refactor: Optimize the signal context overhead

[lunaix-os.git] / lunaix-os / kernel / asm / x86 / interrupt.S

diff --git a/lunaix-os/kernel/asm/x86/interrupt.S b/lunaix-os/kernel/asm/x86/interrupt.S
index 23df5b507a3a0b7c213d1a0407930a0b6c09d23d..80dee1aff37a88af8ba536fc08a82471dbfd3dbe 100644 (file)
--- a/lunaix-os/kernel/asm/x86/interrupt.S
+++ b/lunaix-os/kernel/asm/x86/interrupt.S
@@ -1,7 +1,10 @@
 #define __ASM__
 #include <arch/x86/interrupts.h>
 #define __ASM__
 #include <arch/x86/interrupts.h>

-#include <lunaix/common.h>
+#include <arch/x86/i386_asm.h>
+#include <arch/x86/tss.h>

 #include <lunaix/syscall.h>
 #include <lunaix/syscall.h>

+#include <arch/x86/interrupt.S.inc>
+

 #define __ASM_INTR_DIAGNOSIS
 
 #ifdef __ASM_INTR_DIAGNOSIS
 #define __ASM_INTR_DIAGNOSIS
 
 #ifdef __ASM_INTR_DIAGNOSIS


@@ -16,7 +19,7 @@
 .section .bss
     .align 16
     lo_tmp_stack:
 .section .bss
     .align 16
     lo_tmp_stack:

-        .skip 128
+        .skip 256

     tmp_stack:
 
 /*
     tmp_stack:
 
 /*


@@ -34,20 +37,20 @@
     interrupt_wrapper:
         /*
          Stack layout (layout of struct isr_param)
     interrupt_wrapper:
         /*
          Stack layout (layout of struct isr_param)

-    msa:   [ss]             > 76
-           [esp]            > 72
-           eflags           > 68
-           cs               > 64
-           eip              > 60
-           err_code         > 56
-           vector           > offset = 52
+    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
            ---
            [saved_prev_ctx] > offset = 0
            ---

-           esp
+           esp       > 12 * 4 = 48

            gs
            fs
            es
            gs
            fs
            es

-           ds         > offset = 7 * 4 = 28 + 4
+           ds         > offset = 8 * 4 = 32

            esi
            ebp
            edi
            esi
            ebp
            edi


@@ -62,7 +65,7 @@
         */
         cld
 
         */
         cld
 

-        subl $52, %esp
+        subl $4, %esp

         pushl %esp
 
         subl $16, %esp
         pushl %esp
 
         subl $16, %esp


@@ -80,34 +83,38 @@
         pushl %eax
 
         movl __current, %eax
         pushl %eax
 
         movl __current, %eax

-        movl 8(%eax), %eax
+        movl proc_intr_ctx(%eax), %eax

         incl %eax
         pushl %eax          # nested intr: current depth
 
         incl %eax
         pushl %eax          # nested intr: current depth
 

-        movl 116(%esp), %eax   /* 取出 %cs */
+        movl ics(%esp), %eax   /* 取出 %cs */

         andl $0x3, %eax          /* 判断 RPL */
         jz 1f
 
         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
 
         movw %ax, %gs
         movw %ax, %fs
         movw %ax, %ds
         movw %ax, %es
 

-        # 保存用户栈顶指针。这是因为我们允许系统调用内进行上下文切换，而这样一来，我们就失去了用户栈的信息，
-        # 这样一来，就无法设置信号上下文。这主要是为了实现了pause()而做的准备

         movl __current, %eax
 
         movl __current, %eax
 

-        # 保存x87FPU的状态
-        movl 68(%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

 
 

-        movl 124(%esp), %ebx     # 取出esp
-        movl %ebx, 60(%eax)     # 存入__current->ustack_top
+        # Save x87 context to user stack, rather than kernel's memory.
+        # XXX: what will happen if we triggered a page fault during fxsave?
+        movl iuesp(%esp), %eax
+        andl $stack_alignment, %eax 
+        subl $512, %eax
+        fxsave (%eax)

 
 

+    /* kernel space same-level switch */

     1:
         movl %esp, %eax
     1:
         movl %esp, %eax

-        andl $0xfffffff0, %esp
+        andl $stack_alignment, %esp

         subl $16, %esp
         movl %eax, (%esp)
 
         subl $16, %esp
         movl %eax, (%esp)
 


@@ -121,16 +128,24 @@
 
 #ifdef __ASM_INTR_DIAGNOSIS
         movl %eax, (debug_resv + 8)
 
 #ifdef __ASM_INTR_DIAGNOSIS
         movl %eax, (debug_resv + 8)

