[RFC v5 2/6] powerpc/cpu: Conditionally acquire/release DRC index
Michael Bringmann
mwb at linux.vnet.ibm.com
Wed May 23 09:46:10 AEST 2018
Okay. Moving validity check mentioned at bottom of patch to 4/6,
Provide CPU readd operation.
On 05/22/2018 03:17 PM, Nathan Fontenot wrote:
> On 05/21/2018 12:52 PM, Michael Bringmann wrote:
>> powerpc/cpu: Modify dlpar_cpu_add and dlpar_cpu_remove to allow the
>> skipping of DRC index acquire or release operations during the CPU
>> add or remove operations. This is intended to support subsequent
>> changes to provide a 'CPU readd' operation.
>>
>> Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
>> ---
>> arch/powerpc/platforms/pseries/hotplug-cpu.c | 71 +++++++++++++++-----------
>> 1 file changed, 42 insertions(+), 29 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> index a408217..ec78cc6 100644
>> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> @@ -474,7 +474,7 @@ static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
>> &cdata);
>> }
>>
>> -static ssize_t dlpar_cpu_add(u32 drc_index)
>> +static ssize_t dlpar_cpu_add(u32 drc_index, bool acquire_drc)
>> {
>> struct device_node *dn, *parent;
>> int rc, saved_rc;
>> @@ -499,19 +499,22 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
>> return -EINVAL;
>> }
>>
>> - rc = dlpar_acquire_drc(drc_index);
>> - if (rc) {
>> - pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n",
>> - rc, drc_index);
>> - of_node_put(parent);
>> - return -EINVAL;
>> + if (acquire_drc) {
>> + rc = dlpar_acquire_drc(drc_index);
>> + if (rc) {
>> + pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n",
>> + rc, drc_index);
>> + of_node_put(parent);
>> + return -EINVAL;
>> + }
>> }
>>
>> dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
>> if (!dn) {
>> pr_warn("Failed call to configure-connector, drc index: %x\n",
>> drc_index);
>> - dlpar_release_drc(drc_index);
>> + if (acquire_drc)
>> + dlpar_release_drc(drc_index);
>> of_node_put(parent);
>> return -EINVAL;
>> }
>> @@ -526,8 +529,9 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
>> pr_warn("Failed to attach node %s, rc: %d, drc index: %x\n",
>> dn->name, rc, drc_index);
>>
>> - rc = dlpar_release_drc(drc_index);
>> - if (!rc)
>> + if (acquire_drc)
>> + rc = dlpar_release_drc(drc_index);
>> + if (!rc || acquire_drc)
>> dlpar_free_cc_nodes(dn);
>>
>> return saved_rc;
>> @@ -540,7 +544,7 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
>> dn->name, rc, drc_index);
>>
>> rc = dlpar_detach_node(dn);
>> - if (!rc)
>> + if (!rc && acquire_drc)
>> dlpar_release_drc(drc_index);
>>
>> return saved_rc;
>> @@ -608,7 +612,8 @@ static int dlpar_offline_cpu(struct device_node *dn)
>>
>> }
>>
>> -static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
>> +static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index,
>> + bool release_drc)
>> {
>> int rc;
>>
>> @@ -621,12 +626,14 @@ static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
>> return -EINVAL;
>> }
>>
>> - rc = dlpar_release_drc(drc_index);
>> - if (rc) {
>> - pr_warn("Failed to release drc (%x) for CPU %s, rc: %d\n",
>> - drc_index, dn->name, rc);
>> - dlpar_online_cpu(dn);
>> - return rc;
>> + if (release_drc) {
>> + rc = dlpar_release_drc(drc_index);
>> + if (rc) {
>> + pr_warn("Failed to release drc (%x) for CPU %s, rc: %d\n",
>> + drc_index, dn->name, rc);
>> + dlpar_online_cpu(dn);
>> + return rc;
>> + }
>> }
>>
>> rc = dlpar_detach_node(dn);
>> @@ -635,7 +642,10 @@ static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
>>
>> pr_warn("Failed to detach CPU %s, rc: %d", dn->name, rc);
