xml.cc

/*************************************************************************
 * Copyright (c) 2019-2022, NVIDIA CORPORATION. All rights reserved.
 * Modifications Copyright (c) 2019-2022 Advanced Micro Devices, Inc. All rights reserved.
 *
 * See LICENSE.txt for license information
 ************************************************************************/

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include "check.h"
#include "nvmlwrap.h"
#include "xml.h"
#include "rocm_smi_wrap.h"
#include "archinfo.h"

namespace sccl {
namespace hardware {
namespace topology {
namespace topo {

/**************/
/* XML Struct */
/* Functions  */
/**************/

scclResult_t xmlGetAttrIndex(struct scclXmlNode* node, const char* attrName, int* index) {
    *index           = -1;
    const int nAttrs = node->nAttrs;
    for(int a = 0; a < nAttrs; a++) {
        if(strncmp(node->attrs[a].key, attrName, MAX_STR_LEN) == 0) {
            *index = a;
            return scclSuccess;
        }
    }
    return scclSuccess;
}

scclResult_t xmlGetAttr(struct scclXmlNode* node, const char* attrName, const char** value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    *value = index == -1 ? NULL : node->attrs[index].value;
    return scclSuccess;
}

scclResult_t xmlGetAttrStr(struct scclXmlNode* node, const char* attrName, const char** value) {
    SCCLCHECK(xmlGetAttr(node, attrName, value));
    if(*value == NULL) {
        WARN("Attribute %s of node %s not found", attrName, node->name);
        return scclInternalError;
    }
    return scclSuccess;
}
/**
 * 从XML节点属性中获取整数值
 *
 * @param node XML节点指针
 * @param attrName 属性名称
 * @param value 输出参数，用于存储解析后的整数值
 * @return 成功返回scclSuccess，失败返回错误码
 *
 * @note 该函数会先获取属性字符串值，然后将其转换为整数
 */
scclResult_t xmlGetAttrInt(struct scclXmlNode* node, const char* attrName, int* value) {
    const char* str;
    SCCLCHECK(xmlGetAttrStr(node, attrName, &str));
    *value = strtol(str, NULL, 0);
    return scclSuccess;
}

/**
 * 从XML节点获取整数属性值，若属性不存在则返回默认值
 *
 * @param node XML节点指针
 * @param attrName 要获取的属性名
 * @param value 输出参数，用于存储获取到的整数值
 * @param defaultValue 当属性不存在时返回的默认值
 * @return scclResult_t 操作结果，成功返回scclSuccess
 */
scclResult_t xmlGetAttrIntDefault(struct scclXmlNode* node, const char* attrName, int* value, int defaultValue) {
    const char* str;
    SCCLCHECK(xmlGetAttr(node, attrName, &str));
    *value = str ? strtol(str, NULL, 0) : defaultValue;
    return scclSuccess;
}

// Only set values if not already set
/**
 * @brief 初始化XML节点的整数属性
 *
 * 如果属性不存在则创建并设置值，已存在则不修改
 *
 * @param node XML节点指针
 * @param attrName 属性名称
 * @param value 要设置的整数值
 * @return scclResult_t 返回操作结果(scclSuccess表示成功)
 */
scclResult_t xmlInitAttrInt(struct scclXmlNode* node, const char* attrName, const int value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        snprintf(node->attrs[index].value, MAX_STR_LEN, "%d", value);
    }
    return scclSuccess;
}

/**
 * 初始化XML节点的uint64类型属性
 *
 * @param node XML节点指针
 * @param attrName 属性名称
 * @param value 要设置的属性值(16进制格式)
 * @return 成功返回scclSuccess，失败返回错误码
 *
 * 功能：为指定XML节点添加或更新一个uint64类型的属性，属性值将以"0x%lx"格式存储
 * 注意：如果属性已存在，则直接使用新值覆盖原有值
 */
scclResult_t xmlInitAttrUint64(struct scclXmlNode* node, const char* attrName, const uint64_t value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        snprintf(node->attrs[index].value, MAX_STR_LEN, "0x%lx", value);
    }
    return scclSuccess;
}

scclResult_t xmlGetAttrFloat(struct scclXmlNode* node, const char* attrName, float* value) {
    const char* str;
    SCCLCHECK(xmlGetAttrStr(node, attrName, &str));
    *value = strtof(str, NULL);
    return scclSuccess;
}

scclResult_t xmlInitAttrFloat(struct scclXmlNode* node, const char* attrName, const float value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        snprintf(node->attrs[index].value, MAX_STR_LEN, "%f", value);
    }
    return scclSuccess;
}

scclResult_t xmlFindTag(struct scclXml* xml, const char* tagName, struct scclXmlNode** node) {
    *node = NULL;
    for(int i = 0; i < xml->maxIndex; i++) {
        struct scclXmlNode* n = xml->nodes + i;
        if(strcmp(n->name, tagName) == 0) {
            *node = n;
            return scclSuccess;
        }
    }
    return scclSuccess;
}

scclResult_t xmlFindTagKv(struct scclXml* xml, const char* tagName, struct scclXmlNode** node, const char* attrName, const char* attrValue) {
    *node = NULL;
    for(int i = 0; i < xml->maxIndex; i++) {
        struct scclXmlNode* n = xml->nodes + i;
        if(strcmp(n->name, tagName) == 0) {
            const char* value;
            SCCLCHECK(xmlGetAttr(n, attrName, &value));
            if(value && strcmp(value, attrValue) == 0) {
                *node = n;
                return scclSuccess;
            }
        }
    }
    return scclSuccess;
}

scclResult_t xmlSetAttr(struct scclXmlNode* node, const char* attrName, const char* value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        node->attrs[index].key[MAX_STR_LEN] = '\0';
    }
    strncpy(node->attrs[index].value, value, MAX_STR_LEN);
    node->attrs[index].value[MAX_STR_LEN] = '\0';
    return scclSuccess;
}

