u-boot/include/interrupt.h
Heinrich Schuchardt 9757cae991 riscv: allow resume after exception
If CSRs like seed are readable by S-mode, may not be determinable by
S-mode. For safe driver probing allow to resume via a longjmp after an
exception.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
2023-11-02 16:22:06 +08:00

45 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <asm/setjmp.h>
/**
* struct resume_data - data for resume after interrupt
*/
struct resume_data {
/** @jump: longjmp buffer */
jmp_buf jump;
/** @code: exception code */
ulong code;
};
/**
* set_resume() - set longjmp buffer for resuming after exception
*
* By calling this function it is possible to use a long jump to catch an
* exception. The caller sets the long jump buffer with set_resume() and then
* executes setjmp(). If an exception occurs, the code will return to the
* setjmp caller(). The exception code will be returned in @data->code.
*
* After the critical operation call set_resume(NULL) so that an exception in
* another part of the code will not accidently invoke the long jump.
*
* .. code-block:: c
*
* // This example shows how to use set_resume().
*
* struct resume_data resume;
* int ret;
*
* set_resume(&resume);
* ret = setjmp(resume.jump);
* if (ret) {
* printf("An exception %ld occurred\n", resume.code);
* } else {
* // Do what might raise an exception here.
* }
* set_resume(NULL);
*
* @data: pointer to structure with longjmp address
* Return: 0 before an exception, 1 after an exception occurred
*/
void set_resume(struct resume_data *data);