Commit b782e8d0 authored by Yicong Yang's avatar Yicong Yang Committed by Will Deacon

arm64: arm_pmuv3: Correctly extract and check the PMUVer

Currently we're using "sbfx" to extract the PMUVer from ID_AA64DFR0_EL1
and skip the init/reset if no PMU present when the extracted PMUVer is
negative or is zero. However for PMUv3p8 the PMUVer will be 0b1000 and
PMUVer extracted by "sbfx" will always be negative and we'll skip the
init/reset in __init_el2_debug/reset_pmuserenr_el0 unexpectedly.

So this patch use "ubfx" instead of "sbfx" to extract the PMUVer. If
the PMUVer is implementation defined (0b1111) or not implemented(0b0000)
then skip the reset/init. Previously we'll also skip the init/reset
if the PMUVer is higher than the version we known (currently PMUv3p9),
with this patch we'll only skip if the PMU is not implemented or
implementation defined. This keeps consistence with how we probe
the PMU in the driver with pmuv3_implemented().
Signed-off-by: default avatarYicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240411123030.7201-1-yangyicong@huawei.comSigned-off-by: default avatarWill Deacon <will@kernel.org>
parent 8f9f5041
......@@ -480,9 +480,10 @@ alternative_endif
*/
.macro reset_pmuserenr_el0, tmpreg
mrs \tmpreg, id_aa64dfr0_el1
sbfx \tmpreg, \tmpreg, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
cmp \tmpreg, #1 // Skip if no PMU present
b.lt 9000f
ubfx \tmpreg, \tmpreg, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
cmp \tmpreg, #ID_AA64DFR0_EL1_PMUVer_NI
ccmp \tmpreg, #ID_AA64DFR0_EL1_PMUVer_IMP_DEF, #4, ne
b.eq 9000f // Skip if no PMU present or IMP_DEF
msr pmuserenr_el0, xzr // Disable PMU access from EL0
9000:
.endm
......
......@@ -59,13 +59,14 @@
.macro __init_el2_debug
mrs x1, id_aa64dfr0_el1
sbfx x0, x1, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
cmp x0, #1
b.lt .Lskip_pmu_\@ // Skip if no PMU present
ubfx x0, x1, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
cmp x0, #ID_AA64DFR0_EL1_PMUVer_NI
ccmp x0, #ID_AA64DFR0_EL1_PMUVer_IMP_DEF, #4, ne
b.eq .Lskip_pmu_\@ // Skip if no PMU present or IMP_DEF
mrs x0, pmcr_el0 // Disable debug access traps
ubfx x0, x0, #11, #5 // to EL2 and allow access to
.Lskip_pmu_\@:
csel x2, xzr, x0, lt // all PMU counters from EL1
csel x2, xzr, x0, eq // all PMU counters from EL1
/* Statistical profiling */
ubfx x0, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
......
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