user/sven/linux.git/drivers/dma, branch v3.2.73

dmaengine: mv_xor: bug fix for racing condition in descriptors cleanup

2015-08-12T14:33:15Z

commit 9136291f1dbc1d4d1cacd2840fb35f4f3ce16c46 upstream. This patch fixes a bug in the XOR driver where the cleanup function can be called and free descriptors that never been processed by the engine (which result in data errors). The cleanup function will free descriptors based on the ownership bit in the descriptors. Fixes: ff7b04796d98 ("dmaengine: DMA engine driver for Marvell XOR engine") Signed-off-by: Lior Amsalem Signed-off-by: Maxime Ripard Reviewed-by: Ofer Heifetz Signed-off-by: Vinod Koul [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

dma: mv_xor: Flush descriptors before activating a channel

2014-06-09T12:29:15Z

commit 5a9a55bf9157d3490b0c8c4c81d4708602c26e07 upstream. We need to use writel() instead of writel_relaxed() when starting a channel, to ensure all the descriptors have been flushed before the activation. While at it, remove the unneeded read-modify-write and make the code simpler. Signed-off-by: Lior Amsalem Signed-off-by: Ezequiel Garcia Signed-off-by: Dan Williams [bwh: Backported to 3.2: it was using __raw_readl() and __raw_writel() which are just as wrong] Signed-off-by: Ben Hutchings

ioat: fix tasklet tear down

2014-04-01T23:58:55Z

commit da87ca4d4ca101f177fffd84f1f0a5e4c0343557 upstream. Since commit 77873803363c "net_dma: mark broken" we no longer pin dma engines active for the network-receive-offload use case. As a result the ->free_chan_resources() that occurs after the driver self test no longer has a NET_DMA induced ->alloc_chan_resources() to back it up. A late firing irq can lead to ksoftirqd spinning indefinitely due to the tasklet_disable() performed by ->free_chan_resources(). Only ->alloc_chan_resources() can clear this condition in affected kernels. This problem has been present since commit 3e037454bcfa "I/OAT: Add support for MSI and MSI-X" in 2.6.24, but is now exposed. Given the NET_DMA use case is deprecated we can revisit moving the driver to use threaded irqs. For now, just tear down the irq and tasklet properly by: 1/ Disable the irq from triggering the tasklet 2/ Disable the irq from re-arming 3/ Flush inflight interrupts 4/ Flush the timer 5/ Flush inflight tasklets References: https://lkml.org/lkml/2014/1/27/282 https://lkml.org/lkml/2014/2/19/672 Cc: Ingo Molnar Cc: Steven Rostedt Reported-by: Mike Galbraith Reported-by: Stanislav Fomichev Tested-by: Mike Galbraith Tested-by: Stanislav Fomichev Reviewed-by: Thomas Gleixner Signed-off-by: Dan Williams [bwh: Backported to 3.2: - Adjust context - As there is no ioatdma_device::irq_mode member, check pci_dev::msix_enabled instead] Signed-off-by: Ben Hutchings Acked-by: Dan Williams

dma: ste_dma40: don't dereference free:d descriptor

2014-04-01T23:58:53Z

commit e9baa9d9d520fb0e24cca671e430689de2d4a4b2 upstream. It appears that in the DMA40 driver the DMA tasklet will very often dereference memory for a descriptor just free:d from the DMA40 slab. Nothing happens because no other part of the driver has yet had a chance to claim this memory, but it's really nasty to dereference free:d memory, so let's check the flag before the descriptor is free and store it in a bool variable. Reported-by: Dan Carpenter Signed-off-by: Linus Walleij Signed-off-by: Vinod Koul Signed-off-by: Ben Hutchings

