linux-kernel - [PATCH v2 2/3] clk: divider: Switch from .round_rate to .determine

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 24 May 2021 12:37:32 +0200
From:   Martin Blumenstingl <martin.blumenstingl@...glemail.com>
To:     mturquette@...libre.com, sboyd@...nel.org, narmstrong@...libre.com,
        jbrunet@...libre.com, linux-clk@...r.kernel.org
Cc:     khilman@...libre.com, linux-kernel@...r.kernel.org,
        linux-amlogic@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Subject: [PATCH v2 2/3] clk: divider: Switch from .round_rate to .determine_rate by default

.determine_rate is meant to replace .round_rate. The former comes with a
benefit which is especially relevant on 32-bit systems: since
.determine_rate uses an "unsigned long" (compared to a "signed long"
which is used by .round_rate) the maximum value on 32-bit systems
increases from 2^31 (or approx. 2.14GHz) to 2^32 (or approx. 4.29GHz).
Switch to a .determine_rate implementation by default so 32-bit systems
can benefit from the increased maximum value as well as so we have one
fewer user of .round_rate.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
---
 drivers/clk/clk-divider.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 87ba4966b0e8..9e05e81116af 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -425,8 +425,8 @@ long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
 }
 EXPORT_SYMBOL_GPL(divider_ro_round_rate_parent);
 
-static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
-				unsigned long *prate)
+static int clk_divider_determine_rate(struct clk_hw *hw,
+				      struct clk_rate_request *req)
 {
 	struct clk_divider *divider = to_clk_divider(hw);
 
@@ -437,13 +437,13 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
 		val = clk_div_readl(divider) >> divider->shift;
 		val &= clk_div_mask(divider->width);
 
-		return divider_ro_round_rate(hw, rate, prate, divider->table,
-					     divider->width, divider->flags,
-					     val);
+		return divider_ro_determine_rate(hw, req, divider->table,
+						 divider->width,
+						 divider->flags, val);
 	}
 
-	return divider_round_rate(hw, rate, prate, divider->table,
-				  divider->width, divider->flags);
+	return divider_determine_rate(hw, req, divider->table, divider->width,
+				      divider->flags);
 }
 
 int divider_get_val(unsigned long rate, unsigned long parent_rate,
@@ -500,14 +500,14 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
 
 const struct clk_ops clk_divider_ops = {
 	.recalc_rate = clk_divider_recalc_rate,
-	.round_rate = clk_divider_round_rate,
+	.determine_rate = clk_divider_determine_rate,
 	.set_rate = clk_divider_set_rate,
 };
 EXPORT_SYMBOL_GPL(clk_divider_ops);
 
 const struct clk_ops clk_divider_ro_ops = {
 	.recalc_rate = clk_divider_recalc_rate,
-	.round_rate = clk_divider_round_rate,
+	.determine_rate = clk_divider_determine_rate,
 };
 EXPORT_SYMBOL_GPL(clk_divider_ro_ops);
 
-- 
2.31.1