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powerpc/pseries: Add cpu DLPAR support for drc-info property

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Older firmwares provided information about Dynamic Reconfig
Connectors (DRC) through several device tree properties, namely
ibm,drc-types, ibm,drc-indexes, ibm,drc-names, and
ibm,drc-power-domains. New firmwares have the ability to present this
same information in a much condensed format through a device tree
property called ibm,drc-info.

The existing cpu DLPAR hotplug code only understands the older DRC
property format when validating the drc-index of a cpu during a
hotplug add. This updates those code paths to use the ibm,drc-info
property, when present, instead for validation.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573449697-5448-4-git-send-email-tyreld@linux.ibm.com
This commit is contained in:
Tyrel Datwyler 2019-11-10 23:21:30 -06:00 committed by Michael Ellerman
parent 775fa495af
commit b015f6bc95
1 changed files with 114 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

131
arch/powerpc/platforms/pseries/hotplug-cpu.c
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@ -465,17 +465,67 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
return found;
}
static bool drc_info_valid_index(struct device_node *parent, u32 drc_index)
{
struct property *info;
struct of_drc_info drc;
const __be32 *value;
u32 index;
int count, i, j;
info = of_find_property(parent, "ibm,drc-info", NULL);
if (!info)
return false;
value = of_prop_next_u32(info, NULL, &count);
/* First value of ibm,drc-info is number of drc-info records */
if (value)
value++;
else
return false;
for (i = 0; i < count; i++) {
if (of_read_drc_info_cell(&info, &value, &drc))
return false;
if (strncmp(drc.drc_type, "CPU", 3))
break;
if (drc_index > drc.last_drc_index)
continue;
index = drc.drc_index_start;
for (j = 0; j < drc.num_sequential_elems; j++) {
if (drc_index == index)
return true;
index += drc.sequential_inc;
}
}
return false;
}
static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
{
bool found = false;
int rc, index;
index = 0;
if (of_find_property(parent, "ibm,drc-info", NULL))
return drc_info_valid_index(parent, drc_index);
/* 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.
*/
index = 1;
while (!found) {
u32 drc;
rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
index++, &drc);
if (rc)
break;
@ -718,18 +768,51 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
return rc;
}
static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
static int find_drc_info_cpus_to_add(struct device_node *cpus,
struct property *info,
u32 *cpu_drcs, u32 cpus_to_add)
{
struct of_drc_info drc;
const __be32 *value;
u32 count, drc_index;
int cpus_found = 0;
int i, j;
if (!info)
return -1;
value = of_prop_next_u32(info, NULL, &count);
if (value)
value++;
for (i = 0; i < count; i++) {
of_read_drc_info_cell(&info, &value, &drc);
if (strncmp(drc.drc_type, "CPU", 3))
break;
drc_index = drc.drc_index_start;
for (j = 0; j < drc.num_sequential_elems; j++) {
if (dlpar_cpu_exists(cpus, drc_index))
continue;
cpu_drcs[cpus_found++] = drc_index;
if (cpus_found == cpus_to_add)
return cpus_found;
drc_index += drc.sequential_inc;
}
}
return cpus_found;
}
static int find_drc_index_cpus_to_add(struct device_node *cpus,
u32 *cpu_drcs, u32 cpus_to_add)
{
struct device_node *parent;
int cpus_found = 0;
int index, rc;
parent = of_find_node_by_path("/cpus");
if (!parent) {
pr_warn("Could not find CPU root node in device tree\n");
kfree(cpu_drcs);
return -1;
}
u32 drc_index;
/* Search the ibm,drc-indexes array for possible CPU drcs to
* add. Note that the format of the ibm,drc-indexes array is
@ -738,25 +821,25 @@ static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
*/
index = 1;
while (cpus_found < cpus_to_add) {
u32 drc;
rc = of_property_read_u32_index(cpus, "ibm,drc-indexes",
index++, &drc_index);
rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
index++, &drc);
if (rc)
break;
if (dlpar_cpu_exists(parent, drc))
if (dlpar_cpu_exists(cpus, drc_index))
continue;
cpu_drcs[cpus_found++] = drc;
cpu_drcs[cpus_found++] = drc_index;
}
of_node_put(parent);
return cpus_found;
}
static int dlpar_cpu_add_by_count(u32 cpus_to_add)
{
struct device_node *parent;
struct property *info;
u32 *cpu_drcs;
int cpus_added = 0;
int cpus_found;
@ -768,7 +851,21 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add)
if (!cpu_drcs)
return -EINVAL;
cpus_found = find_dlpar_cpus_to_add(cpu_drcs, cpus_to_add);
parent = of_find_node_by_path("/cpus");
if (!parent) {
pr_warn("Could not find CPU root node in device tree\n");
kfree(cpu_drcs);
return -1;
}
info = of_find_property(parent, "ibm,drc-info", NULL);
if (info)
cpus_found = find_drc_info_cpus_to_add(parent, info, cpu_drcs, cpus_to_add);
else
cpus_found = find_drc_index_cpus_to_add(parent, cpu_drcs, cpus_to_add);
of_node_put(parent);
if (cpus_found < cpus_to_add) {
pr_warn("Failed to find enough CPUs (%d of %d) to add\n",
cpus_found, cpus_to_add);