linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
To: mpe@ellerman.id.au
Cc: benh@kernel.crashing.org, anton@samba.org, paulus@samba.org,
	npiggin@gmail.com, linuxppc-dev@lists.ozlabs.org,
	Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Subject: [PATCH v10 03/17] powerpc/64: Improve inline asm in arch_local_irq_disable
Date: Wed, 20 Dec 2017 09:25:43 +0530	[thread overview]
Message-ID: <1513742157-28768-4-git-send-email-maddy@linux.vnet.ibm.com> (raw)
In-Reply-To: <1513742157-28768-1-git-send-email-maddy@linux.vnet.ibm.com>

From: Nicholas Piggin <npiggin@gmail.com>

arch_local_irq_disable is implemented strangely, with a temporary
output register being set to the desired soft_enabled value via an
immediate input, which is then used to store to memory. This is not
required, the immediate can be specified directly as a register input.

For simple cases at least, assembly is unchanged except register
mapping.

Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hw_irq.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 463b595ca971..d1e76298e393 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -63,13 +63,13 @@ static inline unsigned long arch_local_save_flags(void)
 
 static inline unsigned long arch_local_irq_disable(void)
 {
-	unsigned long flags, zero;
+	unsigned long flags;
 
 	asm volatile(
-		"li %1,%3; lbz %0,%2(13); stb %1,%2(13)"
-		: "=r" (flags), "=&r" (zero)
-		: "i" (offsetof(struct paca_struct, soft_enabled)),\
-		  "i" (IRQ_DISABLED)
+		"lbz %0,%1(13); stb %2,%1(13)"
+		: "=&r" (flags)
+		: "i" (offsetof(struct paca_struct, soft_enabled)),
+		  "r" (IRQ_DISABLED)
 		: "memory");
 
 	return flags;
-- 
2.7.4

  parent reply	other threads:[~2017-12-20  3:56 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-20  3:55 [PATCH v10 00/17] powerpc: "paca->soft_enabled" based local atomic operation implementation Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 01/17] powerpc/64: do not trace irqs-off at interrupt return to soft-disabled context Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 02/17] powerpc/64: Add #defines for paca->soft_enabled flags Madhavan Srinivasan
2018-01-22  3:34   ` [v10, " Michael Ellerman
2017-12-20  3:55 ` Madhavan Srinivasan [this message]
2017-12-20  3:55 ` [PATCH v10 04/17] powerpc/64: Fix arch_local_irq_disable() prototype Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 05/17] powerpc/64: move set_soft_enabled(), rename it, add memory clobber Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 06/17] powerpc/64: Implement and use soft_enabled_return API Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 07/17] powerpc/64: Implement and use soft_enabled_set_return API Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 08/17] powerpc/64: Cleanup hard_irq_disable() macro Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 09/17] powerpc/64: Change soft_enabled from flag to bitmask Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 10/17] powerpc/64: Rename soft_enabled to irq_soft_mask Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 11/17] powerpc/64s: Avoid using EXCEPTION_PROLOG_1 macro in MASKABLE_* Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 12/17] powerpc/64s: Add support to take additional parameter in MASKABLE_* macro Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 13/17] powerpc/64s: Add support to mask perf interrupts and replay them Madhavan Srinivasan
2018-01-15 13:23   ` Nicholas Piggin
2017-12-20  3:55 ` [PATCH v10 14/17] powerpc: Add new kconfig IRQ_DEBUG_SUPPORT Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 15/17] powerpc/64s: Add new set of irq_soft_mask_ functions for PMI masking Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 16/17] powerpc: use generic atomic implementation for local_t Madhavan Srinivasan
2017-12-20  3:55 ` [PATCH v10 17/17] powerpc/64s: Implement local_t using irq soft masking Madhavan Srinivasan
2017-12-20  5:02 ` [PATCH v10 00/17] powerpc: "paca->soft_enabled" based local atomic operation implementation Nicholas Piggin

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=1513742157-28768-4-git-send-email-maddy@linux.vnet.ibm.com \
    --to=maddy@linux.vnet.ibm.com \
    --cc=anton@samba.org \
    --cc=benh@kernel.crashing.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=npiggin@gmail.com \
    --cc=paulus@samba.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).