From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78E02C77B73 for ; Tue, 2 May 2023 20:03:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229766AbjEBUDK (ORCPT ); Tue, 2 May 2023 16:03:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbjEBUDI (ORCPT ); Tue, 2 May 2023 16:03:08 -0400 Received: from mailrelay1-1.pub.mailoutpod2-cph3.one.com (mailrelay1-1.pub.mailoutpod2-cph3.one.com [IPv6:2a02:2350:5:400::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 351E110FF for ; Tue, 2 May 2023 13:03:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ravnborg.org; s=rsa1; h=in-reply-to:content-type:mime-version:references:message-id:subject:cc:to: from:date:from; bh=KtZNQ58vZ5N98TWm6M5w+L57kPYXNb5tAf0VlF8Flpc=; b=Xah1/oyErMFNpxOGfQEez/E+8w0LLHZXJKtrW/ScT0xAhSKJyU1eZ3frWCdrdSF0GTGRRpJhPQrZs I+uBJafShd3l9pu/kBATSdEVDgpUVD6i+FYH+AM1xPvyJ0UmNqbSnLpRvHzxNrVSMZzfiNM1KvbeUW KGgXkpysLgZ/zewOpQiKznhcJPVatUQuOeymT5kBhkjt9Eq3PGZFnXDKGHoufHpJA6S/rh+SALRC4U RIFwlrXy7znYTkNSqweLa/0D/HwYv9u4U6krbhYlJX7lMOSK5LXpPTdXhRVtOt8FJyFPUh9YDeusba Gl27IKREH5sEcHLYQw1s+yrcHZiZ1BQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=ravnborg.org; s=ed1; h=in-reply-to:content-type:mime-version:references:message-id:subject:cc:to: from:date:from; bh=KtZNQ58vZ5N98TWm6M5w+L57kPYXNb5tAf0VlF8Flpc=; b=7QUNa4Iy2G7XUqb7b772O2zddt3FyCgHB/im3Jp8IwJy6rF7WzgO5eusroyZ9PEtznHxDPL5De33H tmENBvLCg== X-HalOne-ID: 56af12f5-e924-11ed-94e2-99461c6a3fe8 Received: from ravnborg.org (2-105-2-98-cable.dk.customer.tdc.net [2.105.2.98]) by mailrelay1 (Halon) with ESMTPSA id 56af12f5-e924-11ed-94e2-99461c6a3fe8; Tue, 02 May 2023 20:03:02 +0000 (UTC) Date: Tue, 2 May 2023 22:03:00 +0200 From: Sam Ravnborg To: Thomas Zimmermann Cc: deller@gmx.de, geert@linux-m68k.org, javierm@redhat.com, daniel@ffwll.ch, vgupta@kernel.org, chenhuacai@kernel.org, kernel@xen0n.name, davem@davemloft.net, James.Bottomley@hansenpartnership.com, arnd@arndb.de, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arch@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org Subject: Re: [PATCH v3 5/6] fbdev: Move framebuffer I/O helpers into Message-ID: <20230502200300.GB319489@ravnborg.org> References: <20230502130223.14719-1-tzimmermann@suse.de> <20230502130223.14719-6-tzimmermann@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230502130223.14719-6-tzimmermann@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Hi Thomas, On Tue, May 02, 2023 at 03:02:22PM +0200, Thomas Zimmermann wrote: > Implement framebuffer I/O helpers, such as fb_read*() and fb_write*(), > in the architecture's header file or the generic one. In reality they are now all implemented in the generic one. > > The common case has been the use of regular I/O functions, such as > __raw_readb() or memset_io(). A few architectures used plain system- > memory reads and writes. Sparc used helpers for its SBus. > > The architectures that used special cases provide the same code in > their __raw_*() I/O helpers. So the patch replaces this code with the > __raw_*() functions and moves it to for all > architectures. Which is also documented here. > > v3: > * implement all architectures with generic helpers > * support reordering and native byte order (Geert, Arnd) > > Signed-off-by: Thomas Zimmermann > --- > include/asm-generic/fb.h | 101 +++++++++++++++++++++++++++++++++++++++ > include/linux/fb.h | 53 -------------------- > 2 files changed, 101 insertions(+), 53 deletions(-) > > diff --git a/include/asm-generic/fb.h b/include/asm-generic/fb.h > index 6922dd248c51..0540eccdbeca 100644 > --- a/include/asm-generic/fb.h > +++ b/include/asm-generic/fb.h > @@ -31,4 +31,105 @@ static inline int fb_is_primary_device(struct fb_info *info) > } > #endif > > +/* > + * I/O helpers for the framebuffer. Prefer these functions over their > + * regular counterparts. The regular I/O functions provide in-order > + * access and swap bytes to/from little-endian ordering. Neither is > + * required for framebuffers. Instead, the helpers read and write > + * raw framebuffer data. Independent operations can be reordered for > + * improved performance. > + */ > + > +#ifndef fb_readb > +static inline u8 fb_readb(const volatile void __iomem *addr) > +{ > + return __raw_readb(addr); > +} > +#define fb_readb fb_readb > +#endif When we need to provide an architecture specific variant the #ifndef foo ... #define foo foo can be added. Right now it is just noise as no architectures provide their own variants. But I am missing something somewhere as I cannot see how this builds. asm-generic now provide the fb_read/fb_write helpers. But for example sparc has an architecture specifc fb.h so it will not use the asm-generic variant. So I wonder how sparc get hold of the asm-generic fb.h file? Maybe it is obvious, but I miss it. Sam