linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Adrian Hunter <adrian.hunter@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	John Stultz <jstultz@google.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	linux-s390@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	x86@kernel.org, "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>,
	Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>,
	Stephen Boyd <sboyd@kernel.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	linux-kernel@vger.kernel.org, Sven Schnelle <svens@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 14/19] timekeeping: Consolidate timekeeping helpers
Date: Fri,  8 Mar 2024 15:15:07 +0200	[thread overview]
Message-ID: <20240308131512.44324-15-adrian.hunter@intel.com> (raw)
In-Reply-To: <20240308131512.44324-1-adrian.hunter@intel.com>

Consolidate timekeeping helpers, making use of timekeeping_cycles_to_ns()
in preference to directly using timekeeping_delta_to_ns().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 kernel/time/timekeeping.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 618328cd4bc4..1bbfe1ff8d24 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -237,7 +237,9 @@ static void timekeeping_check_update(struct timekeeper *tk, u64 offset)
 	}
 }
 
-static inline u64 timekeeping_debug_get_delta(const struct tk_read_base *tkr)
+static inline u64 timekeeping_cycles_to_ns(const struct tk_read_base *tkr, u64 cycles);
+
+static inline u64 timekeeping_debug_get_ns(const struct tk_read_base *tkr)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	u64 now, last, mask, max, delta;
@@ -266,22 +268,22 @@ static inline u64 timekeeping_debug_get_delta(const struct tk_read_base *tkr)
 	 */
 	if (unlikely((~delta & mask) < (mask >> 3))) {
 		tk->underflow_seen = 1;
-		delta = 0;
+		now = last;
 	}
 
 	/* Cap delta value to the max_cycles values to avoid mult overflows */
 	if (unlikely(delta > max)) {
 		tk->overflow_seen = 1;
-		delta = tkr->clock->max_cycles;
+		now = last + max;
 	}
 
-	return delta;
+	return timekeeping_cycles_to_ns(tkr, now);
 }
 #else
 static inline void timekeeping_check_update(struct timekeeper *tk, u64 offset)
 {
 }
-static inline u64 timekeeping_debug_get_delta(const struct tk_read_base *tkr)
+static inline u64 timekeeping_debug_get_ns(const struct tk_read_base *tkr)
 {
 	BUG();
 }
@@ -389,7 +391,7 @@ static __always_inline u64 __timekeeping_get_ns(const struct tk_read_base *tkr)
 static inline u64 timekeeping_get_ns(const struct tk_read_base *tkr)
 {
 	if (IS_ENABLED(CONFIG_DEBUG_TIMEKEEPING))
-		return timekeeping_delta_to_ns(tkr, timekeeping_debug_get_delta(tkr));
+		return timekeeping_debug_get_ns(tkr);
 
 	return __timekeeping_get_ns(tkr);
 }
-- 
2.34.1


  parent reply	other threads:[~2024-03-08 13:23 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-08 13:14 [PATCH 00/19] timekeeping: Handle potential multiplication overflow Adrian Hunter
2024-03-08 13:14 ` [PATCH 01/19] vdso: Consolidate vdso_calc_delta() Adrian Hunter
2024-03-09  2:09   ` John Stultz
2024-03-09  7:48   ` Christophe Leroy
2024-03-08 13:14 ` [PATCH 02/19] vdso: Consolidate nanoseconds calculation Adrian Hunter
2024-03-08 13:14 ` [PATCH 03/19] vdso: Add CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT Adrian Hunter
2024-03-08 13:14 ` [PATCH 04/19] math64: Tidy mul_u64_u32_shr() Adrian Hunter
2024-03-08 13:14 ` [PATCH 05/19] vdso: math64: Provide mul_u64_u32_add_u64_shr() Adrian Hunter
2024-03-08 13:14 ` [PATCH 06/19] vdso: Add vdso_data::max_cycles Adrian Hunter
2024-03-08 13:15 ` [PATCH 07/19] vdso: Make delta calculation overflow safe Adrian Hunter
2024-03-08 13:15 ` [PATCH 08/19] x86/vdso: " Adrian Hunter
2024-03-08 13:15 ` [PATCH 09/19] timekeeping: Move timekeeping helper functions Adrian Hunter
2024-03-08 13:15 ` [PATCH 10/19] timekeeping: Rename fast_tk_get_delta_ns() to __timekeeping_get_ns() Adrian Hunter
2024-03-08 13:15 ` [PATCH 11/19] timekeeping: Tidy timekeeping_cycles_to_ns() slightly Adrian Hunter
2024-03-08 13:15 ` [PATCH 12/19] timekeeping: Reuse timekeeping_cycles_to_ns() Adrian Hunter
2024-03-08 13:15 ` [PATCH 13/19] timekeeping: Refactor timekeeping helpers Adrian Hunter
2024-03-08 13:15 ` Adrian Hunter [this message]
2024-03-08 13:15 ` [PATCH 15/19] timekeeping: Fold in timekeeping_delta_to_ns() Adrian Hunter
2024-03-08 13:15 ` [PATCH 16/19] timekeeping: Prepare timekeeping_cycles_to_ns() for overflow safety Adrian Hunter
2024-03-08 13:15 ` [PATCH 17/19] timekeeping: Make delta calculation overflow safe Adrian Hunter
2024-03-08 13:15 ` [PATCH 18/19] timekeeping: Let timekeeping_cycles_to_ns() handle both under and overflow Adrian Hunter
2024-03-08 13:15 ` [PATCH 19/19] clocksource: Make watchdog and suspend-timing multiplication overflow safe Adrian Hunter

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240308131512.44324-15-adrian.hunter@intel.com \
    --to=adrian.hunter@intel.com \
    --cc=agordeev@linux.ibm.com \
    --cc=aneesh.kumar@kernel.org \
    --cc=anna-maria@linutronix.de \
    --cc=arnd@arndb.de \
    --cc=bhelgaas@google.com \
    --cc=borntraeger@linux.ibm.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=gor@linux.ibm.com \
    --cc=hca@linux.ibm.com \
    --cc=hpa@zytor.com \
    --cc=jstultz@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=naveen.n.rao@linux.ibm.com \
    --cc=npiggin@gmail.com \
    --cc=peterz@infradead.org \
    --cc=rdunlap@infradead.org \
    --cc=sboyd@kernel.org \
    --cc=svens@linux.ibm.com \
    --cc=tglx@linutronix.de \
    --cc=vincenzo.frascino@arm.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).