mirror of https://gitee.com/openkylin/linux.git
61 lines
3.0 KiB
ReStructuredText
61 lines
3.0 KiB
ReStructuredText
======================================================================
|
|
Texas Instruments Keystone Navigator Queue Management SubSystem driver
|
|
======================================================================
|
|
|
|
Driver source code path
|
|
drivers/soc/ti/knav_qmss.c
|
|
drivers/soc/ti/knav_qmss_acc.c
|
|
|
|
The QMSS (Queue Manager Sub System) found on Keystone SOCs is one of
|
|
the main hardware sub system which forms the backbone of the Keystone
|
|
multi-core Navigator. QMSS consist of queue managers, packed-data structure
|
|
processors(PDSP), linking RAM, descriptor pools and infrastructure
|
|
Packet DMA.
|
|
The Queue Manager is a hardware module that is responsible for accelerating
|
|
management of the packet queues. Packets are queued/de-queued by writing or
|
|
reading descriptor address to a particular memory mapped location. The PDSPs
|
|
perform QMSS related functions like accumulation, QoS, or event management.
|
|
Linking RAM registers are used to link the descriptors which are stored in
|
|
descriptor RAM. Descriptor RAM is configurable as internal or external memory.
|
|
The QMSS driver manages the PDSP setups, linking RAM regions,
|
|
queue pool management (allocation, push, pop and notify) and descriptor
|
|
pool management.
|
|
|
|
knav qmss driver provides a set of APIs to drivers to open/close qmss queues,
|
|
allocate descriptor pools, map the descriptors, push/pop to queues etc. For
|
|
details of the available APIs, please refers to include/linux/soc/ti/knav_qmss.h
|
|
|
|
DT documentation is available at
|
|
Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
|
|
|
|
Accumulator QMSS queues using PDSP firmware
|
|
============================================
|
|
The QMSS PDSP firmware support accumulator channel that can monitor a single
|
|
queue or multiple contiguous queues. drivers/soc/ti/knav_qmss_acc.c is the
|
|
driver that interface with the accumulator PDSP. This configures
|
|
accumulator channels defined in DTS (example in DT documentation) to monitor
|
|
1 or 32 queues per channel. More description on the firmware is available in
|
|
CPPI/QMSS Low Level Driver document (docs/CPPI_QMSS_LLD_SDS.pdf) at
|
|
|
|
git://git.ti.com/keystone-rtos/qmss-lld.git
|
|
|
|
k2_qmss_pdsp_acc48_k2_le_1_0_0_9.bin firmware supports upto 48 accumulator
|
|
channels. This firmware is available under ti-keystone folder of
|
|
firmware.git at
|
|
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
|
|
|
|
To use copy the firmware image to lib/firmware folder of the initramfs or
|
|
ubifs file system and provide a sym link to k2_qmss_pdsp_acc48_k2_le_1_0_0_9.bin
|
|
in the file system and boot up the kernel. User would see
|
|
|
|
"firmware file ks2_qmss_pdsp_acc48.bin downloaded for PDSP"
|
|
|
|
in the boot up log if loading of firmware to PDSP is successful.
|
|
|
|
Use of accumulated queues requires the firmware image to be present in the
|
|
file system. The driver doesn't acc queues to the supported queue range if
|
|
PDSP is not running in the SoC. The API call fails if there is a queue open
|
|
request to an acc queue and PDSP is not running. So make sure to copy firmware
|
|
to file system before using these queue types.
|