luckfox-pico-sdk/sysdrv/source/kernel/include/linux/once.h
luckfox-eng29 8f34c2760d project:build.sh: Added fastboot support; custom modifications to U-Boot and kernel implemented using patches.
project:cfg:BoardConfig_IPC: Added fastboot BoardConfig file and firmware post-scripts, distinguishing between
the BoardConfigs for Luckfox Pico Pro and Luckfox Pico Max. project:app: Added fastboot_client and rk_smart_door
for quick boot applications; updated rkipc app to adapt to the latest media library. media:samples: Added more
usage examples. media:rockit: Fixed bugs; removed support for retrieving data frames from VPSS. media:isp:
Updated rkaiq library and related tools to support connection to RKISP_Tuner. sysdrv:Makefile: Added support for
compiling drv_ko on Luckfox Pico Ultra W using Ubuntu; added support for custom root filesystem.
sysdrv:tools:board: Updated Buildroot optional mirror sources, updated some software versions, and stored device
tree files and configuration files that undergo multiple modifications for U-Boot and kernel separately.
sysdrv:source:mcu: Used RISC-V MCU SDK with RT-Thread system, mainly for initializing camera AE during quick
boot. sysdrv:source:uboot: Added support for fastboot; added high baud rate DDR bin for serial firmware upgrades.
sysdrv:source:kernel: Upgraded to version 5.10.160; increased NPU frequency for RV1106G3; added support for
fastboot.

Signed-off-by: luckfox-eng29 <eng29@luckfox.com>
2024-10-14 09:47:04 +08:00

89 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ONCE_H
#define _LINUX_ONCE_H
#include <linux/types.h>
#include <linux/jump_label.h>
/* Helpers used from arbitrary contexts.
* Hard irqs are blocked, be cautious.
*/
bool __do_once_start(bool *done, unsigned long *flags);
void __do_once_done(bool *done, struct static_key_true *once_key,
unsigned long *flags);
/* Variant for process contexts only. */
bool __do_once_slow_start(bool *done);
void __do_once_slow_done(bool *done, struct static_key_true *once_key,
struct module *mod);
/* Call a function exactly once. The idea of DO_ONCE() is to perform
* a function call such as initialization of random seeds, etc, only
* once, where DO_ONCE() can live in the fast-path. After @func has
* been called with the passed arguments, the static key will patch
* out the condition into a nop. DO_ONCE() guarantees type safety of
* arguments!
*
* Not that the following is not equivalent ...
*
* DO_ONCE(func, arg);
* DO_ONCE(func, arg);
*
* ... to this version:
*
* void foo(void)
* {
* DO_ONCE(func, arg);
* }
*
* foo();
* foo();
*
* In case the one-time invocation could be triggered from multiple
* places, then a common helper function must be defined, so that only
* a single static key will be placed there!
*/
#define DO_ONCE(func, ...) \
({ \
bool ___ret = false; \
static bool ___done = false; \
static DEFINE_STATIC_KEY_TRUE(___once_key); \
if (static_branch_unlikely(&___once_key)) { \
unsigned long ___flags; \
___ret = __do_once_start(&___done, &___flags); \
if (unlikely(___ret)) { \
func(__VA_ARGS__); \
__do_once_done(&___done, &___once_key, \
&___flags); \
} \
} \
___ret; \
})
/* Variant of DO_ONCE() for process/sleepable contexts. */
#define DO_ONCE_SLOW(func, ...) \
({ \
bool ___ret = false; \
static bool __section(".data.once") ___done = false; \
static DEFINE_STATIC_KEY_TRUE(___once_key); \
if (static_branch_unlikely(&___once_key)) { \
___ret = __do_once_slow_start(&___done); \
if (unlikely(___ret)) { \
func(__VA_ARGS__); \
__do_once_slow_done(&___done, &___once_key, \
THIS_MODULE); \
} \
} \
___ret; \
})
#define get_random_once(buf, nbytes) \
DO_ONCE(get_random_bytes, (buf), (nbytes))
#define get_random_once_wait(buf, nbytes) \
DO_ONCE(get_random_bytes_wait, (buf), (nbytes)) \
#define get_random_slow_once(buf, nbytes) \
DO_ONCE_SLOW(get_random_bytes, (buf), (nbytes))
#endif /* _LINUX_ONCE_H */