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| author | Tyrel Datwyler <tyreld@linux.ibm.com> | 2019-11-11 08:21:29 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-11-13 08:57:57 +0300 |
| commit | 775fa495af04e0bdb3a00085aaa2d915ed51388f (patch) | |
| tree | c41f52015997401fa155ba3e30891923cbb6a30b /arch/powerpc/platforms | |
| parent | 57409d4fb12c185b2c0689e0496878c8f6bb5b58 (diff) | |
| download | linux-775fa495af04e0bdb3a00085aaa2d915ed51388f.tar.xz | |
powerpc/pseries: Fix drc-info mappings of logical cpus to drc-index
There are a couple subtle errors in the mapping between cpu-ids and a
cpus associated drc-index when using the new ibm,drc-info property.
The first is that while drc-info may have been a supported firmware
feature at boot it is possible we have migrated to a CEC with older
firmware that doesn't support the ibm,drc-info property. In that case
the device tree would have been updated after migration to remove the
ibm,drc-info property and replace it with the older style ibm,drc-*
properties for types, indexes, names, and power-domains. PAPR even
goes as far as dictating that if we advertise support for drc-info
that we are capable of supporting either property type at runtime.
The second is that the first value of the ibm,drc-info property is
the int encoded count of drc-info entries. As such "value" returned
by of_prop_next_u32() is pointing at that count, and not the first
element of the first drc-info entry as is expected by the
of_read_drc_info_cell() helper.
Fix the first by ignoring DRC-INFO firmware feature and instead
testing directly for ibm,drc-info, and then falling back to the
old style ibm,drc-indexes in the case it doesn't exit.
Fix the second by incrementing value to the next element prior to
parsing drc-info entries.
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573449697-5448-3-git-send-email-tyreld@linux.ibm.com
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/pseries/pseries_energy.c | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c index a96874f9492f..09e98d301db0 100644 --- a/arch/powerpc/platforms/pseries/pseries_energy.c +++ b/arch/powerpc/platforms/pseries/pseries_energy.c @@ -36,6 +36,7 @@ static int sysfs_entries; static u32 cpu_to_drc_index(int cpu) { struct device_node *dn = NULL; + struct property *info; int thread_index; int rc = 1; u32 ret = 0; @@ -47,20 +48,18 @@ static u32 cpu_to_drc_index(int cpu) /* Convert logical cpu number to core number */ thread_index = cpu_core_index_of_thread(cpu); - if (firmware_has_feature(FW_FEATURE_DRC_INFO)) { - struct property *info = NULL; + info = of_find_property(dn, "ibm,drc-info", NULL); + if (info) { struct of_drc_info drc; int j; u32 num_set_entries; const __be32 *value; - info = of_find_property(dn, "ibm,drc-info", NULL); - if (info == NULL) - goto err_of_node_put; - value = of_prop_next_u32(info, NULL, &num_set_entries); if (!value) goto err_of_node_put; + else + value++; for (j = 0; j < num_set_entries; j++) { @@ -110,6 +109,7 @@ err: static int drc_index_to_cpu(u32 drc_index) { struct device_node *dn = NULL; + struct property *info; const int *indexes; int thread_index = 0, cpu = 0; int rc = 1; @@ -117,21 +117,18 @@ static int drc_index_to_cpu(u32 drc_index) dn = of_find_node_by_path("/cpus"); if (dn == NULL) goto err; - - if (firmware_has_feature(FW_FEATURE_DRC_INFO)) { - struct property *info = NULL; + info = of_find_property(dn, "ibm,drc-info", NULL); + if (info) { struct of_drc_info drc; int j; u32 num_set_entries; const __be32 *value; - info = of_find_property(dn, "ibm,drc-info", NULL); - if (info == NULL) - goto err_of_node_put; - value = of_prop_next_u32(info, NULL, &num_set_entries); if (!value) goto err_of_node_put; + else + value++; for (j = 0; j < num_set_entries; j++) { |