From 71a7ccb478fcfe1495bcabf4972d859b24264df7 Mon Sep 17 00:00:00 2001 From: Kajol Jain Date: Sat, 29 Jul 2023 13:04:50 +0530 Subject: powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via virtual processor information 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 Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20230729073455.7918-6-kjain@linux.ibm.com --- arch/powerpc/perf/hv-gpci.c | 86 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 84 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/perf') diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c index 73f2ed42705a..de2e1aee9e2c 100644 --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -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); -- cgit v1.2.3