net_dma: mark broken

2014-02-15T19:20:14Z

commit 77873803363c9e831fc1d1e6895c084279090c22 upstream. net_dma can cause data to be copied to a stale mapping if a copy-on-write fault occurs during dma. The application sees missing data. The following trace is triggered by modifying the kernel to WARN if it ever triggers copy-on-write on a page that is undergoing dma: WARNING: CPU: 24 PID: 2529 at lib/dma-debug.c:485 debug_dma_assert_idle+0xd2/0x120() ioatdma 0000:00:04.0: DMA-API: cpu touching an active dma mapped page [pfn=0x16bcd9] Modules linked in: iTCO_wdt iTCO_vendor_support ioatdma lpc_ich pcspkr dca CPU: 24 PID: 2529 Comm: linbug Tainted: G W 3.13.0-rc1+ #353 00000000000001e5 ffff88016f45f688 ffffffff81751041 ffff88017ab0ef70 ffff88016f45f6d8 ffff88016f45f6c8 ffffffff8104ed9c ffffffff810f3646 ffff8801768f4840 0000000000000282 ffff88016f6cca10 00007fa2bb699349 Call Trace: [] dump_stack+0x46/0x58 [] warn_slowpath_common+0x8c/0xc0 [] ? ftrace_pid_func+0x26/0x30 [] warn_slowpath_fmt+0x46/0x50 [] debug_dma_assert_idle+0xd2/0x120 [] do_wp_page+0xd0/0x790 [] handle_mm_fault+0x51c/0xde0 [] ? copy_user_enhanced_fast_string+0x9/0x20 [] __do_page_fault+0x19c/0x530 [] ? _raw_spin_lock_bh+0x16/0x40 [] ? trace_clock_local+0x9/0x10 [] ? rb_reserve_next_event+0x64/0x310 [] ? ioat2_dma_prep_memcpy_lock+0x60/0x130 [ioatdma] [] do_page_fault+0xe/0x10 [] page_fault+0x22/0x30 [] ? __kfree_skb+0x51/0xd0 [] ? copy_user_enhanced_fast_string+0x9/0x20 [] ? memcpy_toiovec+0x52/0xa0 [] skb_copy_datagram_iovec+0x5f/0x2a0 [] tcp_rcv_established+0x674/0x7f0 [] tcp_v4_do_rcv+0x2e5/0x4a0 [..] ---[ end trace e30e3b01191b7617 ]--- Mapped at: [] debug_dma_map_page+0xb9/0x160 [] dma_async_memcpy_pg_to_pg+0x127/0x210 [] dma_memcpy_pg_to_iovec+0x119/0x1f0 [] dma_skb_copy_datagram_iovec+0x11c/0x2b0 [] tcp_rcv_established+0x74a/0x7f0: ...the problem is that the receive path falls back to cpu-copy in several locations and this trace is just one of the areas. A few options were considered to fix this: 1/ sync all dma whenever a cpu copy branch is taken 2/ modify the page fault handler to hold off while dma is in-flight Option 1 adds yet more cpu overhead to an "offload" that struggles to compete with cpu-copy. Option 2 adds checks for behavior that is already documented as broken when using get_user_pages(). At a minimum a debug mode is warranted to catch and flag these violations of the dma-api vs get_user_pages(). Thanks to David for his reproducer. Cc: Dave Jiang Cc: Vinod Koul Cc: Alexander Duyck Reported-by: David Whipple Acked-by: David S. Miller Signed-off-by: Dan Williams Signed-off-by: Ben Hutchings

drivers/dma/pl330.c: fix locking in pl330_free_chan_resources()

2013-07-27T04:34:27Z

commit da331ba8e9c5de72a27e50f71105395bba6eebe0 upstream. tasklet_kill() may sleep so call it before taking pch->lock. Fixes following lockup: BUG: scheduling while atomic: cat/2383/0x00000002 Modules linked in: unwind_backtrace+0x0/0xfc __schedule_bug+0x4c/0x58 __schedule+0x690/0x6e0 sys_sched_yield+0x70/0x78 tasklet_kill+0x34/0x8c pl330_free_chan_resources+0x24/0x88 dma_chan_put+0x4c/0x50 [...] BUG: spinlock lockup suspected on CPU#0, swapper/0/0 lock: 0xe52aa04c, .magic: dead4ead, .owner: cat/2383, .owner_cpu: 1 unwind_backtrace+0x0/0xfc do_raw_spin_lock+0x194/0x204 _raw_spin_lock_irqsave+0x20/0x28 pl330_tasklet+0x2c/0x5a8 tasklet_action+0xfc/0x114 __do_softirq+0xe4/0x19c irq_exit+0x98/0x9c handle_IPI+0x124/0x16c gic_handle_irq+0x64/0x68 __irq_svc+0x40/0x70 cpuidle_wrap_enter+0x4c/0xa0 cpuidle_enter_state+0x18/0x68 cpuidle_idle_call+0xac/0xe0 cpu_idle+0xac/0xf0 Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Acked-by: Jassi Brar Cc: Vinod Koul Cc: Tomasz Figa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

pch_dma: Use GFP_ATOMIC because called from interrupt context

2013-05-30T13:35:09Z

commit 5c1ef59168c485318e40ba485c1eba57d81d0faa upstream. pdc_desc_get() is called from pd_prep_slave_sg, and the function is called from interrupt context(e.g. Uart driver "pch_uart.c"). In fact, I saw kernel error message. So, GFP_ATOMIC must be used not GFP_NOIO. Signed-off-by: Tomoya MORINAGA Signed-off-by: Vinod Koul Signed-off-by: Ben Hutchings