scclResult_t xmlSetAttrIfUnset(struct scclXmlNode* node, const char* attrName, const char* value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index != -1)
        return scclSuccess;
    index = node->nAttrs++;
    strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
    node->attrs[index].key[MAX_STR_LEN] = '\0';
    strncpy(node->attrs[index].value, value, MAX_STR_LEN);
    node->attrs[index].value[MAX_STR_LEN] = '\0';
    return scclSuccess;
}

scclResult_t xmlSetAttrInt(struct scclXmlNode* node, const char* attrName, const int value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        node->attrs[index].key[MAX_STR_LEN] = '\0';
    }
    snprintf(node->attrs[index].value, MAX_STR_LEN, "%d", value);
    node->attrs[index].value[MAX_STR_LEN] = '\0';
    return scclSuccess;
}

scclResult_t xmlSetAttrFloat(struct scclXmlNode* node, const char* attrName, const float value) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1) {
        index = node->nAttrs++;
        strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
        node->attrs[index].key[MAX_STR_LEN] = '\0';
    }
    snprintf(node->attrs[index].value, MAX_STR_LEN, "%g", value);
    node->attrs[index].value[MAX_STR_LEN] = '\0';
    return scclSuccess;
}

scclResult_t xmlUnsetAttr(struct scclXmlNode* node, const char* attrName) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
    if(index == -1)
        return scclSuccess;
    for(int i = index + 1; i < node->nAttrs; i++) {
        strcpy(node->attrs[i - 1].key, node->attrs[i].key);
        strcpy(node->attrs[i - 1].value, node->attrs[i].value);
    }
    node->nAttrs--;
    return scclSuccess;
}

scclResult_t xmlGetSub(struct scclXmlNode* node, const char* subName, struct scclXmlNode** sub) {
    *sub = NULL;
    for(int s = 0; s < node->nSubs; s++) {
        if(strcmp(node->subs[s]->name, subName) == 0) {
            *sub = node->subs[s];
            return scclSuccess;
        }
    }
    return scclSuccess;
}

scclResult_t xmlGetSubKv(struct scclXmlNode* node, const char* subName, struct scclXmlNode** sub, const char* attrName, const char* attrValue) {
    *sub = NULL;
    for(int s = 0; s < node->nSubs; s++) {
        struct scclXmlNode* subNode = node->subs[s];
        if(strcmp(subNode->name, subName) == 0) {
            const char* value;
            SCCLCHECK(xmlGetAttr(subNode, attrName, &value));
            if(value && strcmp(value, attrValue) == 0) {
                *sub = node->subs[s];
                return scclSuccess;
            }
        }
    }
    return scclSuccess;
}
scclResult_t xmlGetSubKvInt(struct scclXmlNode* node, const char* subName, struct scclXmlNode** sub, const char* attrName, const int attrValue) {
    char strValue[10];
    snprintf(strValue, 10, "%d", attrValue);
    SCCLCHECK(xmlGetSubKv(node, subName, sub, attrName, strValue));
    return scclSuccess;
}

scclResult_t xmlAddNode(struct scclXml* xml, struct scclXmlNode* parent, const char* subName, struct scclXmlNode** sub) {
    if(xml->maxIndex == MAX_NODES) {
        WARN("Error : too many XML nodes (max %d)", MAX_NODES);
        return scclInternalError;
    }
    struct scclXmlNode* s = xml->nodes + xml->maxIndex++;
    s->nSubs              = 0;
    s->nAttrs             = 0;
    *sub                  = s;
    s->parent             = parent;
    if(parent)
        parent->subs[parent->nSubs++] = s;
    strncpy(s->name, subName, MAX_STR_LEN);
    s->name[MAX_STR_LEN] = '\0';
    return scclSuccess;
}

scclResult_t xmlRemoveNode(struct scclXmlNode* node) {
    node->type                 = NODE_TYPE_NONE;
    struct scclXmlNode* parent = node->parent;
    if(parent == NULL)
        return scclSuccess;
    int shift = 0;
    for(int s = 0; s < parent->nSubs; s++) {
        if(parent->subs[s] == node)
            shift = 1;
        else if(shift)
            parent->subs[s - 1] = parent->subs[s];
    }
    parent->nSubs--;
    return scclSuccess;
}

scclResult_t kvConvertToInt(const char* str, int* value, struct kvDict* dict) {
    struct kvDict* d = dict;
    while(d->str) {
        if(strncmp(str, d->str, strlen(d->str)) == 0) {
            *value = d->value;
            return scclSuccess;
        }
        d++;
    }
    INFO(SCCL_LOG_GRAPH, "KV Convert to int : could not find value of '%s' in dictionary, falling back to %d", str, d->value);
    *value = d->value;
    return scclSuccess;
}
scclResult_t kvConvertToStr(int value, const char** str, struct kvDict* dict) {
    struct kvDict* d = dict;
    while(d->str) {
        if(value == d->value) {
            *str = d->str;
            return scclSuccess;
        }
        d++;
    }
    WARN("KV Convert to str : could not find value %d in dictionary", value);
    return scclInternalError;
}

namespace xml {
/*******************/
/* XML File Parser */
/*******************/

scclResult_t xmlGetChar(FILE* file, char* c) {
    if(fread(c, 1, 1, file) == 0) {
        WARN("XML Parse : Unexpected EOF");
        return scclInternalError;
    }
    return scclSuccess;
}

scclResult_t xmlGetValue(FILE* file, char* value, char* last) {
    char c;
    SCCLCHECK(xmlGetChar(file, &c));
    if(c != '"' && c != '\'') {
#if INT_OK
        int o = 0;
        do {
            value[o++] = c;
            SCCLCHECK(xmlGetChar(file, &c));
        } while(c >= '0' && c <= '9');
        value[o] = '\0';
        *last    = c;
        return scclSuccess;
#else
        WARN("XML Parse : Expected (double) quote.");
        return scclInternalError;
#endif
    }
    int o = 0;
    do {
        SCCLCHECK(xmlGetChar(file, &c));
        value[o++] = c;
    } while(c != '"');
    value[o - 1] = '\0';
    SCCLCHECK(xmlGetChar(file, last));
    return scclSuccess;
}

