linux-toradex.git/drivers/dma/Kconfig, branch v3.10.76

net_dma: mark broken

2014-01-09T20:24:21+00:00

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: Greg Kroah-Hartman

dma: sh: add Kconfig

2013-04-30T10:20:12+00:00

This patch adds Kconfig in the drivers/dma/sh. This patch also adds
a new config "SH_DMAE_BASE" and the "config SH_DMAE" depends on it.
Since some drivers (e.g. sh_mmcif.c) depends on shdma-base.c if
CONFIG_DMA_ENGINE=y, the "config SH_DMAE_BASE" is set as "bool".

Signed-off-by: Yoshihiro Shimoda 
Acked-by: Kuninori Morimoto 
Signed-off-by: Vinod Koul

dma: acpi-dma: introduce ACPI DMA helpers

2013-04-15T16:34:10+00:00

There is a new generic API to get a DMA channel for a slave device (commit
9a6cecc8 "dmaengine: add helper function to request a slave DMA channel"). In
similar fashion to the DT case (commit aa3da644 "of: Add generic device tree
DMA helpers") we introduce helpers to the DMAC drivers which are enumerated by
ACPI.

The proposed extension provides the following API calls:
	acpi_dma_controller_register(), devm_acpi_dma_controller_register()
	acpi_dma_controller_free(), devm_acpi_dma_controller_free()
	acpi_dma_simple_xlate()
	acpi_dma_request_slave_chan_by_index()
	acpi_dma_request_slave_chan_by_name()

The first two should be used, for example, at probe() and remove() of the
corresponding DMAC driver. At the register stage the DMAC driver supplies a
custom xlate() function to translate a struct dma_spec into struct dma_chan.

Accordingly to the ACPI Fixed DMA resource specification the only two pieces of
information the slave device has are the channel id and the request line (slave
id). Those two are represented by struct dma_spec. The
acpi_dma_request_slave_chan_by_index() provides access to the specifix FixedDMA
resource by its index. Whereas dma_request_slave_channel() takes a string
parameter to identify the DMA resources required by the slave device. To make a
slave device driver work with both DeviceTree and ACPI enumeration a simple
convention is established: "tx" corresponds to the index 0 and "rx" to the
index 1. In case of robust configuration the slave device driver unfortunately
needs to call acpi_dma_request_slave_chan_by_index() directly.

Additionally the patch provides "managed" version of the register/free pair
i.e. devm_acpi_dma_controller_register() and devm_acpi_dma_controller_free().
Usually, the driver uses only devm_acpi_dma_controller_register().

Signed-off-by: Andy Shevchenko 
Reviewed-by: Mika Westerberg 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Vinod Koul

ioatdma: Removing PQ val disable for cb3.3

2013-04-15T04:21:20+00:00

The PQ Val ops work on the newer hardware so we should actually provide support
for it and remove the disabling bits.

Signed-off-by: Dave Jiang 
Acked-by: Dan Williams 
Signed-off-by: Vinod Koul

drivers/Kconfig: add several missing GENERIC_HARDIRQS dependencies

2013-03-21T12:35:37+00:00

With this patch an allmodconfig finally builds on s390 again.

Fixes these build errors:

ERROR: "devm_request_threaded_irq" [drivers/spi/spi-altera.ko] undefined!
ERROR: "devm_request_threaded_irq" [drivers/media/platform/sh_veu.ko] undefined!
ERROR: "devm_request_threaded_irq" [drivers/dma/dw_dmac.ko] undefined!

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma

2013-02-26T17:24:48+00:00

Pull slave-dmaengine updates from Vinod Koul:
 "This is fairly big pull by my standards as I had missed last merge
  window.  So we have the support for device tree for slave-dmaengine,
  large updates to dw_dmac driver from Andy for reusing on different
  architectures.  Along with this we have fixes on bunch of the drivers"

Fix up trivial conflicts, usually due to #include line movement next to
each other.

* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (111 commits)
  Revert "ARM: SPEAr13xx: Pass DW DMAC platform data from DT"
  ARM: dts: pl330: Add #dma-cells for generic dma binding support
  DMA: PL330: Register the DMA controller with the generic DMA helpers
  DMA: PL330: Add xlate function
  DMA: PL330: Add new pl330 filter for DT case.
  dma: tegra20-apb-dma: remove unnecessary assignment
  edma: do not waste memory for dma_mask
  dma: coh901318: set residue only if dma is in progress
  dma: coh901318: avoid unbalanced locking
  dmaengine.h: remove redundant else keyword
  dma: of-dma: protect list write operation by spin_lock
  dmaengine: ste_dma40: do not remove descriptors for cyclic transfers
  dma: of-dma.c: fix memory leakage
  dw_dmac: apply default dma_mask if needed
  dmaengine: ioat - fix spare sparse complain
  dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.c
  ioatdma: fix race between updating ioat->head and IOAT_COMPLETION_PENDING
  dw_dmac: add support for Lynxpoint DMA controllers
  dw_dmac: return proper residue value
  dw_dmac: fill individual length of descriptor
  ...

dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.c

2013-02-13T16:09:37+00:00

as requested by Rob

Suggested-by: Rob Herring 
Signed-off-by: Vinod Koul

dmaengine: sirf: enable the driver support new SiRFmarco SoC

2013-01-08T06:05:03+00:00

The driver supports old up SiRFprimaII SoCs, this patch makes it support
the new SiRFmarco as well.
SiRFmarco, as a SMP SoC, adds new DMA_INT_EN_CLR and DMA_CH_LOOP_CTRL_CLR
registers, to disable IRQ/Channel, we should write 1 to the corresponding
bit in the two CLEAR register.

Tested on SiRFmarco using SPI driver:
    $ /mnt/spidev-sirftest -D /dev/spidev32766.0
    spi mode: 0
    bits per word: 8
    max speed: 500000 Hz (500 KHz)

    00 00 00 00 00 00
    00 00 00 00 00 00
    00 00 00 00 00 00
    00 00 00 00 00 00
    00 00 00 00 00 00
    00 00 00 00 00 00
    00 00 00 00

    $ cat /proc/interrupts
               CPU0       CPU1
     32:       1593          0       GIC  sirfsoc_timer0
     33:          0       3533       GIC  sirfsoc_timer1
     44:          0          0       GIC  sirfsoc_dma
     45:         16          0       GIC  sirfsoc_dma
     47:          6          0       GIC  sirfsoc_spi
     50:       5654          0       GIC  sirfsoc-uart
     ...

Signed-off-by: Barry Song 
Signed-off-by: Vinod Koul

dmaengine: dw_dmac: remove CLK dependency

2013-01-08T06:04:47+00:00

This driver could be used on different platforms. Thus, the HAVE_CLK dependency
is dropped away.

Signed-off-by: Heikki Krogerus 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Felipe Balbi 
Acked-by: Viresh Kumar 
Signed-off-by: Vinod Koul

drivers/dma: remove CONFIG_EXPERIMENTAL

2013-01-07T04:57:46+00:00

This config item has not carried much meaning for a while now and is
almost always enabled by default. As agreed during the Linux kernel
summit, remove it.

CC: Vinod Koul 
CC: Dan Williams 
Signed-off-by: Kees Cook 
Signed-off-by: Vinod Koul