ioat: Fix DMA memory sync direction correct flag

2013-02-06T04:33:23Z

commit ac4989874af56435c308bdde9ad9c837a26f8b23 upstream. ioat does DMA memory sync with DMA_TO_DEVICE direction on a buffer allocated for DMA_FROM_DEVICE dma, resulting in the following warning from dma debug. Fixed the dma_sync_single_for_device() call to use the correct direction. [ 226.288947] WARNING: at lib/dma-debug.c:990 check_sync+0x132/0x550() [ 226.288948] Hardware name: ProLiant DL380p Gen8 [ 226.288951] ioatdma 0000:00:04.0: DMA-API: device driver syncs DMA memory with different direction [device address=0x00000000ffff7000] [size=4096 bytes] [mapped with DMA_FROM_DEVICE] [synced with DMA_TO_DEVICE] [ 226.288953] Modules linked in: iTCO_wdt(+) sb_edac(+) ioatdma(+) microcode serio_raw pcspkr edac_core hpwdt(+) iTCO_vendor_support hpilo(+) dca acpi_power_meter ata_generic pata_acpi sd_mod crc_t10dif ata_piix libata hpsa tg3 netxen_nic(+) sunrpc dm_mirror dm_region_hash dm_log dm_mod [ 226.288967] Pid: 1055, comm: work_for_cpu Tainted: G W 3.3.0-0.20.el7.x86_64 #1 [ 226.288968] Call Trace: [ 226.288974] [] warn_slowpath_common+0x7f/0xc0 [ 226.288977] [] warn_slowpath_fmt+0x46/0x50 [ 226.288980] [] check_sync+0x132/0x550 [ 226.288983] [] debug_dma_sync_single_for_device+0x3f/0x50 [ 226.288988] [] ? wait_for_common+0x72/0x180 [ 226.288995] [] ioat_xor_val_self_test+0x3e5/0x832 [ioatdma] [ 226.288999] [] ? kfree+0x259/0x270 [ 226.289004] [] ioat3_dma_self_test+0x1b/0x20 [ioatdma] [ 226.289008] [] ioat_probe+0x2f8/0x348 [ioatdma] [ 226.289011] [] ioat3_dma_probe+0x1d5/0x2aa [ioatdma] [ 226.289016] [] ioat_pci_probe+0x139/0x17c [ioatdma] [ 226.289020] [] local_pci_probe+0x5c/0xd0 [ 226.289023] [] ? destroy_work_on_stack+0x20/0x20 [ 226.289025] [] do_work_for_cpu+0x18/0x30 [ 226.289029] [] kthread+0xb7/0xc0 [ 226.289033] [] kernel_thread_helper+0x4/0x10 [ 226.289036] [] ? _raw_spin_unlock_irq+0x30/0x50 [ 226.289038] [] ? retint_restore_args+0x13/0x13 [ 226.289041] [] ? kthread_worker_fn+0x1a0/0x1a0 [ 226.289044] [] ? gs_change+0x13/0x13 [ 226.289045] ---[ end trace e1618afc7a606089 ]--- [ 226.289047] Mapped at: [ 226.289048] [] debug_dma_map_page+0x87/0x150 [ 226.289050] [] dma_map_page.constprop.18+0x70/0xb34 [ioatdma] [ 226.289054] [] ioat_xor_val_self_test+0x1d8/0x832 [ioatdma] [ 226.289058] [] ioat3_dma_self_test+0x1b/0x20 [ioatdma] [ 226.289061] [] ioat_probe+0x2f8/0x348 [ioatdma] Signed-off-by: Shuah Khan Signed-off-by: Vinod Koul Signed-off-by: Ben Hutchings

drivers/dma/dmaengine.c: lower the priority of 'failed to get' dma channel message

2012-10-17T02:49:34Z

commit 0eb5a35801df3c438ce3fc91310a415ea4452c00 upstream. Do the same as commit a03a202e95fd ("dmaengine: failure to get a specific DMA channel is not critical") to get rid of the following messages during kernel boot: dmaengine_get: failed to get dma1chan0: (-22) dmaengine_get: failed to get dma1chan1: (-22) dmaengine_get: failed to get dma1chan2: (-22) dmaengine_get: failed to get dma1chan3: (-22) .. Signed-off-by: Fabio Estevam Cc: Vinod Koul Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: also apply changes to this logging statement from commit 634332502366 ('dmaengine: Cleanup logging messages')] Signed-off-by: Ben Hutchings

DMA: PL330: Check the pointer returned by kzalloc

2012-10-10T02:30:56Z

commit 61c6e7531d3b66b33187b8cdd700fd8ab93ffd62 upstream. kzalloc could return NULL. Hence add a check to avoid NULL pointer dereference. Signed-off-by: Sachin Kamat Acked-by: Jassi Brar Signed-off-by: Vinod Koul [bwh: Backported to 3.2: adjust context and error label] Signed-off-by: Ben Hutchings