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2011-06-21net: remove mm.h inclusion from netdevice.hAlexey Dobriyan
Remove linux/mm.h inclusion from netdevice.h -- it's unused (I've checked manually). To prevent mm.h inclusion via other channels also extract "enum dma_data_direction" definition into separate header. This tiny piece is what gluing netdevice.h with mm.h via "netdevice.h => dmaengine.h => dma-mapping.h => scatterlist.h => mm.h". Removal of mm.h from scatterlist.h was tried and was found not feasible on most archs, so the link was cutoff earlier. Hope people are OK with tiny include file. Note, that mm_types.h is still dragged in, but it is a separate story. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-10-27Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (48 commits) DMAENGINE: move COH901318 to arch_initcall dma: imx-dma: fix signedness bug dma/timberdale: simplify conditional ste_dma40: remove channel_type ste_dma40: remove enum for endianess ste_dma40: remove TIM_FOR_LINK option ste_dma40: move mode_opt to separate config ste_dma40: move channel mode to a separate field ste_dma40: move priority to separate field ste_dma40: add variable to indicate valid dma_cfg async_tx: make async_tx channel switching opt-in move async raid6 test to lib/Kconfig.debug dmaengine: Add Freescale i.MX1/21/27 DMA driver intel_mid_dma: change the slave interface intel_mid_dma: fix the WARN_ONs intel_mid_dma: Add sg list support to DMA driver intel_mid_dma: Allow DMAC2 to share interrupt intel_mid_dma: Allow IRQ sharing intel_mid_dma: Add runtime PM support DMAENGINE: define a dummy filter function for ste_dma40 ...
2010-10-26mm: strictly nested kmap_atomic()Peter Zijlstra
Ensure kmap_atomic() usage is strictly nested Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-07move async raid6 test to lib/Kconfig.debugDan Williams
The prompt for "Self test for hardware accelerated raid6 recovery" does not belong in the top level configuration menu. All the options in crypto/async_tx/Kconfig are selected and do not depend on CRYPTO. Kconfig.debug seems like a reasonable fit. Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-08-09Merge branch 'async' of macbook:git/btrfs-unstableDavid Woodhouse
Conflicts: drivers/md/Makefile lib/raid6/unroll.pl
2010-05-21Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: DMAENGINE: extend the control command to include an arg async_tx: trim dma_async_tx_descriptor in 'no channel switch' case DMAENGINE: DMA40 fix for allocation of logical channel 0 DMAENGINE: DMA40 support paused channel status dmaengine: mpc512x: Use resource_size DMA ENGINE: Do not reset 'private' of channel ioat: Remove duplicated devm_kzalloc() calls for ioatdma_device ioat3: disable cacheline-unaligned transfers for raid operations ioat2,3: convert to producer/consumer locking ioat: convert to circ_buf DMAENGINE: Support for ST-Ericssons DMA40 block v3 async_tx: use of kzalloc/kfree requires the include of slab.h dmaengine: provide helper for setting txstate DMAENGINE: generic channel status v2 DMAENGINE: generic slave control v2 dma: timb-dma: Update comment and fix compiler warning dma: Add timb-dma DMAENGINE: COH 901 318 fix bytesleft DMAENGINE: COH 901 318 rename confusing vars
2010-05-17async_tx: trim dma_async_tx_descriptor in 'no channel switch' caseDan Williams
Saves 24 bytes per descriptor (64-bit) when the channel-switching capabilities of async_tx are not required. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-05raid6: fix recovery performance regressionDan Williams
The raid6 recovery code should immediately drop back to the optimized synchronous path when a p+q dma resource is not available. Otherwise we run the non-optimized/multi-pass async code in sync mode. Verified with raid6test (NDISKS=255) Applies to kernels >= 2.6.32. Cc: <stable@kernel.org> Acked-by: NeilBrown <neilb@suse.de> Reported-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-12-17async_tx: expand async raid6 test to cover ioatdma corner caseDan Williams
Add explicit 11 and 12 disks cases to exercise the 0 < src_cnt % 8 < 3 corner case in the ioatdma driver. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-11-19async_tx: build-time toggling of async_{syndrome,xor}_val dma supportDan Williams
ioat3.2 does not support asynchronous error notifications which makes the driver experience latencies when non-zero pq validate results are expected. Provide a mechanism for turning off async_xor_val and async_syndrome_val via Kconfig. This approach is generally useful for any driver that specifies ASYNC_TX_DISABLE_CHANNEL_SWITCH and would like to force the async_tx api to fall back to the synchronous path for certain operations. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-29async_tx: Move ASYNC_RAID6_TEST option to crypto/async_tx/, fix dependenciesDavid Woodhouse
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-19async_tx: fix asynchronous raid6 recovery for ddf layoutsDan Williams
