From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Keerthy <j-keerthy@ti.com>, Tony Lindgren <tony@atomide.com>,
Haojian Zhuang <haojian.zhuang@linaro.org>,
Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org, linux-omap@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH] pinctrl: pinctrl-single: Avoid divisions in context save/restore
Date: Thu, 7 Jun 2018 14:24:34 +0200 [thread overview]
Message-ID: <1528374274-26385-1-git-send-email-geert+renesas@glider.be> (raw)
The divisions (and multiplications) can be avoided by changing the loops
to use increments of mux_bytes instead of 1.
While at it, remove the unneeded casts when assigning void pointers.
This saves +100 bytes of kernel size on arm32/arm64.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Compile-tested only.
As the loops are now identical, the code could be made even smaller by
moving the switch() inside the loop, at the expense of readability.
---
drivers/pinctrl/pinctrl-single.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index 9c3c00515aa0fe20..5de5dedb804928eb 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -1593,19 +1593,19 @@ static int pcs_save_context(struct pcs_device *pcs)
switch (pcs->width) {
case 64:
- regsl = (u64 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- regsl[i] = pcs->read(pcs->base + i * mux_bytes);
+ regsl = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ *regsl++ = pcs->read(pcs->base + i);
break;
case 32:
- regsw = (u32 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- regsw[i] = pcs->read(pcs->base + i * mux_bytes);
+ regsw = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ *regsw++ = pcs->read(pcs->base + i);
break;
case 16:
- regshw = (u16 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- regshw[i] = pcs->read(pcs->base + i * mux_bytes);
+ regshw = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ *regshw++ = pcs->read(pcs->base + i);
break;
}
@@ -1623,19 +1623,19 @@ static void pcs_restore_context(struct pcs_device *pcs)
switch (pcs->width) {
case 64:
- regsl = (u64 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- pcs->write(regsl[i], pcs->base + i * mux_bytes);
+ regsl = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ pcs->write(*regsl++, pcs->base + i);
break;
case 32:
- regsw = (u32 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- pcs->write(regsw[i], pcs->base + i * mux_bytes);
+ regsw = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ pcs->write(*regsw++, pcs->base + i);
break;
case 16:
- regshw = (u16 *)pcs->saved_vals;
- for (i = 0; i < pcs->size / mux_bytes; i++)
- pcs->write(regshw[i], pcs->base + i * mux_bytes);
+ regshw = pcs->saved_vals;
+ for (i = 0; i < pcs->size; i += mux_bytes)
+ pcs->write(*regshw++, pcs->base + i);
break;
}
}
--
2.7.4
next reply other threads:[~2018-06-07 12:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 12:24 Geert Uytterhoeven [this message]
2018-06-08 6:26 ` [PATCH] pinctrl: pinctrl-single: Avoid divisions in context save/restore Tony Lindgren
2018-06-08 6:48 ` Keerthy
2018-06-14 8:33 ` Linus Walleij
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