From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/6] ARM: prefetch: add support for prefetchw using pldw on SMP ARMv7+ CPUs
Date: Tue, 23 Jul 2013 12:36:26 +0100 [thread overview]
Message-ID: <1374579389-32704-4-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1374579389-32704-1-git-send-email-will.deacon@arm.com>
SMP ARMv7 CPUs implement the pldw instruction, which allows them to
prefetch data cachelines in an exclusive state.
This patch defines the prefetchw macro using pldw for CPUs that support
it.
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm/include/asm/processor.h | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index cbdb130..d571697 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -116,12 +116,19 @@ static inline void prefetch(const void *ptr)
:: "p" (ptr));
}
+#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
#define ARCH_HAS_PREFETCHW
-#define prefetchw(ptr) prefetch(ptr)
-
-#define ARCH_HAS_SPINLOCK_PREFETCH
-#define spin_lock_prefetch(x) do { } while (0)
-
+static inline void prefetchw(const void *ptr)
+{
+ __asm__ __volatile__(
+ ".arch_extension mp\n"
+ __ALT_SMP_ASM(
+ WASM(pldw) "\t%a0",
+ WASM(pld) "\t%a0"
+ )
+ :: "p" (ptr));
+}
+#endif
#endif
#define HAVE_ARCH_PICK_MMAP_LAYOUT
--
1.8.2.2
next prev parent reply other threads:[~2013-07-23 11:36 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-23 11:36 [PATCH 0/6] Add support for pldw instruction on v7 MP cores Will Deacon
2013-07-23 11:36 ` [PATCH 1/6] ARM: prefetch: remove redundant "cc" clobber Will Deacon
2013-07-23 19:48 ` Nicolas Pitre
2013-07-24 10:19 ` Will Deacon
2013-07-24 16:16 ` Nicolas Pitre
2013-07-24 16:35 ` Will Deacon
2013-07-24 16:58 ` Russell King - ARM Linux
2013-07-24 17:22 ` Nicolas Pitre
2013-07-23 11:36 ` [PATCH 2/6] ARM: smp_on_up: move inline asm ALT_SMP patching macro out of spinlock.h Will Deacon
2013-07-23 19:55 ` Nicolas Pitre
2013-07-23 11:36 ` Will Deacon [this message]
2013-07-23 20:05 ` [PATCH 3/6] ARM: prefetch: add support for prefetchw using pldw on SMP ARMv7+ CPUs Nicolas Pitre
2013-07-24 10:42 ` Will Deacon
2013-07-23 11:36 ` [PATCH 4/6] ARM: locks: prefetch the destination word for write prior to strex Will Deacon
2013-07-23 20:10 ` Nicolas Pitre
2013-07-24 11:18 ` Will Deacon
2013-07-25 17:31 ` Stephen Boyd
2013-07-25 17:37 ` Stephen Boyd
2013-07-25 17:45 ` Will Deacon
2013-07-25 17:48 ` Will Deacon
2013-07-25 17:55 ` Stephen Boyd
2013-07-25 18:05 ` Will Deacon
2013-07-25 18:22 ` Stephen Boyd
2013-07-25 20:24 ` Nicolas Pitre
2013-07-26 10:34 ` Will Deacon
2013-07-26 14:46 ` Nicolas Pitre
2013-07-23 11:36 ` [PATCH 5/6] ARM: atomics: " Will Deacon
2013-07-23 20:12 ` Nicolas Pitre
2013-07-23 11:36 ` [PATCH 6/6] ARM: bitops: " Will Deacon
2013-07-23 20:15 ` Nicolas Pitre
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=1374579389-32704-4-git-send-email-will.deacon@arm.com \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.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).