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From: Arnd Bergmann <arnd@arndb.de>
To: Christopher Covington <cov@codeaurora.org>
Cc: "Nicolas Pitre" <nicolas.pitre@linaro.org>,
	"Russell King - ARM Linux" <linux@arm.linux.org.uk>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Måns Rullgård" <mans@mansr.com>,
	"linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
	"Stephen Boyd" <sboyd@codeaurora.org>,
	"lkml - Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	"Steven Rostedt" <rostedt@goodmis.org>,
	arm-mail-list <linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions
Date: Mon, 23 Nov 2015 16:32:33 +0100	[thread overview]
Message-ID: <105706554.vF12QZslMx@wuerfel> (raw)
In-Reply-To: <56531F4F.9010100@codeaurora.org>

On Monday 23 November 2015 09:14:39 Christopher Covington wrote:
> On 11/23/2015 03:15 AM, Arnd Bergmann wrote:
> > On Sunday 22 November 2015 21:36:45 Nicolas Pitre wrote:
> >> On Sun, 22 Nov 2015, Arnd Bergmann wrote:
> > 
> > Ok, thanks a lot! So the reporting in /proc/cpuinfo clearly matches
> > the actual features, and we can just treat this as no LPAE / no IDIV
> > for kernel compilation, as nobody ever seems to use THUMB2_KERNEL
> > in practice.
> > 
> > PJ4-MP is like Cortex-A15/A7/A12/A17 and supports both IDIV and LPAE,
> > which leaves the question whether Scorpion or Krait do the same as
> > well, or whether they are outliers and need a special configuration.
> 
> LPAE is only supported in the Krait 450.
> 
> http://www.anandtech.com/show/7537/qualcomms-snapdragon-805-25ghz-128bit-memory-interface-d3d11class-graphics-more
> 
> I'm pretty sure idiv support came earlier, but I don't have the
> specifics on hand.

I have seen that article, but didn't trust it as a canonical
source of information here.

If you can confirm that it's right, that would mean that we
don't support LPAE on mach-qcom, as the only SoC with Krait 450
seems to be APQ8084, and mainline Linux doesn't run on that.

The ones we do support are MSM8x60 (Scorpion), MSM8960
(Krait-without-number),and MSM7874 (Krait 400). Do those all
support IDIV but not LPAE?

	Arnd

  reply	other threads:[~2015-11-23 15:33 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-21  1:23 [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions Stephen Boyd
2015-11-21  1:23 ` [RFC/PATCH 1/3] scripts: Allow recordmcount to be used without tracing enabled Stephen Boyd
2015-11-21  1:23 ` [RFC/PATCH 2/3] recordmcount: Record locations of __aeabi_{u}idiv() calls on ARM Stephen Boyd
2015-11-21 10:13   ` Russell King - ARM Linux
2015-11-23 20:53     ` Stephen Boyd
2015-11-23 20:58       ` Steven Rostedt
2015-11-23 21:03       ` Russell King - ARM Linux
2015-11-23 21:16         ` Stephen Boyd
2015-11-23 21:33           ` Russell King - ARM Linux
2015-11-24  1:04             ` Stephen Boyd
2015-11-21  1:23 ` [RFC/PATCH 3/3] ARM: Replace calls to __aeabi_{u}idiv with udiv/sdiv instructions Stephen Boyd
2015-11-21 11:50   ` Måns Rullgård
2015-11-23 20:49     ` Stephen Boyd
2015-11-23 20:54       ` Måns Rullgård
2015-11-23 21:16         ` Stephen Boyd
2015-11-21 20:39 ` [RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions Arnd Bergmann
2015-11-21 20:45   ` Måns Rullgård
2015-11-21 21:00     ` Arnd Bergmann
2015-11-21 22:11       ` Måns Rullgård
2015-11-21 23:14         ` Arnd Bergmann
2015-11-21 23:21           ` Arnd Bergmann
2015-11-22 13:29             ` Peter Maydell
2015-11-22 19:25               ` Arnd Bergmann
2015-11-22 19:30                 ` Måns Rullgård
2015-11-22 19:47                 ` Russell King - ARM Linux
2015-11-22 19:58                   ` Arnd Bergmann
2015-11-22 20:03                     ` Russell King - ARM Linux
2015-11-22 20:37                       ` Arnd Bergmann
2015-11-22 20:39                         ` Måns Rullgård
2015-11-22 21:18                           ` Arnd Bergmann
2015-11-23  2:36                     ` Nicolas Pitre
2015-11-23  8:15                       ` Arnd Bergmann
2015-11-23 14:14                         ` Christopher Covington
2015-11-23 15:32                           ` Arnd Bergmann [this message]
2015-11-23 20:38                             ` Stephen Boyd
2015-11-23 21:19                               ` Arnd Bergmann
2015-11-23 21:32                                 ` Stephen Boyd
2015-11-23 21:57                                   ` Arnd Bergmann
2015-11-23 23:13                                     ` Stephen Boyd
2015-11-24 10:17                                       ` Arnd Bergmann
2015-11-24 12:15                                         ` Måns Rullgård
2015-11-24 13:45                                           ` Arnd Bergmann
2015-11-25  1:51                                         ` Stephen Boyd
2015-11-25  7:21                                           ` Arnd Bergmann
2015-11-24  0:13                                     ` Stephen Boyd
2015-11-24  8:53                                       ` Stephen Boyd
2015-11-24 10:38                                         ` Arnd Bergmann
2015-11-24 10:42                                           ` Russell King - ARM Linux
2015-11-24 12:10                                             ` Måns Rullgård
2015-11-24 12:23                                               ` Russell King - ARM Linux
2015-11-24 12:29                                                 ` Måns Rullgård
2015-11-24 14:00                                                   ` Russell King - ARM Linux
2015-11-24 14:03                                                     ` Måns Rullgård
2015-11-24 10:39                                         ` Russell King - ARM Linux
2015-11-24 20:07                                           ` Stephen Boyd
2015-11-24 20:35                                             ` Russell King - ARM Linux
2015-11-24 21:11                                               ` Arnd Bergmann
2016-01-13  1:51                                               ` Stephen Boyd
2015-11-24 10:37                                       ` Russell King - ARM Linux

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