The hcall H_GET_PERF_COUNTER_INFO with counter request value as
AFFINITY_DOMAIN_INFORMATION_BY_PARTITION(0XB1), can be used to get
the system affinity domain via partition information. To expose the system
affinity domain via partition information, patch adds sysfs file called
"affinity_domain_via_partition" to the "/sys/devices/hv_gpci/interface/"
of hv_gpci pmu driver.
Add new entry for AFFINITY_DOMAIN_VIA_PAR in sysinfo_counter_request
array, which points to the counter request value
"affinity_domain_via_partition" in hv-gpci.c file. Also add a
new function called "affinity_domain_via_partition_result_parse" to parse
the hcall result and store it in output buffer.
The affinity_domain_via_partition sysfs file is only available for power10
and above platforms. Add a macro called
INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR, which points to the index of NULL
placeholder, for affinity_domain_via_partition attribute in
interface_attrs array. Also updated the value of INTERFACE_NULL_ATTR
macro in hv-gpci.c file.
Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
---
arch/powerpc/perf/hv-gpci.c | 160 +++++++++++++++++++++++++++++++++++-
1 file changed, 159 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index 326b758df7c8..f2fff166290b 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -107,7 +107,8 @@ static ssize_t cpumask_show(struct device *dev,
#define INTERFACE_PROCESSOR_CONFIG_ATTR 7
#define INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR 8
#define INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR 9
-#define INTERFACE_NULL_ATTR 10
+#define INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR 10
+#define INTERFACE_NULL_ATTR 11
/* Counter request value to retrieve system information */
enum {
@@ -115,6 +116,7 @@ enum {
PROCESSOR_CONFIG,
AFFINITY_DOMAIN_VIA_VP, /* affinity domain via virtual processor */
AFFINITY_DOMAIN_VIA_DOM, /* affinity domain via domain */
+ AFFINITY_DOMAIN_VIA_PAR, /* affinity domain via partition */
};
static int sysinfo_counter_request[] = {
@@ -122,6 +124,7 @@ static int sysinfo_counter_request[] = {
[PROCESSOR_CONFIG] = 0x90,
[AFFINITY_DOMAIN_VIA_VP] = 0xA0,
[AFFINITY_DOMAIN_VIA_DOM] = 0xB0,
+ [AFFINITY_DOMAIN_VIA_PAR] = 0xB1,
};
static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE])
__aligned(sizeof(uint64_t));
@@ -458,6 +461,152 @@ static ssize_t affinity_domain_via_domain_show(struct
device *dev, struct device
return ret;
}
+static void affinity_domain_via_partition_result_parse(int returned_values,
+ int element_size, char *buf, size_t *last_element,
+ size_t *n, struct hv_gpci_request_buffer *arg)
+{
+ size_t i = 0, j = 0;
+ size_t k, l, m;
+ uint16_t total_affinity_domain_ele, size_of_each_affinity_domain_ele;
+
+ /*
+ * hcall H_GET_PERF_COUNTER_INFO populates the 'returned_values'
+ * to show the total number of counter_value array elements
+ * returned via hcall.
+ * Unlike other request types, the data structure returned by this
+ * request is variable-size. For this counter request type,
+ * hcall populates 'cv_element_size' corresponds to minimum size of
+ * the structure returned i.e; the size of the structure with no domain
+ * information. Below loop go through all counter_value array
+ * to determine the number and size of each domain array element and
+ * add it to the output buffer.
+ */
+ while (i < returned_values) {
+ k = j;
+ for (; k < j + element_size; k++)
+ *n += sprintf(buf + *n, "%02x", (u8)arg->bytes[k]);
+ *n += sprintf(buf + *n, "\n");
+
+ total_affinity_domain_ele = (u8)arg->bytes[k - 2] << 8 |
(u8)arg->bytes[k - 3];
+ size_of_each_affinity_domain_ele = (u8)arg->bytes[k] << 8 |
(u8)arg->bytes[k - 1];
+
+ for (l = 0; l < total_affinity_domain_ele; l++) {
+ for (m = 0; m < size_of_each_affinity_domain_ele; m++) {
+ *n += sprintf(buf + *n, "%02x",
(u8)arg->bytes[k]);
+ k++;
+ }
+ *n += sprintf(buf + *n, "\n");
+ }
+
+ *n += sprintf(buf + *n, "\n");
+ i++;
+ j = k;
+ }
+
+ *last_element = k;
+}
+
+static ssize_t affinity_domain_via_partition_show(struct device *dev, struct
device_attribute *attr,
+ char *buf)
+{
+ struct hv_gpci_request_buffer *arg;
+ unsigned long ret;
+ size_t n = 0;
+ size_t last_element = 0;
+ u32 starting_index;
+
+ arg = (void *)get_cpu_var(hv_gpci_reqb);
+ memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+ /*
+ * Pass the counter request value 0xB1 corresponds to counter request
+ * type 'Affinity_domain_information_by_partition',
+ * to retrieve the system affinity domain by partition information.