>>
>> - rc = dlpar_acquire_drc(drc_index);
>> + if (release_drc)
>> + rc = dlpar_acquire_drc(drc_index);
>> + else
>> + rc = 0;
>> if (!rc)
>> dlpar_online_cpu(dn);
>>
>> @@ -664,7 +674,7 @@ static struct device_node *cpu_drc_index_to_dn(u32 drc_index)
>> return dn;
>> }
>>
>> -static int dlpar_cpu_remove_by_index(u32 drc_index)
>> +static int dlpar_cpu_remove_by_index(u32 drc_index, bool release_drc)
>> {
>> struct device_node *dn;
>> int rc;
>> @@ -676,7 +686,7 @@ static int dlpar_cpu_remove_by_index(u32 drc_index)
>> return -ENODEV;
>> }
>>
>> - rc = dlpar_cpu_remove(dn, drc_index);
>> + rc = dlpar_cpu_remove(dn, drc_index, release_drc);
>> of_node_put(dn);
>> return rc;
>> }
>> @@ -741,7 +751,7 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
>> }
>>
>> for (i = 0; i < cpus_to_remove; i++) {
>> - rc = dlpar_cpu_remove_by_index(cpu_drcs[i]);
>> + rc = dlpar_cpu_remove_by_index(cpu_drcs[i], true);
>> if (rc)
>> break;
>>
>> @@ -752,7 +762,7 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
>> pr_warn("CPU hot-remove failed, adding back removed CPUs\n");
>>
>> for (i = 0; i < cpus_removed; i++)
>> - dlpar_cpu_add(cpu_drcs[i]);
>> + dlpar_cpu_add(cpu_drcs[i], true);
>>
>> rc = -EINVAL;
>> } else {
>> @@ -843,7 +853,7 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add)
>> }
>>
>> for (i = 0; i < cpus_to_add; i++) {
>> - rc = dlpar_cpu_add(cpu_drcs[i]);
>> + rc = dlpar_cpu_add(cpu_drcs[i], true);
>> if (rc)
>> break;
>>
>> @@ -854,7 +864,7 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add)
>> pr_warn("CPU hot-add failed, removing any added CPUs\n");
>>
>> for (i = 0; i < cpus_added; i++)
>> - dlpar_cpu_remove_by_index(cpu_drcs[i]);
>> + dlpar_cpu_remove_by_index(cpu_drcs[i], true);
>>
>> rc = -EINVAL;
>> } else {
>> @@ -880,7 +890,7 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
>> if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
>> rc = dlpar_cpu_remove_by_count(count);
>> else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
>> - rc = dlpar_cpu_remove_by_index(drc_index);
>> + rc = dlpar_cpu_remove_by_index(drc_index, true);
>> else
>> rc = -EINVAL;
>> break;
>> @@ -888,7 +898,7 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
>> if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
>> rc = dlpar_cpu_add_by_count(count);
>> else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
>> - rc = dlpar_cpu_add(drc_index);
>> + rc = dlpar_cpu_add(drc_index, true);
>> else
>> rc = -EINVAL;
>> break;
>> @@ -913,7 +923,7 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
>> if (rc)
>> return -EINVAL;
>>
>> - rc = dlpar_cpu_add(drc_index);
>> + rc = dlpar_cpu_add(drc_index, true);
>>
>> return rc ? rc : count;
>> }
>> @@ -934,7 +944,7 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
>> return -EINVAL;
>> }
>>
>> - rc = dlpar_cpu_remove(dn, drc_index);
>> + rc = dlpar_cpu_remove(dn, drc_index, true);
>> of_node_put(dn);
>>
>> return rc ? rc : count;
>> @@ -948,6 +958,9 @@ static int pseries_smp_notifier(struct notifier_block *nb,
>> struct of_reconfig_data *rd = data;
>> int err = 0;
>>
>> + if (strcmp(rd->dn->type, "cpu"))
>> + return notifier_from_errno(err);> +
>
> This last change doesn't seem to fit in this patch, should this be a part of a different patch?
>
> -Nathan
>
>> switch (action) {
>> case OF_RECONFIG_ATTACH_NODE:
>> err = pseries_add_processor(rd->dn);
>>
>
>
--
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line 363-5196
External: (512) 286-5196
Cell: (512) 466-0650
mwb at linux.vnet.ibm.com
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