From: Arnd Bergmann <arnd@arndb•de>
To: michael@ellerman•id.au
Cc: Paul Mackerras <paulus@samba•org>,
cbe-oss-dev@ozlabs•org, linuxppc-dev@ozlabs•org
Subject: Re: [Cbe-oss-dev] [patch 11/11] powerpc/cell: Add DMA_ATTR_STRONG_ORDERING dma attribute and use in IOMMU code
Date: Mon, 7 Jul 2008 11:01:24 +0200 [thread overview]
Message-ID: <200807071101.25286.arnd@arndb.de> (raw)
In-Reply-To: <1215388851.19157.0.camel@localhost>
On Monday 07 July 2008, Michael Ellerman wrote:
>
> > It turned out that the firmware sets up the south bridge to never set the 'S'
> > bit on incoming transactions, which overrides the IOPTE_SO_RW bits, on all
> > existing cell hardware.
>
> It seems strange to me that the southbridge is allowed to override the
> setting in the IOMMU page table, but if that's what the doc says ..
That's what I thought at first as well, but it actually makes sense:
If the bridge knows that a data packet has been reordered already
by the originator or one of its own busses, there is no point in
enforcing strong ordering at the IOMMU again.
Arnd <><
prev parent reply other threads:[~2008-07-07 9:01 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-04 19:05 [patch 00/11] Cell patches for 2.6.27 arnd
2008-07-04 19:05 ` [patch 01/11] powerpc/cell: add support for power button of future IBM cell blades arnd
2008-07-07 5:12 ` Benjamin Herrenschmidt
2008-07-07 9:23 ` Christian Krafft
[not found] ` <20080707184756.16e52677@linux.ibm.com>
2008-07-07 16:54 ` [Cbe-oss-dev] [patch 01/02] powerpc/cell: cleanup sysreset_hack for " Christian Krafft
2008-07-07 16:56 ` [Cbe-oss-dev] [patch 02/02] powerpc/cell: add support for power button of future " Christian Krafft
2008-07-09 3:35 ` Benjamin Herrenschmidt
2008-07-09 13:15 ` Arnd Bergmann
2008-07-09 20:45 ` Benjamin Herrenschmidt
2008-07-10 14:34 ` Arnd Bergmann
2008-07-07 5:24 ` [patch 01/11] " Stephen Rothwell
2008-07-07 8:40 ` [Cbe-oss-dev] " Arnd Bergmann
2008-07-04 19:05 ` [patch 02/11] powerpc/axonram: use only one block device major number arnd
2008-07-04 19:05 ` [patch 03/11] powerpc/axonram: enable partitioning of the Axons DDR2 DIMMs arnd
2008-07-04 19:05 ` [patch 04/11] powerpc/spufs: add atomic busy_spus counter to struct cbe_spu_info arnd
2008-07-07 5:19 ` Benjamin Herrenschmidt
2008-07-07 5:30 ` Stephen Rothwell
2008-07-07 8:50 ` [Cbe-oss-dev] " Arnd Bergmann
2008-07-04 19:05 ` [patch 05/11] powerpc/cell: add spu aware cpufreq governor arnd
2008-07-07 5:21 ` Benjamin Herrenschmidt
2008-07-07 5:32 ` Stephen Rothwell
2008-07-07 9:01 ` [Cbe-oss-dev] " Arnd Bergmann
2008-07-07 6:24 ` Stephen Rothwell
2008-07-07 8:58 ` [Cbe-oss-dev] " Arnd Bergmann
2008-07-07 14:59 ` Arnd Bergmann
2008-07-07 15:35 ` Josh Boyer
2008-07-07 21:15 ` Arnd Bergmann
2008-07-07 21:17 ` Josh Boyer
2008-07-08 2:40 ` Stephen Rothwell
2008-07-07 19:56 ` Geoff Levand
2008-07-04 19:05 ` [patch 06/11] powerpc: Add struct iommu_table argument to iommu_map_sg() arnd
2008-07-04 19:05 ` [patch 07/11] powerpc/dma: implement new dma_*map*_attrs() interfaces arnd
2008-07-07 5:27 ` Benjamin Herrenschmidt
2008-07-07 19:15 ` Geoff Levand
2008-07-04 19:05 ` [patch 08/11] powerpc/dma: use the struct dma_attrs in iommu code arnd
2008-07-04 19:05 ` [patch 09/11] powerpc/cell: cell_dma_dev_setup_iommu() return the iommu table arnd
2008-07-04 19:05 ` [patch 10/11] powerpc: move device_to_mask() to dma-mapping.h arnd
2008-07-04 19:05 ` [patch 11/11] powerpc/cell: Add DMA_ATTR_STRONG_ORDERING dma attribute and use in IOMMU code arnd
2008-07-05 5:43 ` [Cbe-oss-dev] " Michael Ellerman
2008-07-05 6:28 ` Benjamin Herrenschmidt
2008-07-05 21:51 ` Arnd Bergmann
2008-07-05 22:20 ` Benjamin Herrenschmidt
2008-07-06 15:15 ` Arnd Bergmann
2008-07-07 0:00 ` Michael Ellerman
2008-07-07 9:01 ` Arnd Bergmann [this message]
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