diff options
| -rw-r--r-- | arch/riscv/lib/interrupts.c | 13 | ||||
| -rw-r--r-- | doc/api/index.rst | 1 | ||||
| -rw-r--r-- | doc/api/interrupt.rst | 6 | ||||
| -rw-r--r-- | include/interrupt.h | 45 |
4 files changed, 65 insertions, 0 deletions
diff --git a/arch/riscv/lib/interrupts.c b/arch/riscv/lib/interrupts.c index 02dbcfd423..a26ccc721f 100644 --- a/arch/riscv/lib/interrupts.c +++ b/arch/riscv/lib/interrupts.c @@ -12,6 +12,7 @@ #include <linux/compat.h> #include <efi_loader.h> #include <hang.h> +#include <interrupt.h> #include <irq_func.h> #include <asm/global_data.h> #include <asm/ptrace.h> @@ -21,6 +22,13 @@ DECLARE_GLOBAL_DATA_PTR; +static struct resume_data *resume; + +void set_resume(struct resume_data *data) +{ + resume = data; +} + static void show_efi_loaded_images(uintptr_t epc) { efi_print_image_infos((void *)epc); @@ -105,6 +113,11 @@ static void _exit_trap(ulong code, ulong epc, ulong tval, struct pt_regs *regs) "Store/AMO page fault", }; + if (resume) { + resume->code = code; + longjmp(resume->jump, 1); + } + if (code < ARRAY_SIZE(exception_code)) printf("Unhandled exception: %s\n", exception_code[code]); else diff --git a/doc/api/index.rst b/doc/api/index.rst index 2f0218c47a..51b2013af3 100644 --- a/doc/api/index.rst +++ b/doc/api/index.rst @@ -12,6 +12,7 @@ U-Boot API documentation efi event getopt + interrupt linker_lists lmb logging diff --git a/doc/api/interrupt.rst b/doc/api/interrupt.rst new file mode 100644 index 0000000000..5721231d91 --- /dev/null +++ b/doc/api/interrupt.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Interrupt API +============= + +.. kernel-doc:: include/interrupt.h diff --git a/include/interrupt.h b/include/interrupt.h new file mode 100644 index 0000000000..46ef2e196d --- /dev/null +++ b/include/interrupt.h @@ -0,0 +1,45 @@ +/* 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); |