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pmcr: Fix pstate setting on Power8

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Fix p-state setting on Power8 by removing the accidental double-indirection of
the pstate_ids table.

The pstate_ids table comes from the OF property "ibm,pstate-ids."  On Power9,
the values happen to be identical to the indices, so the extra indirection was
harmless.  On Power8, the values were out of the range [0, npstates], so
pmcr_set() would fail the spec[0] range check with EINVAL.

While here, include both the value and index in the driver-specific register
array as spec[0] and spec[1] respectively.  They're redundant, but relatively
harmless, and it may aid debugging.

While here, fix the range check to exclude the index npstates, which is one
past the last valid index.

PR:		233693
Reported and tested by:	sbruno
Reviewed by:	jhibbits
This commit is contained in:
cem 2018-12-01 21:37:47 +00:00
parent 9b45b5233b
commit 9ad9aa9b3c
1 changed files with 5 additions and 5 deletions
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10
sys/powerpc/cpufreq/pmcr.c
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@ -174,6 +174,7 @@ pmcr_settings(device_t dev, struct cf_setting *sets, int *count)
for (i = 0; i < npstates; i++) {
sets[i].freq = pstate_freqs[i];
sets[i].spec[0] = pstate_ids[i];
sets[i].spec[1] = i;
sets[i].dev = dev;
}
*count = npstates;
@ -189,13 +190,11 @@ pmcr_set(device_t dev, const struct cf_setting *set)
if (set == NULL)
return (EINVAL);
if (set->spec[0] < 0 || set->spec[0] > npstates)
if (set->spec[1] < 0 || set->spec[1] >= npstates)
return (EINVAL);
pmcr = ((long)pstate_ids[set->spec[0]] << PMCR_LOWERPS_SHIFT) &
PMCR_LOWERPS_MASK;
pmcr |= ((long)pstate_ids[set->spec[0]] << PMCR_UPPERPS_SHIFT) &
PMCR_UPPERPS_MASK;
pmcr = ((long)set->spec[0] << PMCR_LOWERPS_SHIFT) & PMCR_LOWERPS_MASK;
pmcr |= ((long)set->spec[0] << PMCR_UPPERPS_SHIFT) & PMCR_UPPERPS_MASK;
pmcr |= PMCR_VERSION_1;
mtspr(SPR_PMCR, pmcr);
@ -228,6 +227,7 @@ pmcr_get(device_t dev, struct cf_setting *set)
return (EINVAL);
set->spec[0] = pstate;
set->spec[1] = i;
set->freq = pstate_freqs[i];
set->dev = dev;