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Commit 4255b07f authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARCv2: STAR 9000793984: Handle return from intr to Delay Slot 



Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 1f6ccfff

arch/arc/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ int main(void) 
	DEFINE(PT_r5, offsetof(struct pt_regs, r5));

	DEFINE(PT_r6, offsetof(struct pt_regs, r6));

	DEFINE(PT_r7, offsetof(struct pt_regs, r7));

	DEFINE(PT_ret, offsetof(struct pt_regs, ret));



	DEFINE(SZ_CALLEE_REGS, sizeof(struct callee_regs));

	DEFINE(SZ_PT_REGS, sizeof(struct pt_regs));

arch/arc/kernel/entry-arcv2.S

+50 −0
Original line number Diff line number Diff line
@@ -163,6 +163,9 @@ END(EV_TLBProtV) 
;####### Return from Intr #######



debug_marker_l1:

	bbit1.nt r0, STATUS_DE_BIT, .Lintr_ret_to_delay_slot



.Lisr_ret_fast_path:

	; Handle special case #1: (Entry via Exception, Return via IRQ)

	;

	; Exception in U mode, preempted in kernel, Intr taken (K mode), orig
@@ -186,4 +189,51 @@ debug_marker_syscall: 
	EXCEPTION_EPILOGUE

	rtie



;####### Return from Intr to insn in delay slot #######



; Handle special case #2: (Entry via Exception in Delay Slot, Return via IRQ)

;

; Intr returning to a Delay Slot (DS) insn

; (since IRQ NOT allowed in DS in ARCv2, this can only happen if orig

; entry was via Exception in DS which got preempted in kernel).

;

; IRQ RTIE won't reliably restore DE bit and/or BTA, needs handling

.Lintr_ret_to_delay_slot:

debug_marker_ds:



	ld	r2, [@intr_to_DE_cnt]

	add	r2, r2, 1

	st	r2, [@intr_to_DE_cnt]



	ld	r2, [sp, PT_ret]

	ld	r3, [sp, PT_status32]



	bic  	r0, r3, STATUS_U_MASK|STATUS_DE_MASK|STATUS_IE_MASK|STATUS_L_MASK

	st	r0, [sp, PT_status32]



	mov	r1, .Lintr_ret_to_delay_slot_2

	st	r1, [sp, PT_ret]



	st	r2, [sp, 0]

	st	r3, [sp, 4]



	b	.Lisr_ret_fast_path



.Lintr_ret_to_delay_slot_2:

	sub	sp, sp, SZ_PT_REGS

	st	r9, [sp, -4]



	ld	r9, [sp, 0]

	sr	r9, [eret]



	ld	r9, [sp, 4]

	sr	r9, [erstatus]



	ld	r9, [sp, 8]

	sr	r9, [erbta]



	ld	r9, [sp, -4]

	add	sp, sp, SZ_PT_REGS

	rtie



END(ret_from_exception)

arch/arc/kernel/setup.c

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 


#define FIX_PTR(x)  __asm__ __volatile__(";" : "+r"(x))



unsigned int intr_to_DE_cnt;



/* Part of U-boot ABI: see head.S */

int __initdata uboot_tag;

char __initdata *uboot_arg;