[dpdk-dev] [PATCH v5 1/2] net: add run-time architecture specific CRC selection

[Mairtin o Loingsigh <mairtin.oloingsigh@intel.com>]

This patch adds support for run-time selection of the optimal
architecture-specific CRC path, based on the supported instruction set(s)
of the CPU.

The compiler option checks have been moved from the C files to the meson
script. The rte_cpu_get_flag_enabled function is called automatically by
the library at process initialization time to determine which
instructions the CPU supports, with the most optimal supported CRC path
ultimately selected.

Signed-off-by: Mairtin o Loingsigh <mairtin.oloingsigh@intel.com>
Signed-off-by: David Coyle <david.coyle@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
 doc/guides/rel_notes/release_20_11.rst            |   4 +
 lib/librte_net/meson.build                        |  34 ++++++-
 lib/librte_net/net_crc.h                          |  34 +++++++
 lib/librte_net/{net_crc_neon.h => net_crc_neon.c} |  26 ++---
 lib/librte_net/{net_crc_sse.h => net_crc_sse.c}   |  34 ++-----
 lib/librte_net/rte_net_crc.c                      | 116 +++++++++++++++-------
 6 files changed, 168 insertions(+), 80 deletions(-)
 create mode 100644 lib/librte_net/net_crc.h
 rename lib/librte_net/{net_crc_neon.h => net_crc_neon.c} (95%)
 rename lib/librte_net/{net_crc_sse.h => net_crc_sse.c} (94%)

diff --git a/doc/guides/rel_notes/release_20_11.rst b/doc/guides/rel_notes/release_20_11.rst
index 808bdc4e5..b77297f7e 100644
--- a/doc/guides/rel_notes/release_20_11.rst
+++ b/doc/guides/rel_notes/release_20_11.rst
@@ -55,6 +55,10 @@ New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Updated CRC modules of rte_net library.**
+
+  * Added run-time selection of the optimal architecture-specific CRC path.
+
 * **Updated Broadcom bnxt driver.**
 
   Updated the Broadcom bnxt driver with new features and improvements, including:
diff --git a/lib/librte_net/meson.build b/lib/librte_net/meson.build
index 24ed8253b..fa439b9e5 100644
--- a/lib/librte_net/meson.build
+++ b/lib/librte_net/meson.build
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: BSD-3-Clause
-# Copyright(c) 2017 Intel Corporation
+# Copyright(c) 2017-2020 Intel Corporation
 
 headers = files('rte_ip.h',
 	'rte_tcp.h',
@@ -20,3 +20,35 @@ headers = files('rte_ip.h',
 
