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authorMichael Neuling <mikey@neuling.org>2012-09-10 00:35:26 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-09-17 16:31:47 +1000
commitb92a66a65cb4480774066d9a3080c77eb34b7232 (patch)
treeba40ef5be8bdb9b76e36ec1da29db90189d2a821 /arch/powerpc/kernel/exceptions-64s.S
parenteda485f06d17f98bd58559fb5dd331951ffd1608 (diff)
powerpc: Add denormalisation exception handling for POWER6/7
On POWER6 and POWER7 if the input operand to an instruction is a denormalised single precision binary floating point value we can take a denormalisation exception where it's expected that the hypervisor (HV=1) will fix up the inputs before the instruction is run. This adds code to handle this denormalisation exception for POWER6 and POWER7. It also add a CONFIG_PPC_DENORMALISATION option and sets it in pseries/ppc64_defconfig. This is useful on bare metal systems only. Based on patch from Milton Miller. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S123
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 39aa97d3ff88..5eb00569199f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -275,6 +275,31 @@ vsx_unavailable_pSeries_1:
STD_EXCEPTION_PSERIES(0x1300, 0x1300, instruction_breakpoint)
KVM_HANDLER_PR_SKIP(PACA_EXGEN, EXC_STD, 0x1300)
+ . = 0x1500
+ .global denorm_Hypervisor
+denorm_exception_hv:
+ HMT_MEDIUM
+ mtspr SPRN_SPRG_HSCRATCH0,r13
+ mfspr r13,SPRN_SPRG_HPACA
+ std r9,PACA_EXGEN+EX_R9(r13)
+ std r10,PACA_EXGEN+EX_R10(r13)
+ std r11,PACA_EXGEN+EX_R11(r13)
+ std r12,PACA_EXGEN+EX_R12(r13)
+ mfspr r9,SPRN_SPRG_HSCRATCH0
+ std r9,PACA_EXGEN+EX_R13(r13)
+ mfcr r9
+
+#ifdef CONFIG_PPC_DENORMALISATION
+ mfspr r10,SPRN_HSRR1
+ mfspr r11,SPRN_HSRR0 /* save HSRR0 */
+ andis. r10,r10,(HSRR1_DENORM)@h /* denorm? */
+ addi r11,r11,-4 /* HSRR0 is next instruction */
+ bne+ denorm_assist
+#endif
+
+ EXCEPTION_PROLOG_PSERIES_1(denorm_common, EXC_HV)
+ KVM_HANDLER_SKIP(PACA_EXGEN, EXC_STD, 0x1500)
+
#ifdef CONFIG_CBE_RAS
STD_EXCEPTION_HV(0x1600, 0x1602, cbe_maintenance)
KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1602)
@@ -336,6 +361,103 @@ do_stab_bolted_pSeries:
KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x900)
KVM_HANDLER(PACA_EXGEN, EXC_HV, 0x982)
+#ifdef CONFIG_PPC_DENORMALISATION
+denorm_assist:
+BEGIN_FTR_SECTION
+/*
+ * To denormalise we need to move a copy of the register to itself.
+ * For POWER6 do that here for all FP regs.
+ */
+ mfmsr r10
+ ori r10,r10,(MSR_FP|MSR_FE0|MSR_FE1)
+ xori r10,r10,(MSR_FE0|MSR_FE1)
+ mtmsrd r10
+ sync
+ fmr 0,0
+ fmr 1,1
+ fmr 2,2
+ fmr 3,3
+ fmr 4,4
+ fmr 5,5
+ fmr 6,6
+ fmr 7,7
+ fmr 8,8
+ fmr 9,9
+ fmr 10,10
+ fmr 11,11
+ fmr 12,12
+ fmr 13,13
+ fmr 14,14
+ fmr 15,15
+ fmr 16,16
+ fmr 17,17
+ fmr 18,18
+ fmr 19,19
+ fmr 20,20
+ fmr 21,21
+ fmr 22,22
+ fmr 23,23
+ fmr 24,24
+ fmr 25,25
+ fmr 26,26
+ fmr 27,27
+ fmr 28,28
+ fmr 29,29
+ fmr 30,30
+ fmr 31,31
+FTR_SECTION_ELSE
+/*
+ * To denormalise we need to move a copy of the register to itself.
+ * For POWER7 do that here for the first 32 VSX registers only.
+ */
+ mfmsr r10
+ oris r10,r10,MSR_VSX@h
+ mtmsrd r10
+ sync
+ XVCPSGNDP(0,0,0)
+ XVCPSGNDP(1,1,1)
+ XVCPSGNDP(2,2,2)
+ XVCPSGNDP(3,3,3)
+ XVCPSGNDP(4,4,4)
+ XVCPSGNDP(5,5,5)
+ XVCPSGNDP(6,6,6)
+ XVCPSGNDP(7,7,7)
+ XVCPSGNDP(8,8,8)
+ XVCPSGNDP(9,9,9)
+ XVCPSGNDP(10,10,10)
+ XVCPSGNDP(11,11,11)
+ XVCPSGNDP(12,12,12)
+ XVCPSGNDP(13,13,13)
+ XVCPSGNDP(14,14,14)
+ XVCPSGNDP(15,15,15)
+ XVCPSGNDP(16,16,16)
+ XVCPSGNDP(17,17,17)
+ XVCPSGNDP(18,18,18)
+ XVCPSGNDP(19,19,19)
+ XVCPSGNDP(20,20,20)
+ XVCPSGNDP(21,21,21)
+ XVCPSGNDP(22,22,22)
+ XVCPSGNDP(23,23,23)
+ XVCPSGNDP(24,24,24)
+ XVCPSGNDP(25,25,25)
+ XVCPSGNDP(26,26,26)
+ XVCPSGNDP(27,27,27)
+ XVCPSGNDP(28,28,28)
+ XVCPSGNDP(29,29,29)
+ XVCPSGNDP(30,30,30)
+ XVCPSGNDP(31,31,31)
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)
+ mtspr SPRN_HSRR0,r11
+ mtcrf 0x80,r9
+ ld r9,PACA_EXGEN+EX_R9(r13)
+ ld r10,PACA_EXGEN+EX_R10(r13)
+ ld r11,PACA_EXGEN+EX_R11(r13)
+ ld r12,PACA_EXGEN+EX_R12(r13)
+ ld r13,PACA_EXGEN+EX_R13(r13)
+ HRFID
+ b .
+#endif
+
.align 7
/* moved from 0xe00 */
STD_EXCEPTION_HV(., 0xe02, h_data_storage)
@@ -495,6 +617,7 @@ machine_check_common:
STD_EXCEPTION_COMMON(0xe60, hmi_exception, .unknown_exception)
STD_EXCEPTION_COMMON_ASYNC(0xf00, performance_monitor, .performance_monitor_exception)
STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
+ STD_EXCEPTION_COMMON(0x1502, denorm, .unknown_exception)
#ifdef CONFIG_ALTIVEC
STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
#else