The raid6 recovery code currently requires special handling of the 4-disk and 5-disk recovery scenarios for the native layout. Quoting from commit 0a82a623: In these situations the default N-disk algorithm will present 0-source or 1-source operations to dma devices. To cover for dma devices where the minimum source count is 2 we implement 4-disk and 5-disk handling in the recovery code. The ddf layout presents disks=6 and disks=7 to the recovery code in these situations. Instead of looking at the number of disks count the number of non-zero sources in the list and call the special case code when the number of non-failed sources is 0 or 1. [neilb@suse.de: replace 'ddf' flag with counting good sources] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-19async_pq: rename scribble pageDan Williams
The global scribble page is used as a temporary destination buffer when disabling the P or Q result is requested. The local scribble buffer contains memory for performing address conversions. Rename the global variable to avoid confusion. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-19async_pq: kill a stray dma_map() call and other cleanupsDan Williams
- update the kernel doc for async_syndrome to indicate what NULL in the source list means - whitespace fixups Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-16raid6/async_tx: handle holes in block list in async_syndrome_valNeilBrown
async_syndrome_val check the P and Q blocks used for RAID6 calculations. With DDF raid6, some of the data blocks might be NULL, so this needs to be handled in the same way that async_gen_syndrome handles it. As async_syndrome_val calls async_xor, also enhance async_xor to detect and skip NULL blocks in the list. Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16md/async: don't pass a memory pointer as a page pointer.NeilBrown
md/raid6 passes a list of 'struct page *' to the async_tx routines, which then either DMA map them for offload, or take the page_address for CPU based calculations. For RAID6 we sometime leave 'blanks' in the list of pages. For CPU based calcs, we want to treat theses as a page of zeros. For offloaded calculations, we simply don't pass a page to the hardware. Currently the 'blanks' are encoded as a pointer to raid6_empty_zero_page. This is a 4096 byte memory region, not a 'struct page'. This is mostly handled correctly but is rather ugly. So change the code to pass and expect a NULL pointer for the blanks. When taking page_address of a page, we need to check for a NULL and in that case use raid6_empty_zero_page. Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-21async_tx/raid6: add missing dma_unmap calls to the async fail caseDan Williams
If we are unable to offload async_mult() or async_sum_product(), then unmap the buffers before falling through to the synchronous path. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-16raid6test: fix stack overflowDan Williams
Testing on x86_64 with NDISKS=255 yields: do_IRQ: modprobe near stack overflow (cur:ffff88007d19c000,sp:ffff88007d19c128) ...and eventually general protection fault: 0000 [#1] Moving the scribble buffers off the stack allows the test to complete successfully. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08dmaengine, async_tx: support alignment checksDan Williams
Some engines have transfer size and address alignment restrictions. Add a per-operation alignment property to struct dma_device that the async routines and dmatest can use to check alignment capabilities. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08dmaengine, async_tx: add a "no channel switch" allocatorDan Williams
Channel switching is problematic for some dmaengine drivers as the architecture precludes separating the ->prep from ->submit. In these cases the driver can select ASYNC_TX_DISABLE_CHANNEL_SWITCH to modify the async_tx allocator to only return channels that support all of the required asynchronous operations. For example MD_RAID456=y selects support for asynchronous xor, xor validate, pq, pq validate, and memcpy. When ASYNC_TX_DISABLE_CHANNEL_SWITCH=y any channel with all these capabilities is marked DMA_ASYNC_TX allowing async_tx_find_channel() to quickly locate compatible channels with the guarantee that dependency chains will remain on one channel. When ASYNC_TX_DISABLE_CHANNEL_SWITCH=n async_tx_find_channel() may select channels that lead to operation chains that need to cross channel boundaries using the async_tx channel switch capability. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08dmaengine: add fence supportDan Williams
Some engines optimize operation by reading ahead in the descriptor chain such that descriptor2 may start execution before descriptor1 completes. If descriptor2 depends on the result from descriptor1 then a fence is required (on descriptor2) to disable this optimization. The async_tx api could implicitly identify dependencies via the 'depend_tx' parameter, but that would constrain cases where the dependency chain only specifies a completion order rather than a data dependency. So, provide an ASYNC_TX_FENCE to explicitly identify data dependencies. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: raid6 recovery self testDan Williams
