[RFC v5 2/6] powerpc/cpu: Conditionally acquire/release DRC index
Nathan Fontenot
nfont at linux.vnet.ibm.com
Wed May 23 06:17:38 AEST 2018
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);
>
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