The hcall H_GET_PERF_COUNTER_INFO with counter request value as
AFFINITY_DOMAIN_INFORMATION_BY_DOMAIN(0XB0), can be used to get
the system affinity domain via domain information. To expose the system
affinity domain via domain information, patch adds sysfs file called
"affinity_domain_via_domain" to the "/sys/devices/hv_gpci/interface/"
of hv_gpci pmu driver.

Add macro for AFFINITY_DOMAIN_VIA_DOM, which points to the counter
request value for "affinity_domain_via_domain" in hv-gpci.h file.

The affinity_domain_via_domain sysfs file is only available for power10
and above platforms. Add a macro called
INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR, which points to the index of NULL
placeholder, for affinity_domain_via_domain attribute in interface_attrs
array. Also updated the value of INTERFACE_NULL_ATTR macro in hv-gpci.h
file.

Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
---
 arch/powerpc/perf/hv-gpci.c | 77 +++++++++++++++++++++++++++++++++++++
 arch/powerpc/perf/hv-gpci.h |  4 +-
 2 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index cac726f06221..b18f6f2d15b0 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -372,6 +372,71 @@ static ssize_t 
affinity_domain_via_virtual_processor_show(struct device *dev,
        return ret;
 }
 
+static ssize_t affinity_domain_via_domain_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 0xB0 corresponds to request
+        * type 'Affinity_domain_information_by_domain',
+        * to retrieve the system affinity domain information.
+        * starting_index value refers to the starting hardware
+        * processor index.
+        */
+       ret = systeminfo_gpci_request(AFFINITY_DOMAIN_VIA_DOM, 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 value is part of counter_value
+                * buffer elements, use the starting index value in the last
+                * element and add 1 to make subsequent hcalls.
+                */
+               u32 starting_index = arg->bytes[last_element + 1] +
+                       (arg->bytes[last_element] << 8) + 1;
+
+               memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+               ret = systeminfo_gpci_request(AFFINITY_DOMAIN_VIA_DOM,
+                                       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);
 
@@ -403,6 +468,11 @@ static struct attribute *interface_attrs[] = {
         * attribute, set in init function if applicable.
         */
        NULL,
+       /*
+        * This NULL is a placeholder for the affinity_domain_via_domain
+        * attribute, set in init function if applicable.
+        */
+       NULL,
        NULL,
 };
 
@@ -639,6 +709,10 @@ static void sysinfo_device_attr_create(int 
sysinfo_interface_group_index)
                attr->attr.name = "affinity_domain_via_virtual_processor";
                attr->show = affinity_domain_via_virtual_processor_show;
        break;
+       case INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR:
+               attr->attr.name = "affinity_domain_via_domain";
+               attr->show = affinity_domain_via_domain_show;
+       break;
        }
 
        attr->attr.mode = 0444;
@@ -658,6 +732,9 @@ static void add_sysinfo_interface_files(void)
         * interface_attrs attribute array
         */
        sysinfo_device_attr_create(INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR);
+
+       /* Add affinity_domain_via_domain attribute in the interface_attrs 
attribute array */
+       sysinfo_device_attr_create(INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR);
 }
 
 static int hv_gpci_init(void)
diff --git a/arch/powerpc/perf/hv-gpci.h b/arch/powerpc/perf/hv-gpci.h
index c88599fbcaa5..f01c4716ac33 100644
--- a/arch/powerpc/perf/hv-gpci.h
+++ b/arch/powerpc/perf/hv-gpci.h
@@ -27,12 +27,14 @@ enum {
 #define PROCESSOR_BUS_TOPOLOGY 0XD0
 #define PROCESSOR_CONFIG       0X90
 #define AFFINITY_DOMAIN_VIA_VP 0xA0 /* affinity domain via virtual processor */
+#define AFFINITY_DOMAIN_VIA_DOM        0xB0 /* affinity domain via domain */
 
 /* Interface attribute array index to store system information */
 #define INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR  6
 #define INTERFACE_PROCESSOR_CONFIG_ATTR                7
 #define INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR  8
-#define INTERFACE_NULL_ATTR                    9
+#define INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR 9
+#define INTERFACE_NULL_ATTR                    10
 
 #define REQUEST_FILE "../hv-gpci-requests.h"
 #define NAME_LOWER hv_gpci
-- 
2.35.3

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