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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58EFCC433E0 for ; Fri, 31 Jul 2020 09:20:40 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2AA542074B for ; Fri, 31 Jul 2020 09:20:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="FZwnvAoU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AA542074B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 19C076EA45; Fri, 31 Jul 2020 09:20:39 +0000 (UTC) Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6EA506EA45 for ; Fri, 31 Jul 2020 09:20:37 +0000 (UTC) Received: by mail-wm1-x344.google.com with SMTP id k20so8560760wmi.5 for ; Fri, 31 Jul 2020 02:20:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=5jVocStywPD82+GfChijcoaUHvKqOvvxEriAfAxTW/4=; b=FZwnvAoUHl9Swt/48NE+25kn4/CWDumkoY76TkGTBQdRuD4Wzezel+zS41AiSzksQ1 dCQT2iCpayeiVflf2HbyDJBqVk1GEdjM44/JR3XH7QywJZm1twNXXqWCYtEBYTpMQZzK 44/y0hKbQuFxkqiE/j/Ka8Cnw50AFdhNLFiHg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=5jVocStywPD82+GfChijcoaUHvKqOvvxEriAfAxTW/4=; b=ljCxSbMeKaD1KmGcQraoZd5dhoz8IG6N6Pp/M3cRSxvbFe+PH1QIWnMNnxnOwCVa1R O0B6OA18cQHdHfy5hBtZGKeSfkf28XA+HH9cwaIguFVoNkm2hxQpxogQabLC+D1m19P9 Iu+/2NAOIcH6rQ4kpPJb5HXTZtK7/LMphNgwI7KNpb/uutSpso8z95osOJ3BTXVlIa+C l/KAbIN6AcIIeFXwfm6uDT/aLwVqSmUlrgwZzKsjNGuwksPERTavDWArXBK9shew6Yv1 1q1MKnVbe9pCX7mp9CF07EmnJLeizxEjo3XSTGsEHBWu6MsA0WTelhaEdTaSN7Y3NyYE LG2w== X-Gm-Message-State: AOAM531YfGCnMzqxReXfqbbTYOqfJdYeWnS1Ua35Lo1LyQDEusRB8UeL c28LfFAKkHVCDwkmYELuuf5MkA== X-Google-Smtp-Source: ABdhPJwp3j3w5sEDWYnF2pI7XaYPRcnKOh2er2/+NhLeiovwLxLzF2aTTPQP3K/VDueqbZmYSSVGgQ== X-Received: by 2002:a1c:7315:: with SMTP id d21mr2925615wmb.108.1596187236055; Fri, 31 Jul 2020 02:20:36 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id p3sm11561537wma.44.2020.07.31.02.20.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jul 2020 02:20:35 -0700 (PDT) Date: Fri, 31 Jul 2020 11:20:33 +0200 From: daniel@ffwll.ch To: Subject: Re: [PATCH 2/5] fbdev/core: Export framebuffer read and write code as cfb_ function Message-ID: <20200731092033.GV6419@phenom.ffwll.local> References: <20200729134148.6855-1-tzimmermann@suse.de> <20200729134148.6855-3-tzimmermann@suse.de> <20200729135328.GP6419@phenom.ffwll.local> <20200729163603.GA1369638@ravnborg.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200729163603.GA1369638@ravnborg.org> X-Operating-System: Linux phenom 5.7.0-1-amd64 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fbdev@vger.kernel.org, b.zolnierkie@samsung.com, jani.nikula@intel.com, dri-devel@lists.freedesktop.org, kraxel@redhat.com, airlied@redhat.com, natechancellor@gmail.com, peda@axentia.se, dan.carpenter@oracle.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Jul 29, 2020 at 06:36:03PM +0200, Sam Ravnborg wrote: > Hi Daniel. > > On Wed, Jul 29, 2020 at 03:53:28PM +0200, daniel@ffwll.ch wrote: > > On Wed, Jul 29, 2020 at 03:41:45PM +0200, Thomas Zimmermann wrote: > > > DRM fb helpers require read and write functions for framebuffer > > > memory. Export the existing code from fbdev. > > > > > > Signed-off-by: Thomas Zimmermann > > > > Hm I'm not super sure whether we want to actually reuse this stuff ... We > > kinda don't care about the sparc special case, and just having an fbdev > > implementation witch has the switch between memcpy and memcpy_to/from_io > > in one single place sounds a lot simpler ... > > > > This way we can have a clean split between the old horrors of real fbdev > > drivers, and a much cleaner world in drm. It would mean a bit of > > copypasting, but I think that's actually a good thing. > > > > In general my idea for drm fbdev emulation is that for any area we have a > > problem we just ignore the entire fbmem.c code and write our own: mmap, > > backlight handling (still unsolved, and horrible), cfb vs sys here. This > > entire fbmem.c stuff is pretty bad midlayer, trying to avoid code > > duplication here doesn't seem worth it imo. > > > > Thoughts? > > > I can see that fbmem is a mix of ioctl support and other stuff. > We could factor out all the ioctl parts of fbmem.c to a new file > named fbioctl.c. > > And then let the ioctl parts call down into drm stuff and avoid reusing > the fbdev code when we first reach drm code. > This would require local copies of: > sys_read, sys_write, sys_fillrect, sys_copyarea, sys_imageblit > and more I think which I missed. > > With local copies we could avoid some of the special cases and trim the > unctions to what is required by drm only. > And then no more fbmem dependencies and no dependencies to several of > the small helper functions. So less entanglement with fbdev core. > > This