From: Masahiro Yamada <yamada.m@jp.panasonic.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Sascha Hauer <s.hauer@pengutronix.de>,
Masahiro Yamada <yamada.m@jp.panasonic.com>,
Russell King <linux@arm.linux.org.uk>,
Nicolas Pitre <nicolas.pitre@linaro.org>,
Kukjin Kim <kgene.kim@samsung.com>,
Ben Dooks <ben.dooks@codethink.co.uk>,
Heiko Stuebner <heiko@sntech.de>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] ARM: decompressor: remove unused cache flush code
Date: Thu, 22 Jan 2015 14:22:58 +0900 [thread overview]
Message-ID: <1421904178-30882-1-git-send-email-yamada.m@jp.panasonic.com> (raw)
As ARM ARM says, the bit 19-16 of ID_MMFR1 is always 0b0000 because
ARMv7 requires a hierarchical cache implementation.
The line "mcr p15, 0, r10, c7, c14, 0" is not reachable.
Moreover, the v7_flush_dcache_all in arch/arm/mm/cache-v7.S does not
check the ID_MMFR1.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
---
arch/arm/boot/compressed/head.S | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 9dff614..32f0d79 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -1085,15 +1085,9 @@ __armv6_mmu_cache_flush:
__armv7_mmu_cache_flush:
tst r4, #1
bne iflush
- mrc p15, 0, r10, c0, c1, 5 @ read ID_MMFR1
- tst r10, #0xf << 16 @ hierarchical cache (ARMv7)
+ stmfd sp!, {r0-r7, r9-r11}
mov r10, #0
- beq hierarchical
- mcr p15, 0, r10, c7, c14, 0 @ clean+invalidate D
- b iflush
-hierarchical:
mcr p15, 0, r10, c7, c10, 5 @ DMB
- stmfd sp!, {r0-r7, r9-r11}
mrc p15, 1, r0, c0, c0, 1 @ read clidr
ands r3, r0, #0x7000000 @ extract loc from clidr
mov r3, r3, lsr #23 @ left align loc bit field
--
1.9.1
next reply other threads:[~2015-01-22 5:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-22 5:22 Masahiro Yamada [this message]
2015-01-22 8:06 ` Uwe Kleine-König
2015-01-22 15:44 ` Russell King - ARM Linux
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