 sources = files('rte_arp.c', 'rte_ether.c', 'rte_net.c', 'rte_net_crc.c')
 deps += ['mbuf']
+
+if dpdk_conf.has('RTE_ARCH_X86_64')
+	net_crc_sse42_cpu_support = (
+		cc.get_define('__PCLMUL__', args: machine_args) != '')
+	net_crc_sse42_cc_support = (
+		cc.has_argument('-mpclmul') and cc.has_argument('-maes'))
+
+	build_static_net_crc_sse42_lib = 0
+
+	if net_crc_sse42_cpu_support == true
+		sources += files('net_crc_sse.c')
+		cflags += ['-DCC_X86_64_SSE42_PCLMULQDQ_SUPPORT']
+	elif net_crc_sse42_cc_support == true
+		build_static_net_crc_sse42_lib = 1
+		net_crc_sse42_lib_cflags = ['-mpclmul', '-maes']
+		cflags += ['-DCC_X86_64_SSE42_PCLMULQDQ_SUPPORT']
+	endif
+
+	if build_static_net_crc_sse42_lib == 1
+		net_crc_sse42_lib = static_library(
+					'net_crc_sse42_lib',
+					'net_crc_sse.c',
+					dependencies: static_rte_eal,
+					c_args: [cflags,
+						net_crc_sse42_lib_cflags])
+		objs += net_crc_sse42_lib.extract_objects('net_crc_sse.c')
+	endif
+elif (dpdk_conf.has('RTE_ARCH_ARM64') and
+		cc.get_define('__ARM_FEATURE_CRYPTO', args: machine_args) != '')
+	sources += files('net_crc_neon.c')
+	cflags += ['-DCC_ARM64_NEON_PMULL_SUPPORT']
+endif
diff --git a/lib/librte_net/net_crc.h b/lib/librte_net/net_crc.h
new file mode 100644
index 000000000..a1578a56c
--- /dev/null
+++ b/lib/librte_net/net_crc.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2020 Intel Corporation
+ */
+
+#ifndef _NET_CRC_H_
+#define _NET_CRC_H_
+
+/*
+ * Different implementations of CRC
+ */
+
+/* SSE4.2 */
+
+void
+rte_net_crc_sse42_init(void);
+
+uint32_t
+rte_crc16_ccitt_sse42_handler(const uint8_t *data, uint32_t data_len);
+
+uint32_t
+rte_crc32_eth_sse42_handler(const uint8_t *data, uint32_t data_len);
+
+/* NEON */
+
+void
+rte_net_crc_neon_init(void);
+
+uint32_t
+rte_crc16_ccitt_neon_handler(const uint8_t *data, uint32_t data_len);
+
+uint32_t
+rte_crc32_eth_neon_handler(const uint8_t *data, uint32_t data_len);
+
+#endif /* _NET_CRC_H_ */
diff --git a/lib/librte_net/net_crc_neon.h b/lib/librte_net/net_crc_neon.c
similarity index 95%
rename from lib/librte_net/net_crc_neon.h
rename to lib/librte_net/net_crc_neon.c
index 63fa1d4a1..f61d75a8c 100644
--- a/lib/librte_net/net_crc_neon.h
+++ b/lib/librte_net/net_crc_neon.c
@@ -2,17 +2,15 @@
  * Copyright(c) 2017 Cavium, Inc
  */
 
-#ifndef _NET_CRC_NEON_H_
-#define _NET_CRC_NEON_H_
+#include <string.h>
 
+#include <rte_common.h>
 #include <rte_branch_prediction.h>
 #include <rte_net_crc.h>
 #include <rte_vect.h>
 #include <rte_cpuflags.h>
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include "net_crc.h"
 
 /** PMULL CRC computation context structure */
 struct crc_pmull_ctx {
@@ -218,7 +216,7 @@ crc32_eth_calc_pmull(
 	return n;
 }
 
-static inline void
+void
 rte_net_crc_neon_init(void)
 {
 	/* Initialize CRC16 data */
@@ -242,9 +240,8 @@ rte_net_crc_neon_init(void)
 	crc32_eth_pmull.rk7_rk8 = vld1q_u64(eth_k7_k8);
 }
 
-static inline uint32_t
-rte_crc16_ccitt_neon_handler(const uint8_t *data,
-	uint32_t data_len)
+uint32_t
+rte_crc16_ccitt_neon_handler(const uint8_t *data, uint32_t data_len)
 {
 	return (uint16_t)~crc32_eth_calc_pmull(data,
 		data_len,
@@ -252,18 +249,11 @@ rte_crc16_ccitt_neon_handler(const uint8_t *data,
 		&crc16_ccitt_pmull);
 }
 
-static inline uint32_t
-rte_crc32_eth_neon_handler(const uint8_t *data,
-	uint32_t data_len)
+uint32_t
+rte_crc32_eth_neon_handler(const uint8_t *data, uint32_t data_len)
 {
 	return ~crc32_eth_calc_pmull(data,
 		data_len,
 		0xffffffffUL,
 		&crc32_eth_pmull);
 }
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _NET_CRC_NEON_H_ */
diff --git a/lib/librte_net/net_crc_sse.h b/lib/librte_net/net_crc_sse.c
similarity index 94%
rename from lib/librte_net/net_crc_sse.h
rename to lib/librte_net/net_crc_sse.c
index 1c7b7a548..053b54b39 100644
--- a/lib/librte_net/net_crc_sse.h
+++ b/lib/librte_net/net_crc_sse.c
@@ -1,18 +1,16 @@
 /* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2017 Intel Corporation
+ * Copyright(c) 2017-2020 Intel Corporation
  */
 
