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

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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.

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/20230729073455.7918-10-kjain@linux.ibm.com
This commit is contained in:
Kajol Jain 2023-07-29 13:04:54 +05:30 committed by Michael Ellerman
parent ab7e991286
commit a15e0d6a69
1 changed files with 159 additions and 1 deletions
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160
arch/powerpc/perf/hv-gpci.c
View file

@ -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,
};
@ -752,6 +906,10 @@ 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);