-        movl 48(%esp), %eax
-        movl 60(%eax), %eax
+        movl iesp(%esp), %eax
+        movl exeip(%eax), %eax

         movl %eax, (debug_resv + 4) # eip
 #endif
         movl %eax, (debug_resv + 4) # eip
 #endif

-        movl __current, %eax
-        movl 68(%eax), %eax
+        // movl __current, %eax
+        // movl proc_fxstate(%eax), %eax

         
         

-        test %eax, %eax     # do we have stored x87 context?
+        // test %eax, %eax     # do we have stored x87 context?
+
+        movl ics(%esp), %eax
+        andl $3, %eax

         jz 1f 
         jz 1f 

-        fxrstor (%eax)      
+
+        movl iuesp(%esp), %eax
+        andl $stack_alignment, %eax 
+        subl $512, %eax
+        fxrstor (%eax)
+

 1:
         popl %eax   # discard isr_param::depth
         popl %eax
 1:
         popl %eax   # discard isr_param::depth
         popl %eax


@@ -150,20 +165,10 @@
 
         movl %eax, tmp_store
         movl __current, %eax
 
         movl %eax, tmp_store
         movl __current, %eax

+        
+

         # nested intr: restore saved context
         # nested intr: restore saved context

-        popl 8(%eax)       # depth
-        popl 12(%eax)      # eax
-        popl 16(%eax)      # ebx
-        popl 20(%eax)      # ecx
-        popl 24(%eax)      # edx
-        popl 28(%eax)      # edi
-        popl 32(%eax)      # ebp
-        popl 36(%eax)      # esi
-        popl 40(%eax)      # ds
-        popl 44(%eax)      # es
-        popl 48(%eax)      # fs
-        popl 52(%eax)      # gs
-        popl 56(%eax)      # esp
+        popl proc_intr_ctx(%eax)

 
         addl $8, %esp
 
 
         addl $8, %esp
 


@@ -180,8 +185,9 @@
         shll $3, %eax
         addl $12, %eax
         addl %esp, %eax
         shll $3, %eax
         addl $12, %eax
         addl %esp, %eax

-        movl %eax, (_tss + 4)
+        movl %eax, (_tss + tss_esp0_off)

         movl tmp_store, %eax
         movl tmp_store, %eax

+

         iret
 
     .global switch_to
         iret
 
     .global switch_to


@@ -191,8 +197,8 @@
 
         popl %ebx               # next
         movl __current, %eax    
 
         popl %ebx               # next
         movl __current, %eax    

-        movl 64(%eax), %ecx     # __current->pagetable
-        movl 64(%ebx), %eax     # next->pagetable
+        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
         
         cmpl %ecx, %eax         # if(next->pagtable != __current->pagetable) {
         jz 1f


@@ -204,27 +210,36 @@
         # 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
         # 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
         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:
         jmp handle_signal
     1:

-        leal 8(%ebx), %eax
+        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！
         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！

-        leal 8(%eax), %ebx      # arg1 in %eax: addr of proc_sig structure in user stack
+        # 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        # proc_sig->prev_context.proc_regs.ss
+        pushl $UDATA_SEG

         pushl %eax              # esp
         pushl %eax              # esp

-        movl 48(%ebx), %ebx
-        pushl 68(%ebx)          # proc_sig->prev_context.proc_regs.execp->eflags
+
+        movl iexecp(%ebx), %ebx
+        pushl exeflags(%ebx)          # proc_sig->saved_ictx->execp->eflags
+        

         pushl $UCODE_SEG        # cs
         pushl $UCODE_SEG        # cs

-        pushl $sig_wrapper      # eip for sig wrapper
+        pushl psig_sigact(%eax)           # %eip = proc_sig->sigact

 
         movw $UDATA_SEG, %cx    # switch data seg to user mode
         movw %cx, %es
 
         movw $UDATA_SEG, %cx    # switch data seg to user mode
         movw %cx, %es


@@ -232,21 +247,4 @@
         movw %cx, %fs
         movw %cx, %gs
 
         movw %cx, %fs
         movw %cx, %gs
 

-        iret  
-
-.section .usrtext
-    sig_wrapper:                # in user mode
-        movl %esp, %eax
-        and $0xfffffff0, %esp
-        subl $8, %esp
-        pushl %eax              # Addr to proc_sig structure 
-        pushl 4(%eax)           # proc_sig->sig_num     ---- 16 bytes aligned
-
-        call *(%eax)             # invoke signal handler
-
-        # invoke the sigreturn syscall to exit the signal wrapper
-        movl $__SYSCALL_sigreturn, %eax
-        movl 4(%esp), %ebx
-        int $LUNAIX_SYS_CALL    
-
-        ud2                     # never reach!
\ No newline at end of file
+        iret
\ No newline at end of file