[PATCH 03/10] powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show processor config information
Kajol Jain
kjain at linux.ibm.com
Fri Jun 9 21:39:54 AEST 2023
The hcall H_GET_PERF_COUNTER_INFO with counter request value as
PROCESSOR_CONFIG(0X90), can be used to get the system
processor configuration information. To expose the system
processor config information, patch adds sysfs file called
"processor_config" to the "/sys/devices/hv_gpci/interface/"
of hv_gpci pmu driver.
Add macro for PROCESSOR_CONFIG counter request value in hv-gpci.h file.
Also add a new function called "sysinfo_device_attr_create",
which will create and add required device attribute to the
interface_attrs array.
The processor_config sysfs file is only available for power10
and above platforms. Add a new macro called
INTERFACE_PROCESSOR_CONFIG_ATTR, which points to the index of
NULL placefolder, for processor_config attribute in the interface_attrs
array. Also add macro INTERFACE_NULL_ATTR which points to index of NULL
attribute in interface_attrs array.
Signed-off-by: Kajol Jain <kjain at linux.ibm.com>
---
arch/powerpc/perf/hv-gpci.c | 110 +++++++++++++++++++++++++++++++++---
arch/powerpc/perf/hv-gpci.h | 5 +-
2 files changed, 107 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index bca24725699e..c9fe74373e5f 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -237,6 +237,72 @@ static ssize_t processor_bus_topology_show(struct device *dev, struct device_att
return ret;
}
+static ssize_t processor_config_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct hv_gpci_request_buffer *arg;
+ unsigned long ret;
+ size_t n = 0;
+
+ arg = (void *)get_cpu_var(hv_gpci_reqb);
+ memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+ /*
+ * Pass the counter request value 0x90 corresponds to request
+ * type 'Processor_config', to retrieve
+ * the system processor information.
+ * starting_index value implies the starting hardware
+ * processor index.
+ */
+ ret = systeminfo_gpci_request(PROCESSOR_CONFIG, 0, 0, buf, &n, arg);
+
+ if (!ret)
+ return n;
+
+ if (ret != H_PARAMETER)
+ goto out;
+
+ /*
+ * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
+ * implies that buffer can't accommodate all information, and a partial buffer
+ * returned. To handle that, we need to take subsequent requests
+ * with next starting index to retrieve additional (missing) data.
+ * Below loop do subsequent hcalls with next starting index and add it
+ * to buffer util we get all the information.
+ */
+ while (ret == H_PARAMETER) {
+ int returned_values = be16_to_cpu(arg->params.returned_values);
+ int elementsize = be16_to_cpu(arg->params.cv_element_size);
+ int last_element = (returned_values - 1) * elementsize;
+
+ /*
+ * Since the starting index is part of counter_value
+ * buffer elements, use the starting index value in the last
+ * element and add 1 to subsequent hcalls.
+ */
+ u32 starting_index = arg->bytes[last_element + 3] +
+ (arg->bytes[last_element + 2] << 8) +
+ (arg->bytes[last_element + 1] << 16) +
+ (arg->bytes[last_element] << 24) + 1;
+
+ memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+ ret = systeminfo_gpci_request(PROCESSOR_CONFIG, starting_index, 0, buf, &n, arg);
+
+ if (!ret)
+ return n;
+
+ if (ret != H_PARAMETER)
+ goto out;
+ }
+
+ return n;
+
+out:
+ put_cpu_var(hv_gpci_reqb);
+ return ret;
+}
+
static DEVICE_ATTR_RO(kernel_version);
static DEVICE_ATTR_RO(cpumask);
@@ -258,6 +324,11 @@ static struct attribute *interface_attrs[] = {
* attribute, set in init function if applicable.
*/
NULL,
+ /*
+ * This NULL is a placeholder for the processor_config
+ * attribute, set in init function if applicable.
+ */
+ NULL,
NULL,
};
@@ -463,21 +534,46 @@ static int hv_gpci_cpu_hotplug_init(void)
ppc_hv_gpci_cpu_offline);
}
-static void add_sysinfo_interface_files(void)
+static void sysinfo_device_attr_create(int sysinfo_interface_group_index)
{
- struct device_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+ struct device_attribute *attr;
+ if (sysinfo_interface_group_index < INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR ||
+ sysinfo_interface_group_index >= INTERFACE_NULL_ATTR) {
+ pr_info("Wrong interface group index for system information\n");
+ return;
+ }
+
+ attr = kzalloc(sizeof(*attr), GFP_KERNEL);
if (!attr) {
- pr_info("Memory allocation failed for processor_bug_topology interface file\n");
+ pr_info("Mem allocation failed, sysinfo index:%d\n", sysinfo_interface_group_index);
return;
}
- /* Add processor_bus_topology attribute in the interface_attrs attribute array */
sysfs_attr_init(&attr->attr);
- attr->attr.name = "processor_bug_topology";
+
+ switch (sysinfo_interface_group_index) {
+ case INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR:
+ attr->attr.name = "processor_bug_topology";
+ attr->show = processor_bus_topology_show;
+ break;
+ case INTERFACE_PROCESSOR_CONFIG_ATTR:
+ attr->attr.name = "processor_config";
+ attr->show = processor_config_show;
+ break;
+ }
+
attr->attr.mode = 0444;
- attr->show = processor_bus_topology_show;
- interface_attrs[INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR] = &attr->attr;
+ interface_attrs[sysinfo_interface_group_index] = &attr->attr;
+}
+
+static void add_sysinfo_interface_files(void)
+{
+ /* Add processor_bus_topology attribute in the interface_attrs attribute array */
+ sysinfo_device_attr_create(INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR);
+
+ /* Add processor_config attribute in the interface_attrs attribute array */
+ sysinfo_device_attr_create(INTERFACE_PROCESSOR_CONFIG_ATTR);
}
static int hv_gpci_init(void)
diff --git a/arch/powerpc/perf/hv-gpci.h b/arch/powerpc/perf/hv-gpci.h
index ff76bc010823..0d324a7c684b 100644
--- a/arch/powerpc/perf/hv-gpci.h
+++ b/arch/powerpc/perf/hv-gpci.h
@@ -24,10 +24,13 @@ enum {
};
/* Counter request value to retrieve system information */
-#define PROCESSOR_BUS_TOPOLOGY 0XD0
+#define PROCESSOR_BUS_TOPOLOGY 0XD0
+#define PROCESSOR_CONFIG 0X90
/* Interface attribute array index to store system information */
#define INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR 6
+#define INTERFACE_PROCESSOR_CONFIG_ATTR 7
+#define INTERFACE_NULL_ATTR 8
#define REQUEST_FILE "../hv-gpci-requests.h"
#define NAME_LOWER hv_gpci
--
2.35.3
More information about the Linuxppc-dev
mailing list