[PATCH] clk: sophgo: avoid open-coded 64-bit division

Arnd Bergmann posted 1 patch 1 year, 10 months ago
drivers/clk/sophgo/clk-cv18xx-pll.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
[PATCH] clk: sophgo: avoid open-coded 64-bit division
Posted by Arnd Bergmann 1 year, 10 months ago
From: Arnd Bergmann <arnd@arndb.de>

On 32-bit architectures, the 64-bit division leads to a link failure:

arm-linux-gnueabi-ld: drivers/clk/sophgo/clk-cv18xx-pll.o: in function `fpll_calc_rate':
clk-cv18xx-pll.c:(.text.fpll_calc_rate+0x26): undefined reference to `__aeabi_uldivmod'

This one is not called in a fast path, and there is already another div_u64()
variant used in the same function, so convert it to div64_u64_rem().

Fixes: 80fd61ec4612 ("clk: sophgo: Add clock support for CV1800 SoC")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/clk/sophgo/clk-cv18xx-pll.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/clk/sophgo/clk-cv18xx-pll.c b/drivers/clk/sophgo/clk-cv18xx-pll.c
index c546dad1791c..29e24098bf5f 100644
--- a/drivers/clk/sophgo/clk-cv18xx-pll.c
+++ b/drivers/clk/sophgo/clk-cv18xx-pll.c
@@ -205,8 +205,7 @@ static unsigned long fpll_calc_rate(unsigned long parent_rate,
 	unsigned long rate;
 
 	dividend <<= PLL_SYN_FACTOR_DOT_POS - 1;
-	rate = dividend / factor;
-	dividend %= factor;
+	rate = div64_u64_rem(dividend, factor, &dividend);
 
 	if (is_full_parent) {
 		dividend <<= 1;
-- 
2.39.2
Re: [PATCH] clk: sophgo: avoid open-coded 64-bit division
Posted by Stephen Boyd 1 year, 9 months ago
Quoting Arnd Bergmann (2024-04-15 06:45:20)
> From: Arnd Bergmann <arnd@arndb.de>
> 
> On 32-bit architectures, the 64-bit division leads to a link failure:
> 
> arm-linux-gnueabi-ld: drivers/clk/sophgo/clk-cv18xx-pll.o: in function `fpll_calc_rate':
> clk-cv18xx-pll.c:(.text.fpll_calc_rate+0x26): undefined reference to `__aeabi_uldivmod'
> 
> This one is not called in a fast path, and there is already another div_u64()
> variant used in the same function, so convert it to div64_u64_rem().
> 
> Fixes: 80fd61ec4612 ("clk: sophgo: Add clock support for CV1800 SoC")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---

Applied to clk-next