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2014-10-09mm/dmapool.c: fixed a brace coding style issuePaul McQuade
Remove 3 brace coding style for any arm of this statement Signed-off-by: Paul McQuade <paulmcquad@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09mm: dmapool: add/remove sysfs file outside of the pool lock lockSebastian Andrzej Siewior
cat /sys/.../pools followed by removal the device leads to: |====================================================== |[ INFO: possible circular locking dependency detected ] |3.17.0-rc4+ #1498 Not tainted |------------------------------------------------------- |rmmod/2505 is trying to acquire lock: | (s_active#28){++++.+}, at: [<c017f754>] kernfs_remove_by_name_ns+0x3c/0x88 | |but task is already holding lock: | (pools_lock){+.+.+.}, at: [<c011494c>] dma_pool_destroy+0x18/0x17c | |which lock already depends on the new lock. |the existing dependency chain (in reverse order) is: | |-> #1 (pools_lock){+.+.+.}: | [<c0114ae8>] show_pools+0x30/0xf8 | [<c0313210>] dev_attr_show+0x1c/0x48 | [<c0180e84>] sysfs_kf_seq_show+0x88/0x10c | [<c017f960>] kernfs_seq_show+0x24/0x28 | [<c013efc4>] seq_read+0x1b8/0x480 | [<c011e820>] vfs_read+0x8c/0x148 | [<c011ea10>] SyS_read+0x40/0x8c | [<c000e960>] ret_fast_syscall+0x0/0x48 | |-> #0 (s_active#28){++++.+}: | [<c017e9ac>] __kernfs_remove+0x258/0x2ec | [<c017f754>] kernfs_remove_by_name_ns+0x3c/0x88 | [<c0114a7c>] dma_pool_destroy+0x148/0x17c | [<c03ad288>] hcd_buffer_destroy+0x20/0x34 | [<c03a4780>] usb_remove_hcd+0x110/0x1a4 The problem is the lock order of pools_lock and kernfs_mutex in dma_pool_destroy() vs show_pools() call path. This patch breaks out the creation of the sysfs file outside of the pools_lock mutex. The newly added pools_reg_lock ensures that there is no race of create vs destroy code path in terms whether or not the sysfs file has to be deleted (and was it deleted before we try to create a new one) and what to do if device_create_file() failed. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-18Fix unbalanced mutex in dma_pool_create().Krzysztof Hałasa
dma_pool_create() needs to unlock the mutex in error case. The bug was introduced in the 3.16 by commit cc6b664aa26d ("mm/dmapool.c: remove redundant NULL check for dev in dma_pool_create()")/ Signed-off-by: Krzysztof Hałasa <khc@piap.pl> Cc: stable@vger.kernel.org # v3.16 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04mm/dmapool.c: reuse devres_release() to free resourcesAndy Shevchenko
Instead of calling an additional routine in dmam_pool_destroy() rely on what dmam_pool_release() is doing. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04mm/dmapool.c: remove redundant NULL check for dev in dma_pool_create()Daeseok Youn
"dev" cannot be NULL because it is already checked before calling dma_pool_create(). If dev ever was NULL, the code would oops in dev_to_node() after enabling CONFIG_NUMA. It is possible that some driver is using dev==NULL and has never been run on a NUMA machine. Such a driver is probably outdated, possibly buggy and will need some attention if it starts triggering NULL derefs. Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-05mm: Fix printk typo in dmapool.cHiroshige Sato
Fix printk typo in dmapool.c Signed-off-by: Hiroshige Sato <sato.vintage@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-12-11dmapool: make DMAPOOL_DEBUG detect corruption of free markerMatthieu CASTET
This can help to catch the case where hardware is writing after dma free. [akpm@linux-foundation.org: tidy code, fix comment, use sizeof(page->offset), use pr_err()] Signed-off-by: Matthieu Castet <matthieu.castet@parrot.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-11mm: dmapool: use provided gfp flags for all dma_alloc_coherent() callsMarek Szyprowski
dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag, regardless the flags provided by the caller. This causes excessive pruning of emergency memory pools without any good reason. Additionaly, on ARM architecture any driver which is using dmapools will sooner or later trigger the following error: "ERROR: 256 KiB atomic DMA coherent pool is too small! Please increase it with coherent_pool= kernel parameter!". Increasing the coherent pool size usually doesn't help much and only delays such error, because all GFP_ATOMIC DMA allocations are always served from the special, very limited memory pool. This patch changes the dmapool code to correctly use gfp flags provided by the dmapool caller. Reported-by: Soeren Moch <smoch@web.de> Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Soeren Moch <smoch@web.de> Cc: stable@vger.kernel.org
2011-10-31mm: fix implicit stat.h usage in dmapool.cPaul Gortmaker
