From: Qian Cai <cai@lca.pw>
To: will@kernel.org, catalin.marinas@arm.com
Cc: rrichter@cavium.com, robin.murphy@arm.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH v2] arm64/prefetch: fix a -Wtype-limits warning
Date: Fri, 2 Aug 2019 20:33:58 -0400 [thread overview]
Message-ID: <20190803003358.992-1-cai@lca.pw> (raw)
The commit d5370f754875 ("arm64: prefetch: add alternative pattern for
CPUs without a prefetcher") introduced MIDR_IS_CPU_MODEL_RANGE() to be
used in has_no_hw_prefetch() with rv_min=0 which generates a compilation
warning from GCC,
In file included from ./arch/arm64/include/asm/cache.h:8,
from ./include/linux/cache.h:6,
from ./include/linux/printk.h:9,
from ./include/linux/kernel.h:15,
from ./include/linux/cpumask.h:10,
from arch/arm64/kernel/cpufeature.c:11:
arch/arm64/kernel/cpufeature.c: In function 'has_no_hw_prefetch':
./arch/arm64/include/asm/cputype.h:59:26: warning: comparison of
unsigned expression >= 0 is always true [-Wtype-limits]
_model == (model) && rv >= (rv_min) && rv <= (rv_max); \
^~
arch/arm64/kernel/cpufeature.c:889:9: note: in expansion of macro
'MIDR_IS_CPU_MODEL_RANGE'
return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
^~~~~~~~~~~~~~~~~~~~~~~
Fix it by making "rv" a "s32".
Signed-off-by: Qian Cai <cai@lca.pw>
---
v2: Use "s32" for "rv", so "variant 0/revision 0" can be covered.
arch/arm64/include/asm/cputype.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index e7d46631cc42..d52fe8651c2d 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -54,7 +54,7 @@
#define MIDR_IS_CPU_MODEL_RANGE(midr, model, rv_min, rv_max) \
({ \
u32 _model = (midr) & MIDR_CPU_MODEL_MASK; \
- u32 rv = (midr) & (MIDR_REVISION_MASK | MIDR_VARIANT_MASK); \
+ s32 rv = (midr) & (MIDR_REVISION_MASK | MIDR_VARIANT_MASK); \
\
_model == (model) && rv >= (rv_min) && rv <= (rv_max); \
})
--
2.20.1 (Apple Git-117)
next reply other threads:[~2019-08-03 0:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-03 0:33 Qian Cai [this message]
2019-08-05 10:00 ` [PATCH v2] arm64/prefetch: fix a -Wtype-limits warning Will Deacon
2019-08-05 12:03 ` Qian Cai
2019-08-05 17:03 ` Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190803003358.992-1-cai@lca.pw \
--to=cai@lca.pw \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=rrichter@cavium.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).