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b366fa2f49
DPIF AVX512 optimizations currently rely on DPDK availability while they can be used without DPDK. Besides, checking for availability of some isa only has to be done once and won't change while a OVS process runs. Resolve isa availability in constructors by using a simplified query based on cpuid API that comes from the compiler. Note: this also fixes the check on BMI2 availability: DPDK had a bug for this isa, see https://git.dpdk.org/dpdk/commit/?id=aae3037ab1e0. Suggested-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: David Marchand <david.marchand@redhat.com> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
69 lines
1.9 KiB
C
69 lines
1.9 KiB
C
/*
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* Copyright (c) 2021, Red Hat, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <config.h>
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#include "cpu.h"
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#include "openvswitch/compiler.h"
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#ifdef __x86_64__
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#include <cpuid.h>
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#include <inttypes.h>
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#include "openvswitch/util.h"
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enum x86_reg {
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EAX,
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EBX,
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ECX,
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EDX,
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};
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#define X86_LEAF_MASK 0x80000000
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#define X86_EXT_FEATURES_LEAF 0x00000007
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static bool x86_has_isa(uint32_t leaf, enum x86_reg reg, uint32_t bit)
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{
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uint32_t regs[4];
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ovs_assert(__get_cpuid_max(leaf & X86_LEAF_MASK, NULL) >= leaf);
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__cpuid_count(leaf, 0, regs[EAX], regs[EBX], regs[ECX], regs[EDX]);
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return (regs[reg] & ((uint32_t) 1 << bit)) != 0;
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}
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static bool x86_isa[OVS_CPU_ISA_X86_LAST - OVS_CPU_ISA_X86_FIRST + 1];
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#define X86_ISA(leaf, reg, bit, name) \
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OVS_CONSTRUCTOR(cpu_isa_ ## name) { \
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x86_isa[name - OVS_CPU_ISA_X86_FIRST] = x86_has_isa(leaf, reg, bit); \
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}
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X86_ISA(X86_EXT_FEATURES_LEAF, EBX, 8, OVS_CPU_ISA_X86_BMI2)
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X86_ISA(X86_EXT_FEATURES_LEAF, EBX, 16, OVS_CPU_ISA_X86_AVX512F)
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X86_ISA(X86_EXT_FEATURES_LEAF, EBX, 30, OVS_CPU_ISA_X86_AVX512BW)
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X86_ISA(X86_EXT_FEATURES_LEAF, ECX, 1, OVS_CPU_ISA_X86_AVX512VBMI)
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X86_ISA(X86_EXT_FEATURES_LEAF, ECX, 14, OVS_CPU_ISA_X86_VPOPCNTDQ)
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#endif
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bool
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cpu_has_isa(enum ovs_cpu_isa isa OVS_UNUSED)
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{
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#ifdef __x86_64__
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if (isa >= OVS_CPU_ISA_X86_FIRST &&
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isa <= OVS_CPU_ISA_X86_LAST) {
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return x86_isa[isa - OVS_CPU_ISA_X86_FIRST];
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}
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#endif
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return false;
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}
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