From 5473eb1c07009956be5f4df65d51f8e24d8eb1de Mon Sep 17 00:00:00 2001 From: Mihai Caraman Date: Mon, 6 Aug 2012 03:27:04 +0000 Subject: [PATCH] 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: Mihai Caraman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/exception-64e.h | 1 + arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kernel/exceptions-64e.S | 21 +++++++++++++++++++-- 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64e.h b/arch/powerpc/include/asm/exception-64e.h index ac13addb8495..e73452f09019 100644 --- a/arch/powerpc/include/asm/exception-64e.h +++ b/arch/powerpc/include/asm/exception-64e.h @@ -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 diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 43bb15fc899b..c195bf0e6241 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -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 diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 0243b1b29031..0f58a95fd216 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -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);