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* at_hdmac: implement a private tx_listDan Williams2009-09-092-8/+10
| | | | | | | | | | Drop at_hdmac's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* mv_xor: implement a private tx_listDan Williams2009-09-092-5/+6
| | | | | | | | | Drop mv_xor's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Cc: Saeed Bishara <saeed@marvell.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* ioat: implement a private tx_listDan Williams2009-09-092-4/+6
| | | | | | | | | Drop ioatdma's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* iop-adma: implement a private tx_listDan Williams2009-09-091-4/+5
| | | | | | | | Drop iop-adma's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* fsldma: implement a private tx_listDan Williams2009-09-092-7/+10
| | | | | | | | | | Drop fsldma's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Cc: Li Yang <leoli@freescale.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* dw_dmac: implement a private tx_listDan Williams2009-09-092-9/+11
| | | | | | | | | Drop dw_dmac's use of tx_list from struct dma_async_tx_descriptor in preparation for removal of this field. Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge branch 'ioat' into dmaengineDan Williams2009-09-0914-2044/+2608
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| * net_dma: poll for a descriptor after allocation failureDan Williams2009-09-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | Handle descriptor allocation failures by polling for a descriptor. The driver will force forward progress when polled. In the best case this polling interval will be the time it takes for one dma memcpy transaction to complete. In the worst case, channel hang, we will need to wait 100ms for the cleanup watchdog to fire (ioatdma driver). Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat2,3: dynamically resize descriptor ringDan Williams2009-09-093-31/+187
| | | | | | | | | | | | | | | | | | | | | | | | Increment the allocation order of the descriptor ring every time we run out of descriptors up to a maximum of allocation order specified by the module parameter 'ioat_max_alloc_order'. After each idle period decrement the allocation order to a minimum order of 'ioat_ring_alloc_order' (i.e. the default ring size, tunable as a module parameter). Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: switch watchdog and reset handler from workqueue to timerDan Williams2009-09-096-436/+396
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support dynamic resizing of the descriptor ring or polling for a descriptor in the presence of a hung channel the reset handler needs to make progress while in a non-preemptible context. The current workqueue implementation precludes polling channel reset completion under spin_lock(). This conversion also allows us to return to opportunistic cleanup in the ioat2 case as the timer implementation guarantees at least one cleanup after every descriptor is submitted. This means the worst case completion latency becomes the timer frequency (for exceptional circumstances), but with the benefit of avoiding busy waiting when the lock is contended. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat1: trim ioat_dma_desc_swDan Williams2009-09-093-5/+7
| | | | | | | | | | | | | | | | Save 4 bytes per software descriptor by transmitting tx_cnt in an unused portion of the hardware descriptor. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: ___devinit annotate the initialization pathsDan Williams2009-09-095-20/+24
| | | | | | | | | | | | | | Mark all single use initialization routines with __devinit. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: preserve chanctrl bits when re-arming interruptsDan Williams2009-09-093-14/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | The register write in ioat_dma_cleanup_tasklet is unfortunate in two ways: 1/ It clears the extra 'enable' bits that we set at alloc_chan_resources time 2/ It gives the impression that it disables interrupts when it is in fact re-arming interrupts [ Impact: fix, persist the value of the chanctrl register when re-arming ] Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: ignore reserved bits for chancnt and xfercapDan Williams2009-09-092-0/+14
| | | | | | | | | | | | | | | | Don't trust that the reserved bits are always zero, also sanity check the returned value. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: cleanup completion status readsDan Williams2009-09-094-75/+46
| | | | | | | | | | | | | | | | | | | | The cleanup path makes an effort to only perform an atomic read of the 64-bit completion address. However in the 32-bit case it does not matter if we read the upper-32 and lower-32 non-atomically because the upper-32 will always be zero. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: add some dev_dbg() callsDan Williams2009-09-094-4/+81
| | | | | | | | | | | | | | Provide some output for debugging the driver. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat1: kill unused unmap parametersDan Williams2009-09-092-4/+0
