Hello Michael, Do you suggest any change for this patchset? Any chance it can get in this merge window?
Best regards, Leonardo Bras On Wed, 2020-08-05 at 00:04 -0300, Leonardo Bras wrote: > 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(-) >