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Diffstat (limited to 'roms/skiboot/doc/opal-api/opal_nx_coproc_init-167.rst')
| -rw-r--r-- | roms/skiboot/doc/opal-api/opal_nx_coproc_init-167.rst | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/roms/skiboot/doc/opal-api/opal_nx_coproc_init-167.rst b/roms/skiboot/doc/opal-api/opal_nx_coproc_init-167.rst new file mode 100644 index 000000000..b22c5a078 --- /dev/null +++ b/roms/skiboot/doc/opal-api/opal_nx_coproc_init-167.rst @@ -0,0 +1,36 @@ +.. _opal_nx_coproc_init: + +OPAL_NX_COPROC_INIT +=================== + +This OPAL call resets read offset and queued entries in high and normal +priority receive FIFO control registers. The kernel initializes read +offset entry in RXFIFO that it maintains during initialization. So this +register reset is needed for NX module reload or in kexec boot to make sure +read offset value matches with kernel entries. Otherwise NX reads requests +with wrong offset in RxFIFO which could cause NX request failures. + +The kernel initiates this call for each coprocessor type such as 842 and +GZIP per NX instance. + +Arguments +--------- +:: + + ``uint32_t chip_id`` + Contains value of the chip number identified at boot time. + + ``uint32_t pid`` + Contains NX coprocessor type (pid from the device tree). + +Returns +------- +OPAL_SUCCESS + The call to reset readOffset and queued entries for high and normal + FIFOs was successful. + +OPAL_PARAMETER + Indicates invalid chip ID or NX coprocessor type. + +OPAL_UNSUPPORTED + Not supported on P7 and P8. |