#define __ASM__
#include <arch/x86/interrupts.h>
+#include <arch/x86/i386_asm.h>
+#include <arch/x86/tss.h>
+#include <lunaix/syscall.h>
+#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
+#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:
+
+/*
+ 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.
+
+ Be aware the twists, offsets and hidden dependencies!
+
+*/
+
+#define regsize 4
- isr_template LUNAIX_SYS_PANIC
+/* stack layout: saved interrupt context */
+ .struct 0
+idepth:
+ .struct idepth + regsize
+ieax:
+ .struct ieax + regsize
+iebx:
+ .struct iebx + regsize
+iecx:
+ .struct iecx + regsize
+iedx:
+ .struct iedx + regsize
+iedi:
+ .struct iedi + regsize
+iebp:
+ .struct iebp + regsize
+iesi:
+ .struct iesi + regsize
+ids:
+ .struct ids + regsize
+ies:
+ .struct ies + regsize
+ifs:
+ .struct ifs + regsize
+igs:
+ .struct igs + regsize
+iesp:
+ .struct iesp + regsize
+isave_prev:
+ .struct isave_prev + regsize
+ivec:
+ .struct ivec + regsize
+iecode:
+ .struct iecode + regsize
+ieip:
+ .struct ieip + regsize
+ics:
+ .struct ics + regsize
+ieflags:
+ .struct ieflags + regsize
+iuesp:
+ .struct iuesp + regsize
+iuss:
- 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
+/* stack layout: execution (flow-control) state context */
+ .struct 0
+exsave_prev:
+ .struct exsave_prev + regsize
+exvec:
+ .struct exvec + regsize
+execode:
+ .struct execode + regsize
+exeip:
+ .struct exeip + regsize
+excs:
+ .struct excs + regsize
+exeflags:
+ .struct exeflags + regsize
+exuesp:
+ .struct exuesp + regsize
+exuss:
+
+/* struct layout: critical section of struct proc_info */
+ .struct 0
+proc_pid:
+ .struct proc_pid + regsize
+proc_parent:
+ .struct proc_parent + regsize
+proc_intr_ctx:
+ .struct proc_intr_ctx + regsize
+proc_ustack_top:
+ .struct proc_ustack_top + regsize
+proc_page_table:
+ .struct proc_page_table + regsize
+proc_fxstate:
+
+.section .text
+ .global interrupt_wrapper
interrupt_wrapper:
+ /*
+ Stack layout (layout of struct isr_param)
+ msa: [ss] > 76 -> 28
+ [esp] > 72 -> 24
+ eflags > 68 -> 20
+ cs > 64 -> 16
+ eip > 60 -> 12
+ err_code > 56 -> 8
+ vector > offset = 52 -> 4
+ [saved_prev_ctx] > offset = 0
+ ---
+ esp > 12 * 4 = 48
+ gs
+ fs
+ es
+ ds > offset = 8 * 4 = 32
+ esi
+ ebp
+ edi
+ edx
+ ecx
+ ebx
+ eax
+ lsa: depth > offset = 0
+
+ las: Least Significant Address
+ msa: Most Significant Address
+ */
+ cld
+
+ subl $4, %esp
pushl %esp
+
+ subl $16, %esp
+ movw %gs, 12(%esp)
+ movw %fs, 8(%esp)
+ movw %es, 4(%esp)
+ movw %ds, (%esp)
+
pushl %esi
pushl %ebp
pushl %edi
pushl %ebx
pushl %eax
+ 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 */
+ movw %ax, %gs
+ movw %ax, %fs
+ movw %ax, %ds
+ movw %ax, %es
+
+ movl __current, %eax
+
+ # FIXME: Save x87 context to user stack, rather than kernel's memory.
+ # 保存x87FPU的状态
+ movl proc_fxstate(%eax), %ebx
+ fxsave (%ebx)
+
+ # 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 iuesp(%esp), %ebx # 取出esp
+ movl %ebx, proc_ustack_top(%eax) # 存入__current->ustack_top
+
+ 1:
movl %esp, %eax
andl $0xfffffff0, %esp
subl $16, %esp
movl %eax, (%esp)
call intr_handler
- popl %esp
+ movl (%esp), %eax
+
+ .global soft_iret
+ soft_iret:
+ 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 __current, %eax
+ movl proc_fxstate(%eax), %eax
+
+ test %eax, %eax # do we have stored x87 context?
+ jz 1f
+ fxrstor (%eax)
+
+1:
+ popl %eax # discard isr_param::depth
popl %eax
popl %ebx
popl %ecx
popl %edi
popl %ebp
popl %esi
- popl %esp
+
+ movw (%esp), %ds
+ movw 4(%esp), %es
+ movw 8(%esp), %fs
+ movw 12(%esp), %gs
+
+ 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
+ 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
+
+ # 更新 tss
+ movl proc_intr_ctx(%ebx), %eax # proc->intr_ctx
+ movl iesp(%eax), %eax # intr_ctx->esp
+ movl %eax, (tss_esp0_off + _tss)
+
+ call signal_dispatch # kernel/signal.c
+
+ test %eax, %eax # do we have signal to handle?
+ jz 1f
+ 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
+ leal 12(%eax), %ebx # %ebx = &proc_sig->prev_context
+
+ pushl $UDATA_SEG # proc_sig->prev_context.proc_regs.ss
+ pushl %eax # esp
+
+ movl 48(%ebx), %ebx
+ pushl 68(%ebx) # proc_sig->prev_context.proc_regs.execp->eflags
+
+ pushl $UCODE_SEG # cs
+ pushl 4(%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
git://scm.lunaixsky.com / lunaix-os.git / blobdiff