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Commit 5473eb1c authored by Mihai Caraman's avatar Mihai Caraman Committed by Benjamin Herrenschmidt
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powerpc/booke64: Use GSRR registers in Guest Doorbell interrupts 



Guest Doorbell interrupts use guest save and restore registers. Add a new
Guest Doorbell exception type to accommodate GSRR0/1 SPRs usage in exception
prolog and fix the exception handler.

Signed-off-by: default avatarMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent a1310757

arch/powerpc/include/asm/exception-64e.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
 * critical data

 */



#define PACA_EXGDBELL PACA_EXGEN



/* We are out of SPRGs so we save some things in the PACA. The normal

 * exception frame is smaller than the CRIT or MC one though

arch/powerpc/include/asm/reg.h

+1 −0
Original line number Diff line number Diff line
@@ -863,6 +863,7 @@ 
#define SPRN_SPRG_TLB_EXFRAME	SPRN_SPRG2

#define SPRN_SPRG_TLB_SCRATCH	SPRN_SPRG6

#define SPRN_SPRG_GEN_SCRATCH	SPRN_SPRG0

#define SPRN_SPRG_GDBELL_SCRATCH SPRN_SPRG_GEN_SCRATCH



#define SET_PACA(rX)	mtspr	SPRN_SPRG_PACA,rX

#define GET_PACA(rX)	mfspr	rX,SPRN_SPRG_PACA

arch/powerpc/kernel/exceptions-64e.S

+19 −2
Original line number Diff line number Diff line
@@ -59,6 +59,10 @@ 
#define SPRN_GEN_SRR0	SPRN_SRR0

#define SPRN_GEN_SRR1	SPRN_SRR1



#define	GDBELL_SET_KSTACK	GEN_SET_KSTACK

#define SPRN_GDBELL_SRR0	SPRN_GSRR0

#define SPRN_GDBELL_SRR1	SPRN_GSRR1



#define CRIT_SET_KSTACK						            \

	ld	r1,PACA_CRIT_STACK(r13);				    \

	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
@@ -89,10 +93,13 @@ 
#define MC_EXCEPTION_PROLOG(n, addition)				    \

	EXCEPTION_PROLOG(n, MC, addition##_MC(n))



#define GDBELL_EXCEPTION_PROLOG(n, addition)				    \

	EXCEPTION_PROLOG(n, GDBELL, addition##_GDBELL(n))



/* Variants of the "addition" argument for the prolog

 */

#define PROLOG_ADDITION_NONE_GEN(n)

#define PROLOG_ADDITION_NONE_GDBELL(n)

#define PROLOG_ADDITION_NONE_CRIT(n)

#define PROLOG_ADDITION_NONE_DBG(n)

#define PROLOG_ADDITION_NONE_MC(n)
@@ -543,8 +550,18 @@ kernel_dbg_exc: 
//	b	ret_from_crit_except

	b	.



/* Guest Doorbell */

	MASKABLE_EXCEPTION(0x2c0, guest_doorbell, .unknown_exception, ACK_NONE)

/*

 *	Guest doorbell interrupt

 *	This general exception use GSRRx save/restore registers

 */

	START_EXCEPTION(guest_doorbell);

	GDBELL_EXCEPTION_PROLOG(0x2c0, PROLOG_ADDITION_NONE)

	EXCEPTION_COMMON(0x2c0, PACA_EXGEN, INTS_KEEP)

	addi	r3,r1,STACK_FRAME_OVERHEAD

	bl	.save_nvgprs

	INTS_RESTORE_HARD

	bl	.unknown_exception

	b	.ret_from_except



/* Guest Doorbell critical Interrupt */

	START_EXCEPTION(guest_doorbell_crit);