scclResult_t xmlGetToken(FILE* file, char* name, char* value, char* last) {
    char c;
    char* ptr = name;
    int o     = 0;
    do {
        SCCLCHECK(xmlGetChar(file, &c));
        if(c == '=') {
            ptr[o] = '\0';
            if(value == NULL) {
                WARN("XML Parse : Unexpected value with name %s", ptr);
                return scclInternalError;
            }
            return xmlGetValue(file, value, last);
        }
        ptr[o] = c;
        if(o == MAX_STR_LEN - 1) {
            ptr[o] = '\0';
            WARN("Error : name %s too long (max %d)", ptr, MAX_STR_LEN);
            return scclInternalError;
        }
        o++;
    } while(c != ' ' && c != '>' && c != '/' && c != '\n' && c != '\r');
    ptr[o - 1] = '\0';
    *last      = c;
    return scclSuccess;
}

// Shift the 3-chars string by one char and append c at the end
#define SHIFT_APPEND(s, c) \
    do {                   \
        s[0] = s[1];       \
        s[1] = s[2];       \
        s[2] = c;          \
    } while(0)
scclResult_t xmlSkipComment(FILE* file, char* start, char next) {
    // Start from something neutral with \0 at the end.
    char end[4] = "...";

    // Inject all trailing chars from previous reads. We don't need
    // to check for --> here because there cannot be a > in the name.
    for(int i = 0; i < strlen(start); i++)
        SHIFT_APPEND(end, start[i]);
    SHIFT_APPEND(end, next);

    // Stop when we find "-->"
    while(strcmp(end, "-->") != 0) {
        int c;
        if(fread(&c, 1, 1, file) != 1) {
            WARN("XML Parse error : unterminated comment");
            return scclInternalError;
        }
        SHIFT_APPEND(end, c);
    }
    return scclSuccess;
}

scclResult_t xmlGetNode(FILE* file, struct scclXmlNode* node) {
    node->type = NODE_TYPE_NONE;
    char c     = ' ';
    while(c == ' ' || c == '\n' || c == '\r') {
        if(fread(&c, 1, 1, file) == 0)
            return scclSuccess;
    }
    if(c != '<') {
        WARN("XML Parse error : expecting '<', got '%c'", c);
        return scclInternalError;
    }
    // Read XML element name
    SCCLCHECK(xmlGetToken(file, node->name, NULL, &c));

    // Check for comments
    if(strncmp(node->name, "!--", 3) == 0) {
        SCCLCHECK(xmlSkipComment(file, node->name + 3, c));
        return xmlGetNode(file, node);
    }

    // Check for closing tag
    if(node->name[0] == '\0' && c == '/') {
        node->type = NODE_TYPE_CLOSE;
        // Re-read the name, we got '/' in the first call
        SCCLCHECK(xmlGetToken(file, node->name, NULL, &c));
        if(c != '>') {
            WARN("XML Parse error : unexpected trailing %c in closing tag %s", c, node->name);
            return scclInternalError;
        }
        return scclSuccess;
    }

    node->type = NODE_TYPE_OPEN;

    // Get Attributes
    int a = 0;
    while(c == ' ') {
        SCCLCHECK(xmlGetToken(file, node->attrs[a].key, node->attrs[a].value, &c));
        if(a == MAX_ATTR_COUNT) {
            INFO(SCCL_LOG_TOPO, "XML Parse : Ignoring extra attributes (max %d)", MAX_ATTR_COUNT);
            // Actually we need to still consume the extra attributes so we have an extra one.
        } else
            a++;
    }
    node->nAttrs = a;
    if(c == '/') {
        node->type = NODE_TYPE_SINGLE;
        char str[MAX_STR_LEN];
        SCCLCHECK(xmlGetToken(file, str, NULL, &c));
    }
    if(c != '>') {
        WARN("XML Parse : expected >, got '%c'", c);
        return scclInternalError;
    }
    return scclSuccess;
}

typedef scclResult_t (*xmlHandlerFunc_t)(FILE*, struct scclXml*, struct scclXmlNode*);

struct xmlHandler {
    const char* name;
    xmlHandlerFunc_t func;
};

scclResult_t xmlLoadSub(FILE* file, struct scclXml* xml, struct scclXmlNode* head, struct xmlHandler handlers[], int nHandlers) {
    if(head && head->type == NODE_TYPE_SINGLE)
        return scclSuccess;
    while(1) {
        if(xml->maxIndex == MAX_NODES) {
            WARN("Error : XML parser is limited to 1024 nodes");
            return scclInternalError;
        }
        struct scclXmlNode* node = xml->nodes + xml->maxIndex;
        memset(node, 0, sizeof(struct scclXmlNode));
        SCCLCHECK(xmlGetNode(file, node));
        if(node->type == NODE_TYPE_NONE) {
            if(head) {
                WARN("XML Parse : unterminated %s", head->name);
                return scclInternalError;
            } else {
                // All done
                return scclSuccess;
            }
        }
        if(head && node->type == NODE_TYPE_CLOSE) {
            if(strcmp(node->name, head->name) != 0) {
                WARN("XML Mismatch : %s / %s", head->name, node->name);
                return scclInternalError;
            }
            return scclSuccess;
        }
        int found = 0;
        for(int h = 0; h < nHandlers; h++) {
            if(strcmp(node->name, handlers[h].name) == 0) {
                if(head)
                    head->subs[head->nSubs++] = node;
                node->parent = head;
                node->nSubs  = 0;
                xml->maxIndex++;
                SCCLCHECK(handlers[h].func(file, xml, node));
                found = 1;
                break;
            }
        }
        if(!found) {
            if(nHandlers)
                INFO(SCCL_LOG_TOPO, "Ignoring element %s", node->name);
            SCCLCHECK(xmlLoadSub(file, xml, node, NULL, 0));
        }
    }
}

