Clang warns:
drivers/dma/fsl-dpaa2-qdma/dpdmai.c:148:25: warning: variable 'cfg' is
uninitialized when used within its own initialization [-Wuninitialized]
DPDMAI_CMD_CREATE(cmd, cfg);
~~~~~~~~~~~~~~~~~~~~~~~^~~~
drivers/dma/fsl-dpaa2-qdma/dpdmai.c:42:24: note: expanded from macro
'DPDMAI_CMD_CREATE'
typeof(_cfg) (cfg) = (_cfg); \
~~~ ^~~~
1 warning generated.
Looking at the preprocessed source, we can see that this is true.
int dpdmai_create(struct fsl_mc_io *mc_io, u32 cmd_flags,
const struct dpdmai_cfg *cfg, u16 *token)
{
struct fsl_mc_command cmd = { 0 };
int err;
cmd.header = mc_encode_cmd_header((((0x90E) << 4) | 0), cmd_flags, 0);
do {
typeof(cmd)(cmd) = (cmd);
typeof(cfg)(cfg) = (cfg);
((cmd).params[0] |= mc_enc((8), (8), (cfg)->priorities[0]));
((cmd).params[0] |= mc_enc((16), (8), (cfg)->priorities[1]));
} while (0);
I cannot see a good reason to create another version of cfg when the
parameter one will work perfectly fine and cmd can just be used as is.
Remove them to fix this warning.
Fixes: f2835adf8a ("dmaengine: fsl-dpaa2-qdma: Add the DPDMAI(Data Path DMA Interface) support")
Link: https://github.com/ClangBuiltLinux/linux/issues/746
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20191022171648.37732-1-natechancellor@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
DPPA2(Data Path Acceleration Architecture 2) qDMA supports
virtualized channel by allowing DMA jobs to be enqueued into
different work queues. Core can initiate a DMA transaction by
preparing a frame descriptor(FD) for each DMA job and enqueuing
this job through a hardware portal. DPAA2 components can also
prepare a FD and enqueue a DMA job through a hardware portal.
The qDMA prefetches DMA jobs through DPAA2 hardware portal. It
then schedules and dispatches to internal DMA hardware engines,
which generate read and write requests. Both qDMA source data and
destination data can be either contiguous or non-contiguous using
one or more scatter/gather tables.
The qDMA supports global bandwidth flow control where all DMA
transactions are stalled if the bandwidth threshold has been reached.
Also supported are transaction based read throttling.
Add NXP dppa2 qDMA to support some of Layerscape SoCs.
such as: LS1088A, LS208xA, LX2, etc.
Signed-off-by: Peng Ma <peng.ma@nxp.com>
Link: https://lore.kernel.org/r/20190930020440.7754-2-peng.ma@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The MC(Management Complex) exports the DPDMAI(Data Path DMA Interface)
object as an interface to operate the DPAA2(Data Path Acceleration
Architecture 2) qDMA Engine. The DPDMAI enables sending frame-based
requests to qDMA and receiving back confirmation response on transaction
completion, utilizing the DPAA2 QBMan(Queue Manager and Buffer Manager
hardware) infrastructure. DPDMAI object provides up to two priorities for
processing qDMA requests.
The following list summarizes the DPDMAI main features and capabilities:
1. Supports up to two scheduling priorities for processing
service requests.
- Each DPDMAI transmit queue is mapped to one of two service
priorities, allowing further prioritization in hardware between
requests from different DPDMAI objects.
2. Supports up to two receive queues for incoming transaction
completion confirmations.
- Each DPDMAI receive queue is mapped to one of two receive
priorities, allowing further prioritization between other
interfaces when associating the DPDMAI receive queues to DPIO
or DPCON(Data Path Concentrator) objects.
3. Supports different scheduling options for processing received
packets:
- Queues can be configured either in 'parked' mode (default),
or attached to a DPIO object, or attached to DPCON object.
4. Allows interaction with one or more DPIO objects for
dequeueing/enqueueing frame descriptors(FD) and for
acquiring/releasing buffers.
5. Supports enable, disable, and reset operations.
Add dpdmai to support some platforms with dpaa2 qdma engine.
Signed-off-by: Peng Ma <peng.ma@nxp.com>
Link: https://lore.kernel.org/r/20190930020440.7754-1-peng.ma@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Nathan Chancellor