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From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Cc: Christophe Leroy <christophe.leroy@c-s.fr>,
	Arnd Bergmann <arnd@arndb.de>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	linux-kernel@vger.kernel.org,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: [RFC PATCH 0/5] powerpc: make iowrite32be etc. inline
Date: Thu, 31 Oct 2019 01:31:49 +0100	[thread overview]
Message-ID: <20191031003154.21969-1-linux@rasmusvillemoes.dk> (raw)

When trying to make the QUICC Engine drivers compile on arm, I
mechanically (with coccinelle) changed out_be32() to iowrite32be()
etc. Christophe pointed out [1][2] that that would pessimize the
powerpc SOCs since the IO accesses now incur a function call
overhead. He asked that I try to make those io accessors inline on
ppc, and this is the best I could come up with.

At first I tried something that wouldn't need to touch anything
outside arch/powerpc/, but I ended up with conditional inclusion of
asm-generic headers and/or duplicating a lot of their contents.

The diffstat may become a little better if kernel/iomap.c can indeed
be removed (due to !CONFIG_PPC_INDIRECT_PIO &&
CONFIG_PPC_INDIRECT_MMIO never happening).

[1] https://lore.kernel.org/lkml/6ee121cf-0e3d-4aa0-2593-fcb00995e429@c-s.fr/
[2] https://lore.kernel.org/lkml/886d5218-6d6b-824c-3ab9-63aafe41ff40@c-s.fr/

Rasmus Villemoes (5):
  asm-generic: move pcu_iounmap from iomap.h to pci_iomap.h
  asm-generic: employ "ifndef foo; define foo foo" idiom in iomap.h
  powerpc: move pci_iounmap() from iomap.c to pci-common.c
  powerpc: make pcibios_vaddr_is_ioport() static
  powerpc: make iowrite32 and friends static inline when no indirection

 arch/powerpc/include/asm/io.h         | 172 ++++++++++++++++++++++++++
 arch/powerpc/include/asm/pci-bridge.h |   9 --
 arch/powerpc/kernel/Makefile          |   2 +-
 arch/powerpc/kernel/iomap.c           |  13 --
 arch/powerpc/kernel/pci-common.c      |  15 ++-
 include/asm-generic/iomap.h           | 104 +++++++++++++---
 include/asm-generic/pci_iomap.h       |   7 ++
 7 files changed, 282 insertions(+), 40 deletions(-)

-- 
2.23.0


             reply	other threads:[~2019-10-31  0:32 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-31  0:31 Rasmus Villemoes [this message]
2019-10-31  0:31 ` [RFC PATCH 1/5] asm-generic: move pcu_iounmap from iomap.h to pci_iomap.h Rasmus Villemoes
2019-10-31  0:31 ` [RFC PATCH 2/5] asm-generic: employ "ifndef foo; define foo foo" idiom in iomap.h Rasmus Villemoes
2019-10-31  0:31 ` [RFC PATCH 3/5] powerpc: move pci_iounmap() from iomap.c to pci-common.c Rasmus Villemoes
2019-10-31  0:31 ` [RFC PATCH 4/5] powerpc: make pcibios_vaddr_is_ioport() static Rasmus Villemoes
2019-10-31  0:31 ` [RFC PATCH 5/5] powerpc: make iowrite32 and friends static inline when no indirection Rasmus Villemoes
2019-10-31  7:38 ` [RFC PATCH 0/5] powerpc: make iowrite32be etc. inline Rasmus Villemoes
2019-10-31 13:46   ` Arnd Bergmann

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