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#ifndef __SCONST_H__
#define __SCONST_H__
#include "kernel/const.h"
#include "kernel/procoffsets.h"
/*
* offset to current process pointer right after trap, we assume we always have
* error code on the stack
*/
#define CURR_PROC_PTR 20
/*
* tests whether the interrupt was triggered in kernel. If so, jump to the
* label. Displacement tell the macro ha far is the CS value saved by the trap
* from the current %esp. The kernel code segment selector has the lower 3 bits
* zeroed
*/
#define TEST_INT_IN_KERNEL(displ, label) \
cmpl $KERN_CS_SELECTOR, displ(%esp) ;\
je label ;
/*
* saves the basic interrupt context (no error code) to the process structure
*
* displ is the displacement of %esp from the original stack after trap
* pptr is the process structure pointer
* tmp is an available temporary register
*/
#define SAVE_TRAP_CTX(displ, pptr, tmp) \
movl (0 + displ)(%esp), tmp ;\
movl tmp, PCREG(pptr) ;\
movl (4 + displ)(%esp), tmp ;\
movl tmp, CSREG(pptr) ;\
movl (8 + displ)(%esp), tmp ;\
movl tmp, PSWREG(pptr) ;\
movl (12 + displ)(%esp), tmp ;\
movl tmp, SPREG(pptr)
/*
* restore kernel segments. %cs is already set and %fs, %gs are not used */
#define RESTORE_KERNEL_SEGS \
mov $KERN_DS_SELECTOR, %si ;\
mov %si, %ds ;\
mov %si, %es ;\
movw $0, %si ;\
mov %si, %gs ;\
mov %si, %fs ;
#define SAVE_GP_REGS(pptr) \
mov %eax, AXREG(pptr) ;\
mov %ecx, CXREG(pptr) ;\
mov %edx, DXREG(pptr) ;\
mov %ebx, BXREG(pptr) ;\
mov %esi, SIREG(pptr) ;\
mov %edi, DIREG(pptr) ;
#define RESTORE_GP_REGS(pptr) \
movl AXREG(pptr), %eax ;\
movl CXREG(pptr), %ecx ;\
movl DXREG(pptr), %edx ;\
movl BXREG(pptr), %ebx ;\
movl SIREG(pptr), %esi ;\
movl DIREG(pptr), %edi ;
/*
* save the context of the interrupted process to the structure in the process
* table. It pushses the %ebp to stack to get a scratch register. After %esi is
* saved, we can use it to get the saved %ebp from stack and save it to the
* final location
*
* displ is the stack displacement. In case of an exception, there are two extra
* value on the stack - error code and the exception number
*/
#define SAVE_PROCESS_CTX(displ, trapcode) \
\
cld /* set the direction flag to a known state */ ;\
\
push %ebp ;\
;\
movl (CURR_PROC_PTR + 4 + displ)(%esp), %ebp ;\
\
SAVE_GP_REGS(%ebp) ;\
movl $trapcode, P_KERN_TRAP_STYLE(%ebp) ;\
pop %esi /* get the orig %ebp and save it */ ;\
mov %esi, BPREG(%ebp) ;\
\
RESTORE_KERNEL_SEGS ;\
SAVE_TRAP_CTX(displ, %ebp, %esi) ;
/*
* clear the IF flag in eflags which are stored somewhere in memory, e.g. on
* stack. iret or popf will load the new value later
*/
#define CLEAR_IF(where) \
mov where, %eax ;\
andl $0xfffffdff, %eax ;\
mov %eax, where ;
#endif /* __SCONST_H__ */
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