powerpc, KVM: Split HVMODE_206 cpu feature bit into separate HV and architecture bits
This replaces the single CPU_FTR_HVMODE_206 bit with two bits, one to
indicate that we have a usable hypervisor mode, and another to indicate
that the processor conforms to PowerISA version 2.06. We also add
another bit to indicate that the processor conforms to ISA version 2.01
and set that for PPC970 and derivatives.
Some PPC970 chips (specifically those in Apple machines) have a
hypervisor mode in that MSR[HV] is always 1, but the hypervisor mode
is not useful in the sense that there is no way to run any code in
supervisor mode (HV=0 PR=0). On these processors, the LPES0 and LPES1
bits in HID4 are always 0, and we use that as a way of detecting that
hypervisor mode is not useful.
Where we have a feature section in assembly code around code that
only applies on POWER7 in hypervisor mode, we use a construct like
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
The definition of END_FTR_SECTION_IFSET is such that the code will
be enabled (not overwritten with nops) only if all bits in the
provided mask are set.
Note that the CPU feature check in __tlbie() only needs to check the
ARCH_206 bit, not the HVMODE bit, because __tlbie() can only get called
if we are running bare-metal, i.e. in hypervisor mode.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kernel/cpu_setup_power7.S b/arch/powerpc/kernel/cpu_setup_power7.S
index 2ef6749..76797c5 100644
--- a/arch/powerpc/kernel/cpu_setup_power7.S
+++ b/arch/powerpc/kernel/cpu_setup_power7.S
@@ -45,12 +45,12 @@
blr
__init_hvmode_206:
- /* Disable CPU_FTR_HVMODE_206 and exit if MSR:HV is not set */
+ /* Disable CPU_FTR_HVMODE and exit if MSR:HV is not set */
mfmsr r3
rldicl. r0,r3,4,63
bnelr
ld r5,CPU_SPEC_FEATURES(r4)
- LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE_206)
+ LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
xor r5,r5,r6
std r5,CPU_SPEC_FEATURES(r4)
blr
diff --git a/arch/powerpc/kernel/cpu_setup_ppc970.S b/arch/powerpc/kernel/cpu_setup_ppc970.S
index 27f2507..12fac8d 100644
--- a/arch/powerpc/kernel/cpu_setup_ppc970.S
+++ b/arch/powerpc/kernel/cpu_setup_ppc970.S
@@ -76,7 +76,7 @@
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
- beqlr
+ beq no_hv_mode
mfspr r0,SPRN_HID0
li r11,5 /* clear DOZE and SLEEP */
@@ -90,7 +90,7 @@
/* Do nothing if not running in HV mode */
mfmsr r0
rldicl. r0,r0,4,63
- beqlr
+ beq no_hv_mode
mfspr r0,SPRN_HID0
li r11,0x15 /* clear DOZE and SLEEP */
@@ -109,6 +109,14 @@
sync
isync
+ /* Try to set LPES = 01 in HID4 */
+ mfspr r0,SPRN_HID4
+ clrldi r0,r0,1 /* clear LPES0 */
+ ori r0,r0,HID4_LPES1 /* set LPES1 */
+ sync
+ mtspr SPRN_HID4,r0
+ isync
+
/* Save away cpu state */
LOAD_REG_ADDR(r5,cpu_state_storage)
@@ -117,11 +125,21 @@
std r3,CS_HID0(r5)
mfspr r3,SPRN_HID1
std r3,CS_HID1(r5)
- mfspr r3,SPRN_HID4
- std r3,CS_HID4(r5)
+ mfspr r4,SPRN_HID4
+ std r4,CS_HID4(r5)
mfspr r3,SPRN_HID5
std r3,CS_HID5(r5)
+ /* See if we successfully set LPES1 to 1; if not we are in Apple mode */
+ andi. r4,r4,HID4_LPES1
+ bnelr
+
+no_hv_mode:
+ /* Disable CPU_FTR_HVMODE and exit, since we don't have HV mode */
+ ld r5,CPU_SPEC_FEATURES(r4)
+ LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
+ andc r5,r5,r6
+ std r5,CPU_SPEC_FEATURES(r4)
blr
/* Called with no MMU context (typically MSR:IR/DR off) to
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 5bc06fd..a534538 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -75,7 +75,7 @@
b .power7_wakeup_noloss
2: b .power7_wakeup_loss
9:
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE_206)
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#endif /* CONFIG_PPC_P7_NAP */
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
NOTEST, 0x100)
@@ -173,7 +173,7 @@
_MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt,
EXC_STD, SOFTEN_TEST_PR)
KVM_HANDLER(PACA_EXGEN, EXC_STD, 0x500)
- ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE_206)
+ ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
STD_EXCEPTION_PSERIES(0x600, 0x600, alignment)
KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x600)
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index efeb881..0a5a899 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -167,7 +167,7 @@
* if we do a GET_PACA() before the feature fixups have been
* applied
*/
- if (cpu_has_feature(CPU_FTR_HVMODE_206))
+ if (cpu_has_feature(CPU_FTR_HVMODE))
mtspr(SPRN_SPRG_HPACA, local_paca);
#endif
mtspr(SPRN_SPRG_PACA, local_paca);