From: Leonardo Bras <leobras.c@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Leonardo Bras <leobras.c@gmail.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>,
Ram Pai <linuxram@us.ibm.com>,
Brian King <brking@linux.vnet.ibm.com>,
Murilo Fossa Vicentini <muvic@linux.ibm.com>,
David Dai <zdai@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 0/4] Allow bigger 64bit window by removing default DMA window
Date: Wed, 5 Aug 2020 00:04:51 -0300 [thread overview]
Message-ID: <20200805030455.123024-1-leobras.c@gmail.com> (raw)
There are some devices in which a hypervisor may only allow 1 DMA window
to exist at a time, and in those cases, a DDW is never created to them,
since the default DMA window keeps using this resource.
LoPAR recommends this procedure:
1. Remove the default DMA window,
2. Query for which configs the DDW can be created,
3. Create a DDW.
Patch #1:
Create defines for outputs of ibm,ddw-applicable, so it's easier to
identify them.
Patch #2:
- After LoPAR level 2.8, there is an extension that can make
ibm,query-pe-dma-windows to have 6 outputs instead of 5. This changes the
order of the outputs, and that can cause some trouble.
- query_ddw() was updated to check how many outputs the
ibm,query-pe-dma-windows is supposed to have, update the rtas_call() and
deal correctly with the outputs in both cases.
- This patch looks somehow unrelated to the series, but it can avoid future
problems on DDW creation.
Patch #3 moves the window-removing code from remove_ddw() to
remove_dma_window(), creating a way to delete any DMA window, so it can be
used to delete the default DMA window.
Patch #4 makes use of the remove_dma_window() from patch #3 to remove the
default DMA window before query_ddw(). It also implements a new rtas call
to recover the default DMA window, in case anything fails after it was
removed, and a DDW couldn't be created.
---
Changes since v4:
- Removed patches 5+ in order to deal with a feature at a time
- Remove unnecessary parentesis in patch #4
- Changed patch #4 title from
"Remove default DMA window before creating DDW"
- Included David Dai tested-by
- v4 link: http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=190051&state=%2A&archive=both
Changes since v3:
- Introduces new patch #5, to prepare for an important change in #6
- struct iommu_table was not being updated, so include a way to do this
in patch #6.
- Improved patch #4 based in a suggestion from Alexey, to make code
more easily understandable
- v3 link: http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=187348&state=%2A&archive=both
Changes since v2:
- Change the way ibm,ddw-extensions is accessed, using a proper function
instead of doing this inline everytime it's used.
- Remove previous patch #6, as it doesn't look like it would be useful.
- Add new patch, for changing names from direct* to dma*, as indirect
mapping can be used from now on.
- Fix some typos, corrects some define usage.
- v2 link: http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=185433&state=%2A&archive=both
Changes since v1:
- Add defines for ibm,ddw-applicable and ibm,ddw-extensions outputs
- Merge aux function query_ddw_out_sz() into query_ddw()
- Merge reset_dma_window() patch (prev. #2) into remove default DMA
window patch (#4).
- Keep device_node *np name instead of using pdn in remove_*()
- Rename 'device_node *pdn' into 'parent' in new functions
- Rename dfl_win to default_win
- Only remove the default DMA window if there is no window available
in first query.
- Check if default DMA window can be restored before removing it.
- Fix 'unitialized use' (found by travis mpe:ci-test)
- New patches #5 and #6
- v1 link: http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=184420&state=%2A&archive=both
Special thanks for Alexey Kardashevskiy, Brian King and
Oliver O'Halloran for the feedback provided!
Leonardo Bras (4):
powerpc/pseries/iommu: Create defines for operations in
ibm,ddw-applicable
powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows
powerpc/pseries/iommu: Move window-removing part of remove_ddw into
remove_dma_window
powerpc/pseries/iommu: Allow bigger 64bit window by removing default
DMA window
arch/powerpc/platforms/pseries/iommu.c | 242 ++++++++++++++++++++-----
1 file changed, 195 insertions(+), 47 deletions(-)
--
2.25.4
next reply other threads:[~2020-08-05 3:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-05 3:04 Leonardo Bras [this message]
2020-08-05 3:04 ` [PATCH v5 1/4] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable Leonardo Bras
2020-08-05 3:16 ` Alexey Kardashevskiy
2020-08-05 3:04 ` [PATCH v5 2/4] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows Leonardo Bras
2020-08-05 3:16 ` Alexey Kardashevskiy
2020-08-05 3:04 ` [PATCH v5 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window Leonardo Bras
2020-08-05 3:17 ` Alexey Kardashevskiy
2020-08-05 3:04 ` [PATCH v5 4/4] powerpc/pseries/iommu: Allow bigger 64bit window by removing default DMA window Leonardo Bras
2020-08-05 3:17 ` Alexey Kardashevskiy
2020-08-05 18:08 ` [PATCH v5 0/4] " Leonardo Bras
2020-08-12 4:42 ` Leonardo Bras
2020-09-09 13:27 ` Michael Ellerman
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