| | | | | | | | | | | | | | | | | | The unified ioat1/ioat2 ioat_dma_unmap() implementation derives the source and dest addresses from the unmap descriptor. There is no longer a need to track this information in struct ioat_desc_sw. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat2,3: convert to a true ring bufferDan Williams2009-09-096-686/+1122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the current linked list munged into a ring with a native ring buffer implementation. The benefit of this approach is reduced overhead as many parameters can be derived from ring position with simple pointer comparisons and descriptor allocation/freeing becomes just a manipulation of head/tail pointers. It requires a contiguous allocation for the software descriptor information. Since this arrangement is significantly different from the ioat1 chain, move ioat2,3 support into its own file and header. Common routines are exported from driver/dma/ioat/dma.[ch]. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: prepare the code for ioat[12]_dma_chan splitDan Williams2009-09-092-370/+390
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prepare the code for the conversion of the ioat2 linked-list-ring into a native ring buffer. After this conversion ioat2 channels will share less of the ioat1 infrastructure, but there will still be places where sharing is possible. struct ioat_chan_common is created to house the channel attributes that will remain common between ioat1 and ioat2 channels. For every routine that accesses both common and hardware specific fields the old unified 'ioat_chan' pointer is split into an 'ioat' and 'chan' pointer. Where 'chan' references common fields and 'ioat' the hardware/version specific. [ Impact: pure structure member movement/variable renames, no logic changes ] Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: fix self test interruptsDan Williams2009-09-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | If a callback is to be attached to a descriptor the channel needs to know at ->prep time so it can set the interrupt enable bit. This is in preparation for moving descriptor ioat2 descriptor preparation from ->submit to ->prep. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat1: move descriptor allocation from submit to prepDan Williams2009-09-091-89/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The async_tx api assumes that after a successful ->prep a subsequent ->submit will not fail due to a lack of resources. This also fixes a bug in the allocation failure case. Previously the descriptors allocated prior to the allocation failure would not be returned to the free list. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: define descriptor control bit-fieldDan Williams2009-09-092-32/+34
| | | | | | | | | | | | | | | | | | This cleans up a mess of and'ing and or'ing bit definitions, and allows simple assignments from the specified dma_ctrl_flags parameter. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: fix type mismatch for ->dmacountDan Williams2009-09-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->dmacount tracks the sequence number of active descriptors. It is written to the DMACOUNT register to update the channel's view of pending descriptors in the chain. The register is 16-bits so ->dmacount should be unsigned and 16-bit as well. Also modify ->desccount to maintain alignment. This was never a problem in practice because we never compared dmacount values, but this is a bug waiting to happen. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: split ioat_dma_probe into core/version-specific routinesDan Williams2009-09-093-155/+200
| | | | | | | | | | | | | | | | | | | | | | | | Towards the removal of ioatdma_device.version split the initialization path into distinct versions. This conversion: 1/ moves version specific probe code to version specific routines 2/ removes the need for ioat_device 3/ turns off the ioat1 msi quirk if the device is reinitialized for intx Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: kill function prototype ifdef guardsDan Williams2009-09-091-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | The only .c files that utilize these protected prototypes depend on CONFIG_INTEL_IOATDMA=y, so there is no value gained in providing empty prototypes. [ Impact: pure cleanup ] Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: cleanup some long deref chains and 80 column collisionsDan Williams2009-09-092-167/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | * reduce device->common. to dma-> in ioat_dma_{probe,remove,selftest} * ioat_lookup_chan_by_index to ioat_chan_by_index * multi-line function definitions * ioat_desc_sw.async_tx to ioat_desc_sw.txd * desc->txd. to tx-> in cleanup routine Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: convert ioat_probe to pcim/devmDan Williams2009-09-094-141/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The driver currently duplicates much of what these routines offer, so just use the common code. For example ->irq_mode tracks what interrupt mode was initialized, which duplicates the ->msix_enabled and ->msi_enabled handling in pcim_release. This also adds a check to the return value of dma_async_device_register, which can fail. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: move definitions to dma.hDan Williams2009-09-092-14/+16
