iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via virtual processor information

Browse Source 
The hcall H_GET_PERF_COUNTER_INFO with counter request value as
AFFINITY_DOMAIN_INFORMATION_BY_VIRTUAL_PROCESSOR(0XA0), can be used to get
the system affinity domain via virtual processor information. To expose
the system affinity domain via virtual processor information, patch adds
sysfs file called "affinity_domain_via_virtual_processor" to the
"/sys/devices/hv_gpci/interface/" of hv_gpci pmu driver.

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

Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230729073455.7918-6-kjain@linux.ibm.com
This commit is contained in:
Kajol Jain 2023-07-29 13:04:50 +05:30 committed by Michael Ellerman
parent 3255171d3e
commit 71a7ccb478
1 changed files with 84 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
arch/powerpc/perf/hv-gpci.c
View File

@ -105,17 +105,20 @@ static ssize_t cpumask_show(struct device *dev,
/* 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 INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR 8
#define INTERFACE_NULL_ATTR 9
/* Counter request value to retrieve system information */
enum {
PROCESSOR_BUS_TOPOLOGY,
PROCESSOR_CONFIG
PROCESSOR_CONFIG,
AFFINITY_DOMAIN_VIA_VP, /* affinity domain via virtual processor */
};
static int sysinfo_counter_request[] = {
[PROCESSOR_BUS_TOPOLOGY] = 0xD0,
[PROCESSOR_CONFIG] = 0x90,
[AFFINITY_DOMAIN_VIA_VP] = 0xA0,
};
static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));
@ -316,6 +319,76 @@ out:
return ret;
}
static ssize_t affinity_domain_via_virtual_processor_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 0xA0 corresponds to request
* type 'Affinity_domain_information_by_virutal_processor',
* to retrieve the system affinity domain information.
* starting_index value refers to the starting hardware
* processor index.
*/
ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_VP],
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 secondary index to retrieve additional (missing) data.
* Below loop do subsequent hcalls with next secondary 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 and secondary index type is part of the
* counter_value buffer elements, use the starting index value in the
* last array element as subsequent starting index, and use secondary index
* value in the last array element plus 1 as subsequent secondary index.
* For counter request '0xA0', starting index points to partition id
* and secondary index points to corresponding virtual processor index.
*/
u32 starting_index = arg->bytes[last_element + 1] + (arg->bytes[last_element] << 8);
u16 secondary_index = arg->bytes[last_element + 3] +
(arg->bytes[last_element + 2] << 8) + 1;
memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_VP],
starting_index, secondary_index, 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);
@ -342,6 +415,11 @@ static struct attribute *interface_attrs[] = {
* attribute, set in init function if applicable.
*/
NULL,
/*
* This NULL is a placeholder for the affinity_domain_via_virtual_processor
* attribute, set in init function if applicable.
*/
NULL,
NULL,
};
@ -592,6 +670,10 @@ static struct device_attribute *sysinfo_device_attr_create(int
attr->attr.name = "processor_config";
attr->show = processor_config_show;
break;
case INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR:
attr->attr.name = "affinity_domain_via_virtual_processor";
attr->show = affinity_domain_via_virtual_processor_show;
break;
}
} else
pr_devel("hcall failed, with error: 0x%lx\n", ret);