Adding more context and information related the data exposed
through device discovery notably for FEC and FFT operations.
Signed-off-by: Nicolas Chautru <nicolas.chau...@intel.com>
---
doc/guides/prog_guide/bbdev.rst | 60 ++++++++++++++++++++++++++++-----
lib/bbdev/rte_bbdev.h | 6 ++++
2 files changed, 57 insertions(+), 9 deletions(-)
diff --git a/doc/guides/prog_guide/bbdev.rst b/doc/guides/prog_guide/bbdev.rst
index c43e478eda..01a8a6d79b 100644
--- a/doc/guides/prog_guide/bbdev.rst
+++ b/doc/guides/prog_guide/bbdev.rst
@@ -261,16 +261,58 @@ information:
structure, this is where capabilities reside along with other specifics like:
maximum queue sizes and priority level.
-.. code-block:: c
+.. literalinclude:: ../../../lib/bbdev/rte_bbdev.h
+ :language: c
+ :start-after: Structure rte_bbdev_driver_info 8<
+ :end-before: >8 End of structure rte_bbdev_driver_info.
- struct rte_bbdev_info {
- int socket_id;
- const char *dev_name;
- const struct rte_device *device;
- uint16_t num_queues;
- bool started;
- struct rte_bbdev_driver_info drv;
- };
+.. literalinclude:: ../../../lib/bbdev/rte_bbdev.h
+ :language: c
+ :start-after: Structure rte_bbdev_info 8<
+ :end-before: >8 End of structure rte_bbdev_info.
+
+Capabilities details for LDPC Decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+On top of the ``RTE_BBDEV_LDPC_<*>`` capabilities the device also exposes the
LLR numerical
+representation expected by the decoder as a fractional fixed-point
representation.
+For instance, when the representation (``llr_size``, ``llr_decimals``) = (8,
2) respectively,
+this means that each input LLR in the data provided by the application must be
computed as 8 total
+bits (including sign bit) where 2 of these are fractions bits (also referred
to as S8.2 format).
+It is up to the user application during LLR generation to scale the LLR
according to this
+optimal numerical representation. Any mis-scaled LLR would cause wireless
performance degradation.
+
+The ``harq_buffer_size`` exposes the amount of dedicated DDR made available
for the device operation.
+This is specific for accelerator non-integrated on the CPU (separate PCIe
device) which may
+include separate on-card memory.
+
+Capabilities details for FFT function
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The total number of distinct time windows supported for the post-FFT
point-wise multiplication is
+exposed as ``fft_windows_num``. The ``window_index`` provided for each cyclic
shift in each
+``rte_bbdev_op_fft`` operation is expected to be limited to that size.
+
+The information related to the width of each of these pre-configured window is
also exposed
+using the ``fft_window_width`` array. This provides the number of non-null
samples used for each
+window index when scaling back the size to a reference of 1024 FFT. The actual
shape size is
+effectively scaled up or down based on the dynamic size of the FFT operation
being used.
+
+This allows to distinguish different version of the flexible pointwise
windowing applied to the
+FFT and exposes this platform configuration to the application.
+
+Other optional capabilities exposed during device discovery
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The device status can be used to expose additional information related to the
state of the
+platform notably based on its configuration state or related to error
management
+(correctable or non).
+
+The queue topology exposed to the device is provided on top of the
capabilities. This provides
+the number of queues available for the exposed bbdev device (the physical
device may have more)
+for each operation as well as the different level of priority available for
arbitration.
+These are based on the arrays and parameters ``num_queues``,
``queue_priority``,
+``max_num_queues``, ``queue_size_lim``.
Operation Processing
diff --git a/lib/bbdev/rte_bbdev.h b/lib/bbdev/rte_bbdev.h
index d12e2e7fbc..925c78cae1 100644
--- a/lib/bbdev/rte_bbdev.h
+++ b/lib/bbdev/rte_bbdev.h
@@ -313,6 +313,8 @@ int
rte_bbdev_stats_reset(uint16_t dev_id);
/** Device information supplied by the device's driver */
+
+/* Structure rte_bbdev_driver_info 8< */
struct rte_bbdev_driver_info {
/** Driver name */
const char *driver_name;
@@ -352,6 +354,7 @@ struct rte_bbdev_driver_info {
/** FFT windowing width for 2048 FFT - size defined in capability. */
uint16_t *fft_window_width;
};
+/* >8 End of structure rte_bbdev_driver_info. */
/** Macro used at end of bbdev PMD list */
#define RTE_BBDEV_END_OF_CAPABILITIES_LIST() \
@@ -361,6 +364,8 @@ struct rte_bbdev_driver_info {
* Device information structure used by an application to discover a devices
* capabilities and current configuration
*/
+
+/* Structure rte_bbdev_info 8< */
struct rte_bbdev_info {
int socket_id; /**< NUMA socket that device is on */
const char *dev_name; /**< Unique device name */
@@ -369,6 +374,7 @@ struct rte_bbdev_info {
bool started; /**< Set if device is currently started */
struct rte_bbdev_driver_info drv; /**< Info from device driver */
};
+/* >8 End of structure rte_bbdev_info. */
/**
* Retrieve information about a device.
--
2.34.1
