linux-kernel - [PATCH 2/2] x86/cpu: Remove write_tsc() and write_rdtscp

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Message-Id: <20210504225632.1532621-3-seanjc@google.com>
Date:   Tue,  4 May 2021 15:56:32 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org
Cc:     "H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
        Reiji Watanabe <reijiw@...gle.com>,
        Jim Mattson <jmattson@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Sean Christopherson <seanjc@...gle.com>
Subject: [PATCH 2/2] x86/cpu: Remove write_tsc() and write_rdtscp_aux() wrappers

Drop write_tsc() and write_rdtscp_aux(); the former has no users, and the
latter has only a single user and is slightly misleading since the only
in-kernel consumer of MSR_TSC_AUX is RDPID, not RDTSCP.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/msr.h   | 4 ----
 arch/x86/kernel/cpu/common.c | 2 +-
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index e16cccdd0420..a3f87f1015d3 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -324,10 +324,6 @@ static inline int wrmsrl_safe(u32 msr, u64 val)
 	return wrmsr_safe(msr, (u32)val,  (u32)(val >> 32));
 }
 
-#define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high))
-
-#define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
-
 struct msr *msrs_alloc(void);
 void msrs_free(struct msr *msrs);
 int msr_set_bit(u32 msr, u8 bit);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1e576cc831c1..0fc80c5ba5ae 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1851,7 +1851,7 @@ static inline void setup_getcpu(int cpu)
 	struct desc_struct d = { };
 
 	if (boot_cpu_has(X86_FEATURE_RDTSCP) || boot_cpu_has(X86_FEATURE_RDPID))
-		write_rdtscp_aux(cpudata);
+		wrmsr(MSR_TSC_AUX, cpudata, 0);
 
 	/* Store CPU and node number in limit. */
 	d.limit0 = cpudata;
-- 
2.31.1.527.g47e6f16901-goog