+ * starting_index value refers to the starting hardware
+ * processor index.
+ */
+ arg->params.counter_request =
cpu_to_be32(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_PAR]);
+ arg->params.starting_index = cpu_to_be32(0);
+
+ ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
+ virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
+
+ if (!ret)
+ goto parse_result;
+
+ /*
+ * ret value as 'H_PARAMETER' implies that the current buffer size
+ * can't accommodate all the information, and a partial buffer
+ * returned. To handle that, we need to make 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) {
+ affinity_domain_via_partition_result_parse(
+ be16_to_cpu(arg->params.returned_values) - 1,
+ be16_to_cpu(arg->params.cv_element_size), buf,
+ &last_element, &n, arg);
+
+ if (n >= PAGE_SIZE) {
+ put_cpu_var(hv_gpci_reqb);
+ pr_debug("System information exceeds PAGE_SIZE\n");
+ return -EFBIG;
+ }
+
+ /*
+ * Since the starting index value is part of counter_value
+ * buffer elements, use the starting_index value in the last
+ * element and add 1 to make subsequent hcalls.
+ */
+ starting_index = (u8)arg->bytes[last_element] << 8 |
+ (u8)arg->bytes[last_element + 1];
+
+ memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+ arg->params.counter_request = cpu_to_be32(
+
sysinfo_counter_request[AFFINITY_DOMAIN_VIA_PAR]);
+ arg->params.starting_index = cpu_to_be32(starting_index);
+
+ ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
+ virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
+
+ if (ret && (ret != H_PARAMETER))
+ goto out;
+ }
+
+parse_result:
+ affinity_domain_via_partition_result_parse(
+ be16_to_cpu(arg->params.returned_values),
+ be16_to_cpu(arg->params.cv_element_size),
+ buf, &last_element, &n, arg);
+
+ put_cpu_var(hv_gpci_reqb);
+ return n;
+
+out:
+ put_cpu_var(hv_gpci_reqb);
+
+ /*
+ * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL',
+ * which means that the current buffer size cannot accommodate
+ * all the information and a partial buffer returned.
+ * hcall fails incase of ret value other than H_SUCCESS or H_PARAMETER.
+ *
+ * ret value as H_AUTHORITY implies that partition is not permitted to
retrieve
+ * performance information, and required to set
+ * "Enable Performance Information Collection" option.
+ */
+ if (ret == H_AUTHORITY)
+ return -EPERM;
+
+ /*
+ * hcall can fail with other possible ret value like
H_PRIVILEGE/H_HARDWARE
+ * because of invalid buffer-length/address or due to some hardware
+ * error.
+ */
+ return -EIO;
+}
+
static DEVICE_ATTR_RO(kernel_version);
static DEVICE_ATTR_RO(cpumask);
@@ -494,6 +643,11 @@ static struct attribute *interface_attrs[] = {
* attribute, set in init function if applicable.
*/
NULL,
+ /*
+ * This NULL is a placeholder for the affinity_domain_via_partition
+ * attribute, set in init function if applicable.
+ */
+ NULL,
NULL,
};
@@ -755,6 +909,10 @@ static struct device_attribute
*sysinfo_device_attr_create(int
attr->attr.name = "affinity_domain_via_domain";
attr->show = affinity_domain_via_domain_show;
break;
+ case INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR:
+ attr->attr.name = "affinity_domain_via_partition";
+ attr->show = affinity_domain_via_partition_show;
+ break;
}
} else
pr_devel("hcall failed, with error: 0x%lx\n", ret);
--
2.31.1
