sparc/kernel/etrap_32.S

3  * etrap.S: Sparc trap window preparation for entry into the
33 	/* SEVEN WINDOW PATCH INSTRUCTIONS */
54 	 * to call c-code and the trap cannot be handled in-window)
62 	/* 2 3 4  window number
66 	 * O == Current window before trap
67 	 * T == Window entered when trap occurred
68 	 * S == Window we will need to save if (1<<T) == %wim
79 	/* Calculate mask of trap window.  See if from user
93 	/* See if we are in the trap window. */
95 	bne	trap_setup_kernel_spill		! in trap window, clean up
98 	/* Trap from kernel with a window available.
113 	sll	%t_wim, 0x7, %t_wim	! patched on 7 window Sparcs
116 	and	%g2, 0xff, %g2		! patched on 7 window Sparcs
123 	/* Save the kernel window onto the corresponding stack. */
161 	/* See if we are in the trap window. */
166 	/* Trap from user, but not into the invalid window.
168 	 * any window from the %wim at trap time until
169 	 * the window right before the one we are in now,
170 	 * is a user window.  A diagram:
172 	 *      7 6 5 4 3 2 1 0    window number
176 	 * Window 'I' is the invalid window in our example,
177 	 * window 'L' is the window the user was in when
178 	 * the trap occurred, window T is the trap window
242 	/* From user/kernel into invalid window w/bad user