-#ifndef _RTE_NET_CRC_SSE_H_
-#define _RTE_NET_CRC_SSE_H_
+#include <string.h>
 
+#include <rte_common.h>
 #include <rte_branch_prediction.h>
+#include <rte_cpuflags.h>
 
-#include <x86intrin.h>
-#include <cpuid.h>
+#include "net_crc.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include <x86intrin.h>
 
 /** PCLMULQDQ CRC computation context structure */
 struct crc_pclmulqdq_ctx {
@@ -259,8 +257,7 @@ crc32_eth_calc_pclmulqdq(
 	return n;
 }
 
-
-static inline void
+void
 rte_net_crc_sse42_init(void)
 {
 	uint64_t k1, k2, k5, k6;
@@ -303,12 +300,10 @@ rte_net_crc_sse42_init(void)
 	 * use other data types such as float, double, etc.
 	 */
 	_mm_empty();
-
 }
 
-static inline uint32_t
-rte_crc16_ccitt_sse42_handler(const uint8_t *data,
-	uint32_t data_len)
+uint32_t
+rte_crc16_ccitt_sse42_handler(const uint8_t *data, uint32_t data_len)
 {
 	/** return 16-bit CRC value */
 	return (uint16_t)~crc32_eth_calc_pclmulqdq(data,
@@ -317,18 +312,11 @@ rte_crc16_ccitt_sse42_handler(const uint8_t *data,
 		&crc16_ccitt_pclmulqdq);
 }
 
-static inline uint32_t
-rte_crc32_eth_sse42_handler(const uint8_t *data,
-	uint32_t data_len)
+uint32_t
+rte_crc32_eth_sse42_handler(const uint8_t *data, uint32_t data_len)
 {
 	return ~crc32_eth_calc_pclmulqdq(data,
 		data_len,
 		0xffffffffUL,
 		&crc32_eth_pclmulqdq);
 }
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _RTE_NET_CRC_SSE_H_ */
diff --git a/lib/librte_net/rte_net_crc.c b/lib/librte_net/rte_net_crc.c
index 4f5b9e828..d271d5205 100644
--- a/lib/librte_net/rte_net_crc.c
+++ b/lib/librte_net/rte_net_crc.c
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2017 Intel Corporation
+ * Copyright(c) 2017-2020 Intel Corporation
  */
 
 #include <stddef.h>
@@ -10,17 +10,7 @@
 #include <rte_common.h>
 #include <rte_net_crc.h>
 
-#if defined(RTE_ARCH_X86_64) && defined(__PCLMUL__)
-#define X86_64_SSE42_PCLMULQDQ     1
-#elif defined(RTE_ARCH_ARM64) && defined(__ARM_FEATURE_CRYPTO)
-#define ARM64_NEON_PMULL           1
-#endif
-
-#ifdef X86_64_SSE42_PCLMULQDQ
-#include <net_crc_sse.h>
-#elif defined ARM64_NEON_PMULL
-#include <net_crc_neon.h>
-#endif
+#include "net_crc.h"
 
 /** CRC polynomials */
 #define CRC32_ETH_POLYNOMIAL 0x04c11db7UL
@@ -41,25 +31,27 @@ rte_crc32_eth_handler(const uint8_t *data, uint32_t data_len);
 typedef uint32_t
 (*rte_net_crc_handler)(const uint8_t *data, uint32_t data_len);
 
-static rte_net_crc_handler *handlers;
+static const rte_net_crc_handler *handlers;
 