The removal of the implicitly everywhere module.h and its child includes will reveal this implicit stat.h usage: mm/dmapool.c:108: error: ‘S_IRUGO’ undeclared here (not in a function) Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31mm: Map most files to use export.h instead of module.hPaul Gortmaker
The files changed within are only using the EXPORT_SYMBOL macro variants. They are not using core modular infrastructure and hence don't need module.h but only the export.h header. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-25devres: fix possible use after freeMaxin B John
devres uses the pointer value as key after it's freed, which is safe but triggers spurious use-after-free warnings on some static analysis tools. Rearrange code to avoid such warnings. Signed-off-by: Maxin B. John <maxin.john@gmail.com> Reviewed-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc()Andrew Morton
As it stands this code will degenerate into a busy-wait if the calling task has signal_pending(). Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13mm/dmapool.c: take lock only once in dma_pool_free()Rolf Eike Beer
dma_pool_free() scans for the page to free in the pool list holding the pool lock. Then it releases the lock basically to acquire it immediately again. Modify the code to only take the lock once. This will do some additional loops and computations with the lock held in if memory debugging is activated. If it is not activated the only new operations with this lock is one if and one substraction. Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26mm: add a might_sleep_if() to dma_pool_alloc()Dima Zavin
Buggy drivers (e.g. fsl_udc) could call dma_pool_alloc from atomic context with GFP_KERNEL. In most instances, the first pool_alloc_page call would succeed and the sleeping functions would never be called. This allowed the buggy drivers to slip through the cracks. Add a might_sleep_if() checking for __GFP_WAIT in flags. Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30dmapools: protect page_list walk in show_pools()Thomas Gleixner
show_pools() walks the page_list of a pool w/o protection against the list modifications in alloc/free. Take pool->lock to avoid stomping into nirvana. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON tooAndi Kleen
Previously it was only enabled for CONFIG_DEBUG_SLAB. Not hooked into the slub runtime debug configuration, so you currently only get it with CONFIG_SLUB_DEBUG_ON, not plain CONFIG_SLUB_DEBUG Acked-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-04pool: Improve memory usage for devices which can't cross boundariesMatthew Wilcox
The previous implementation simply refused to allocate more than a boundary's worth of data from an entire page. Some users didn't know this, so specified things like SMP_CACHE_BYTES, not realising the horrible waste of memory that this was. It's fairly easy to correct this problem, just by ensuring we don't cross a boundary within a page. This even helps drivers like EHCI (which can't cross a 4k boundary) on machines with larger page sizes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net>
2007-12-04Change dmapool free block managementMatthew Wilcox
Use a list of free blocks within a page instead of using a bitmap. Update documentation to reflect this. As well as being a slight reduction in memory allocation, locked ops and lines of code, it speeds up a transaction processing benchmark by 0.4%. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-04dmapool: Tidy up includes and add commentsMatthew Wilcox
We were missing a copyright statement and license, so add GPLv2, David Brownell's copyright and my copyright. The asm/io.h include was superfluous, but we were missing a few other necessary includes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-04dmapool: Validate parameters to dma_pool_createMatthew Wilcox
Check that 'align' is a power of two, like the API specifies. Align 'size' to 'align' correctly -- the current code has an off-by-one. The ALIGN macro in kernel.h doesn't. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net>
2007-12-04Avoid taking waitqueue lock in dmapoolMatthew Wilcox
With one trivial change (taking the lock slightly earlier on wakeup from schedule), all uses of the waitq are under the pool lock, so we can use the locked (or __) versions of the wait queue functions, and avoid the extra spinlock. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net>
2007-12-04dmapool: Fix style problemsMatthew Wilcox
Run Lindent and fix all issues reported by checkpatch.pl Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-04Move dmapool.c to mm/ directoryMatthew Wilcox
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>