/**************/
/* XML Writer */
/**************/

scclResult_t scclTopoDumpXmlRec(int indent, FILE* file, struct scclXmlNode* node) {
    for(int i = 0; i < indent; i++)
        fprintf(file, " ");
    fprintf(file, "<%s", node->name);

    for(int a = 0; a < node->nAttrs; a++) {
        fprintf(file, " %s=\"%s\"", node->attrs[a].key, node->attrs[a].value);
    }
    if(node->nSubs == 0) {
        fprintf(file, "/>\n");
    } else {
        fprintf(file, ">\n");
        for(int s = 0; s < node->nSubs; s++) {
            SCCLCHECK(scclTopoDumpXmlRec(indent + 2, file, node->subs[s]));
        }
        for(int i = 0; i < indent; i++)
            fprintf(file, " ");
        fprintf(file, "</%s>\n", node->name);
    }
    return scclSuccess;
}

/****************************************/
/* Parser rules for our specific format */
/****************************************/

scclResult_t scclTopoXmlLoadNvlink(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    SCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadGpu(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {

    struct xmlHandler handlers[] = {{"xgmi", scclTopoXmlLoadNvlink}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadNet(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    SCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadNic(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    struct xmlHandler handlers[] = {{"net", scclTopoXmlLoadNet}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadPci(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    struct xmlHandler handlers[] = {{"pci", scclTopoXmlLoadPci}, {"gpu", scclTopoXmlLoadGpu}, {"nic", scclTopoXmlLoadNic}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 3));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadCpu(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    struct xmlHandler handlers[] = {{"pci", scclTopoXmlLoadPci}, {"nic", scclTopoXmlLoadNic}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 2));
    return scclSuccess;
}

scclResult_t scclTopoXmlLoadSystem(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    int version;
    SCCLCHECK(xmlGetAttrInt(head, "version", &version));
    if(version != SCCL_TOPO_XML_VERSION) {
        WARN("XML Topology has wrong version %d, %d needed", version, SCCL_TOPO_XML_VERSION);
        return scclInvalidUsage;
    }
    const char* name;
    SCCLCHECK(xmlGetAttr(head, "name", &name));
    if(name != NULL)
        INFO(SCCL_LOG_TOPO, "Loading topology %s", name);
    else
        INFO(SCCL_LOG_TOPO, "Loading unnamed topology");

    struct xmlHandler handlers[] = {{"cpu", scclTopoXmlLoadCpu}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
    return scclSuccess;
}

/**********************/
/* XML creation       */
/* from autodetection */
/**********************/

#define BUSID_SIZE (sizeof("0000:00:00.0"))
#define BUSID_REDUCED_SIZE (sizeof("0000:00"))
static void memcpylower(char* dst, const char* src, const size_t size) {
    for(int i = 0; i < size; i++)
        dst[i] = tolower(src[i]);

    return;
}
static scclResult_t getPciPath(const char* busId, char** path) {
    char busPath[] = "/sys/class/pci_bus/0000:00/../../0000:00:00.0";
    memcpylower(busPath + sizeof("/sys/class/pci_bus/") - 1, busId, BUSID_REDUCED_SIZE - 1);
    memcpylower(busPath + sizeof("/sys/class/pci_bus/0000:00/../../") - 1, busId, BUSID_SIZE - 1);
    *path = realpath(busPath, NULL);
    if(*path == NULL) {
        WARN("Could not find real path of %s", busPath);
        return scclSystemError;
    }
    return scclSuccess;
}

scclResult_t scclTopoSetAttrFromSys(struct scclXmlNode* pciNode, const char* path, const char* fileName, const char* attrName) {
    char strValue[MAX_STR_LEN];
    SCCLCHECK(scclTopoGetStrFromSys(path, fileName, strValue));
    if(strValue[0] != '\0') {
        SCCLCHECK(xmlSetAttr(pciNode, attrName, strValue));
    }
    INFO(SCCL_LOG_TOPO, "Read from sys %s/%s -> %s=%s", path, fileName, attrName, strValue);
    return scclSuccess;
}

scclResult_t scclTopoGetXmlFromCpu(struct scclXmlNode* cpuNode, struct scclXml* xml) {
    int index;
    SCCLCHECK(xmlGetAttrIndex(cpuNode, "affinity", &index));
    if(index == -1) {
        const char* numaId;
        SCCLCHECK(xmlGetAttr(cpuNode, "numaid", &numaId));
        if(numaId == NULL) {
            WARN("GetXmlFromCpu : could not find CPU numa ID.");
            return scclInternalError;
        }
        // Set affinity
        char cpumaskPath[] = "/sys/devices/system/node/node0000";
        sprintf(cpumaskPath, "/sys/devices/system/node/node%s", numaId);
        SCCLCHECK(scclTopoSetAttrFromSys(cpuNode, cpumaskPath, "cpumap", "affinity"));
    }

    SCCLCHECK(xmlGetAttrIndex(cpuNode, "arch", &index));
    if(index == -1) {
        // Fill CPU type / vendor / model
#if defined(__PPC__)
        SCCLCHECK(xmlSetAttr(cpuNode, "arch", "ppc64"));
#elif defined(__aarch64__)
        SCCLCHECK(xmlSetAttr(cpuNode, "arch", "arm64"));
#elif defined(__x86_64__)
        SCCLCHECK(xmlSetAttr(cpuNode, "arch", "x86_64"));
#endif
    }

#if defined(__x86_64__)
    SCCLCHECK(xmlGetAttrIndex(cpuNode, "vendor", &index));
    if(index == -1) {
        union {
            struct {
                // CPUID 0 String register order
                uint32_t ebx;
                uint32_t edx;
                uint32_t ecx;
            };
            char vendor[12];
        } cpuid0;

        asm volatile("cpuid" : "=b"(cpuid0.ebx), "=c"(cpuid0.ecx), "=d"(cpuid0.edx) : "a"(0) : "memory");
        char vendor[13];
        strncpy(vendor, cpuid0.vendor, 12);
        vendor[12] = '\0';
        SCCLCHECK(xmlSetAttr(cpuNode, "vendor", vendor));
    }