-static rte_net_crc_handler handlers_scalar[] = {
+static const rte_net_crc_handler handlers_scalar[] = {
 	[RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_handler,
 	[RTE_NET_CRC32_ETH] = rte_crc32_eth_handler,
 };
-
-#ifdef X86_64_SSE42_PCLMULQDQ
-static rte_net_crc_handler handlers_sse42[] = {
+#ifdef CC_X86_64_SSE42_PCLMULQDQ_SUPPORT
+static const rte_net_crc_handler handlers_sse42[] = {
 	[RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_sse42_handler,
 	[RTE_NET_CRC32_ETH] = rte_crc32_eth_sse42_handler,
 };
-#elif defined ARM64_NEON_PMULL
-static rte_net_crc_handler handlers_neon[] = {
+#endif
+#ifdef CC_ARM64_NEON_PMULL_SUPPORT
+static const rte_net_crc_handler handlers_neon[] = {
 	[RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_neon_handler,
 	[RTE_NET_CRC32_ETH] = rte_crc32_eth_neon_handler,
 };
 #endif
 
+/* Scalar handling */
+
 /**
  * Reflect the bits about the middle
  *
@@ -142,29 +134,82 @@ rte_crc32_eth_handler(const uint8_t *data, uint32_t data_len)
 		crc32_eth_lut);
 }
 
+/* SSE4.2/PCLMULQDQ handling */
+
+#define SSE42_PCLMULQDQ_CPU_SUPPORTED \
+	rte_cpu_get_flag_enabled(RTE_CPUFLAG_PCLMULQDQ)
+
+static const rte_net_crc_handler *
+sse42_pclmulqdq_get_handlers(void)
+{
+#ifdef CC_X86_64_SSE42_PCLMULQDQ_SUPPORT
+	if (SSE42_PCLMULQDQ_CPU_SUPPORTED)
+		return handlers_sse42;
+#endif
+	return NULL;
+}
+
+static uint8_t
+sse42_pclmulqdq_init(void)
+{
+#ifdef CC_X86_64_SSE42_PCLMULQDQ_SUPPORT
+	if (SSE42_PCLMULQDQ_CPU_SUPPORTED) {
+		rte_net_crc_sse42_init();
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/* NEON/PMULL handling */
+
+#define NEON_PMULL_CPU_SUPPORTED \
+	rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)
+
+static const rte_net_crc_handler *
+neon_pmull_get_handlers(void)
+{
+#ifdef CC_ARM64_NEON_PMULL_SUPPORT
+	if (NEON_PMULL_CPU_SUPPORTED)
+		return handlers_neon;
+#endif
+	return NULL;
+}
+
+static uint8_t
+neon_pmull_init(void)
+{
+#ifdef CC_ARM64_NEON_PMULL_SUPPORT
+	if (NEON_PMULL_CPU_SUPPORTED) {
+		rte_net_crc_neon_init();
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/* Public API */
+
 void
 rte_net_crc_set_alg(enum rte_net_crc_alg alg)
 {
+	handlers = NULL;
+
 	switch (alg) {
-#ifdef X86_64_SSE42_PCLMULQDQ
 	case RTE_NET_CRC_SSE42:
-		handlers = handlers_sse42;
-		break;
-#elif defined ARM64_NEON_PMULL
-		/* fall-through */
+		handlers = sse42_pclmulqdq_get_handlers();
+		break; /* for x86, always break here */
 	case RTE_NET_CRC_NEON:
-		if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)) {
-			handlers = handlers_neon;
-			break;
-		}
-#endif
+		handlers = neon_pmull_get_handlers();
 		/* fall-through */
 	case RTE_NET_CRC_SCALAR:
 		/* fall-through */
 	default:
-		handlers = handlers_scalar;
 		break;
 	}
+
+	if (handlers == NULL)
+		handlers = handlers_scalar;
 }
 
 uint32_t
@@ -188,15 +233,10 @@ RTE_INIT(rte_net_crc_init)
 
 	rte_net_crc_scalar_init();
 
-#ifdef X86_64_SSE42_PCLMULQDQ
-	alg = RTE_NET_CRC_SSE42;
-	rte_net_crc_sse42_init();
-#elif defined ARM64_NEON_PMULL
-	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)) {
+	if (sse42_pclmulqdq_init())
+		alg = RTE_NET_CRC_SSE42;
+	if (neon_pmull_init())
 		alg = RTE_NET_CRC_NEON;
-		rte_net_crc_neon_init();
-	}
-#endif
 
 	rte_net_crc_set_alg(alg);
 }
-- 
2.12.3