From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 11/12] ARM: mvebu: Relocate Armada 370 PCIe device tree nodes
Date: Wed, 19 Jun 2013 20:55:41 +0200 [thread overview]
Message-ID: <201306192055.41678.arnd@arndb.de> (raw)
In-Reply-To: <20130619165348.GA32155@obsidianresearch.com>
On Wednesday 19 June 2013, Jason Gunthorpe wrote:
>
> Today 18:53:48
>
> On Wed, Jun 19, 2013 at 02:11:58PM +0200, Arnd Bergmann wrote:
>
> > > Mmm.. and why is this option acceptable?
> >
> > As I explained on IRC, there is no requirement to pick a specific bus
> > aperture. The only two sensible choices are to make the bus address
> > the same as the CPU address, or to make the bus address start at 0,
> > which is what this does.
>
> PCI bus addresses must not alias other addresess in the system or
> you'll get weirdness. For instance DMA initiated from the PCI bus at
> address 0, intended to read from SDRAM at 0 must not be claimed by
> another device on the PCI bus. IMHO, a 1:1 mapping between PCI and CPU
> is strongly preferred. Any other configuration will need some
> additional techniques to avoid aliasing.
Ah, good point. You are obviously right, it should definitely be a 1:1
mapping, anything else just creates a mess. I was working on a system
like that before, it wasn't pretty (you have to provide separate
dma_map_ops then).
Arnd
next prev parent reply other threads:[~2013-06-19 18:55 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-18 11:25 [PATCH v3 00/12] MBus device tree binding Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 01/12] bus: mvebu-mbus: Factor out initialization details Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 02/12] bus: mvebu-mbus: Introduce device tree binding Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 03/12] bus: mvebu-mbus: Add static window allocation to the DT binding Ezequiel Garcia
2013-06-18 16:14 ` Arnd Bergmann
2013-06-18 17:12 ` Thomas Petazzoni
2013-06-18 17:16 ` Arnd Bergmann
2013-06-18 21:34 ` Ezequiel Garcia
2013-06-18 21:45 ` Arnd Bergmann
2013-06-19 18:52 ` Ezequiel Garcia
2013-06-19 19:08 ` Arnd Bergmann
2013-06-19 19:29 ` Ezequiel Garcia
2013-06-19 19:37 ` Jason Cooper
2013-06-18 17:46 ` Jason Gunthorpe
2013-06-18 18:24 ` Sebastian Hesselbarth
2013-06-18 18:39 ` Arnd Bergmann
2013-06-18 18:44 ` Sebastian Hesselbarth
2013-06-18 18:47 ` Jason Gunthorpe
2013-06-18 18:59 ` Sebastian Hesselbarth
2013-06-18 19:10 ` Jason Gunthorpe
2013-06-18 19:27 ` Sebastian Hesselbarth
2013-06-18 20:49 ` Ezequiel Garcia
2013-06-18 20:55 ` Jason Gunthorpe
2013-06-18 21:10 ` Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 04/12] ARM: mvebu: Initialize MBus using " Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 05/12] ARM: mvebu: Remove the harcoded BootROM window allocation Ezequiel Garcia
2013-06-18 17:39 ` Jason Gunthorpe
2013-06-18 19:43 ` Ezequiel Garcia
2013-06-18 19:51 ` Jason Gunthorpe
2013-06-18 20:02 ` Ezequiel Garcia
2013-06-18 20:10 ` Jason Gunthorpe
2013-06-18 20:39 ` Ezequiel Garcia
2013-06-19 10:02 ` Ezequiel Garcia
2013-06-19 16:58 ` Jason Gunthorpe
2013-06-19 17:58 ` Ezequiel Garcia
2013-06-19 18:03 ` Jason Gunthorpe
2013-06-19 18:17 ` Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 06/12] memory: mvebu-devbus: Remove address decoding window workaround Ezequiel Garcia
2013-06-18 11:39 ` Jason Cooper
2013-06-18 12:17 ` Thomas Petazzoni
2013-06-18 12:33 ` Jason Cooper
2013-06-18 12:48 ` Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 07/12] ARM: mvebu: Use the preprocessor on Armada 370/XP device tree files Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 08/12] ARM: mvebu: Add MBus to Armada 370/XP device tree Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 09/12] ARM: mvebu: Add BootROM " Ezequiel Garcia
2013-06-18 11:25 ` [PATCH v3 10/12] ARM: mvebu: Relocate Armada 370/XP DeviceBus device tree nodes Ezequiel Garcia
2013-06-18 16:16 ` Arnd Bergmann
2013-06-18 22:09 ` Ezequiel Garcia
2013-06-18 22:14 ` Ezequiel Garcia
2013-06-19 12:03 ` Arnd Bergmann
2013-06-18 11:25 ` [PATCH v3 11/12] ARM: mvebu: Relocate Armada 370 PCIe " Ezequiel Garcia
2013-06-18 16:29 ` Arnd Bergmann
2013-06-18 17:15 ` Thomas Petazzoni
2013-06-18 17:18 ` Arnd Bergmann
2013-06-18 17:21 ` Thomas Petazzoni
2013-06-18 18:22 ` Arnd Bergmann
2013-06-18 19:02 ` Jason Gunthorpe
2013-06-18 21:20 ` Arnd Bergmann
2013-06-18 21:40 ` Ezequiel Garcia
2013-06-19 12:06 ` Arnd Bergmann
2013-06-18 21:35 ` Arnd Bergmann
2013-06-19 11:12 ` Ezequiel Garcia
2013-06-19 12:11 ` Arnd Bergmann
2013-06-19 16:53 ` Jason Gunthorpe
2013-06-19 18:55 ` Arnd Bergmann [this message]
2013-06-18 11:25 ` [PATCH v3 12/12] ARM: mvebu: Relocate Armada XP " Ezequiel Garcia
2013-06-18 11:33 ` [PATCH v3 00/12] MBus device tree binding Sebastian Hesselbarth
2013-06-18 13:07 ` Ezequiel Garcia
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