From nobody Fri Feb 03 16:50:31 2023 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4P7hVH6ks3z3kW1l; Fri, 3 Feb 2023 16:50:31 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4P7hVH65cZz3tL5; Fri, 3 Feb 2023 16:50:31 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1675443031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=YERnMaj7lgslK3JafaP9Z1IKbndVaKkfEl73UoqfnMs=; b=RBVOYKuoWx/2Mz2gwdeFeUhtzfWCiFfGm5ifGwrPE5/w5fn1dB/q02zRrPpMiLl3hh+VEO pi3aOSDJfjg4zA4yNsisf+z8U+rVIwuKd7IwWC5mbnVKS8EeNCHen86+f4EvzHnK6AgAul dWXQMbYl+NCXthTXFkPK4MdbhsnMC67NVlFNYk7KioPhUVcjZ7a6WjE8vTbW8OoklMCbFa gh4zmhbnQpCryz6UDFUM7W59HsGZQONMDI3LusPv3qqSKFb+SPM2LvWXmB23YEJWH0HKCA 39aWEH2+y0vX5/5VbhUNm/jSFhuAd4aksWBkTc8nsMBfvGYZI/qpTMGdDFS+Kg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1675443031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=YERnMaj7lgslK3JafaP9Z1IKbndVaKkfEl73UoqfnMs=; b=aDnorSCmnewL8sod1ZTinxrDgPYWEXZzFPC7YiYXWDsI4WmyZ1nDDQ3sBIkGz1u1AyHz5i gMRB0lduEl0YvNenvr8JmnPqo6aQAPd6jsO0QK5kb03iw7o93nfd6NyCB/R0cg1v9qg21W CGdGMJ8PzrViGFE9ypotghuocnvx4t3Xbr7oG5F64gN31/TFykiiR6OyRzxp5Wt1r3+6tX RzGHhpdDN0Q0+BhrVIEJtCYyelRi7L5whINpR0xEU0f0LGg9ZZYvX0fynWMjyoJGv+1f31 zzvQk6GlnV29+e8/AV8Gh/UUEp73NCqaKCX94zGug7A2hym9FvMfVrnazA9MdQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1675443031; a=rsa-sha256; cv=none; b=er3yZLenQ5xy+ZKkZWICAUq4Z9ynK70bdQ3J/HrNcPPLCinrsSCfQV7XnYpptrxsTDOe7O oo9CCuI2vHbG87pQPsIiO5qDoA8uVTjNv8pkFRTGG56Zm3UAH4RBTqxZYfv1dO/J0WSWuK qWauZQeBlVskY+R2fjVgeZUs9p4Q1AI0IQ4b/ZBEVStZZfk9zHqQgG/zbaOik90aTcwwwO tKffb+mZPGOWxSYmqFHgy0hEe2rR72JshPyazIH0d0AzgKklHRi1tD7fvs+z7k/oIo9hwn nHN0mQBSsXiVljajvZsJPSIo8IjpkZgr8u2CAQCCb5LN9BUqAh1ctWDrJHFxNg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4P7hVH59B9zhlp; Fri, 3 Feb 2023 16:50:31 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 313GoVgR009061; Fri, 3 Feb 2023 16:50:31 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 313GoVqE009060; Fri, 3 Feb 2023 16:50:31 GMT (envelope-from git) Date: Fri, 3 Feb 2023 16:50:31 GMT Message-Id: <202302031650.313GoVqE009060@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 26d105199ec8 - main - libc: Fall back to rdtsc when using pvclock and rdtscp is not available List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 26d105199ec89d6eaec8a9ca70e3b05ca65e3aac Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=26d105199ec89d6eaec8a9ca70e3b05ca65e3aac commit 26d105199ec89d6eaec8a9ca70e3b05ca65e3aac Author: Mark Johnston AuthorDate: 2023-02-03 15:53:20 +0000 Commit: Mark Johnston CommitDate: 2023-02-03 16:47:11 +0000 libc: Fall back to rdtsc when using pvclock and rdtscp is not available In preparation for a follow-up revision wherein kvmclock may export timekeeping info to userspace even in the absence of AMDID_RDTSCP, fall back to using rdtsc when rdtscp isn't available. This mimics pvclock_read_time_info() in the kernel. Reviewed by: kib Tested by: Shrikanth R Kamath MFC after: 2 weeks Sponsored by: Klara, Inc. Sponsored by: Juniper Networks, Inc. Differential Revision: https://reviews.freebsd.org/D38341 --- lib/libc/x86/sys/__vdso_gettc.c | 42 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) diff --git a/lib/libc/x86/sys/__vdso_gettc.c b/lib/libc/x86/sys/__vdso_gettc.c index b3f3de9f4203..7159d46c0113 100644 --- a/lib/libc/x86/sys/__vdso_gettc.c +++ b/lib/libc/x86/sys/__vdso_gettc.c @@ -101,6 +101,13 @@ rdtsc32_mb_lfence(void) return (rdtsc32()); } +static uint64_t +rdtsc_mb_lfence(void) +{ + lfence(); + return (rdtsc()); +} + static u_int rdtsc32_mb_mfence(void) { @@ -108,38 +115,62 @@ rdtsc32_mb_mfence(void) return (rdtsc32()); } +static uint64_t +rdtsc_mb_mfence(void) +{ + mfence(); + return (rdtsc()); +} + static u_int rdtsc32_mb_none(void) { return (rdtsc32()); } +static uint64_t +rdtsc_mb_none(void) +{ + return (rdtsc()); +} + static u_int rdtscp32_(void) { return (rdtscp32()); } +static uint64_t +rdtscp_(void) +{ + return (rdtscp()); +} + struct tsc_selector_tag { u_int (*ts_rdtsc32)(void); + uint64_t (*ts_rdtsc)(void); u_int (*ts_rdtsc_low)(const struct vdso_timehands *); }; static const struct tsc_selector_tag tsc_selector[] = { [0] = { /* Intel, LFENCE */ .ts_rdtsc32 = rdtsc32_mb_lfence, + .ts_rdtsc = rdtsc_mb_lfence, .ts_rdtsc_low = rdtsc_low_mb_lfence, }, [1] = { /* AMD, MFENCE */ .ts_rdtsc32 = rdtsc32_mb_mfence, + .ts_rdtsc = rdtsc_mb_mfence, .ts_rdtsc_low = rdtsc_low_mb_mfence, }, [2] = { /* No SSE2 */ - .ts_rdtsc32 = rdtsc32_mb_none, - .ts_rdtsc_low = rdtsc_low_mb_none, + .ts_rdtsc32 = rdtsc32_mb_none, + .ts_rdtsc = rdtsc_mb_none, + .ts_rdtsc_low = rdtsc_low_mb_none, }, [3] = { /* RDTSCP */ .ts_rdtsc32 = rdtscp32_, + .ts_rdtsc = rdtscp_, .ts_rdtsc_low = rdtscp_low, }, }; @@ -193,6 +224,11 @@ DEFINE_UIFUNC(static, u_int, __vdso_gettc_rdtsc32, (void)) return (tsc_selector[tsc_selector_idx(cpu_feature)].ts_rdtsc32); } +DEFINE_UIFUNC(static, uint64_t, __vdso_gettc_rdtsc, (void)) +{ + return (tsc_selector[tsc_selector_idx(cpu_feature)].ts_rdtsc); +} + #define HPET_DEV_MAP_MAX 10 static volatile char *hpet_dev_map[HPET_DEV_MAP_MAX]; @@ -325,7 +361,7 @@ __vdso_pvclock_gettc(const struct vdso_timehands *th, u_int *tc) version = atomic_load_acq_32(&ti->version); stable = (ti->flags & th->th_x86_pvc_stable_mask) != 0; if (stable) { - tsc = rdtscp(); + tsc = __vdso_gettc_rdtsc(); } else { (void)rdtscp_aux(&cpuid_ti); ti = &pvclock_timeinfos[cpuid_ti];