    SCCLCHECK(xmlGetAttrIndex(cpuNode, "familyid", &index));
    if(index == -1) {
        union {
            struct {
                unsigned steppingId : 4;
                unsigned modelId : 4;
                unsigned familyId : 4;
                unsigned processorType : 2;
                unsigned resv0 : 2;
                unsigned extModelId : 4;
                unsigned extFamilyId : 8;
                unsigned resv1 : 4;
            };
            uint32_t val;
        } cpuid1;
        asm volatile("cpuid" : "=a"(cpuid1.val) : "a"(1) : "memory");
        int familyId = cpuid1.familyId + (cpuid1.extFamilyId << 4);
        int modelId  = cpuid1.modelId + (cpuid1.extModelId << 4);
        SCCLCHECK(xmlSetAttrInt(cpuNode, "familyid", familyId));
        SCCLCHECK(xmlSetAttrInt(cpuNode, "modelid", modelId));
    }
#endif
    return scclSuccess;
}

scclResult_t scclTopoGetPciNode(struct scclXml* xml, const char* busId, struct scclXmlNode** pciNode) {
    SCCLCHECK(xmlFindTagKv(xml, "pci", pciNode, "busid", busId));
    if(*pciNode == NULL) {
        SCCLCHECK(xmlAddNode(xml, NULL, "pci", pciNode));
        SCCLCHECK(xmlSetAttr(*pciNode, "busid", busId));
    }
    return scclSuccess;
}

// Check whether a string is in BDF format or not.
// BDF (Bus-Device-Function) is "BBBB:BB:DD.F" where B, D and F are hex digits.
// There can be trailing chars.
int isHex(char c) { return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')); }
int checkBDFFormat(char* bdf) {
    if(bdf[4] != ':' || bdf[7] != ':' || bdf[10] != '.')
        return 0;
    if(isHex(bdf[0]) == 0 || isHex(bdf[1] == 0) || isHex(bdf[2] == 0) || isHex(bdf[3] == 0) || isHex(bdf[5] == 0) || isHex(bdf[6] == 0) || isHex(bdf[8] == 0) ||
       isHex(bdf[9] == 0) || isHex(bdf[11] == 0))
        return 0;
    return 1;
}

scclResult_t scclTopoGetXmlFromSys(struct scclXmlNode* pciNode, struct scclXml* xml) {
    // Fill info, then parent
    const char* busId;
    SCCLCHECK(xmlGetAttr(pciNode, "busid", &busId));
    char* path = NULL;
    getPciPath(busId, &path);

    if(path) {
        SCCLCHECK(scclTopoSetAttrFromSys(pciNode, path, "class", "class"));
    }
    int index;
    SCCLCHECK(xmlGetAttrIndex(pciNode, "vendor", &index));
    if(index == -1) {
        if(path)
            scclTopoSetAttrFromSys(pciNode, path, "vendor", "vendor");
    }
    SCCLCHECK(xmlGetAttrIndex(pciNode, "device", &index));
    if(index == -1) {
        if(path)
            scclTopoSetAttrFromSys(pciNode, path, "device", "device");
    }
    SCCLCHECK(xmlGetAttrIndex(pciNode, "subsystem_vendor", &index));
    if(index == -1) {
        if(path)
            scclTopoSetAttrFromSys(pciNode, path, "subsystem_vendor", "subsystem_vendor");
    }
    SCCLCHECK(xmlGetAttrIndex(pciNode, "subsystem_device", &index));
    if(index == -1) {
        if(path)
            scclTopoSetAttrFromSys(pciNode, path, "subsystem_device", "subsystem_device");
    }
    SCCLCHECK(xmlGetAttrIndex(pciNode, "link_speed", &index));
    if(index == -1) {
        if(path) {
            char deviceSpeedStr[MAX_STR_LEN];
            float deviceSpeed;
            SCCLCHECK(scclTopoGetStrFromSys(path, "max_link_speed", deviceSpeedStr));
            sscanf(deviceSpeedStr, "%f GT/s", &deviceSpeed);
            char portSpeedStr[MAX_STR_LEN];
            float portSpeed;
            SCCLCHECK(scclTopoGetStrFromSys(path, "../max_link_speed", portSpeedStr));
            if(portSpeedStr[0])
                sscanf(portSpeedStr, "%f GT/s", &portSpeed);
            else
                portSpeed = deviceSpeed;
            SCCLCHECK(xmlSetAttr(pciNode, "link_speed", portSpeed < deviceSpeed ? portSpeedStr : deviceSpeedStr));
        } else {
            SCCLCHECK(xmlSetAttr(pciNode, "link_speed", ""));
        }
    }
    SCCLCHECK(xmlGetAttrIndex(pciNode, "link_width", &index));
    if(index == -1) {
        if(path) {
            char strValue[MAX_STR_LEN];
            SCCLCHECK(scclTopoGetStrFromSys(path, "max_link_width", strValue));
            int deviceWidth = strtol(strValue, NULL, 0);
            SCCLCHECK(scclTopoGetStrFromSys(path, "../max_link_width", strValue));
            int portWidth;
            if(strValue[0])
                portWidth = strtol(strValue, NULL, 0);
            else
                portWidth = deviceWidth;
            SCCLCHECK(xmlSetAttrInt(pciNode, "link_width", std::min(deviceWidth, portWidth)));
        } else {
            SCCLCHECK(xmlSetAttr(pciNode, "link_width", ""));
        }
    }
    struct scclXmlNode* parent = pciNode->parent;
    if(parent == NULL) {
        if(path) {
            // Save that for later in case next step is a CPU
            char numaIdStr[MAX_STR_LEN];
            SCCLCHECK(scclTopoGetStrFromSys(path, "numa_node", numaIdStr));
            // Workaround kernel bug for now
            if(strcmp(numaIdStr, "-1") == 0)
                strcpy(numaIdStr, "0");