| | | | | | | | | | | | | | | | | | Some of these defines may be useful outside of dma.c and the header is private so there are no namespace pollution concerns. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * ioat: move to drivers/dma/ioat/Dan Williams2009-07-289-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | When first created the ioat driver was the only inhabitant of drivers/dma/. Now, it is the only multi-file (more than a .c and a .h) driver in the directory. Moving it to an ioat/ subdirectory allows the naming convention to be cleaned up, and allows for future splitting of the source files by hardware version (v1, v2, and v3). Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge commit 'v2.6.31-rc1' into dmaengineDan Williams2009-09-083128-316787/+457895
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| * \ Merge git://git.infradead.org/battery-2.6Linus Torvalds2009-06-247-17/+401
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.infradead.org/battery-2.6: da9030_battery: Fix race between event handler and monitor Add MAX17040 Fuel Gauge driver w1: ds2760_battery: add support for sleep mode feature w1: ds2760: add support for EEPROM read and write ds2760_battery: cleanups in ds2760_battery_probe()
| | * | da9030_battery: Fix race between event handler and monitorMike Rapoport2009-06-081-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are cases when charging monitor and the event handler try to change the charger state simultaneously. For instance, a charger is connected to the system, there's the detection event and the event handler tries to enable charging. It is possible that the periodic charging monitor runs at the same time and it still thinks there's no external charger. So it tries to disable the charging. As the result, even if the conditions necessary to charge the battery hold, there will be no actual charging. The patch changes the event handler so that instead of enabling/ disabling the charger immediately it would rather make the monitor run. The monitor code then decides what should be the charger state. Signed-off-by: Mike Rapoport <mike@compulab.co.il> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
| | * | Add MAX17040 Fuel Gauge driverMinkyu Kang2009-06-083-1/+319
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The MAX17040 is a I2C interfaced Fuel Gauge systems for lithium-ion batteries This patch adds support the MAX17040 Fuel Gauge Signed-off-by: Minkyu Kang <mk7.kang@samsung.com> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
| | * | w1: ds2760_battery: add support for sleep mode featureDaniel Mack2009-06-082-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for ds2760's sleep mode feature. With this feature enabled, the chip enters a deep sleep mode and disconnects from the battery when the w1 line is held down for more than 2 seconds. This new behaviour can be switched on and off using a new module parameter. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Acked-by: Matt Reimer <mreimer@vpop.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
| | * | w1: ds2760: add support for EEPROM read and writeDaniel Mack2009-06-082-0/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to modify the DS2762's status registers and to add support for sleep mode, there is need for functions to write the internal EEPROM. Signed-off-by: Daniel Mack <daniel@caiaq.de> Acked-by: Matt Reimer <mreimer@vpop.net> Acked-by: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
| | * | ds2760_battery: cleanups in ds2760_battery_probe()Daniel Mack2009-06-081-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Removed struct ds2760_platform_data which wasn't defined anywhere. Indentation cleanups. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Acked-by: Matt Reimer <mreimer@vpop.net> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
| * | | Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linusLinus Torvalds2009-06-2413-469/+507
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: Staging: octeon-ethernet: Fix race freeing transmit buffers. Staging: octeon-ethernet: Convert to use net_device_ops. MIPS: Cavium: Add CPU hotplugging code. MIPS: SMP: Allow suspend and hibernation if CPU hotplug is available MIPS: Add arch generic CPU hotplug DMA: txx9dmac: use dma_unmap_single if DMA_COMPL_{SRC,DEST}_UNMAP_SINGLE set MIPS: Sibyte: Fix build error if CONFIG_SERIAL_SB1250_DUART is undefined. MIPS: MIPSsim: Fix build error if MSC01E_INT_BASE is undefined. MIPS: Hibernation: Remove SMP TLB and cacheflushing code. MIPS: Build fix - include <linux/smp.h> into all smp_processor_id() users. MIPS: bug.h Build fix - include <linux/compiler.h>.
