linux-kernel - [PATCH 4.9 02/16] powerpc/64s: move some exception handlers out of line

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Date:   Fri, 20 Nov 2020 12:03:07 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>, dja@...ens.net
Subject: [PATCH 4.9 02/16] powerpc/64s: move some exception handlers out of line

From: Daniel Axtens <dja@...ens.net>

(backport only)

We're about to grow the exception handlers, which will make a bunch of them
no longer fit within the space available. We move them out of line.

This is a fiddly and error-prone business, so in the interests of reviewability
I haven't merged this in with the addition of the entry flush.

Signed-off-by: Daniel Axtens <dja@...ens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/powerpc/kernel/exceptions-64s.S |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -519,6 +519,10 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TY
 EXC_REAL_BEGIN(data_access_slb, 0x380, 0x400)
 	SET_SCRATCH0(r13)
 	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	b tramp_data_access_slb
+EXC_REAL_END(data_access_slb, 0x380, 0x400)
+
+TRAMP_REAL_BEGIN(tramp_data_access_slb)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_DAR
@@ -537,7 +541,6 @@ EXC_REAL_BEGIN(data_access_slb, 0x380, 0
 	mtctr	r10
 	bctr
 #endif
-EXC_REAL_END(data_access_slb, 0x380, 0x400)
 
 EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x4400)
 	SET_SCRATCH0(r13)
@@ -587,6 +590,10 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TY
 EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x500)
 	SET_SCRATCH0(r13)
 	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	b tramp_instruction_access_slb
+EXC_REAL_END(instruction_access_slb, 0x480, 0x500)
+
+TRAMP_REAL_BEGIN(tramp_instruction_access_slb)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
@@ -600,7 +607,6 @@ EXC_REAL_BEGIN(instruction_access_slb, 0
 	mtctr	r10
 	bctr
 #endif
-EXC_REAL_END(instruction_access_slb, 0x480, 0x500)
 
 EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x4500)
 	SET_SCRATCH0(r13)