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From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: Andy Gross <andy.gross@linaro.org>,
	David Brown <david.brown@linaro.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Hans de Goede <hdegoede@redhat.com>,
	Michal Hocko <mhocko@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@surriel.com>,
	Laura Abbott <labbott@redhat.com>,
	Vlastimil Babka <vbabka@suse.cz>
Cc: "Martijn Coenen" <maco@android.com>,
	"Mimi Zohar" <zohar@linux.vnet.ibm.com>,
	"Stephen Boyd" <sboyd@kernel.org>,
	"Vikram Mulukutla" <markivx@codeaurora.org>,
	"Arve Hjønnevåg" <arve@android.com>,
	"Todd Kjos" <tkjos@android.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	linux-security-module@vger.kernel.org,
	"Chris Wright" <chrisw@sous-sol.org>,
	"David Howells" <dhowells@redhat.com>,
	"Alan Cox" <alan@linux.intel.com>,
	"Kees Cook" <keescook@chromium.org>,
	"Darren Hart" <dvhart@infradead.org>,
	"Andy Shevchenko" <andy@infradead.org>,
	"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	platform-driver-x86@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	"Peter Jones" <pjones@redhat.com>,
	"Dave Olsthoorn" <dave@bewaar.me>,
	"Will Deacon" <will.deacon@arm.com>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Matt Fleming" <matt@codeblueprint.co.uk>,
	"Josh Triplett" <josh@joshtriplett.org>,
	dmitry.torokhov@gmail.com, "Jonathan Corbet" <corbet@lwn.net>,
	mfuzzey@parkeon.com, "Kalle Valo" <kvalo@codeaurora.org>,
	"Arend Van Spriel" <arend.vanspriel@broadcom.com>,
	"Linus Torvalds" <torvalds@linux-foundation.org>,
	nbroeking@me.com, "Torsten Duwe" <duwe@suse.de>,
	x86@kernel.org, linux-efi <linux-efi@vger.kernel.org>,
	"open list:ANDROID DRIVERS" <devel@driverdev.osuosl.org>,
	linux-arm-msm@vger.kernel.org, mcgrof@kernel.org
Subject: Do Qualcomm drivers use DMA buffers for request_firmware_into_buf()?
Date: Wed, 6 Jun 2018 22:32:57 +0200	[thread overview]
Message-ID: <20180606203257.GH4511@wotan.suse.de> (raw)
In-Reply-To: <20180601192346.GQ4511@wotan.suse.de>

On Fri, Jun 01, 2018 at 09:23:46PM +0200, Luis R. Rodriguez wrote:
> On Tue, May 08, 2018 at 03:38:05PM +0000, Luis R. Rodriguez wrote:
> > On Fri, May 04, 2018 at 12:44:37PM -0700, Martijn Coenen wrote:
> > > 
> > > I think the Qualcomm folks owning this (Andy, David, Bjorn, already
> > > cc'd here) are better suited to answer that question.
> > 
> > Andy, David, Bjorn?
> 
> Andy, David, Bjorn?

A month now with no answer...

Perhaps someone who has this hardware can find out empirically for us, as
follows (mm folks is this right?):

page = virt_to_page(address);
if (!page)
   fail closed...
if (page_zone(page) == ZONE_DMA || page_zone(page) == ZONE_DMA32)
	this is a DMA buffer
else
	not DMA!

Note that when request_firmware_into_buf() was being reviewed Mimi had asked back
in 2016 [0] that if a DMA buffer was going to be used READING_FIRMWARE_DMA should be
used otherwise READING_FIRMWARE_PREALLOC_BUFFER was fine.

If it is a DMA buffer *now*, why / how did this change?

[0] https://patchwork.kernel.org/patch/9074611/

  Luis

  reply	other threads:[~2018-06-06 20:33 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-08 17:40 [PATCH v3 0/5] efi/firmware/platform-x86: Add EFI embedded fw support Hans de Goede
2018-04-08 17:40 ` [PATCH v3 1/5] efi: Export boot-services code and data as debugfs-blobs Hans de Goede
2018-04-16  8:23   ` Ard Biesheuvel
2018-04-24 13:11     ` Hans de Goede
2018-04-23 11:55   ` Greg Kroah-Hartman
2018-04-08 17:40 ` [PATCH v3 2/5] efi: Add embedded peripheral firmware support Hans de Goede
2018-04-16  8:28   ` Ard Biesheuvel
2018-04-24 13:17     ` Hans de Goede
2018-04-17  0:17   ` Luis R. Rodriguez
2018-04-17  8:58     ` Hans de Goede
2018-04-17  9:19     ` Hans de Goede
2018-04-23 21:11   ` Luis R. Rodriguez
2018-04-24 15:09     ` Hans de Goede
2018-04-24 16:07       ` Mimi Zohar
2018-04-24 18:33         ` Hans de Goede
2018-04-24 23:42         ` Luis R. Rodriguez
2018-04-25  5:00           ` Mimi Zohar
2018-04-25 17:55             ` Luis R. Rodriguez
2018-05-04  0:21               ` Luis R. Rodriguez
2018-05-04 15:26                 ` Martijn Coenen
2018-05-04 19:44               ` Martijn Coenen
2018-05-08 15:38                 ` Luis R. Rodriguez
2018-05-08 16:10                   ` Luis R. Rodriguez
2018-06-07 16:49                     ` Bjorn Andersson
2018-06-07 18:22                       ` Luis R. Rodriguez
2018-06-01 19:23                   ` Luis R. Rodriguez
2018-06-06 20:32                     ` Luis R. Rodriguez [this message]
2018-06-07 16:18                       ` Do Qualcomm drivers use DMA buffers for request_firmware_into_buf()? Bjorn Andersson
     [not found]                         ` <CAKv+Gu8+Fq7BD4XD-YCyXzZh0mg6Z2k-0styj0cw6_uZfaqy4Q@mail.gmail.com>
     [not found]                           ` <20180607163308.GA18834@kroah.com>
2018-06-08  6:41                             ` Vlastimil Babka
2018-06-07 16:33             ` [PATCH v3 2/5] efi: Add embedded peripheral firmware support Bjorn Andersson
2018-04-08 17:40 ` [PATCH v3 3/5] platform/x86: Rename silead_dmi to touchscreen_dmi Hans de Goede
2018-04-09  8:07   ` Andy Shevchenko
2018-04-20  0:20     ` Darren Hart
2018-04-08 17:40 ` [PATCH v3 4/5] platform/x86: touchscreen_dmi: Add EFI embedded firmware info support Hans de Goede
2018-04-08 17:40 ` [PATCH v3 5/5] platform/x86: touchscreen_dmi: Add info for the Chuwi Vi8 Plus tablet Hans de Goede
2018-04-09  8:10   ` Andy Shevchenko

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