arch/ia64/fsys.rst

14 "fsys-mode".  To recap, the normal states of execution are:
32 In contrast, fsys-mode has the following special properties:
41   - execution is interruptible and preemptible (an fsys-mode handler
46     in fsys-mode (they point to the user-level stacks, which may
49 In summary, fsys-mode is much more similar to running in user-mode
51 privilege level is at level 0, this means that fsys-mode requires some
55 How to tell fsys-mode
58 Linux operates in fsys-mode when (a) the privilege level is 0 (most
73 TRUE if the CPU state pointed to by "regs" was executing in fsys-mode.
81 The file arch/ia64/kernel/fsys.S contains a table of fsyscall-handlers
87 example, fsys.S contains fsys_getpid(), which is a hand-tuned version
176 The delivery of (asynchronous) signals must be delayed until fsys-mode
179 checks whether the interrupted task was in fsys-mode and, if so, sets
180 PSR.lp and returns immediately.  When fsys-mode is exited via the
195 PSR.be	Cleared when entering fsys-mode.  A srlz.d instruction is used
198 	restored upon return from an fsys-mode handler.  In other
203 PSR.mfl Unchanged.  Note: fsys-mode handlers must not write-registers!
204 PSR.mfh	Unchanged.  Note: fsys-mode handlers must not write-registers!
205 PSR.ic	Unchanged.  Note: fsys-mode handlers can clear the bit, if needed.
206 PSR.i	Unchanged.  Note: fsys-mode handlers can clear the bit, if needed.
209 PSR.dfl	Unchanged.  Note: fsys-mode handlers must not write-registers!
210 PSR.dfh	Unchanged.  Note: fsys-mode handlers must not write-registers!
220 	fsys-mode, the trap-handler modifies the saved machine state
226 	the fsys-mode handler will return directly to user-level.  This
229 	left fsys-mode, so no special treatment is needed.
243 PSR.ed	Unchanged.  Note: This bit could only have an effect if an fsys-mode
247 PSR.bn	Unchanged.  Note: fsys-mode handlers may clear the bit, if needed.