Port drivers/md/raid6test/test.c to use the async raid6 recovery routines. This is meant as a unit test for raid6 acceleration drivers. In addition to the 16-drive test case this implements tests for the 4-disk and 5-disk special cases (dma devices can not generically handle less than 2 sources), and adds a test for the D+Q case. Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: add support for asynchronous RAID6 recovery operationsDan Williams
async_raid6_2data_recov() recovers two data disk failures async_raid6_datap_recov() recovers a data disk and the P disk These routines are a port of the synchronous versions found in drivers/md/raid6recov.c. The primary difference is breaking out the xor operations into separate calls to async_xor. Two helper routines are introduced to perform scalar multiplication where needed. async_sum_product() multiplies two sources by scalar coefficients and then sums (xor) the result. async_mult() simply multiplies a single source by a scalar. This implemention also includes, in contrast to the original synchronous-only code, special case handling for the 4-disk and 5-disk array cases. In these situations the default N-disk algorithm will present 0-source or 1-source operations to dma devices. To cover for dma devices where the minimum source count is 2 we implement 4-disk and 5-disk handling in the recovery code. [ Impact: asynchronous raid6 recovery routines for 2data and datap cases ] Cc: Yuri Tikhonov <yur@emcraft.com> Cc: Ilya Yanok <yanok@emcraft.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: add support for asynchronous GF multiplicationDan Williams
[ Based on an original patch by Yuri Tikhonov ] This adds support for doing asynchronous GF multiplication by adding two additional functions to the async_tx API: async_gen_syndrome() does simultaneous XOR and Galois field multiplication of sources. async_syndrome_val() validates the given source buffers against known P and Q values. When a request is made to run async_pq against more than the hardware maximum number of supported sources we need to reuse the previous generated P and Q values as sources into the next operation. Care must be taken to remove Q from P' and P from Q'. For example to perform a 5 source pq op with hardware that only supports 4 sources at a time the following approach is taken: p, q = PQ(src0, src1, src2, src3, COEF({01}, {02}, {04}, {08})) p', q' = PQ(p, q, q, src4, COEF({00}, {01}, {00}, {10})) p' = p + q + q + src4 = p + src4 q' = {00}*p + {01}*q + {00}*q + {10}*src4 = q + {10}*src4 Note: 4 is the minimum acceptable maxpq otherwise we punt to synchronous-software path. The DMA_PREP_CONTINUE flag indicates to the driver to reuse p and q as sources (in the above manner) and fill the remaining slots up to maxpq with the new sources/coefficients. Note1: Some devices have native support for P+Q continuation and can skip this extra work. Devices with this capability can advertise it with dma_set_maxpq. It is up to each driver how to handle the DMA_PREP_CONTINUE flag. Note2: The api supports disabling the generation of P when generating Q, this is ignored by the synchronous path but is implemented by some dma devices to save unnecessary writes. In this case the continuation algorithm is simplified to only reuse Q as a source. Cc: H. Peter Anvin <hpa@zytor.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: remove walk of tx->parent chain in dma_wait_for_async_txDan Williams
We currently walk the parent chain when waiting for a given tx to complete however this walk may race with the driver cleanup routine. The routines in async_raid6_recov.c may fall back to the synchronous path at any point so we need to be prepared to call async_tx_quiesce() (which calls dma_wait_for_async_tx). To remove the ->parent walk we guarantee that every time a dependency is attached ->issue_pending() is invoked, then we can simply poll the initial descriptor until completion. This also allows for a lighter weight 'issue pending' implementation as there is no longer a requirement to iterate through all the channels' ->issue_pending() routines as long as operations have been submitted in an ordered chain. async_tx_issue_pending() is added for this case. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: kill needless module_{init|exit}Dan Williams
If module_init and module_exit are nops then neither need to be defined. [ Impact: pure cleanup ] Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: add sum check flagsDan Williams
Replace the flat zero_sum_result with a collection of flags to contain the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed solomon syndrome) zero-sum result. Use the SUM_CHECK_ namespace instead of DMA_ since these flags will be used on non-dma-zero-sum enabled platforms. Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03async_xor: permit callers to pass in a 'dma/page scribble' regionDan Williams