| | * | | Staging: octeon-ethernet: Fix race freeing transmit buffers.David Daney2009-06-244-66/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing code had the following race: Thread-1 Thread-2 inc/read in_use inc/read in_use inc tx_free_list[qos].len inc tx_free_list[qos].len The actual in_use value was incremented twice, but thread-1 is going to free memory based on its stale value, and will free one too many times. The result is that memory is freed back to the kernel while its packet is still in the transmit buffer. If the memory is overwritten before it is transmitted, the hardware will put a valid checksum on it and send it out (just like it does with good packets). If by chance the TCP flags are clobbered but not the addresses or ports, the result can be a broken TCP stream. The fix is to track the number of freed packets in a single location (a Fetch-and-Add Unit register). That way it can never get out of sync with itself. We try to free up to MAX_SKB_TO_FREE (currently 10) buffers at a time. If fewer are available we adjust the free count with the difference. The action of claiming buffers to free is atomic so two threads cannot claim the same buffers. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | Staging: octeon-ethernet: Convert to use net_device_ops.David Daney2009-06-2410-396/+390
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the driver to use net_device_ops as it is now mandatory. Also compensate for the removal of struct sk_buff's dst field. The changes are mostly mechanical, the content of ethernet-common.c was moved to ethernet.c and ethernet-common.{c,h} are removed. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| | * | | DMA: txx9dmac: use dma_unmap_single if DMA_COMPL_{SRC,DEST}_UNMAP_SINGLE setAtsushi Nemoto2009-06-241-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does not change actual behaviour since dma_unmap_page is just an alias of dma_unmap_single on MIPS. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Ralf Baechle <ralf@linux-mips.org> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds2009-06-2427-415/+3377
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (48 commits) dm mpath: change to be request based dm: disable interrupt when taking map_lock dm: do not set QUEUE_ORDERED_DRAIN if request based dm: enable request based option dm: prepare for request based option dm raid1: add userspace log dm: calculate queue limits during resume not load dm log: fix create_log_context to use logical_block_size of log device dm target:s introduce iterate devices fn dm table: establish queue limits by copying table limits dm table: replace struct io_restrictions with struct queue_limits dm table: validate device logical_block_size dm table: ensure targets are aligned to logical_block_size dm ioctl: support cookies for udev dm: sysfs add suspended attribute dm table: improve warning message when devices not freed before destruction dm mpath: add service time load balancer dm mpath: add queue length load balancer dm mpath: add start_io and nr_bytes to path selectors dm snapshot: use barrier when writing exception store ...
