[RFC v4 3/4] hotplug/drcinfo: Fix hot-add CPU issues
Michael Bringmann
mwb at linux.vnet.ibm.com
Wed May 23 02:37:14 AEST 2018
This patch applies a common parse function for the ibm,drc-info
property that can be modified by a callback function to the
hot-add CPU code. Candidate code is replaced by a call to the
parser including a pointer to a local context-specific functions,
and local data.
In addition, a bug in the release of the previous patch set may
break things in some of the CPU DLPAR operations. For instance,
when attempting to hot-add a new CPU or set of CPUs, the original
patch failed to always properly calculate the available resources,
and aborted the operation.
Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
Fixes: 3f38000eda48 ("powerpc/firmware: Add definitions for new drc-info firmwar
e feature" -- end of patch series applied to powerpc next)
---
Changes in V4:
-- Update code to account for latest kernel checkins.
-- Rebased to 4.17-rc5 kernel
-- Compress some more code
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 118 +++++++++++++++++------
arch/powerpc/platforms/pseries/pseries_energy.c | 107 +++++++++++----------
2 files changed, 141 insertions(+), 84 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 6ef77ca..ceacad9 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -411,27 +411,63 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
return found;
}
-static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
+static bool check_cpu_drc_index(struct device_node *parent,
+ int (*cb)(struct of_drc_info *drc,
+ void *data, void *not_used,
+ int *ret_code),
+ void *cdata)
{
bool found = false;
- int rc, index;
- index = 0;
- while (!found) {
- u32 drc;
+ if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
+ if (drc_info_parser(parent, cb, "CPU", cdata))
+ found = true;
+ } else {
+ int index = 0;
- rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
- index++, &drc);
- if (rc)
- break;
+ while (!found) {
+ u32 drc;
- if (drc == drc_index)
- found = true;
+ if (of_property_read_u32_index(parent,
+ "ibm,drc-indexes",
+ index++, &drc))
+ break;
+ if (cb(NULL, cdata, &drc, NULL))
+ found = true;
+ }
}
return found;
}
+struct valid_drc_index_struct {
+ u32 targ_drc_index;
+};
+
+static int valid_drc_index_cb(struct of_drc_info *drc, void *idata,
+ void *drc_index, int *ret_code)
+{
+ struct valid_drc_index_struct *cdata = idata;
+
+ if (drc) {
+ if (!((drc->drc_index_start <= cdata->targ_drc_index) &&
+ (cdata->targ_drc_index <= drc->last_drc_index)))
+ return 0;
+ } else {
+ if (*((u32 *)drc_index) != cdata->targ_drc_index)
+ return 0;
+ }
+ (*ret_code) = 1;
+ return 1;
+}
+
+static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
+{
+ struct valid_drc_index_struct cdata = { drc_index };
+
+ return check_cpu_drc_index(parent, valid_drc_index_cb, &cdata);
+}
+
static ssize_t dlpar_cpu_add(u32 drc_index)
{
struct device_node *dn, *parent;
@@ -721,11 +757,43 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
return rc;
}
+struct cpus_to_add_struct {
+ struct device_node *parent;
+ u32 *cpu_drcs;
+ u32 cpus_to_add;
+ u32 cpus_found;
+};
+
+static int cpus_to_add_cb(struct of_drc_info *drc, void *idata,
+ void *drc_index, int *ret_code)
+{
+ struct cpus_to_add_struct *cdata = idata;
+
+ if (drc) {
+ int k;
+
+ for (k = 0; (k < drc->num_sequential_elems) &&
+ (cdata->cpus_found < cdata->cpus_to_add); k++) {
+ u32 idrc = drc->drc_index_start +
+ (k * drc->sequential_inc);
+
+ if (dlpar_cpu_exists(cdata->parent, idrc))
+ continue;
+ cdata->cpu_drcs[cdata->cpus_found++] = idrc;
+ }
+ } else {
+ if (!dlpar_cpu_exists(cdata->parent, *((u32 *)drc_index)))
+ cdata->cpu_drcs[cdata->cpus_found++] =
+ *((u32 *)drc_index);
+ }
+ return 0;
+}
+
static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
{
struct device_node *parent;
- int cpus_found = 0;
- int index, rc;
+ struct cpus_to_add_struct cdata = {
+ NULL, cpu_drcs, cpus_to_add, 0 };
parent = of_find_node_by_path("/cpus");
if (!parent) {
@@ -734,28 +802,14 @@ static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
return -1;
}
- /* Search the ibm,drc-indexes array for possible CPU drcs to
- * add. Note that the format of the ibm,drc-indexes array is
- * the number of entries in the array followed by the array
- * of drc values so we start looking at index = 1.