async_xor() needs space to perform dma and page address conversions. In most cases the code can simply reuse the struct page * array because the size of the native pointer matches the size of a dma/page address. In order to support archs where sizeof(dma_addr_t) is larger than sizeof(struct page *), or to preserve the input parameters, we utilize a memory region passed in by the caller. Since the code is now prepared to handle the case where it cannot perform address conversions on the stack, we no longer need the !HIGHMEM64G dependency in drivers/dma/Kconfig. [ Impact: don't clobber input buffers for address conversions ] Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03async_tx: structify submission arguments, add scribbleDan Williams
Prepare the api for the arrival of a new parameter, 'scribble'. This will allow callers to identify scratchpad memory for dma address or page address conversions. As this adds yet another parameter, take this opportunity to convert the common submission parameters (flags, dependency, callback, and callback argument) into an object that is passed by reference. Also, take this opportunity to fix up the kerneldoc and add notes about the relevant ASYNC_TX_* flags for each routine. [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ] Signed-off-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03async_tx: kill ASYNC_TX_DEP_ACK flagDan Williams
In support of inter-channel chaining async_tx utilizes an ack flag to gate whether a dependent operation can be chained to another. While the flag is not set the chain can be considered open for appending. Setting the ack flag closes the chain and flags the descriptor for garbage collection. The ASYNC_TX_DEP_ACK flag essentially means "close the chain after adding this dependency". Since each operation can only have one child the api now implicitly sets the ack flag at dependency submission time. This removes an unnecessary management burden from clients of the api. [ Impact: clean up and enforce one dependency per operation ] Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-08async_tx: rename zero_sum to valDan Williams
'zero_sum' does not properly describe the operation of generating parity and checking that it validates against an existing buffer. Change the name of the operation to 'val' (for 'validate'). This is in anticipation of the p+q case where it is a requirement to identify the target parity buffers separately from the source buffers, because the target parity buffers will not have corresponding pq coefficients. Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25dmaengine: allow dma support for async_tx to be toggledDan Williams
Provide a config option for blocking the allocation of dma channels to the async_tx api. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25async_tx: provide __async_inline for HAS_DMA=n archsDan Williams
To allow an async_tx routine to be compiled away on HAS_DMA=n arch it needs to be declared __always_inline otherwise the compiler may emit code and cause a link error. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06dmaengine: replace dma_async_client_register with dmaengine_getDan Williams
Now that clients no longer need to be notified of channel arrival dma_async_client_register can simply increment the dmaengine_ref_count. Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06dmaengine: provide a common 'issue_pending_all' implementationDan Williams
async_tx and net_dma each have open-coded versions of issue_pending_all, so provide a common routine in dmaengine. The implementation needs to walk the global device list, so implement rcu to allow dma_issue_pending_all to run lockless. Clients protect themselves from channel removal events by holding a dmaengine reference. Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06dmaengine: centralize channel allocation, introduce dma_find_channelDan Williams
Allowing multiple clients to each define their own channel allocation scheme quickly leads to a pathological situation. For memory-to-memory offload all clients can share a central allocator. This simply moves the existing async_tx allocator to dmaengine with minimal fixups: * async_tx.c:get_chan_ref_by_cap --> dmaengine.c:nth_chan * async_tx.c:async_tx_rebalance --> dmaengine.c:dma_channel_rebalance * split out common code from async_tx.c:__async_tx_find_channel --> dma_find_channel Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06dmaengine: up-level reference counting to the module levelDan Williams
Simply, if a client wants any dmaengine channel then prevent all dmaengine modules from being removed. Once the clients are done re-enable module removal. Why?, beyond reducing complication: 1/ Tracking reference counts per-transaction in an efficient manner, as is currently done, requires a complicated scheme to avoid cache-line bouncing effects. 2/ Per-transaction ref-counting gives the false impression that a dma-driver can be gracefully removed ahead of its user (net, md, or dma-slave) 3/ None of the in-tree dma-drivers talk to hot pluggable hardware, but if such an engine were built one day we still would not need to notify clients of remove events. The driver can simply return NULL to a ->prep() request, something that is much easier for a client to handle. Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-05dmaengine: remove dependency on async_txDan Williams