| | * | | | dm mpath: change to be request basedKiyoshi Ueda2009-06-221-65/+128
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts dm-multipath target to request-based from bio-based. Basically, the patch just converts the I/O unit from struct bio to struct request. In the course of the conversion, it also changes the I/O queueing mechanism. The change in the I/O queueing is described in details as follows. I/O queueing mechanism change ----------------------------- In I/O submission, map_io(), there is no mechanism change from bio-based, since the clone request is ready for retry as it is. However, in I/O complition, do_end_io(), there is a mechanism change from bio-based, since the clone request is not ready for retry. In do_end_io() of bio-based, the clone bio has all needed memory for resubmission. So the target driver can queue it and resubmit it later without memory allocations. The mechanism has almost no overhead. On the other hand, in do_end_io() of request-based, the clone request doesn't have clone bios, so the target driver can't resubmit it as it is. To resubmit the clone request, memory allocation for clone bios is needed, and it takes some overheads. To avoid the overheads just for queueing, the target driver doesn't queue the clone request inside itself. Instead, the target driver asks dm core for queueing and remapping the original request of the clone request, since the overhead for queueing is just a freeing memory for the clone request. As a result, the target driver doesn't need to record/restore the information of the original request for resubmitting the clone request. So dm_bio_details in dm_mpath_io is removed. multipath_busy() --------------------- The target driver returns "busy", only when the following case: o The target driver will map I/Os, if map() function is called and o The mapped I/Os will wait on underlying device's queue due to their congestions, if map() function is called now. In other cases, the target driver doesn't return "busy". Otherwise, dm core will keep the I/Os and the target driver can't do what it wants. (e.g. the target driver can't map I/Os now, so wants to kill I/Os.) Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm: disable interrupt when taking map_lockKiyoshi Ueda2009-06-221-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch disables interrupt when taking map_lock to avoid lockdep warnings in request-based dm. request-based dm takes map_lock after taking queue_lock with disabling interrupt: spin_lock_irqsave(queue_lock) q->request_fn() == dm_request_fn() => dm_get_table() => read_lock(map_lock) while queue_lock could be (but isn't) taken in interrupt context. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Christof Schmitt <christof.schmitt@de.ibm.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm: do not set QUEUE_ORDERED_DRAIN if request basedKiyoshi Ueda2009-06-223-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Request-based dm doesn't have barrier support yet. So we need to set QUEUE_ORDERED_DRAIN only for bio-based dm. Since the device type is decided at the first table loading time, the flag set is deferred until then. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm: enable request based optionKiyoshi Ueda2009-06-224-26/+285
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables request-based dm. o Request-based dm and bio-based dm coexist, since there are some target drivers which are more fitting to bio-based dm. Also, there are other bio-based devices in the kernel (e.g. md, loop). Since bio-based device can't receive struct request, there are some limitations on device stacking between bio-based and request-based. type of underlying device bio-based request-based ---------------------------------------------- bio-based OK OK request-based -- OK The device type is recognized by the queue flag in the kernel, so dm follows that. o The type of a dm device is decided at the first table binding time. Once the type of a dm device is decided, the type can't be changed. o Mempool allocations are deferred to at the table loading time, since mempools for request-based dm are different from those for bio-based dm and needed mempool type is fixed by the type of table. o Currently, request-based dm supports only tables that have a single target. To support multiple targets, we need to support request splitting or prevent bio/request from spanning multiple targets. The former needs lots of changes in the block layer, and the latter needs that all target drivers support merge() function. Both will take a time. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm: prepare for request based optionKiyoshi Ueda2009-06-223-4/+716
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds core functions for request-based dm. When struct mapped device (md) is initialized, md->queue has an I/O scheduler and the following functions are used for request-based dm as the queue functions: make_request_fn: dm_make_request() pref_fn: dm_prep_fn() request_fn: dm_request_fn() softirq_done_fn: dm_softirq_done() lld_busy_fn: dm_lld_busy() Actual initializations are done in another patch (PATCH 2). Below is a brief summary of how request-based dm behaves, including: - making request from bio - cloning, mapping and dispatching request - completing request and bio - suspending md - resuming md bio to request ============== md->queue->make_request_fn() (dm_make_request()) calls __make_request() for a bio submitted to the md. Then, the bio is kept in the queue as a new request or merged into another request in the queue if possible. Cloning and Mapping =================== Cloning and mapping are done in md->queue->request_fn() (dm_request_fn()), when requests are dispatched after they are sorted by the I/O