On 07/13/2018 03:17 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 <m...@linux.vnet.ibm.com>
---
Changes in patch:
-- Move new validity check added to pseries_smp_notifier
to another patch
-- Revise one of checks for 'acquire_drc' in dlpar_cpu_add.
-- Revise one of checks for 'release_drc' in dlpar_cpu_remove.
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 71 +++++++++++++++-----------
1 file changed, 40 insertions(+), 31 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c
b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 6ef77ca..7ede3b0 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -432,7 +432,7 @@ static bool valid_cpu_drc_index(struct device_node *parent,
u32 drc_index)
return found;
}
-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;
@@ -457,19 +457,22 @@ 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;
}
@@ -484,9 +487,11 @@ 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)
- dlpar_free_cc_nodes(dn);
+ if (acquire_drc) {
+ rc = dlpar_release_drc(drc_index);
+ if (!rc)
+ dlpar_free_cc_nodes(dn);
+ }
return saved_rc;
}
@@ -498,7 +503,7 @@ 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;
@@ -566,7 +571,8 @@ 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;
@@ -579,12 +585,14 @@ 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);
@@ -593,8 +601,9 @@ 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 (!rc)
+ if (release_drc)
+ rc = dlpar_acquire_drc(drc_index);
+ if (!release_drc || !rc)
dlpar_online_cpu(dn);
This is likely wrong. At this point you're in a if (rc) so rc is already
non-zero. If release_drc is false this checks an invalid rc state.
-Nathan
return saved_rc;
@@ -622,7 +631,7 @@ 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;
@@ -634,7 +643,7 @@ 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;
}
@@ -699,7 +708,7 @@ 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;
@@ -710,7 +719,7 @@ 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 {
@@ -780,7 +789,7 @@ 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;
@@ -791,7 +800,7 @@ 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 {
@@ -817,7 +826,7 @@ 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;
@@ -825,7 +834,7 @@ 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;
@@ -850,7 +859,7 @@ 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;
}
@@ -871,7 +880,7 @@ 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;
