X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=arch%2Farc%2Fkernel%2Fentry-arcv2.S;h=12d5f12d10d23b96cbb2ace74a2629aa1ac7257a;hb=a79a9c765f95a73e087f11f0994297cd69987bda;hp=14254b866fdccda0e5c21b762b7b6cebea360458;hpb=273cbf61c3ddee9574ef1f4959b9bc6db5b24271;p=linux-2.6-microblaze.git

diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S
index 14254b866fdc..a7e6a2174187 100644
--- a/arch/arc/kernel/entry-arcv2.S
+++ b/arch/arc/kernel/entry-arcv2.S
@@ -10,6 +10,7 @@
 #include <asm/errno.h>
 #include <asm/arcregs.h>
 #include <asm/irqflags.h>
+#include <asm/mmu.h>
 
 ; A maximum number of supported interrupts in the core interrupt controller.
 ; This number is not equal to the maximum interrupt number (256) because
@@ -67,7 +68,7 @@ reserved:
 
 ENTRY(handle_interrupt)
 
-	INTERRUPT_PROLOGUE  irq
+	INTERRUPT_PROLOGUE
 
 	# irq control APIs local_irq_save/restore/disable/enable fiddle with
 	# global interrupt enable bits in STATUS32 (.IE for 1 prio, .E[] for 2 prio)
@@ -79,7 +80,7 @@ ENTRY(handle_interrupt)
 	#
 	# Note this disable is only for consistent book-keeping as further interrupts
 	# will be disabled anyways even w/o this. Hardware tracks active interrupts
-	# seperately in AUX_IRQ_ACTIVE.active and will not take new interrupts
+	# seperately in AUX_IRQ_ACT.active and will not take new interrupts
 	# unless this one returns (or higher prio becomes pending in 2-prio scheme)
 
 	IRQ_DISABLE
@@ -200,17 +201,18 @@ restore_regs:
 	ld	r0, [sp, PT_status32]	; U/K mode at time of entry
 	lr	r10, [AUX_IRQ_ACT]
 
-	bmsk	r11, r10, 15	; AUX_IRQ_ACT.ACTIVE
+	bmsk	r11, r10, 15		; extract AUX_IRQ_ACT.active
 	breq	r11, 0, .Lexcept_ret	; No intr active, ret from Exception
 
 ;####### Return from Intr #######
 
+.Lisr_ret:
+
 debug_marker_l1:
 	; bbit1.nt r0, STATUS_DE_BIT, .Lintr_ret_to_delay_slot
 	btst	r0, STATUS_DE_BIT		; Z flag set if bit clear
 	bnz	.Lintr_ret_to_delay_slot	; branch if STATUS_DE_BIT set
 
-.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
@@ -223,7 +225,7 @@ debug_marker_l1:
 	bset.nz	r11, r11, AUX_IRQ_ACT_BIT_U	; NZ means U
 	sr	r11, [AUX_IRQ_ACT]
 
-	INTERRUPT_EPILOGUE  irq
+	INTERRUPT_EPILOGUE
 	rtie
 
 ;####### Return from Exception / pure kernel mode #######
@@ -244,8 +246,8 @@ debug_marker_syscall:
 ;
 ; IRQ RTIE won't reliably restore DE bit and/or BTA, needs workaround
 ;
-; Solution is return from Intr w/o any delay slot quirks into a kernel trampoline
-; and from pure kernel mode return to delay slot which handles DS bit/BTA correctly
+; Solution is to drop out of interrupt context into pure kernel mode
+; and return from pure kernel mode which does right things for delay slot
 
 .Lintr_ret_to_delay_slot:
 debug_marker_ds:
@@ -254,48 +256,9 @@ debug_marker_ds:
 	add	r2, r2, 1
 	st	r2, [@intr_to_DE_cnt]
 
-	ld	r2, [sp, PT_ret]
-	ld	r3, [sp, PT_status32]
-
-	; STAT32 for Int return created from scratch
-	; (No delay dlot, disable Further intr in trampoline)
-
-	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]
-
-	; Orig exception PC/STAT32 safekept @orig_r0 and @event stack slots
-	st	r2, [sp, 0]
-	st	r3, [sp, 4]
-
-	b	.Lisr_ret_fast_path
-
-.Lintr_ret_to_delay_slot_2:
-	; Trampoline to restore orig exception PC/STAT32/BTA/AUX_USER_SP
-	sub	sp, sp, SZ_PT_REGS
-	st	r9, [sp, -4]
-
-	ld	r9, [sp, 0]
-	sr	r9, [eret]
-
-	ld	r9, [sp, 4]
-	sr	r9, [erstatus]
-
-	; restore AUX_USER_SP if returning to U mode
-	bbit0	r9, STATUS_U_BIT, 1f
-	ld	r9, [sp, PT_sp]
-	sr	r9, [AUX_USER_SP]
-
-1:
-	ld	r9, [sp, 8]
-	sr	r9, [erbta]
-
-	ld	r9, [sp, -4]
-	add	sp, sp, SZ_PT_REGS
-
-	; return from pure kernel mode to delay slot
-	rtie
+	; drop out of interrupt context (clear AUX_IRQ_ACT.active)
+	bmskn	r11, r10, 15
+	sr	r11, [AUX_IRQ_ACT]
+	b	.Lexcept_ret
 
 END(ret_from_exception)