+ /* Search the appropriate property for possible CPU drcs to
+ * add.
*/
- index = 1;
- while (cpus_found < cpus_to_add) {
- u32 drc;
-
- rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
- index++, &drc);
- if (rc)
- break;
-
- if (dlpar_cpu_exists(parent, drc))
- continue;
-
- cpu_drcs[cpus_found++] = drc;
- }
+ cdata.parent = parent;
+ check_cpu_drc_index(parent, cpus_to_add_cb, &cdata);
of_node_put(parent);
- return cpus_found;
+ return cdata.cpus_found;
}
static int dlpar_cpu_add_by_count(u32 cpus_to_add)
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 5261975..d8d7750 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -36,6 +36,26 @@
/* Helper Routines to convert between drc_index to cpu numbers */
+struct cpu_to_drc_index_struct {
+ u32 thread_index;
+ u32 ret;
+};
+
+static int cpu_to_drc_index_cb(struct of_drc_info *drc, void *idata,
+ void *not_used, int *ret_code)
+{
+ struct cpu_to_drc_index_struct *cdata = idata;
+ int ret = 0;
+
+ if (cdata->thread_index < drc->last_drc_index) {
+ cdata->ret = drc->drc_index_start +
+ (cdata->thread_index * drc->sequential_inc);
+ ret = 1;
+ }
+ (*ret_code) = ret;
+ return ret;
+}
+
static u32 cpu_to_drc_index(int cpu)
{
struct device_node *dn = NULL;
@@ -51,30 +71,14 @@ static u32 cpu_to_drc_index(int cpu)
thread_index = cpu_core_index_of_thread(cpu);
if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
- struct property *info = NULL;
- 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;
+ struct cpu_to_drc_index_struct cdata = {
+ thread_index, 0 };
- value = info->value;
- num_set_entries = of_read_number(value++, 1);
-
- for (j = 0; j < num_set_entries; j++) {
-
- of_read_drc_info_cell(&info, &value, &drc);
- if (strncmp(drc.drc_type, "CPU", 3))
- goto err;
-
- if (thread_index < drc.last_drc_index)
- break;
- }
-
- ret = drc.drc_index_start + (thread_index * drc.sequential_inc);
+ rc = drc_info_parser(dn, &cpu_to_drc_index_cb,
+ "CPU", &cdata);
+ if (rc < 0)
+ goto err_of_node_put;
+ ret = cdata.ret;
} else {
const __be32 *indexes;
@@ -100,11 +104,33 @@ static u32 cpu_to_drc_index(int cpu)
return ret;
}
+struct drc_index_to_cpu_struct {
+ u32 drc_index;
+ u32 thread_index;
+ u32 cpu;
+};
+
+static int drc_index_to_cpu_cb(struct of_drc_info *drc,
+ void *idata, void *not_used, int *ret_code)
+{
+ struct drc_index_to_cpu_struct *cdata = idata;
+
+ if (cdata->drc_index > drc->last_drc_index) {
+ cdata->cpu += drc->num_sequential_elems;
+ } else {
+ cdata->cpu += ((cdata->drc_index - drc->drc_index_start) /
+ drc->sequential_inc);
+ cdata->thread_index = cpu_first_thread_of_core(cdata->cpu);
+ }
+ (*ret_code) = 0;
+ return 0;
+}
+
static int drc_index_to_cpu(u32 drc_index)
{
struct device_node *dn = NULL;
const int *indexes;
- int thread_index = 0, cpu = 0;
+ int thread_index = 0;
int rc = 1;
dn = of_find_node_by_path("/cpus");
@@ -112,36 +138,13 @@ static int drc_index_to_cpu(u32 drc_index)
goto err;
if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
- struct property *info = NULL;
- 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 = info->value;
- num_set_entries = of_read_number(value++, 1);
-
- for (j = 0; j < num_set_entries; j++) {
+ struct drc_index_to_cpu_struct cdata = {
+ drc_index, 0, 0 };
- of_read_drc_info_cell(&info, &value, &drc);
- if (strncmp(drc.drc_type, "CPU", 3))
- goto err;
+ rc = drc_info_parser(dn, &drc_index_to_cpu_cb,
+ "CPU", &cdata);
+ thread_index = cdata.thread_index;
- if (drc_index > drc.last_drc_index) {
- cpu += drc.num_sequential_elems;
- continue;
- }
- cpu += ((drc_index - drc.drc_index_start) /
- drc.sequential_inc);
-
- thread_index = cpu_first_thread_of_core(cpu);
- rc = 0;
- break;
- }
} else {
unsigned long int i;
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