Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935324AbeAHQ5o (ORCPT + 1 other); Mon, 8 Jan 2018 11:57:44 -0500 Received: from ozlabs.org ([103.22.144.67]:59113 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757033AbeAHQzt (ORCPT ); Mon, 8 Jan 2018 11:55:49 -0500 From: Michael Ellerman To: linuxppc-dev@ozlabs.org Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, npiggin@gmail.com, anton@samba.org, mikey@neuling.org, oohall@gmail.com, paulus@samba.org Subject: [PATCH 06/11] powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL Date: Tue, 9 Jan 2018 03:54:48 +1100 Message-Id: <20180108165453.26066-6-mpe@ellerman.id.au> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180108165453.26066-1-mpe@ellerman.id.au> References: <20180108165453.26066-1-mpe@ellerman.id.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Nicholas Piggin In the SLB miss handler we may be returning to user or kernel. We need to add a check early on and save the result in the cr4 register, and then we bifurcate the return path based on that. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/exceptions-64s.S | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 5502b0147c4e..ed356194f09c 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -598,6 +598,9 @@ EXC_COMMON_BEGIN(slb_miss_common) stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */ std r10,PACA_EXSLB+EX_LR(r13) /* save LR */ + andi. r9,r11,MSR_PR // Check for exception from userspace + cmpdi cr4,r9,MSR_PR // And save the result in CR4 for later + /* * Test MSR_RI before calling slb_allocate_realmode, because the * MSR in r11 gets clobbered. However we still want to allocate @@ -624,9 +627,32 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) /* All done -- return from exception. */ + bne cr4,1f /* returning to kernel */ + +.machine push +.machine "power4" + mtcrf 0x80,r9 + mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */ + mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */ + mtcrf 0x02,r9 /* I/D indication is in cr6 */ + mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */ +.machine pop + + RESTORE_CTR(r9, PACA_EXSLB) + RESTORE_PPR_PACA(PACA_EXSLB, r9) + mr r3,r12 + ld r9,PACA_EXSLB+EX_R9(r13) + ld r10,PACA_EXSLB+EX_R10(r13) + ld r11,PACA_EXSLB+EX_R11(r13) + ld r12,PACA_EXSLB+EX_R12(r13) + ld r13,PACA_EXSLB+EX_R13(r13) + RFI_TO_USER + b . /* prevent speculative execution */ +1: .machine push .machine "power4" mtcrf 0x80,r9 + mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */ mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */ mtcrf 0x02,r9 /* I/D indication is in cr6 */ mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */ @@ -640,9 +666,10 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) ld r11,PACA_EXSLB+EX_R11(r13) ld r12,PACA_EXSLB+EX_R12(r13) ld r13,PACA_EXSLB+EX_R13(r13) - rfid + RFI_TO_KERNEL b . /* prevent speculative execution */ + 2: std r3,PACA_EXSLB+EX_DAR(r13) mr r3,r12 mfspr r11,SPRN_SRR0 -- 2.14.3