scheduler. dm_request_fn() checks busy state of underlying devices using target's busy() function and stops dispatching requests to keep them on the dm device's queue if busy. It helps better I/O merging, since no merge is done for a request once it is dispatched to underlying devices. Actual cloning and mapping are done in dm_prep_fn() and map_request() called from dm_request_fn(). dm_prep_fn() clones not only request but also bios of the request so that dm can hold bio completion in error cases and prevent the bio submitter from noticing the error. (See the "Completion" section below for details.) After the cloning, the clone is mapped by target's map_rq() function and inserted to underlying device's queue using blk_insert_cloned_request(). Completion ========== Request completion can be hooked by rq->end_io(), but then, all bios in the request will have been completed even error cases, and the bio submitter will have noticed the error. To prevent the bio completion in error cases, request-based dm clones both bio and request and hooks both bio->bi_end_io() and rq->end_io(): bio->bi_end_io(): end_clone_bio() rq->end_io(): end_clone_request() Summary of the request completion flow is below: blk_end_request() for a clone request => blk_update_request() => bio->bi_end_io() == end_clone_bio() for each clone bio => Free the clone bio => Success: Complete the original bio (blk_update_request()) Error: Don't complete the original bio => blk_finish_request() => rq->end_io() == end_clone_request() => blk_complete_request() => dm_softirq_done() => Free the clone request => Success: Complete the original request (blk_end_request()) Error: Requeue the original request end_clone_bio() completes the original request on the size of the original bio in successful cases. Even if all bios in the original request are completed by that completion, the original request must not be completed yet to keep the ordering of request completion for the stacking. So end_clone_bio() uses blk_update_request() instead of blk_end_request(). In error cases, end_clone_bio() doesn't complete the original bio. It just frees the cloned bio and gives over the error handling to end_clone_request(). end_clone_request(), which is called with queue lock held, completes the clone request and the original request in a softirq context (dm_softirq_done()), which has no queue lock, to avoid a deadlock issue on submission of another request during the completion: - The submitted request may be mapped to the same device - Request submission requires queue lock, but the queue lock has been held by itself and it doesn't know that The clone request has no clone bio when dm_softirq_done() is called. So target drivers can't resubmit it again even error cases. Instead, they can ask dm core for requeueing and remapping the original request in that cases. suspend ======= Request-based dm uses stopping md->queue as suspend of the md. For noflush suspend, just stops md->queue. For flush suspend, inserts a marker request to the tail of md->queue. And dispatches all requests in md->queue until the marker comes to the front of md->queue. Then, stops dispatching request and waits for the all dispatched requests to complete. After that, completes the marker request, stops md->queue and wake up the waiter on the suspend queue, md->wait. resume ====== Starts md->queue. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm raid1: add userspace logJonthan Brassow2009-06-225-0/+1004
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm: calculate queue limits during resume not loadMike Snitzer2009-06-223-87/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, device-mapper maintains a separate instance of 'struct queue_limits' for each table of each device. When the configuration of a device is to be changed, first its table is loaded and this structure is populated, then the device is 'resumed' and the calculated queue_limits are applied. This places restrictions on how userspace may process related devices, where it is often advantageous to 'load' tables for several devices at once before 'resuming' them together. As the new queue_limits only take effect after the 'resume', if they are changing and one device uses another, the latter must be 'resumed' before the former may be 'loaded'. This patch moves the calculation of these queue_limits out of the 'load' operation into 'resume'. Since we are no longer pre-calculating this struct, we no longer need to maintain copies within our dm structs. dm_set_device_limits() now passes the 'start' of the device's data area (aka pe_start) as the 'offset' to blk_stack_limits(). init_valid_queue_limits() is replaced by blk_set_default_limits(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: martin.petersen@oracle.com Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm log: fix create_log_context to use logical_block_size of log deviceMike Snitzer2009-06-221-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | create_log_context() must use the logical_block_size from the log disk, where the I/O happens, not the target's logical_block_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| | * | | | dm target:s introduce iterate devices fnMike Snitzer2009-06-226-6/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add .iterate_devices to 'struct target_type' to allow a function to be called for all devices in a DM target. Implemented it for all targets except those in dm-snap.c (origin and snapshot). (The raid1 version number jumps to 1.12 because we originally reserved 1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors' instead.) Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: martin.petersen@oracle.com
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-22 17:04:03 +0100