From: Kajol Jain Date: Sat, 29 Jul 2023 07:34:54 +0000 (+0530) Subject: powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via... X-Git-Tag: v6.6-pxa1908~412^2~76 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=a15e0d6a6929e737f71578ed4b05531fed5a96e8;p=linux.git 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: Athira Rajeev Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20230729073455.7918-10-kjain@linux.ibm.com --- diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c index 3f765cdf9298..39dbe6b348df 100644 --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -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 @@ out: 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);