diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 12:51:47 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 13:08:57 +0300 |
| commit | 46f9caf1a246a5c0622fa8cc7e673658e925f97e (patch) | |
| tree | 588a28905c70adcd36e135af702a8e4293b20288 /arch/powerpc/platforms/powernv/idle.c | |
| parent | eacc818864bb01828280f4d64334c4e5ae6a4daf (diff) | |
| download | linux-46f9caf1a246a5c0622fa8cc7e673658e925f97e.tar.xz | |
powerpc/64s: Keep AMOR SPR a constant ~0 at runtime
This register controls supervisor SPR modifications, and as such is only
relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never
restores it coming back out to the host, so it can be kept constant and
avoid the mtSPR in KVM guest entry.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-10-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/platforms/powernv/idle.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/idle.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index 86e787502e42..3bc84e2fe064 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -306,8 +306,8 @@ struct p7_sprs { /* per thread SPRs that get lost in shallow states */ u64 amr; u64 iamr; - u64 amor; u64 uamor; + /* amor is restored to constant ~0 */ }; static unsigned long power7_idle_insn(unsigned long type) @@ -378,7 +378,6 @@ static unsigned long power7_idle_insn(unsigned long type) if (cpu_has_feature(CPU_FTR_ARCH_207S)) { sprs.amr = mfspr(SPRN_AMR); sprs.iamr = mfspr(SPRN_IAMR); - sprs.amor = mfspr(SPRN_AMOR); sprs.uamor = mfspr(SPRN_UAMOR); } @@ -397,7 +396,7 @@ static unsigned long power7_idle_insn(unsigned long type) */ mtspr(SPRN_AMR, sprs.amr); mtspr(SPRN_IAMR, sprs.iamr); - mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_AMOR, ~0); mtspr(SPRN_UAMOR, sprs.uamor); } } @@ -686,7 +685,6 @@ static unsigned long power9_idle_stop(unsigned long psscr) sprs.amr = mfspr(SPRN_AMR); sprs.iamr = mfspr(SPRN_IAMR); - sprs.amor = mfspr(SPRN_AMOR); sprs.uamor = mfspr(SPRN_UAMOR); srr1 = isa300_idle_stop_mayloss(psscr); /* go idle */ @@ -707,7 +705,7 @@ static unsigned long power9_idle_stop(unsigned long psscr) */ mtspr(SPRN_AMR, sprs.amr); mtspr(SPRN_IAMR, sprs.iamr); - mtspr(SPRN_AMOR, sprs.amor); + mtspr(SPRN_AMOR, ~0); mtspr(SPRN_UAMOR, sprs.uamor); /* |