Lee Duncan <lduncan@xxxxxxxx> writes: > As pointed out by Christoph Hellwig, many of the users > of the ida index routines call them with the same calling > pattern, so why not make some helper functions to help > clean up and simplify the code a bit. > > After looking at all the uses of the ida routines, I > noticed that most of clients of this API used the > same sequence -- but not all of them. So I picked > the most common and seemingly most correct sequence, > and I made inline helper functions for that, creating: > > - ida_get_index() -- get an 'ida' index, with proper > locking and retry > > - ida_put_index() -- release/return an index allocated > by ida_get_index(), with proper locking > > I converted the following drivers to use the new helper > routines, because they matched the calling sequence > used by the helper functions: > > scsi/sd.c SCSI disk > base/soc.c sound? > block/mtip32xxx/mtip32xx.c PCI block? > block/nvme-core.c Intel SSD? > block/rsxx/core.c IBM Flash? > > Obviously, only one of these is a SCSI driver, so > I hope this is still the right place to post this. I think drawing this to attention of a wider audience (i.e. add lkml to Cc) would be a good idea. Other than that, I'm OK with it. > > NOTE 1: the soc.c driver actually had normal locking > around it's 'get' call, but it had no locking around > it's 'put' (release) calls, so since the helper routines > have locking, that means the soc.c driver now has > locking when it releases an index. > > There were other drivers that used ida in a way > that meant I could not easily modify them: > > drivers/iommu/iommu.c: > - uses unlikely(...) > - uses a mutex instead of spinlock > > drivers/misc/cb710/core.c: > - calls return from within the 'get' while loop > - uses spin_lock_irq*() > > drivers/scsi/osd/osd_uld.c: > - uses no locking at all for indexes [See NOTE 2] > > drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c > - uses 'unlikely()' in 'get' while loop > - uses 'goto's out of 'get' while loop > Regarding the above, maybe Cc the maintainers of said drivers to the cover letter, so they can comment on the IDA usage. > NOTE 2: Not sure if this is a bug in the osd code, since > I did not look at it very closely. > > The only client driver changes I was able to functionally > test where the sd.c changes. I also tested the helper > functions using the hosts.c module, where they worked > fine, but those changes were later reverted in favor of > using idr there instead. (See previous patch series.) > > Lee Duncan (6): > Add ida helper routines > SCSI: Update sd driver to use new ida helper functions. > Update soc driver to use new ida helper functions. > Update soc driver to use new ida helper functions. > Update nvme-core driver to use new ida helper functions. > Update rsxx core driver to use new ida helper functions. > > drivers/base/soc.c | 17 +++------------- > drivers/block/mtip32xx/mtip32xx.c | 22 ++++---------------- > drivers/block/nvme-core.c | 14 ++----------- > drivers/block/rsxx/core.c | 16 ++------------- > drivers/scsi/sd.c | 18 +++-------------- > include/linux/idr.h | 42 +++++++++++++++++++++++++++++++++++++++ > 6 files changed, 56 insertions(+), 73 deletions(-) -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
