From: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
To: dev@dpdk.org
Cc: konstantin.ananyev@intel.com, bruce.richardson@intel.com
Subject: [dpdk-dev] [PATCH] eal/x86: use cpuid builtin
Date: Wed, 23 Aug 2017 16:00:27 +0100 [thread overview]
Message-ID: <20170823150027.70565-2-sergio.gonzalez.monroy@intel.com> (raw)
In-Reply-To: <20170823150027.70565-1-sergio.gonzalez.monroy@intel.com>
GCC does have the __get_cpuid_count builtin which checks for maximum
supported leaf, but implementations differ between CLANG and GCC.
This change provides an implementation compatible with both GCC and
CLANG 3.4+.
Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---
lib/librte_eal/common/arch/x86/rte_cpuflags.c | 40 ++++++---------------------
1 file changed, 8 insertions(+), 32 deletions(-)
diff --git a/lib/librte_eal/common/arch/x86/rte_cpuflags.c b/lib/librte_eal/common/arch/x86/rte_cpuflags.c
index 0138257..7d4a0fe 100644
--- a/lib/librte_eal/common/arch/x86/rte_cpuflags.c
+++ b/lib/librte_eal/common/arch/x86/rte_cpuflags.c
@@ -36,6 +36,7 @@
#include <stdio.h>
#include <errno.h>
#include <stdint.h>
+#include <cpuid.h>
enum cpu_register_t {
RTE_REG_EAX = 0,
@@ -156,38 +157,12 @@ const struct feature_entry rte_cpu_feature_table[] = {
FEAT_DEF(INVTSC, 0x80000007, 0, RTE_REG_EDX, 8)
};
-/*
- * Execute CPUID instruction and get contents of a specific register
- *
- * This function, when compiled with GCC, will generate architecture-neutral
- * code, as per GCC manual.
- */
-static void
-rte_cpu_get_features(uint32_t leaf, uint32_t subleaf, cpuid_registers_t out)
-{
-#if defined(__i386__) && defined(__PIC__)
- /* %ebx is a forbidden register if we compile with -fPIC or -fPIE */
- asm volatile("movl %%ebx,%0 ; cpuid ; xchgl %%ebx,%0"
- : "=r" (out[RTE_REG_EBX]),
- "=a" (out[RTE_REG_EAX]),
- "=c" (out[RTE_REG_ECX]),
- "=d" (out[RTE_REG_EDX])
- : "a" (leaf), "c" (subleaf));
-#else
- asm volatile("cpuid"
- : "=a" (out[RTE_REG_EAX]),
- "=b" (out[RTE_REG_EBX]),
- "=c" (out[RTE_REG_ECX]),
- "=d" (out[RTE_REG_EDX])
- : "a" (leaf), "c" (subleaf));
-#endif
-}
-
int
rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature)
{
const struct feature_entry *feat;
cpuid_registers_t regs;
+ unsigned int maxleaf;
if (feature >= RTE_CPUFLAG_NUMFLAGS)
/* Flag does not match anything in the feature tables */
@@ -199,13 +174,14 @@ rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature)
/* This entry in the table wasn't filled out! */
return -EFAULT;
- rte_cpu_get_features(feat->leaf & 0xffff0000, 0, regs);
- if (((regs[RTE_REG_EAX] ^ feat->leaf) & 0xffff0000) ||
- regs[RTE_REG_EAX] < feat->leaf)
+ maxleaf = __get_cpuid_max(feat->leaf & 0x80000000, NULL);
+
+ if (maxleaf < feat->leaf)
return 0;
- /* get the cpuid leaf containing the desired feature */
- rte_cpu_get_features(feat->leaf, feat->subleaf, regs);
+ __cpuid_count(feat->leaf, feat->subleaf,
+ regs[RTE_REG_EAX], regs[RTE_REG_EBX],
+ regs[RTE_REG_ECX], regs[RTE_REG_EDX]);
/* check if the feature is enabled */
return (regs[feat->reg] >> feat->bit) & 1;
--
2.9.5
next prev parent reply other threads:[~2017-08-23 15:00 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-23 15:00 [dpdk-dev] [PATCH] eal/x86: implement x86 specific tsc hz Sergio Gonzalez Monroy
2017-08-23 15:00 ` Sergio Gonzalez Monroy [this message]
2017-10-04 23:39 ` [dpdk-dev] [PATCH] eal/x86: use cpuid builtin Ferruh Yigit
2017-10-11 20:00 ` Thomas Monjalon
2017-09-04 9:38 ` [dpdk-dev] [PATCH] eal/x86: implement x86 specific tsc hz Van Haaren, Harry
2017-09-04 10:24 ` Bruce Richardson
2017-09-04 10:32 ` Bruce Richardson
2017-10-02 10:09 ` [dpdk-dev] [PATCH v2] " Sergio Gonzalez Monroy
2017-10-02 11:17 ` [dpdk-dev] [PATCH v3] " Sergio Gonzalez Monroy
2017-10-02 11:24 ` Jerin Jacob
2017-10-02 11:27 ` Sergio Gonzalez Monroy
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