10d91611f4
Reimplement Book3S idle code in C, moving POWER7/8/9 implementation speific HV idle code to the powernv platform code. Book3S assembly stubs are kept in common code and used only to save the stack frame and non-volatile GPRs before executing architected idle instructions, and restoring the stack and reloading GPRs then returning to C after waking from idle. The complex logic dealing with threads and subcores, locking, SPRs, HMIs, timebase resync, etc., is all done in C which makes it more maintainable. This is not a strict translation to C code, there are some significant differences: - Idle wakeup no longer uses the ->cpu_restore call to reinit SPRs, but saves and restores them itself. - The optimisation where EC=ESL=0 idle modes did not have to save GPRs or change MSR is restored, because it's now simple to do. ESL=1 sleeps that do not lose GPRs can use this optimization too. - KVM secondary entry and cede is now more of a call/return style rather than branchy. nap_state_lost is not required because KVM always returns via NVGPR restoring path. - KVM secondary wakeup from offline sequence is moved entirely into the offline wakeup, which avoids a hwsync in the normal idle wakeup path. Performance measured with context switch ping-pong on different threads or cores, is possibly improved a small amount, 1-3% depending on stop state and core vs thread test for shallow states. Deep states it's in the noise compared with other latencies. KVM improvements: - Idle sleepers now always return to caller rather than branch out to KVM first. - This allows optimisations like very fast return to caller when no state has been lost. - KVM no longer requires nap_state_lost because it controls NVGPR save/restore itself on the way in and out. - The heavy idle wakeup KVM request check can be moved out of the normal host idle code and into the not-performance-critical offline code. - KVM nap code now returns from where it is called, which makes the flow a bit easier to follow. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Squash the KVM changes in] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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.. | ||
book3s.c | ||
book3s.h | ||
book3s_32_mmu.c | ||
book3s_32_mmu_host.c | ||
book3s_32_sr.S | ||
book3s_64_mmu.c | ||
book3s_64_mmu_host.c | ||
book3s_64_mmu_hv.c | ||
book3s_64_mmu_radix.c | ||
book3s_64_slb.S | ||
book3s_64_vio.c | ||
book3s_64_vio_hv.c | ||
book3s_emulate.c | ||
book3s_exports.c | ||
book3s_hv.c | ||
book3s_hv_builtin.c | ||
book3s_hv_hmi.c | ||
book3s_hv_interrupts.S | ||
book3s_hv_nested.c | ||
book3s_hv_ras.c | ||
book3s_hv_rm_mmu.c | ||
book3s_hv_rm_xics.c | ||
book3s_hv_rm_xive.c | ||
book3s_hv_rmhandlers.S | ||
book3s_hv_tm.c | ||
book3s_hv_tm_builtin.c | ||
book3s_interrupts.S | ||
book3s_mmu_hpte.c | ||
book3s_paired_singles.c | ||
book3s_pr.c | ||
book3s_pr_papr.c | ||
book3s_rmhandlers.S | ||
book3s_rtas.c | ||
book3s_segment.S | ||
book3s_xics.c | ||
book3s_xics.h | ||
book3s_xive.c | ||
book3s_xive.h | ||
book3s_xive_template.c | ||
booke.c | ||
booke.h | ||
booke_emulate.c | ||
booke_interrupts.S | ||
bookehv_interrupts.S | ||
e500.c | ||
e500.h | ||
e500_emulate.c | ||
e500_mmu.c | ||
e500_mmu_host.c | ||
e500_mmu_host.h | ||
e500mc.c | ||
emulate.c | ||
emulate_loadstore.c | ||
fpu.S | ||
irq.h | ||
Kconfig | ||
Makefile | ||
mpic.c | ||
powerpc.c | ||
timing.c | ||
timing.h | ||
tm.S | ||
trace.h | ||
trace_book3s.h | ||
trace_booke.h | ||
trace_hv.h | ||
trace_pr.h |