            // Go up one level in the PCI tree. Rewind two "/" and follow the upper PCI
            // switch, or stop if we reach a CPU root complex.
            int slashCount = 0;
            int parentOffset;
            for(parentOffset = strlen(path) - 1; parentOffset > 0; parentOffset--) {
                if(path[parentOffset] == '/') {
                    slashCount++;
                    path[parentOffset] = '\0';
                    int start          = parentOffset - 1;
                    while(start > 0 && path[start] != '/')
                        start--;
                    // Check whether the parent path looks like "BBBB:BB:DD.F" or not.
                    if(checkBDFFormat(path + start + 1) == 0) {
                        // This a CPU root complex. Create a CPU tag and stop there.
                        struct scclXmlNode* topNode;
                        SCCLCHECK(xmlFindTag(xml, "system", &topNode));
                        SCCLCHECK(xmlGetSubKv(topNode, "cpu", &parent, "numaid", numaIdStr));
                        if(parent == NULL) {
                            SCCLCHECK(xmlAddNode(xml, topNode, "cpu", &parent));
                            SCCLCHECK(xmlSetAttr(parent, "numaid", numaIdStr));
                        }
                    } else if(slashCount == 2) {
                        // Continue on the upper PCI switch
                        for(int i = strlen(path) - 1; i > 0; i--) {
                            if(path[i] == '/') {
                                SCCLCHECK(xmlFindTagKv(xml, "pci", &parent, "busid", path + i + 1));
                                if(parent == NULL) {
                                    SCCLCHECK(xmlAddNode(xml, NULL, "pci", &parent));
                                    SCCLCHECK(xmlSetAttr(parent, "busid", path + i + 1));
                                }
                                break;
                            }
                        }
                    }
                }
                if(parent)
                    break;
            }
        } else {
            // No information on /sys, attach GPU to unknown CPU
            SCCLCHECK(xmlFindTagKv(xml, "cpu", &parent, "numaid", "-1"));
            if(parent == NULL) {
                struct scclXmlNode* topNode;
                SCCLCHECK(xmlFindTag(xml, "system", &topNode));
                SCCLCHECK(xmlAddNode(xml, topNode, "cpu", &parent));
                SCCLCHECK(xmlSetAttr(parent, "numaid", "-1"));
                SCCLCHECK(scclTopoGetXmlFromCpu(parent, xml));
            }
        }
        pciNode->parent               = parent;
        parent->subs[parent->nSubs++] = pciNode;
    }
    if(strcmp(parent->name, "pci") == 0) {
        SCCLCHECK(scclTopoGetXmlFromSys(parent, xml));
    } else if(strcmp(parent->name, "cpu") == 0) {
        SCCLCHECK(scclTopoGetXmlFromCpu(parent, xml));
    }
    free(path);
    return scclSuccess;
}

scclResult_t scclTopoGetXmlFromGpu(struct scclXmlNode* pciNode, uint32_t rocmDev, struct scclXml* xml, struct scclXmlNode** gpuNodeRet) {
    struct scclXmlNode* gpuNode = NULL;
    SCCLCHECK(xmlGetSub(pciNode, "gpu", &gpuNode));
    if(gpuNode == NULL)
        SCCLCHECK(xmlAddNode(xml, pciNode, "gpu", &gpuNode));

    int index = -1;

    int dev = -1;
    SCCLCHECK(xmlGetAttrIndex(gpuNode, "dev", &index));
    if(index == -1) {
        if(rocmDev == -1) {
            const char* busId;
            SCCLCHECK(xmlGetAttr(pciNode, "busid", &busId));
            if(busId == NULL || hipDeviceGetByPCIBusId(&dev, busId) != hipSuccess)
                dev = -1;
        } else {
            dev = rocmDev;
        }
        SCCLCHECK(xmlSetAttrInt(gpuNode, "dev", dev));
    }
    SCCLCHECK(xmlGetAttrInt(gpuNode, "dev", &dev));
    if(dev == -1) {
        *gpuNodeRet = NULL;
        return scclSuccess;
    }

    SCCLCHECK(xmlGetAttrIndex(gpuNode, "sm", &index));
    if(index == -1) {
        int hipMajor, hipMinor;
        hipDeviceProp_t devProp;
        HIPCHECK(hipGetDeviceProperties(&devProp, 0));
        hipMajor = devProp.major;
        hipMinor = devProp.minor;
        SCCLCHECK(xmlSetAttrInt(gpuNode, "sm", hipMajor * 10 + hipMinor));
    }
    int sm;
    SCCLCHECK(xmlGetAttrInt(gpuNode, "sm", &sm));

    const char* gcn;
    const char* gcnArchName;
    SCCLCHECK(xmlGetAttrIndex(gpuNode, "gcn", &index));
    if(index == -1) {
        hipDeviceProp_t devProp;
        HIPCHECK(hipGetDeviceProperties(&devProp, 0));
        // extract only the releveant info from the gcnArchName attribute
        // e.g.: convert "gfx908:sramecc+:xnack-" to "gfx908"
        char gcnArchNameSubstr[6];
        GcnArchNameFormat(devProp.gcnArchName, gcnArchNameSubstr);
        gcn = gcnArchNameSubstr;
        SCCLCHECK(xmlSetAttr(gpuNode, "gcn", gcn));
    }
    SCCLCHECK(xmlGetAttr(gpuNode, "gcn", &gcn));
    convertGcnArchToGcnArchName(gcn, &gcnArchName);
    SCCLCHECK(xmlSetAttr(gpuNode, "gcn", gcnArchName));

    scclHipDeviceArch_t arch;
    SCCLCHECK(xmlGetAttrIndex(gpuNode, "arch", &index));
    if(index == -1) {
        hipDeviceProp_t devProp;
        HIPCHECK(hipGetDeviceProperties(&devProp, 0));
        memcpy(&arch.arch, &devProp.arch, sizeof(hipDeviceArch_t));
        SCCLCHECK(xmlSetAttrInt(gpuNode, "arch", arch.value));
    }
    SCCLCHECK(xmlGetAttrInt(gpuNode, "arch", &arch.value));

