[dpdk-dev] [PATCH v2 1/3] eal: introduce big and little endian types

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

From: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

This commit introduces new rte_{le,be}{16,32,64}_t types and updates
rte_{le,be,cpu}_to_{le,be,cpu}_*() accordingly.

These types are added for documentation purposes, mainly to clarify the
byte ordering to use for storage when not CPU order. Doing so eliminates
uncertainty and conversion mistakes.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>

---

This is a rehash of Nelio's original patch [1] that drops all changes to
protocol header structures and only focuses on adding these new types for
documentation purposes.

[1] http://dpdk.org/ml/archives/dev/2016-November/050060.html
---
 .../common/include/generic/rte_byteorder.h      | 38 +++++++++++++-------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/lib/librte_eal/common/include/generic/rte_byteorder.h b/lib/librte_eal/common/include/generic/rte_byteorder.h
index e00bccb..df8cc84 100644
--- a/lib/librte_eal/common/include/generic/rte_byteorder.h
+++ b/lib/librte_eal/common/include/generic/rte_byteorder.h
@@ -76,6 +76,20 @@
 #endif
 
 /*
+ * The following types should be used when handling values according to a
+ * specific byte ordering, which may differ from that of the host CPU.
+ *
+ * Libraries, public APIs and applications are encouraged to use them for
+ * documentation purposes.
+ */
+typedef uint16_t rte_be16_t; /**< 16-bit big-endian value. */
+typedef uint32_t rte_be32_t; /**< 32-bit big-endian value. */
+typedef uint64_t rte_be64_t; /**< 64-bit big-endian value. */
+typedef uint16_t rte_le16_t; /**< 16-bit little-endian value. */
+typedef uint32_t rte_le32_t; /**< 32-bit little-endian value. */
+typedef uint64_t rte_le64_t; /**< 64-bit little-endian value. */
+
+/*
  * An internal function to swap bytes in a 16-bit value.
  *
  * It is used by rte_bswap16() when the value is constant. Do not use
@@ -143,65 +157,65 @@ static uint64_t rte_bswap64(uint64_t x);
 /**
  * Convert a 16-bit value from CPU order to little endian.
  */
-static uint16_t rte_cpu_to_le_16(uint16_t x);
+static rte_le16_t rte_cpu_to_le_16(uint16_t x);
 
 /**
  * Convert a 32-bit value from CPU order to little endian.
  */
-static uint32_t rte_cpu_to_le_32(uint32_t x);
+static rte_le32_t rte_cpu_to_le_32(uint32_t x);
 
 /**
  * Convert a 64-bit value from CPU order to little endian.
  */
-static uint64_t rte_cpu_to_le_64(uint64_t x);
+static rte_le64_t rte_cpu_to_le_64(uint64_t x);
 
 
 /**
  * Convert a 16-bit value from CPU order to big endian.
  */
-static uint16_t rte_cpu_to_be_16(uint16_t x);
+static rte_be16_t rte_cpu_to_be_16(uint16_t x);
 
 /**
  * Convert a 32-bit value from CPU order to big endian.
  */
-static uint32_t rte_cpu_to_be_32(uint32_t x);
+static rte_be32_t rte_cpu_to_be_32(uint32_t x);
 
 /**
  * Convert a 64-bit value from CPU order to big endian.
  */
-static uint64_t rte_cpu_to_be_64(uint64_t x);
+static rte_be64_t rte_cpu_to_be_64(uint64_t x);
 
 
 /**
  * Convert a 16-bit value from little endian to CPU order.
  */
-static uint16_t rte_le_to_cpu_16(uint16_t x);
+static uint16_t rte_le_to_cpu_16(rte_le16_t x);
 
 /**
  * Convert a 32-bit value from little endian to CPU order.
  */
-static uint32_t rte_le_to_cpu_32(uint32_t x);
+static uint32_t rte_le_to_cpu_32(rte_le32_t x);
 
 /**
  * Convert a 64-bit value from little endian to CPU order.
  */
-static uint64_t rte_le_to_cpu_64(uint64_t x);
+static uint64_t rte_le_to_cpu_64(rte_le64_t x);
 
 
 /**
  * Convert a 16-bit value from big endian to CPU order.
  */
-static uint16_t rte_be_to_cpu_16(uint16_t x);
+static uint16_t rte_be_to_cpu_16(rte_be16_t x);
 
 /**
  * Convert a 32-bit value from big endian to CPU order.
  */
-static uint32_t rte_be_to_cpu_32(uint32_t x);
+static uint32_t rte_be_to_cpu_32(rte_be32_t x);
 
 /**
  * Convert a 64-bit value from big endian to CPU order.
  */
-static uint64_t rte_be_to_cpu_64(uint64_t x);
+static uint64_t rte_be_to_cpu_64(rte_be64_t x);
 
 #endif /* __DOXYGEN__ */
 
-- 
2.1.4