X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/8357bda627bdf02c1b69eecf27993182239fb463..bb793d5c6918efee6a86de442463a7c9aaa4ecdd:/lunaix-os/kernel/asm/x86/interrupt.S?ds=sidebyside diff --git a/lunaix-os/kernel/asm/x86/interrupt.S b/lunaix-os/kernel/asm/x86/interrupt.S index 4647e95..f308503 100644 --- a/lunaix-os/kernel/asm/x86/interrupt.S +++ b/lunaix-os/kernel/asm/x86/interrupt.S @@ -1,67 +1,43 @@ #define __ASM__ #include -#include -// #define __ASM_INTR_DIAGNOSIS - -.macro isr_template vector, no_error_code=1 - .global _asm_isr\vector - .type _asm_isr\vector, @function - _asm_isr\vector: - .if \no_error_code - pushl $0x0 - .endif - pushl $\vector - jmp interrupt_wrapper -.endm +#include +#include +#include +#include + +#define __ASM_INTR_DIAGNOSIS #ifdef __ASM_INTR_DIAGNOSIS .section .bss .global debug_resv debug_resv: .skip 16 + tmp_store: + .skip 4 #endif -.section .text - isr_template FAULT_DIVISION_ERROR - isr_template FAULT_GENERAL_PROTECTION, no_error_code=0 - isr_template FAULT_PAGE_FAULT, no_error_code=0 +.section .bss + .align 16 + lo_tmp_stack: + .skip 256 + tmp_stack: - isr_template LUNAIX_SYS_PANIC - isr_template LUNAIX_SYS_CALL +/* + This perhaps the ugliest part in the project. + It contains code to handle arbitrary depth of + nested interrupt and all those corner cases and + nasty gotchas. - isr_template APIC_ERROR_IV - isr_template APIC_LINT0_IV - isr_template APIC_TIMER_IV - isr_template APIC_SPIV_IV - isr_template RTC_TIMER_IV - isr_template PC_KBD_IV + Be aware the twists, offsets and hidden dependencies! +*/ + +.section .text + .global interrupt_wrapper interrupt_wrapper: - /* - Stack layout - msa: [ss] - [esp] - eflags - cs - eip - err_code - vector > offset = 28 + 16 + 4 = 48 - esp - gs - fs - es - ds > offset = 7 * 4 = 28 - esi - ebp - edi - edx - ecx - ebx - lsa: eax > offset = 0 - - las: Least Significant Address - msa: Most Significant Address - */ + cld + + subl $4, %esp pushl %esp subl $16, %esp @@ -78,28 +54,69 @@ pushl %ebx pushl %eax - movl 60(%esp), %eax /* 取出 %cs */ + movl __current, %eax + movl proc_intr_ctx(%eax), %eax + incl %eax + pushl %eax # nested intr: current depth + + movl ics(%esp), %eax /* 取出 %cs */ andl $0x3, %eax /* 判断 RPL */ jz 1f - movw $KDATA_SEG, %ax /* 如果从用户模式转来，则切换至内核数据段 */ + /* crossing the user/kernel boundary */ + movw $KDATA_SEG, %ax movw %ax, %gs movw %ax, %fs movw %ax, %ds movw %ax, %es + movl __current, %ebx + + # Save x87 context to user stack, rather than kernel's memory. + # XXX what will happen if we triggered a page fault during fxsave? + # FIXME can we remove this overhead? + movl iuesp(%esp), %eax + andl $stack_alignment, %eax + subl $512, %eax + fxsave (%eax) + + # 保存用户栈顶指针。因为我们允许同级中断的产生，所以需要该手段跟踪用户栈的地址。 + movl %eax, proc_ustack_top(%ebx) # 存入__current->ustack_top + + /* kernel space same-level switch */ 1: movl %esp, %eax - andl $0xfffffff0, %esp + andl $stack_alignment, %esp subl $16, %esp movl %eax, (%esp) call intr_handler + movl (%esp), %eax + .global soft_iret soft_iret: - popl %esp + movl %eax, %esp +#ifdef __ASM_INTR_DIAGNOSIS + movl %eax, (debug_resv + 8) + movl iesp(%esp), %eax + movl exeip(%eax), %eax + movl %eax, (debug_resv + 4) # eip +#endif + + movl ics(%esp), %eax + andl $3, %eax + jz 1f + + movl __current, %eax + movl proc_ustack_top(%eax), %eax + test %eax, %eax + jz 1f + fxrstor (%eax) + +1: + popl %eax # discard isr_param::depth popl %eax popl %ebx popl %ecx @@ -115,17 +132,88 @@ movl 16(%esp), %esp + movl %eax, tmp_store + movl __current, %eax + + # nested intr: restore saved context + popl proc_intr_ctx(%eax) + addl $8, %esp #ifdef __ASM_INTR_DIAGNOSIS - cmpl $0, (%esp) - jz 1f - iret -1: - movl $__current, %eax - movl (%esp), %ebx - movl $debug_resv, %ecx - ud2 -#else - iret + movl (%esp), %eax + movl %eax, debug_resv #endif + # 处理TSS.ESP的一些边界条件。如果是正常iret（即从内核模式*优雅地*退出） + # 那么TSS.ESP0应该为iret进行弹栈后，%esp的值。 + # 所以这里的边界条件是：如返回用户模式，iret会额外弹出8个字节（ss,esp） + movl 4(%esp), %eax + andl $3, %eax + setnz %al + shll $3, %eax + addl $12, %eax + addl %esp, %eax + movl %eax, (_tss + tss_esp0_off) + movl tmp_store, %eax + + iret + + .global switch_to + switch_to: + # 约定 + # arg1: 目标进程PCB地址 (next + + popl %ebx # next + movl __current, %eax + movl proc_page_table(%eax), %ecx # __current->pagetable + movl proc_page_table(%ebx), %eax # next->pagetable + + cmpl %ecx, %eax # if(next->pagtable != __current->pagetable) { + jz 1f + movl %eax, %cr3 # cpu_lcr3(next->pagetable) + # } + 1: + movl %ebx, __current # __current = next + + # 我们已经处在了新的地址空间，为了避免影响其先前的栈布局 + # 需要使用一个临时的栈空间 + movl $tmp_stack, %esp + + call signal_dispatch # kernel/signal.c + + test %eax, %eax # do we have signal to handle? + jz 1f + + # 更新 tss + movl proc_intr_ctx(%ebx), %ecx # __current->intr_ctx + movl %ecx, (tss_esp0_off + _tss) + + jmp handle_signal + + 1: + movl proc_intr_ctx(%ebx), %eax + jmp soft_iret + + .global handle_signal + handle_signal: + # 注意1：任何对proc_sig的布局改动，都须及时的保证这里的一致性！ + # 注意2：handle_signal在调用之前，须确保proc_sig已经写入用户栈！ + # arg1 in %eax: addr of proc_sig structure in user stack + movl psig_saved_ictx(%eax), %ebx # %ebx = &proc_sig->saved_ictx + + pushl $UDATA_SEG + pushl %eax # esp + + movl iexecp(%ebx), %ebx + pushl exeflags(%ebx) # proc_sig->saved_ictx->execp->eflags + + pushl $UCODE_SEG # cs + pushl psig_sigact(%eax) # %eip = proc_sig->sigact + + movw $UDATA_SEG, %cx # switch data seg to user mode + movw %cx, %es + movw %cx, %ds + movw %cx, %fs + movw %cx, %gs + + iret \ No newline at end of file