw(9), ccw_device_get_path_mask(9), ccw_device_get_chp_desc(9), ccw_device_get_util_str(9), ccw_device_get_id(9), ccw_device_tm_start_timeout_key(9), ccw_device_tm_start_key(9), ccw_device_tm_start(9), ccw_device_tm_start_timeout(9), ccw_device_get_mdc(9), ccw_device_tm_intrg(9), ccw_device_get_schid(9), ccw_device_pnso(9), ccw_device_get_cssid(9), ccw_device_get_iid(9), ccw_device_get_chpid(9), ccw_device_get_chid(9).

okay bye bestie 🫶 this one is from source ./drivers/s390/cio, dated October 2026, and it's the ccw_device_s..._timeout_key(9) page. slay. 💖