[dpdk-dev] [PATCH 03/11] lib: add armv8 rte_cpuflags.h

[David Hunt <david.hunt@intel.com>]

From: Benjamin Boren <Ben.Boren@intel.com>

Signed-off-by: Benjamin Boren <Ben.Boren@intel.com>
Signed-off-by: David Hunt <david.hunt@intel.com>
---
 .../common/include/arch/arm64/rte_cpuflags.h       | 137 +++++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 lib/librte_eal/common/include/arch/arm64/rte_cpuflags.h

diff --git a/lib/librte_eal/common/include/arch/arm64/rte_cpuflags.h b/lib/librte_eal/common/include/arch/arm64/rte_cpuflags.h
new file mode 100644
index 0000000..b4dcf9d
--- /dev/null
+++ b/lib/librte_eal/common/include/arch/arm64/rte_cpuflags.h
@@ -0,0 +1,137 @@
+/*
+ *   BSD LICENSE
+ *
+ *   Copyright (C) IBM Corporation 2014.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of IBM Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef _RTE_CPUFLAGS_ARM_64_H_
+#define _RTE_CPUFLAGS_ARM_64_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <elf.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "generic/rte_cpuflags.h"
+
+/* Symbolic values for the entries in the auxiliary table */
+#define AT_HWCAP  16
+#define AT_HWCAP2 26
+#define AT_PLATFORM 15
+
+/* software based registers */
+enum cpu_register_t {
+	REG_HWCAP = 0,
+	AARCH_MODE,
+};
+
+/**
+ * Enumeration of all CPU features supported
+ */
+enum rte_cpu_flag_t {
+	RTE_CPUFLAG_FP = 0,
+	RTE_CPUFLAG_ASIMD,
+	RTE_CPUFLAG_EVTSTRM,
+	RTE_CPUFLAG_AARCH64,
+	RTE_CPUFLAG_AARCH32,
+	/* The last item */
+	RTE_CPUFLAG_NUMFLAGS,/**< This should always be the last! */
+};
+
+static const struct feature_entry cpu_feature_table[] = {
+	FEAT_DEF(FP, 0x00000001, 0, REG_HWCAP,  0)
+	FEAT_DEF(ASIMD, 0x00000001, 0, REG_HWCAP,  1)
+	FEAT_DEF(EVTSTRM, 0x00000001, 0, REG_HWCAP,  2)
+	FEAT_DEF(AARCH64, 0x00000001, 0, AARCH_MODE, 3)
+	FEAT_DEF(AARCH32, 0x00000001, 0, AARCH_MODE, 4)
+};
+
+/*
+ * Read AUXV software register and get cpu features for Power
+ */
+static inline void
+rte_cpu_get_features(__attribute__((unused)) uint32_t leaf,
+	__attribute__((unused)) uint32_t subleaf, cpuid_registers_t out)
+{
+	int auxv_fd;
+	Elf64_auxv_t auxv;
+
+	auxv_fd = open("/proc/self/auxv", O_RDONLY);
+	assert(auxv_fd);
+	while (read(auxv_fd, &auxv,
+		sizeof(Elf64_auxv_t)) == sizeof(Elf64_auxv_t)) {
+		if (auxv.a_type == AT_HWCAP)
+			out[REG_HWCAP] = auxv.a_un.a_val;
+		if (auxv.a_type == AT_PLATFORM) {
+			if (strcmp((const char *)auxv.a_un.a_val,
+					"aarch64") == 0)
+				out[AARCH_MODE] = (1 << 3);
+			else if (strcmp((const char *)auxv.a_un.a_val,
+					"aarch32") == 0)
+				out[AARCH_MODE] =  (1 << 4);
+		}
+	}
+}
+
+/*
+ * Checks if a particular flag is available on current machine.
+ */
+static inline int
+rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature)
+{
+	const struct feature_entry *feat;
+	cpuid_registers_t regs = {0};
+
+	if (feature >= RTE_CPUFLAG_NUMFLAGS)
+		/* Flag does not match anything in the feature tables */
+		return -ENOENT;
+
+	feat = &cpu_feature_table[feature];
+
+	if (!feat->leaf)
+		/* This entry in the table wasn't filled out! */
+		return -EFAULT;
+
+	/* get the cpuid leaf containing the desired feature */
+	rte_cpu_get_features(feat->leaf, feat->subleaf, regs);
+
+	/* check if the feature is enabled */
+	return (regs[feat->reg] >> feat->bit) & 1;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_CPUFLAGS_ARM_64_H_ */
-- 
2.1.4