diff --git a/cpu/x86/idt.c b/cpu/x86/idt.c index a75b704e8..d561f49f7 100644 --- a/cpu/x86/idt.c +++ b/cpu/x86/idt.c @@ -57,6 +57,10 @@ typedef struct intr_gate_desc { */ static intr_gate_desc_t idt[NUM_DESC] __attribute__ ((aligned(8))); +/* XXX: If you change this function prototype, make sure you fix the assembly + * code in SET_INTERRUPT_HANDLER macro in interrupt.h. Otherwise, you might + * face a very-hard-to-find bug in the interrupt handling system. + */ void idt_set_intr_gate_desc(int intr_num, uint32_t offset) { diff --git a/cpu/x86/interrupt.h b/cpu/x86/interrupt.h new file mode 100644 index 000000000..3310dad02 --- /dev/null +++ b/cpu/x86/interrupt.h @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2015, Intel Corporation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the copyright holder nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef INTERRUPT_H +#define INTERRUPT_H + +#include + +#include "idt.h" + +struct interrupt_context { + uint32_t edi; + uint32_t esi; + uint32_t ebp; + uint32_t esp; + uint32_t ebx; + uint32_t edx; + uint32_t ecx; + uint32_t eax; + uint32_t error_code; + uint32_t eip; +}; + +/* Helper macro to register interrupt handler function. + * + * num: Interrupt number (0-255) + * has_error_code: 0 if interrupt doesn't push error code onto the + * stack. Otherwise, set this argument to 1. + * handler: Pointer to function that should be called once the + * interrupt is raised. In case has_error_code == 0 + * the function prototype should be the following: + * void handler(void) + * Otherwise, it should be: + * void handler(struct interrupt_context context) + * + * Since there is no easy way to write an Interrupt Service Routines + * (ISR) in C (for further information on this, see [1]), we provide + * this helper macro. It basically provides an assembly trampoline + * to a C function (handler parameter) which, indeed, handles the + * interrupt. + * + * [1] http://wiki.osdev.org/Interrupt_Service_Routines + * + * XXX: If you are debugging at assembly level, make sure you don't be misled + * by the "trampolineXX" symbol name. The suffix number is NOT related to the + * interrupt number at all. The suffix number is a unique random number to + * guarantee there is no symbol name clashing. + */ +#define SET_INTERRUPT_HANDLER(num, has_error_code, handler) \ + do { \ + __asm__ __volatile__ ( \ + "push $trampoline%=\n\t" \ + "push %0\n\t" \ + "call %P1\n\t" \ + "add $8, %%esp\n\t" \ + "jmp skip_trampoline%=\n\t" \ + ".align 4\n\t" \ + "trampoline%=:\n\t" \ + " pushal\n\t" \ + " call %P2\n\t" \ + " popal\n\t" \ + " .if " #has_error_code "\n\t" \ + " add $4, %%esp\n\t" \ + " .endif\n\t" \ + " iret\n\t" \ + "skip_trampoline%=:\n\t" \ + :: "g" (num), "i" (idt_set_intr_gate_desc), "i" (handler) \ + ); \ + } while (0) + +/* Disable maskable hardware interrupts */ +#define DISABLE_IRQ() \ + do { \ + __asm__ ("cli"); \ + } while (0) + +/* Enable maskable hardware interrupts */ +#define ENABLE_IRQ() \ + do { \ + __asm__ ("sti"); \ + } while (0) + +#endif /* INTERRUPT_H */