Commit a15e0d6a authored by Kajol Jain's avatar Kajol Jain Committed by Michael Ellerman
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powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain... 


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

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: default avatarAthira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: default avatarKajol Jain <kjain@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230729073455.7918-10-kjain@linux.ibm.com
parent ab7e9912

arch/powerpc/perf/hv-gpci.c

+159 −1
Original line number Diff line number Diff line
@@ -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);