Merge branch 'sparc64-context-wrap-fixes'

Pavel Tatashin says:

sparc64: context wrap fixes

This patch series contains fixes for context wrap: when we are out of
context ids, and need to get a new version.

It fixes memory corruption issues which happen when more than number of
context ids (currently set to 8K) number of processes are started
simultaneously, and processes can get a wrong context.

sparc64: new context wrap:
- contains explanation of new wrap method, and also explanation of races
  that it solves
sparc64: reset mm cpumask after wrap
- explains issue of not reseting cpu mask on a wrap

Signed-off-by: David S. Miller <>