From: Alexander Kochetkov <al.kochet@gmail.com>
To: Dan Williams <dan.j.williams@intel.com>,
Vinod Koul <vinod.koul@intel.com>,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rockchip@lists.infradead.org, hhb@rock-chips.com,
shawn.lin@rock-chips.com, caesar.wang@rock-chips.com,
sugar.zhang@rock-chips.com, ulysses.huang@rock-chips.com
Cc: Alexander Kochetkov <al.kochet@gmail.com>
Subject: [PATCH 2/2] dmaengine: pl330: don't emit code for one iteration loop
Date: Fri, 14 Apr 2017 17:35:30 +0300 [thread overview]
Message-ID: <1492180531-1780-3-git-send-email-al.kochet@gmail.com> (raw)
In-Reply-To: <1492180531-1780-1-git-send-email-al.kochet@gmail.com>
The patch remove one iteration outer loop in the _loop().
Removing loop saves 4 bytes of MicroCode buffer. This
savings make sense for free-running cyclic transfer
implementation.
DMALP_0 0
...
DMALPENDA_0 bjmpto_9
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
---
drivers/dma/pl330.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 56a2377..6126dde 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1268,7 +1268,7 @@ static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
lpend.bjump = 0;
szlpend = _emit_LPEND(1, buf, &lpend);
- if (lcnt0) {
+ if (lcnt0 > 1) {
szlp *= 2;
szlpend *= 2;
}
@@ -1284,7 +1284,7 @@ static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
off = 0;
- if (lcnt0) {
+ if (lcnt0 > 1) {
off += _emit_LP(dry_run, &buf[off], 0, lcnt0);
ljmp0 = off;
}
@@ -1300,7 +1300,7 @@ static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
lpend.bjump = off - ljmp1;
off += _emit_LPEND(dry_run, &buf[off], &lpend);
- if (lcnt0) {
+ if (lcnt0 > 1) {
lpend.cond = ALWAYS;
lpend.forever = false;
lpend.loop = 0;
@@ -1309,7 +1309,7 @@ static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
}
*bursts = lcnt1 * cyc;
- if (lcnt0)
+ if (lcnt0 > 1)
*bursts *= lcnt0;
return off;
--
1.7.9.5
next prev parent reply other threads:[~2017-04-14 14:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-14 14:35 [PATCH 0/2] Free running cyclic transfer implementation for pl330 Alexander Kochetkov
2017-04-14 14:35 ` [PATCH 1/2] dmaengine: pl330: make cyclic transfer free runnable Alexander Kochetkov
2017-04-14 18:04 ` Krzysztof Kozlowski
2017-04-14 14:35 ` Alexander Kochetkov [this message]
2017-04-18 2:26 ` [PATCH 0/2] Free running cyclic transfer implementation for pl330 sugar
2017-04-26 17:01 ` Alexander Kochetkov
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