commit afa1d226ef13f36bc98093b34e63d2209f16e1db
author Joel Stanley <joel@jms.id.au> Fri Sep 27 15:35:04 2019 +0930
committer Joel Stanley <joel@jms.id.au> Sat Sep 28 21:15:07 2019 +0930
tree 298b0501c78647a9e0a52ca686c40b7548532709
parent 424475d4b9c9af78813326c427225bf76a9236f9

Remove endian swapping abstraction

All supported kernels (and since 4.10) emit data in big endian. This
removes the run time abstraction and uses htobe32 unconditionally.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Change-Id: Ibdfae6b7b958c876e4ab0c89ecb130ec58ce2fac

cfam_access.cpp

diff --git a/cfam_access.cpp b/cfam_access.cpp
index 2538eb0..810a281 100644
--- a/cfam_access.cpp
+++ b/cfam_access.cpp
@@ -66,7 +66,7 @@
                                metadata::PATH(target->getCFAMPath().c_str()));
     }
 
-    data = target->swapEndian(data);
+    data = htobe32(data);
 
     rc = write(target->getCFAMFD(), &data, cfamRegSize);
     if (rc < 0)
@@ -110,7 +110,7 @@
             metadata::CALLOUT_DEVICE_PATH(target->getCFAMPath().c_str()));
     }
 
-    return target->swapEndian(data);
+    return be32toh(data);
 }
 
 void writeRegWithMask(const std::unique_ptr<Target>& target,

targeting.cpp

diff --git a/targeting.cpp b/targeting.cpp
index 7dd68ef..a9f3d8e 100644
--- a/targeting.cpp
+++ b/targeting.cpp
@@ -60,22 +60,11 @@
     }
 }
 
-static uint32_t noEndianSwap(uint32_t data)
-{
-    return data;
-}
-
-static uint32_t endianSwap(uint32_t data)
-{
-    return htobe32(data);
-}
-
 Targeting::Targeting(const std::string& fsiMasterDev,
                      const std::string& fsiSlaveDir) :
     fsiMasterPath(fsiMasterDev),
     fsiSlaveBasePath(fsiSlaveDir)
 {
-    swap_endian_t swapper = endianSwap;
     std::regex exp{"fsi1/slave@([0-9]{2}):00", std::regex::extended};
 
     if (!fs::exists(fsiMasterPath))
@@ -86,13 +75,10 @@
         exp = expOld;
         fsiMasterPath = fsiMasterDevPathOld;
         fsiSlaveBasePath = fsiSlaveBaseDirOld;
-
-        // And don't swap the endianness of CFAM data
-        swapper = noEndianSwap;
     }
 
     // Always create P0, the FSI master.
-    targets.push_back(std::make_unique<Target>(0, fsiMasterPath, swapper));
+    targets.push_back(std::make_unique<Target>(0, fsiMasterPath));
     try
     {
         // Find the the remaining P9s dynamically based on which files show up
@@ -112,7 +98,7 @@
 
                 path += "/raw";
 
-                targets.push_back(std::make_unique<Target>(pos, path, swapper));
+                targets.push_back(std::make_unique<Target>(pos, path));
             }
         }
     }

targeting.hpp

diff --git a/targeting.hpp b/targeting.hpp
index 6d86b50..0ddae26 100644
--- a/targeting.hpp
+++ b/targeting.hpp
@@ -20,8 +20,6 @@
 constexpr auto fsiSlaveBaseDirOld =
     "/sys/devices/platform/fsi-master/slave@00:00/hub@00/";
 
-typedef uint32_t (*swap_endian_t)(uint32_t);
-
 /**
  * Represents a specific P9 processor in the system.  Used by
  * the access APIs to specify the chip to operate on.
@@ -34,12 +32,9 @@
      *
      * @param[in] - The logical position of the target
      * @param[in] - The sysfs device path
-     * @param[in] - The function pointer for swapping endianness
      */
-    Target(size_t position, const std::string& devPath,
-           const swap_endian_t swapper) :
-        pos(position),
-        cfamPath(devPath), doSwapEndian(swapper)
+    Target(size_t position, const std::string& devPath) :
+        pos(position), cfamPath(devPath)
     {
     }
 
@@ -71,16 +66,6 @@
      */
     int getCFAMFD();
 
-    /**
-     * Returns correct byte-order data. (May or may not swap it depending
-     * on the function received during construction from Targeting and the
-     * host endianness).
-     */
-    inline uint32_t swapEndian(uint32_t data) const
-    {
-        return doSwapEndian(data);
-    }
-
   private:
     /**
      * The logical position of this target
@@ -96,11 +81,6 @@
      * The file descriptor to use for read/writeCFAMReg
      */
     std::unique_ptr<openpower::util::FileDescriptor> cfamFD;
-
-    /**
-     * The function pointer for swapping endianness
-     */
-    const swap_endian_t doSwapEndian;
 };
 
 /**