From: Kajol Jain Date: Sat, 29 Jul 2023 07:34:52 +0000 (+0530) Subject: powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via... X-Git-Tag: v6.6-pxa1908~412^2~78 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=a69a57cac1ec8995bb0b571dfccc3fe2f046719a;p=linux.git powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via domain information 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 new entry for AFFINITY_DOMAIN_VIA_DOM in sysinfo_counter_request array, which points to the counter request value "affinity_domain_via_domain" in hv-gpci.c 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.c file. Reviewed-by: Athira Rajeev Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20230729073455.7918-8-kjain@linux.ibm.com --- diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c index de2e1aee9e2c..3f765cdf9298 100644 --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -106,19 +106,22 @@ static ssize_t cpumask_show(struct device *dev, #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 /* Counter request value to retrieve system information */ enum { PROCESSOR_BUS_TOPOLOGY, PROCESSOR_CONFIG, AFFINITY_DOMAIN_VIA_VP, /* affinity domain via virtual processor */ + AFFINITY_DOMAIN_VIA_DOM, /* affinity domain via domain */ }; static int sysinfo_counter_request[] = { [PROCESSOR_BUS_TOPOLOGY] = 0xD0, [PROCESSOR_CONFIG] = 0x90, [AFFINITY_DOMAIN_VIA_VP] = 0xA0, + [AFFINITY_DOMAIN_VIA_DOM] = 0xB0, }; static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t)); @@ -389,6 +392,72 @@ out: 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(sysinfo_counter_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(sysinfo_counter_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); @@ -420,6 +489,11 @@ 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, }; @@ -674,6 +748,10 @@ static struct device_attribute *sysinfo_device_attr_create(int 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; } } else pr_devel("hcall failed, with error: 0x%lx\n", ret);