powerpc/64s: Prepare to handle data interrupts vs d-side MCE reentrancy

A subsequent fix for data interrupts (those that set DAR / DSISR)
requires some interrupt macros to be open-coded, and also requires
the 0x300 interrupt handler to be moved out-of-line.

This patch does that without changing behaviour, which makes the later
fix a smaller change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

@@ -574,8 +574,23 @@ EXC_COMMON_BEGIN(mce_return)
 	RFI_TO_KERNEL
 	b	.
 
-EXC_REAL(data_access, 0x300, 0x80)
-EXC_VIRT(data_access, 0x4300, 0x80, 0x300)
+EXC_REAL_BEGIN(data_access, 0x300, 0x80)
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXGEN)
+	b	tramp_real_data_access
+EXC_REAL_END(data_access, 0x300, 0x80)
+
+TRAMP_REAL_BEGIN(tramp_real_data_access)
+EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, 0x300)
+EXCEPTION_PROLOG_2(data_access_common, EXC_STD)
+
+EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXGEN)
+EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0x300)
+EXCEPTION_PROLOG_2_RELON(data_access_common, EXC_STD)
+EXC_VIRT_END(data_access, 0x4300, 0x80)
+
 TRAMP_KVM_SKIP(PACA_EXGEN, 0x300)
 
 EXC_COMMON_BEGIN(data_access_common)
@@ -604,11 +619,20 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 
 
 EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
-EXCEPTION_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, KVMTEST_PR, 0x380);
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXSLB)
+	b	tramp_real_data_access_slb
 EXC_REAL_END(data_access_slb, 0x380, 0x80)
 
+TRAMP_REAL_BEGIN(tramp_real_data_access_slb)
+EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
+EXCEPTION_PROLOG_2(data_access_slb_common, EXC_STD)
+
 EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
-EXCEPTION_RELON_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, NOTEST, 0x380);
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXSLB)
+EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380)
+EXCEPTION_PROLOG_2_RELON(data_access_slb_common, EXC_STD)
 EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
 
 TRAMP_KVM_SKIP(PACA_EXSLB, 0x380)
@@ -711,8 +735,20 @@ TRAMP_KVM_HV(PACA_EXGEN, 0x500)
 EXC_COMMON_ASYNC(hardware_interrupt_common, 0x500, do_IRQ)
 
 
-EXC_REAL(alignment, 0x600, 0x100)
-EXC_VIRT(alignment, 0x4600, 0x100, 0x600)
+EXC_REAL_BEGIN(alignment, 0x600, 0x100)
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXGEN)
+EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, 0x600)
+EXCEPTION_PROLOG_2(alignment_common, EXC_STD)
+EXC_REAL_END(alignment, 0x600, 0x100)
+
+EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
+SET_SCRATCH0(r13)		/* save r13 */
+EXCEPTION_PROLOG_0(PACA_EXGEN)
+EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0x600)
+EXCEPTION_PROLOG_2_RELON(alignment_common, EXC_STD)
+EXC_VIRT_END(alignment, 0x4600, 0x100)
+
 TRAMP_KVM(PACA_EXGEN, 0x600)
 EXC_COMMON_BEGIN(alignment_common)
 	mfspr	r10,SPRN_DAR