    struct scclXmlNode* nvlNode = NULL;
    SCCLCHECK(xmlGetSub(gpuNode, "nvlink", &nvlNode));
    if(nvlNode == NULL) {
        const char* busId;
        SCCLCHECK(xmlGetAttr(pciNode, "busid", &busId));
        uint32_t deviceCnt;
        SCCLCHECK(rocm_smi_getNumDevice(&deviceCnt));
        for(int i = 0; i < deviceCnt; i++) {
            if(i != dev) {
                RSMI_IO_LINK_TYPE rsmi_type;
                int hops, count;
                if(rocm_smi_getLinkInfo(dev, i, &rsmi_type, &hops, &count) == scclSuccess) {
                    if(rsmi_type >= RSMI_IOLINK_TYPE_XGMI && hops >= 1) {
                        char busIdStr[] = "00000000:00:00.0";
                        SCCLCHECK(rocm_smi_getDevicePciBusIdString(i, busIdStr, sizeof(busIdStr)));
                        char lowerId[NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE];
                        for(int c = 0; c < NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE; c++) {
                            lowerId[c] = tolower(busIdStr[c]);
                            if(busIdStr[c] == 0)
                                break;
                        }
                        SCCLCHECK(xmlGetSubKv(gpuNode, "xgmi", &nvlNode, "target", lowerId));
                        if(nvlNode == NULL) {
                            SCCLCHECK(xmlAddNode(xml, gpuNode, "xgmi", &nvlNode));
                            SCCLCHECK(xmlSetAttr(nvlNode, "target", lowerId));
                            SCCLCHECK(xmlSetAttrInt(nvlNode, "count", count));
                        }
                    }
                }
            }
        }
    }
    // Fill target classes
    for(int s = 0; s < gpuNode->nSubs; s++) {
        struct scclXmlNode* sub = gpuNode->subs[s];
        if(strcmp(sub->name, "xgmi") != 0)
            continue;
        int index;
        SCCLCHECK(xmlGetAttrIndex(sub, "tclass", &index));
        if(index == -1) {
            const char* busId;
            SCCLCHECK(xmlGetAttr(sub, "target", &busId));
            char* path;
            getPciPath(busId, &path);
            if(path == NULL || strcmp(busId, "fffffff:ffff:ff") == 0) {
                // Remote NVLink device is not visible inside this VM. Assume NVSwitch.
                SCCLCHECK(xmlSetAttr(sub, "tclass", "0x068000"));
            } else {
                SCCLCHECK(scclTopoSetAttrFromSys(sub, path, "class", "tclass"));
                free(path);
            }
        }
    }
    *gpuNodeRet = gpuNode;
    return scclSuccess;
}

// Returns the subsystem name of a path, i.e. the end of the path
// where sysPath/subsystem points to.
scclResult_t scclTopoGetSubsystem(const char* sysPath, char* subSys) {
    char subSysPath[PATH_MAX];
    sprintf(subSysPath, "%s/subsystem", sysPath);
    char* path = realpath(subSysPath, NULL);
    if(path == NULL) {
        subSys[0] = '\0';
    } else {
        int offset;
        for(offset = strlen(path); offset > 0 && path[offset] != '/'; offset--)
            ;
        strcpy(subSys, path + offset + 1);
        free(path);
    }
    return scclSuccess;
}

scclResult_t scclTopoTrimXmlRec(struct scclXmlNode* node) {
    const char* str;
    SCCLCHECK(xmlGetAttr(node, "keep", &str));
    if(str && strcmp(str, "1") == 0) {
        SCCLCHECK(xmlUnsetAttr(node, "keep"));
    } else {
        // Copy nSubs and subs as they could change as we trim recursively.
        struct scclXmlNode* subs[MAX_SUBS];
        int nSubs = node->nSubs;
        memcpy(subs, node->subs, node->nSubs * sizeof(struct scclXmlNode*));
        for(int s = 0; s < nSubs; s++) {
            SCCLCHECK(scclTopoTrimXmlRec(subs[s]));
        }
        if(node->nSubs == 0)
            SCCLCHECK(xmlRemoveNode(node));
    }
    return scclSuccess;
}

/**************************************************/
/* Parser rules for the user-defined graph search */
/**************************************************/

scclResult_t scclTopoXmlGraphLoadGpu(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    SCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
    return scclSuccess;
}

scclResult_t scclTopoXmlGraphLoadNet(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    SCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
    return scclSuccess;
}

scclResult_t scclTopoXmlGraphLoadChannel(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    struct xmlHandler handlers[] = {{"net", scclTopoXmlGraphLoadNet}, {"gpu", scclTopoXmlGraphLoadGpu}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 2));
    return scclSuccess;
}

scclResult_t scclTopoXmlGraphLoadGraph(FILE* file, struct scclXml* xml, struct scclXmlNode* head) {
    struct xmlHandler handlers[] = {{"channel", scclTopoXmlGraphLoadChannel}};
    SCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
    return scclSuccess;
}

scclResult_t scclTopoXmlGraphLoadGraphs(FILE* file, struct scclXml* xmlGraph, struct scclXmlNode* head) {
    int version;
    SCCLCHECK(xmlGetAttrInt(head, "version", &version));
    if(version != SCCL_GRAPH_XML_VERSION) {
        WARN("XML Graph has wrong version %d, %d needed", version, SCCL_GRAPH_XML_VERSION);
        return scclInvalidUsage;
    }
    const char* name;
    SCCLCHECK(xmlGetAttr(head, "name", &name));
    if(name != NULL)
        INFO(SCCL_LOG_TOPO, "Loading graphs for topology %s", name);
    else
        INFO(SCCL_LOG_TOPO, "Loading graphs");

    struct xmlHandler handlers[] = {{"graph", scclTopoXmlGraphLoadGraph}};
    SCCLCHECK(xmlLoadSub(file, xmlGraph, head, handlers, 1));
    return scclSuccess;
}