all sounds simple so I am surely missing a lot a ugly details here. > > And should we touch this anyway we need a test suite to verify not too > much breaks. To the best of my knowledge there is not yet such a test > suite :-( Maybe because people caring about fbdev are limited. Well my idea was to not refactor anything, but just have drm copies of the various fb_ops callbacks. Definitely not even more refactoring :-) -Daniel > > Sam > > > > > > > -Daniel > > > > > --- > > > drivers/video/fbdev/core/fbmem.c | 53 ++++++++++++++++++++++---------- > > > include/linux/fb.h | 5 +++ > > > 2 files changed, 41 insertions(+), 17 deletions(-) > > > > > > diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c > > > index dd0ccf35f7b7..b496ff90db3e 100644 > > > --- a/drivers/video/fbdev/core/fbmem.c > > > +++ b/drivers/video/fbdev/core/fbmem.c > > > @@ -759,25 +759,18 @@ static struct fb_info *file_fb_info(struct file *file) > > > return info; > > > } > > > > > > -static ssize_t > > > -fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) > > > +ssize_t fb_cfb_read(struct fb_info *info, char __user *buf, size_t count, > > > + loff_t *ppos) > > > { > > > unsigned long p = *ppos; > > > - struct fb_info *info = file_fb_info(file); > > > u8 *buffer, *dst; > > > u8 __iomem *src; > > > int c, cnt = 0, err = 0; > > > unsigned long total_size; > > > > > > - if (!info || ! info->screen_base) > > > - return -ENODEV; > > > - > > > if (info->state != FBINFO_STATE_RUNNING) > > > return -EPERM; > > > > > > - if (info->fbops->fb_read) > > > - return info->fbops->fb_read(info, buf, count, ppos); > > > - > > > total_size = info->screen_size; > > > > > > if (total_size == 0) > > > @@ -823,16 +816,12 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) > > > > > > return (err) ? err : cnt; > > > } > > > +EXPORT_SYMBOL(fb_cfb_read); > > > > > > static ssize_t > > > -fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) > > > +fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) > > > { > > > - unsigned long p = *ppos; > > > struct fb_info *info = file_fb_info(file); > > > - u8 *buffer, *src; > > > - u8 __iomem *dst; > > > - int c, cnt = 0, err = 0; > > > - unsigned long total_size; > > > > > > if (!info || !info->screen_base) > > > return -ENODEV; > > > @@ -840,8 +829,20 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) > > > if (info->state != FBINFO_STATE_RUNNING) > > > return -EPERM; > > > > > > - if (info->fbops->fb_write) > > > - return info->fbops->fb_write(info, buf, count, ppos); > > > + if (info->fbops->fb_read) > > > + return info->fbops->fb_read(info, buf, count, ppos); > > > + else > > > + return fb_cfb_read(info, buf, count, ppos); > > > +} > > > + > > > +ssize_t fb_cfb_write(struct fb_info *info, const char __user *buf, > > > + size_t count, loff_t *ppos) > > > +{ > > > + unsigned long p = *ppos; > > > + u8 *buffer, *src; > > > + u8 __iomem *dst; > > > + int c, cnt = 0, err = 0; > > > + unsigned long total_size; > > > > > > total_size = info->screen_size; > > > > > > @@ -895,6 +896,24 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) > > > > > > return (cnt) ? cnt : err; > > > } > > > +EXPORT_SYMBOL(fb_cfb_write); > > > + > > > +static ssize_t > > > +fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) > > > +{ > > > + struct fb_info *info = file_fb_info(file); > > > + > > > + if (!info || !info->screen_base) > > > + return -ENODEV; > > > + > > > + if (info->state != FBINFO_STATE_RUNNING) > > > + return -EPERM; > > > + > > > + if (info->fbops->fb_write) > > > + return info->fbops->fb_write(info, buf, count, ppos); > > > + else > > > + return fb_cfb_write(info, buf, count, ppos); > > > +} > > > > > > int > > > fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var) > > > diff --git a/include/linux/fb.h b/include/linux/fb.h > > > index 714187bc13ac..12ad83963db5 100644 > > > --- a/include/linux/fb.h > > > +++ b/include/linux/fb.h > > > @@ -593,6 +593,11 @@ extern int fb_blank(struct fb_info *info, int blank); > > > extern void cfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect); > > > extern void cfb_copyarea(struct fb_info *info, const struct fb_copyarea *area); > > > extern void cfb_imageblit(struct fb_info *info, const struct fb_image *image); > > > +extern ssize_t fb_cfb_read(struct fb_info *info, char __user *buf, > > > + size_t count, loff_t *ppos); > > > +extern ssize_t fb_cfb_write(struct fb_info *info, const char __user *buf, > > > + size_t count, loff_t *ppos); > > > + > > > /* > > > * Drawing operations where framebuffer is in system RAM > > > */ > > > -- > > > 2.27.0 > > > > > > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel