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>
Using LOAD_REG_IMMEDIATE to get the address of kernel symbols
generates 5 instructions where LOAD_REG_ADDR can do it in one,
and will generate R_PPC64_ADDR16_* relocations in the output when
we get to making the kernel as a position-independent executable,
which we'd rather not have to handle. This changes various bits
of assembly code to use LOAD_REG_ADDR when we need to get the
address of a symbol, or to use suitable position-independent code
for cases where we can't access the TOC for various reasons, or
if we're not running at the address we were linked at.
It also cleans up a few minor things; there's no reason to save and
restore SRR0/1 around RTAS calls, __mmu_off can get the return
address from LR more conveniently than the caller can supply it in
R4 (and we already assume elsewhere that EA == RA if the MMU is on
in early boot), and enable_64b_mode was using 5 instructions where
2 would do.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Without this patch, on an idle system I get:
cpu-power-0:21.638
cpu-power-1:27.102
cpu-power-2:29.343
cpu-power-3:25.784
Total: 103.8W
With this patch:
cpu-power-0:11.730
cpu-power-1:17.185
cpu-power-2:18.547
cpu-power-3:17.528
Total: 65.0W
If I lower HZ to 100, I can get it as low as:
cpu-power-0:10.938
cpu-power-1:16.021
cpu-power-2:17.245
cpu-power-3:16.145
Total: 60.2W
Another (older) Quad G5 went from 54W to 39W at HZ=250.
Coming back out of Deep Nap takes 40-70 cycles longer than coming back
from just Nap (which already takes quite a while). I don't think it'll
be a performance issue (interrupt latency on an idle system), but in
case someone does measurements feel free to report them.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cleanup CPU inits a bit more, Geoff Levand already did some earlier.
* Move CPU state save to cpu_setup, since cpu_setup is only ever done
on cpu 0 on 64-bit and save is never done more than once.
* Rename __restore_cpu_setup to __restore_cpu_ppc970 and add
function pointers to the cputable to use instead. Powermac always
has 970 so no need to check there.
* Rename __970_cpu_preinit to __cpu_preinit_ppc970 and check PVR before
calling it instead of in it, it's too early to use cputable.
* Rename pSeries_secondary_smp_init to generic_secondary_smp_init since
everyone but powermac and iSeries use it.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Rename cpu_setup_power4.S to cpu_setup_ppc970.S, since that's
really what it is.
No functional or other changes.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