} // namespace xml

scclResult_t scclTopoGetXmlFromFile(const char* xmlTopoFile, struct scclXml* xml, int warn) {
    FILE* file = fopen(xmlTopoFile, "r");
    if(file == NULL) {
        if(warn) {
            WARN("Could not open XML topology file %s : %s", xmlTopoFile, strerror(errno));
        }
        return scclSuccess;
    }
    INFO(SCCL_LOG_TOPO, "Loading topology file %s", xmlTopoFile);
    struct xml::xmlHandler handlers[] = {{"system", xml::scclTopoXmlLoadSystem}};
    xml->maxIndex                     = 0;
    SCCLCHECK(xml::xmlLoadSub(file, xml, NULL, handlers, 1));
    fclose(file);
    return scclSuccess;
}

scclResult_t scclTopoDumpXmlToFile(const char* xmlTopoFile, struct scclXml* xml) {
    FILE* file = fopen(xmlTopoFile, "w");
    if(file == NULL) {
        WARN("Unable to open %s, not dumping topology.", xmlTopoFile);
        return scclSuccess;
    }
    SCCLCHECK(xml::scclTopoDumpXmlRec(0, file, xml->nodes));
    fclose(file);
    return scclSuccess;
}

scclResult_t scclTopoFillGpu(struct scclXml* xml, const char* busId, struct scclXmlNode** gpuNode) {
    struct scclXmlNode* node;
    SCCLCHECK(xml::scclTopoGetPciNode(xml, busId, &node));
    SCCLCHECK(xmlSetAttrIfUnset(node, "class", "0x03"));
    SCCLCHECK(xml::scclTopoGetXmlFromSys(node, xml));
    uint32_t devIndex;
    static int rocmsmiInit = 0;
    if(rocmsmiInit == 0) {
        rocmsmiInit = (rocm_smi_init() != scclSuccess) ? 2 : 1;
    }
    if(rocmsmiInit == 1) {
        if(rocm_smi_getDeviceIndexByPciBusId(busId, &devIndex) != scclSuccess)
            devIndex = -1;
    }
    SCCLCHECK(xml::scclTopoGetXmlFromGpu(node, devIndex, xml, gpuNode));
    return scclSuccess;
}

scclResult_t scclTopoFillNet(struct scclXml* xml, const char* pciPath, const char* netName, struct scclXmlNode** netNode) {
    SCCLCHECK(xmlFindTagKv(xml, "net", netNode, "name", netName));
    if(*netNode != NULL)
        return scclSuccess;

    const char* pciSysPath = pciPath;
    if(pciSysPath) {
        char subSystem[PATH_MAX];
        SCCLCHECK(xml::scclTopoGetSubsystem(pciSysPath, subSystem));
        // This is not a PCI device (virtual, usb, ...).
        if(strcmp(subSystem, "pci") != 0) {
            INFO(SCCL_LOG_TOPO, "Topology detection: network path %s is not a PCI device (%s). Attaching to first CPU", pciSysPath, subSystem);
            pciSysPath = NULL;
        }
    }

    struct scclXmlNode* parent = NULL;
    if(pciSysPath) {
        int offset;
        for(offset = strlen(pciSysPath) - 1; pciSysPath[offset] != '/'; offset--)
            ;
        char busId[NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE];
        strcpy(busId, pciSysPath + offset + 1);
        SCCLCHECK(xml::scclTopoGetPciNode(xml, busId, &parent));
        SCCLCHECK(xmlSetAttrIfUnset(parent, "class", "0x02"));
        SCCLCHECK(xml::scclTopoGetXmlFromSys(parent, xml));
    } else {
        // Virtual NIC, no PCI device, attach to first CPU
        SCCLCHECK(xmlFindTag(xml, "cpu", &parent));
    }

    struct scclXmlNode* nicNode = NULL;
    SCCLCHECK(xmlGetSub(parent, "nic", &nicNode));
    if(nicNode == NULL) {
        SCCLCHECK(xmlAddNode(xml, parent, "nic", &nicNode));
    }

    // We know that this net does not exist yet (we searched for it at the
    // beginning of this function), so we can add it.
    SCCLCHECK(xmlAddNode(xml, nicNode, "net", netNode));
    SCCLCHECK(xmlSetAttr(*netNode, "name", netName));
    return scclSuccess;
}

scclResult_t scclTopoGetXmlGraphFromFile(const char* xmlGraphFile, struct scclXml* xml) {
    FILE* file = fopen(xmlGraphFile, "r");
    if(file == NULL) {
        WARN("Could not open XML graph file %s : %s", xmlGraphFile, strerror(errno));
        return scclSystemError;
    }
    struct xml::xmlHandler handlers[] = {{"graphs", xml::scclTopoXmlGraphLoadGraphs}};
    xml->maxIndex                     = 0;
    SCCLCHECK(xml::xmlLoadSub(file, xml, NULL, handlers, 1));
    fclose(file);
    return scclSuccess;
}

scclResult_t scclTopoTrimXml(struct scclXml* xml) {
    SCCLCHECK(xml::scclTopoTrimXmlRec(xml->nodes));
    return scclSuccess;
}

scclResult_t scclTopoGetStrFromSys(const char* path, const char* fileName, char* strValue) {
    char filePath[PATH_MAX];
    sprintf(filePath, "%s/%s", path, fileName);
    int offset = 0;
    FILE* file;
    if((file = fopen(filePath, "r")) != NULL) {
        while(feof(file) == 0 && ferror(file) == 0 && offset < MAX_STR_LEN) {
            int len = fread(strValue + offset, 1, MAX_STR_LEN - offset, file);
            offset += len;
        }
        fclose(file);
    }
    if(offset == 0) {
        strValue[0] = '\0';
        INFO(SCCL_LOG_TOPO, "Topology detection : could not read %s, ignoring", filePath);
    } else {
        strValue[offset - 1] = '\0';
    }
    return scclSuccess;
}

} // namespace topo
} // namespace topology
} // namespace hardware
} // namespace sccl