async_tx.ko is a consumer of dma channels. A circular dependency arises if modules in drivers/dma rely on common code in async_tx.ko. It prevents either module from being unloaded. Move dma_wait_for_async_tx and async_tx_run_dependencies to dmaeninge.o where they should have been from the beginning. Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-12-08async_xor: dma_map destination DMA_BIDIRECTIONALDan Williams
Mapping the destination multiple times is a misuse of the dma-api. Since the destination may be reused as a source, ensure that it is only mapped once and that it is mapped bidirectionally. This appears to add ugliness on the unmap side in that it always reads back the destination address from the descriptor, but gcc can determine that dma_unmap is a nop and not emit the code that calculates its arguments. Cc: <stable@kernel.org> Cc: Saeed Bishara <saeed@marvell.com> Acked-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-09-13async_tx: make async_tx_run_dependencies() easier to readDan Williams
* Rename 'next' to 'dep' * Move the channel switch check inside the loop to simplify termination Acked-by: Ilya Yanok <yanok@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-09-05async_tx: fix the bug in async_tx_run_dependenciesYuri Tikhonov
Should clear the next pointer of the TX if we are sure that the next TX (say NXT) will be submitted to the channel too. Overwise, we break the chain of descriptors, because we lose the information about the next descriptor to run. So next time, when invoke async_tx_run_dependencies() with TX, it's TX->next will be NULL, and NXT will be never submitted. Cc: <stable@kernel.org> [2.6.26] Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-08-05async_tx: fix missing braces in async_xor_zero_sumDan Williams
Found-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (24 commits) I/OAT: I/OAT version 3.0 support I/OAT: tcp_dma_copybreak default value dependent on I/OAT version I/OAT: Add watchdog/reset functionality to ioatdma iop_adma: cleanup iop_chan_xor_slot_count iop_adma: document how to calculate the minimum descriptor pool size iop_adma: directly reclaim descriptors on allocation failure async_tx: make async_tx_test_ack a boolean routine async_tx: remove depend_tx from async_tx_sync_epilog async_tx: export async_tx_quiesce async_tx: fix handling of the "out of descriptor" condition in async_xor async_tx: ensure the xor destination buffer remains dma-mapped async_tx: list_for_each_entry_rcu() cleanup dmaengine: Driver for the Synopsys DesignWare DMA controller dmaengine: Add slave DMA interface dmaengine: add DMA_COMPL_SKIP_{SRC,DEST}_UNMAP flags to control dma unmap dmaengine: Add dma_client parameter to device_alloc_chan_resources dmatest: Simple DMA memcpy test client dmaengine: DMA engine driver for Marvell XOR engine iop-adma: fix platform driver hotplug/coldplug dmaengine: track the number of clients using a channel ... Fixed up conflict in drivers/dca/dca-sysfs.c manually
2008-07-17async_tx: remove depend_tx from async_tx_sync_epilogDan Williams
All callers of async_tx_sync_epilog have called async_tx_quiesce on the depend_tx, so async_tx_sync_epilog need only call the callback to complete the operation. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-17async_tx: export async_tx_quiesceDan Williams
Replace open coded "wait and acknowledge" instances with async_tx_quiesce. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-17async_tx: fix handling of the "out of descriptor" condition in async_xorDan Williams
Ensure forward progress is made when a dmaengine driver is unable to allocate an xor descriptor by breaking the dependency chain with async_tx_quisce() and issue any pending descriptors. Tested with iop-adma by setting device->max_xor = 2 to force multiple calls to device_prep_dma_xor for each call to async_xor and limiting the descriptor slot pool to 5. Discovered that the minimum descriptor pool size for iop-adma is 2 * iop_chan_xor_slot_cnt(device->max_xor) + 1. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-17async_tx: ensure the xor destination buffer remains dma-mappedDan Williams
When the number of source buffers for an xor operation exceeds the hardware channel maximum async_xor creates a chain of dependent operations. The result of one operation is reused as an input to the next to continue the xor calculation. The destination buffer should remain mapped for the duration of the entire chain. To provide this guarantee the code must no longer be allowed to fallback to the synchronous path as this will preclude the buffer from being unmapped, i.e. the dma-driver will potentially miss the descriptor with !DMA_COMPL_SKIP_DEST_UNMAP. Cc: Neil Brown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-17async_tx: list_for_each_entry_rcu() cleanupLi Zefan
In the rcu update side, don't use list_for_each_entry_rcu(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>