From: biju.das@bp.renesas.com (Biju Das)
To: cip-dev@lists.cip-project.org
Subject: [cip-dev] [PATCH 4.19.y-cip 14/23] math64: New DIV64_U64_ROUND_CLOSEST helper
Date: Mon, 15 Jul 2019 14:29:59 +0100 [thread overview]
Message-ID: <1563197408-59548-15-git-send-email-biju.das@bp.renesas.com> (raw)
In-Reply-To: <1563197408-59548-1-git-send-email-biju.das@bp.renesas.com>
From: Simon Horman <horms+renesas@verge.net.au>
commit cb8be119d21d8a0affc3598a928dd0baf5da238f upstream.
Provide DIV64_U64_ROUND_CLOSEST helper which performs division rounded to
the closest integer using an unsigned 64bit dividend and divisor.
This will be used in a follow-up patch to allow calculation of clock
divisors with high frequency parents in the R-Car Gen3 CPG MSSR driver
where overflow occurs if either the dividend or divisor is 32bit.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
---
include/linux/math64.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/include/linux/math64.h b/include/linux/math64.h
index bb2c84a..65bef21 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -284,4 +284,17 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
#define DIV64_U64_ROUND_UP(ll, d) \
({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); })
+/**
+ * DIV64_U64_ROUND_CLOSEST - unsigned 64bit divide with 64bit divisor rounded to nearest integer
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 64bit divisor
+ *
+ * Divide unsigned 64bit dividend by unsigned 64bit divisor
+ * and round to closest integer.
+ *
+ * Return: dividend / divisor rounded to nearest integer
+ */
+#define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \
+ ({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
+
#endif /* _LINUX_MATH64_H */
--
2.7.4
next prev parent reply other threads:[~2019-07-15 13:29 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-15 13:29 [cip-dev] [PATCH 4.19.y-cip 00/23] Clock enhancements Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 01/23] clk: renesas: r8a774a1: Add CPEX clock Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 02/23] clk: renesas: rcar-gen3: Set state when registering SD clocks Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 03/23] clk: renesas: rcar-gen3: Add documentation for " Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 04/23] clk: renesas: rcar-gen3: Add HS400 quirk for SD clock Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 05/23] clk: renesas: Remove usage of CLK_IS_BASIC Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 06/23] clk: renesas: r8a774a1: Add missing CANFD clock Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 07/23] clk: renesas: rcar-gen3: Factor out cpg_reg_modify() Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 08/23] clk: renesas: rcar-gen3: Add spinlock Biju Das
2019-07-16 11:17 ` Pavel Machek
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 09/23] clk: renesas: r8a774a1: Fix LAST_DT_CORE_CLK Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 10/23] clk: renesas: rcar-gen3: Pass name/offset to cpg_sd_clk_register() Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 11/23] clk: renesas: rcar-gen3: Parameterise Z and Z2 clock fixed divisor Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 12/23] clk: renesas: rcar-gen3: Parameterise Z and Z2 clock offset Biju Das
2019-07-15 13:29 ` [cip-dev] [PATCH 4.19.y-cip 13/23] clk: renesas: rcar-gen3: Remove CLK_TYPE_GEN3_Z2 Biju Das
2019-07-15 13:29 ` Biju Das [this message]
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 15/23] clk: renesas: rcar-gen3: Support Z and Z2 clocks with high frequency parents Biju Das
2019-07-16 11:22 ` Pavel Machek
2019-07-16 12:01 ` Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 16/23] clk: renesas: r8a774c0: Add Z2 clock Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 17/23] clk: renesas: rcar-gen3: Correct parent clock of EHCI/OHCI Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 18/23] clk: renesas: rcar-gen3: Correct parent clock of HS-USB Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 19/23] clk: renesas: rcar-gen3: Correct parent clock of SYS-DMAC Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 20/23] clk: renesas: rcar-gen3: Correct parent clock of Audio-DMAC Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 21/23] clk: renesas: rcar-gen3: Fix cpg_sd_clock_round_rate() return value Biju Das
2019-07-16 11:24 ` Pavel Machek
2019-07-16 11:56 ` Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 22/23] clk: renesas: rcar-gen3: Remove unused variable Biju Das
2019-07-15 13:30 ` [cip-dev] [PATCH 4.19.y-cip 23/23] arm64: dts: renesas: r8a774c0: Add OPPs table for cpu devices Biju Das
2019-07-15 19:50 ` [cip-dev] [PATCH 4.19.y-cip 00/23] Clock enhancements Pavel Machek
2019-07-15 21:57 ` Pavel Machek
2019-07-16 6:45 ` Biju Das
2019-07-16 11:28 ` Pavel Machek
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