PHAL: refactoring common_utils

Moved pdbg specific utils function into new file.
This will help to avoid adding additional phal library
dependency for apps , which are not really consumed
phal repos.

Signed-off-by: Jayanth Othayoth <ojayanth@in.ibm.com>
Change-Id: Ibabd8096afe8402551d1314f0ff5b89cac891aad
diff --git a/extensions/phal/pdbg_utils.cpp b/extensions/phal/pdbg_utils.cpp
new file mode 100644
index 0000000..748b73c
--- /dev/null
+++ b/extensions/phal/pdbg_utils.cpp
@@ -0,0 +1,141 @@
+extern "C"
+{
+#include <libpdbg.h>
+}
+
+#include "extensions/phal/pdbg_utils.hpp"
+#include "extensions/phal/phal_error.hpp"
+
+#include <fmt/format.h>
+
+#include <phosphor-logging/log.hpp>
+
+namespace openpower
+{
+namespace phal
+{
+
+using namespace phosphor::logging;
+
+pdbg_target* getFsiTarget(struct pdbg_target* procTarget)
+{
+
+    struct pdbg_target* fsiTarget = nullptr;
+    pdbg_for_each_target("fsi", procTarget, fsiTarget)
+    {
+        // grab first one we find
+        break;
+    }
+    if (!fsiTarget)
+    {
+        log<level::ERR>(
+            "fsi path of target not found",
+            entry("PROC_TARGET_PATH=%s", pdbg_target_path(procTarget)));
+        return nullptr;
+    }
+
+    return fsiTarget;
+}
+
+uint32_t probeTarget(struct pdbg_target* procTarget)
+{
+    struct pdbg_target* pibTarget = nullptr;
+    pdbg_for_each_target("pib", procTarget, pibTarget)
+    {
+        // grab first one we find
+        break;
+    }
+    if (!pibTarget)
+    {
+        log<level::ERR>(
+            "pib path of target not found",
+            entry("PROC_TARGET_PATH=%s", pdbg_target_path(procTarget)));
+        return -1;
+    }
+    // probe PIB and ensure it's enabled
+    if (PDBG_TARGET_ENABLED != pdbg_target_probe(pibTarget))
+    {
+        log<level::ERR>(
+            "probe on pib target failed",
+            entry("PIB_TARGET_PATH=%s", pdbg_target_path(pibTarget)));
+        return -1;
+    }
+    return 0;
+}
+
+uint32_t getCFAM(struct pdbg_target* procTarget, const uint32_t reg,
+                 uint32_t& val)
+{
+
+    pdbg_target* fsiTarget = getFsiTarget(procTarget);
+    if (nullptr == fsiTarget)
+    {
+        log<level::ERR>("getCFAM: fsi path or target not found");
+        return -1;
+    }
+
+    auto rc = probeTarget(procTarget);
+    if (rc)
+    {
+        // probe function logged details to journal
+        return rc;
+    }
+
+    rc = fsi_read(fsiTarget, reg, &val);
+    if (rc)
+    {
+        log<level::ERR>(
+            "failed to read input cfam", entry("RC=%u", rc),
+            entry("CFAM=0x%X", reg),
+            entry("FSI_TARGET_PATH=%s", pdbg_target_path(fsiTarget)));
+        return rc;
+    }
+    return 0;
+}
+
+uint32_t putCFAM(struct pdbg_target* procTarget, const uint32_t reg,
+                 const uint32_t val)
+{
+    pdbg_target* fsiTarget = getFsiTarget(procTarget);
+    if (nullptr == fsiTarget)
+    {
+        log<level::ERR>("putCFAM: fsi path or target not found");
+        return -1;
+    }
+
+    auto rc = probeTarget(procTarget);
+    if (rc)
+    {
+        // probe function logged details to journal
+        return rc;
+    }
+
+    rc = fsi_write(fsiTarget, reg, val);
+    if (rc)
+    {
+        log<level::ERR>(
+            "failed to write input cfam", entry("RC=%u", rc),
+            entry("CFAM=0x%X", reg),
+            entry("FSI_TARGET_PATH=%s", pdbg_target_path(fsiTarget)));
+        return rc;
+    }
+    return 0;
+}
+
+void setDevtreeEnv()
+{
+    // PDBG_DTB environment variable set to CEC device tree path
+    static constexpr auto PDBG_DTB_PATH =
+        "/var/lib/phosphor-software-manager/pnor/rw/DEVTREE";
+
+    if (setenv("PDBG_DTB", PDBG_DTB_PATH, 1))
+    {
+        log<level::ERR>(
+            fmt::format("Failed to set PDBG_DTB: ({})", strerror(errno))
+                .c_str());
+        throw std::runtime_error("Failed to set PDBG_DTB");
+    }
+}
+
+} // namespace phal
+} // namespace openpower