Add uuid support using inband information

Added chipset specific uuid retrieving functionality
This is used by zeDeviceGetProperties


Related-To: LOCI-2636

Signed-off-by: Joshua Santosh Ranjan <joshua.santosh.ranjan@intel.com>

shared/source/os_interface/linux/pmt_util.cpp

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2021 Intel Corporation
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+#include "shared/source/os_interface/linux/pmt_util.h"
+
+#include "shared/source/helpers/debug_helpers.h"
+#include "shared/source/os_interface/linux/sys_calls.h"
+#include "shared/source/utilities/directory.h"
+
+#include <climits>
+
+#include <algorithm>
+#include <cstring>
+#include <fcntl.h>
+#include <map>
+#include <sstream>
+#include <string_view>
+
+namespace NEO {
+
+void PmtUtil::getTelemNodesInPciPath(std::string_view rootPciPath, std::map<uint32_t, std::string> &telemPciPath) {
+
+    // if bdf = 0000:3a:00.0
+    // link = "../../devices/pci0000:37/0000:37:01.0/0000:38:00.0/0000:39:01.0/0000:3a:00.0/drm/renderD128/",
+    // then root path = "/pci0000:37/0000:37:01.0"
+    auto telemNodeList = Directory::getFiles("/sys/class/intel_pmt");
+    std::string_view telemDirString("/sys/class/intel_pmt/telem");
+    telemPciPath.clear();
+
+    // Get the telem nodes under the same root pci path
+    for (auto &telemNode : telemNodeList) {
+        char symlink[256] = {'\0'};
+        std::size_t pos = telemNode.find(telemDirString);
+        if (pos != std::string::npos) {
+            pos += telemDirString.length();
+            int len = SysCalls::readlink(telemNode.c_str(), symlink, sizeof(symlink) - 1);
+            if (len != -1) {
+                symlink[len] = '\0';
+                std::string_view symlinkString(symlink);
+                if (symlinkString.find(rootPciPath.data()) != std::string::npos) {
+                    int index = std::stoi(telemNode.substr(pos));
+                    telemPciPath[index] = telemNode;
+                }
+            }
+        }
+    }
+}
+
+bool PmtUtil::readGuid(std::string_view telemDir, std::array<char, PmtUtil::guidStringSize> &guidString) {
+    std::ostringstream guidFilename;
+    guidFilename << telemDir << "/guid";
+    int fd = SysCalls::open(guidFilename.str().c_str(), O_RDONLY);
+    if (fd <= 0) {
+        return false;
+    }
+    guidString.fill('\0');
+    ssize_t bytesRead = SysCalls::pread(fd, guidString.data(), guidString.size() - 1, 0);
+    SysCalls::close(fd);
+    if (bytesRead <= 0) {
+        return false;
+    }
+    std::replace(guidString.begin(), guidString.end(), '\n', '\0');
+    return true;
+}
+
+bool PmtUtil::readOffset(std::string_view telemDir, uint64_t &offset) {
+
+    std::ostringstream offsetFilename;
+    offsetFilename << telemDir << "/offset";
+    int fd = SysCalls::open(offsetFilename.str().c_str(), O_RDONLY);
+    if (fd <= 0) {
+        return false;
+    }
+    offset = ULONG_MAX;
+    std::array<char, 16> offsetString = {'\0'};
+    ssize_t bytesRead = SysCalls::pread(fd, offsetString.data(), offsetString.size() - 1, 0);
+    if (bytesRead > 0) {
+        std::replace(offsetString.begin(), offsetString.end(), '\n', '\0');
+        offset = std::strtoul(offsetString.data(), nullptr, 10);
+    }
+    SysCalls::close(fd);
+
+    if (offset == ULONG_MAX) {
+        return false;
+    }
+    return true;
+}
+
+ssize_t PmtUtil::readTelem(std::string_view telemDir, const std::size_t count, const uint64_t offset, void *data) {
+
+    if (data == nullptr) {
+        return 0;
+    }
+
+    ssize_t bytesRead = 0;
+    std::ostringstream telemFilename;
+    telemFilename << telemDir << "/telem";
+    int fd = SysCalls::open(telemFilename.str().c_str(), O_RDONLY);
+    if (fd > 0) {
+        bytesRead = SysCalls::pread(fd, data, count, offset);
+        SysCalls::close(fd);
+    }
+    return bytesRead;
+}
+
+} // namespace NEO