eal/arm: detect arm architecture in cpu flags

Based on the patch by David Hunt and Armuta Zende:

  lib: added support for armv7 architecture

Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
Signed-off-by: Amruta Zende <amruta.zende@intel.com>
Signed-off-by: David Hunt <david.hunt@intel.com>

lib/librte_eal/common/include/arch/arm/rte_cpuflags.h

@@ -52,10 +52,15 @@ extern "C" {
 #define AT_HWCAP2 26
 #endif
 
+#ifndef AT_PLATFORM
+#define AT_PLATFORM 15
+#endif
+
 /* software based registers */
 enum cpu_register_t {
 	REG_HWCAP = 0,
 	REG_HWCAP2,
+	REG_PLATFORM,
 };
 
 /**
@@ -89,6 +94,8 @@ enum rte_cpu_flag_t {
 	RTE_CPUFLAG_SHA1,
 	RTE_CPUFLAG_SHA2,
 	RTE_CPUFLAG_CRC32,
+	RTE_CPUFLAG_AARCH32,
+	RTE_CPUFLAG_AARCH64,
 	/* The last item */
 	RTE_CPUFLAG_NUMFLAGS,/**< This should always be the last! */
 };
@@ -121,6 +128,8 @@ static const struct feature_entry cpu_feature_table[] = {
 	FEAT_DEF(SHA1,      0x00000001, 0, REG_HWCAP2,  2)
 	FEAT_DEF(SHA2,      0x00000001, 0, REG_HWCAP2,  3)
 	FEAT_DEF(CRC32,     0x00000001, 0, REG_HWCAP2,  4)
+	FEAT_DEF(AARCH32,   0x00000001, 0, REG_PLATFORM, 0)
+	FEAT_DEF(AARCH64,   0x00000001, 0, REG_PLATFORM, 1)
 };
 
 /*
@@ -141,6 +150,12 @@ rte_cpu_get_features(__attribute__((unused)) uint32_t leaf,
 			out[REG_HWCAP] = auxv.a_un.a_val;
 		else if (auxv.a_type == AT_HWCAP2)
 			out[REG_HWCAP2] = auxv.a_un.a_val;
+		else if (auxv.a_type == AT_PLATFORM) {
+			if (!strcmp((const char *)auxv.a_un.a_val, "aarch32"))
+				out[REG_PLATFORM] = 0x0001;
+			else if (!strcmp((const char *)auxv.a_un.a_val, "aarch64"))
+				out[REG_PLATFORM] = 0x0002;
+		}
 	}
 }