Commit c5c3fdd6 authored by Wayne Ren's avatar Wayne Ren Committed by Anas Nashif
Browse files

arch: arc: fix the bug in _firq_enter 



* In ARC, pop reg ==> sp=sp-4; *sp= b; The original codes have bug that
  the save of ilink (st ilink [sp]) will crash the interruptted stack's
  content. This commit fixes this bug and makes the codes easier to
  understand

Signed-off-by: default avatarWayne Ren <wei.ren@synopsys.com>
parent 69889809

arch/arc/core/fast_irq.S

+11 −6
Original line number Diff line number Diff line
@@ -101,20 +101,25 @@ firq_nest: 
	 * save original value of _ARC_V2_USER_SP and ilink into

	 * the stack of interrupted context first, then restore them later

	 */

	st ilink, [sp]

	lr ilink, [_ARC_V2_USER_SP]

	st ilink, [sp, -4]

	push ilink

	PUSHAX ilink, _ARC_V2_USER_SP



	/* sp here is the sp of interrupted context */

	sr sp, [_ARC_V2_USER_SP]

	/* here, bank 0 sp must go back to the value before push and

	 * PUSHAX as we will switch to bank1, the pop and POPAX later will

	 * change bank1's sp, not bank0's sp

	 */

	add sp, sp, 8



	/* switch back to banked reg, only ilink can be used */

	lr ilink, [_ARC_V2_STATUS32]

	or ilink, ilink, _ARC_V2_STATUS32_RB(1)

	kflag ilink

	lr sp, [_ARC_V2_USER_SP]

	ld ilink, [sp, -4]

	sr ilink, [_ARC_V2_USER_SP]

	ld ilink, [sp]



	POPAX ilink, _ARC_V2_USER_SP

	pop ilink

firq_nest_1:

#else

firq_nest:

arch/arc/include/swap_macros.h

+12 −0
Original line number Diff line number Diff line
@@ -365,6 +365,18 @@ 
#endif

.endm



/* macro to push aux reg through reg */

.macro PUSHAX reg aux

	lr \reg, [\aux]

	st.a \reg, [sp, -4]

.endm



/* macro to pop aux reg through reg */

.macro POPAX reg aux

	ld.ab \reg, [sp, 4]

	sr \reg, [\aux]

.endm



#endif /* _ASMLANGUAGE */



#endif /*  ZEPHYR_ARCH_ARC_INCLUDE_SWAP_MACROS_H_ */

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