Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.
However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.
Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.
This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.
Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.
I was using this definition for testing:
#define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))
which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.
I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.
[ Updated the 9p parts as per Al Viro - Linus ]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull dmaengine updates from Vinod Koul:
"This time round the update brings in following changes:
- new tegra driver for ADMA device
- support for Xilinx AXI Direct Memory Access Engine and Xilinx AXI
Central Direct Memory Access Engine and few updates to this driver
- new cyclic capability to sun6i and few updates
- slave-sg support in bcm2835
- updates to many drivers like designware, hsu, mv_xor, pxa, edma,
qcom_hidma & bam"
* tag 'dmaengine-4.7-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (84 commits)
dmaengine: ioatdma: disable relaxed ordering for ioatdma
dmaengine: of_dma: approximate an average distribution
dmaengine: core: Use IS_ENABLED() instead of checking for built-in or module
dmaengine: edma: Re-evaluate errors when ccerr is triggered w/o error event
dmaengine: qcom_hidma: add support for object hierarchy
dmaengine: qcom_hidma: add debugfs hooks
dmaengine: qcom_hidma: implement lower level hardware interface
dmaengine: vdma: Add clock support
Documentation: DT: vdma: Add clock support for dmas
dmaengine: vdma: Add config structure to differentiate dmas
MAINTAINERS: Update Tegra DMA maintainers
dmaengine: tegra-adma: Add support for Tegra210 ADMA
Documentation: DT: Add binding documentation for NVIDIA ADMA
dmaengine: vdma: Add Support for Xilinx AXI Central Direct Memory Access Engine
Documentation: DT: vdma: update binding doc for AXI CDMA
dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine
Documentation: DT: vdma: update binding doc for AXI DMA
dmaengine: vdma: Rename xilinx_vdma_ prefix to xilinx_dma
dmaengine: slave means at least one of DMA_SLAVE, DMA_CYCLIC
dmaengine: mv_xor: Allow selecting mv_xor for mvebu only compatible SoC
...
ioatdma by default is in snoop mode. Relaxed ordering according to spec
does not do anything in snoop mode. However, it causes hang or significant
performance degrade when tested with NTB. Disabling in the driver due to
some BIOS do not configure it correctly.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Currently the following DT description would result in dmac0 always
being tried first and dmac1 second if dmac0 was unavailable. This
results in heavier use of dmac0 then of dmac1. This patch adds an
approximate average distribution over the two nodes lessening the load
of anyone of them.
i2c6: i2c@e60b0000 {
...
dmas = <&dmac0 0x77>, <&dmac0 0x78>,
<&dmac1 0x77>, <&dmac1 0x78>;
dma-names = "tx", "rx", "tx", "rx";
...
};
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
When the ccerr handler is called but the error registers indicate no error
events we need to command eDMA to re-evaluate the errors. Otherwise we can
receive flood of error interrupts.
Reported-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
In order to create a relationship model between the channels and the
management object, we are adding support for object hierarchy to the
drivers. This patch simplifies the userspace application development.
We will not have to traverse different firmware paths based on device
tree or ACPI based kernels.
No matter what flavor of kernel is used, objects will be represented as
platform devices.
The new layout is as follows:
hidmam_10: hidma-mgmt@0x5A000000 {
compatible = "qcom,hidma-mgmt-1.0";
...
hidma_10: hidma@0x5a010000 {
compatible = "qcom,hidma-1.0";
...
}
}
The hidma_mgmt_init detects each instance of the hidma-mgmt-1.0 objects
in device tree and calls into the channel driver to create platform devices
for each child of the management object.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Add debugfs hooks for debugging the execution behavior of the DMA
channel. The debugfs hooks get initialized by the probe function and
uninitialized by the remove function.
A stats file is created in debugfs. The stats file will show the
information about each HIDMA channel as well as each asynchronous job
queued and completed at a given time.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This patch implements the hardware hooks for the HIDMA channel driver.
The main functions of interest are:
- hidma_ll_init
- hidma_ll_request
- hidma_ll_queue_request
- hidma_ll_hw_start
OS layer calls the hidma_ll_init function during probe to set up the
hardware. At this moment, the number of supported descriptors are also
given. On each request, a descriptor is allocated from the free pool and
filled in with the transfer parameters. Multiple requests can be queued
into the hardware via the OS interface. When client is ready for requests
to be executed, start method is called.
Completions are delivered via callbacks via tasklet.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Added basic clock support for axi dma's.
The clocks are requested at probe and released at remove.
Reviewed-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This patch adds config structure in the driver to differentiate
AXI DMA's and to add more features(clock support etc..) to these DMA's.
Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Add support for the Tegra210 Audio DMA controller that is used for
transferring data between system memory and the Audio sub-system.
The driver only supports cyclic transfers because this is being solely
used for audio.
This driver is based upon the work by Dara Ramesh <dramesh@nvidia.com>.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This patch adds support for the AXI Central Direct Memory Access
(AXI CDMA) core to the existing vdma driver, AXI CDMA is a
soft Xilinx IP core that provides high-bandwidth
Direct Memory Access(DMA) between a memory-mapped
source address and a memory-mapped destination address.
Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Arnd Bergmann
Linus Torvalds
Vinod Koul
Dave Jiang
Niklas Söderlund
Javier Martinez Canillas
Peter Ujfalusi
Sinan Kaya
Kedareswara rao Appana
Jon Hunter