Allocate the S/G list in the tag, not on the stack.  The enforces the rule that while many maps can exist and be loaded per tag, bus_dmamap_load() and friends can only be called on one map at a time from the tag.  This is enforced via the mutex arguments in the tag.
Allocate the S/G list in the tag, not on the stack.  The enforces the rule
that while many maps can exist and be loaded per tag, bus_dmamap_load() and
friends can only be called on one map at a time from the tag.  This is
enforced via the mutex arguments in the tag.

Fixing this bug means that s/g lists can be arbitrarily long in length, and
also removes an ugly GNU-ism from the code.  No API or ABI change is
incurred.  Similar changes for other platforms is forthcoming.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase