WebSVN – HelenOS – Diff – /trunk/kernel/arch/sparc64/src/trap/trap_table.S



	/*
	 * Normal window spills will go to the userspace window buffer.
	 */
	wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(2), %wstate
 
	wrpr %g0, NWINDOWS - 1, %cleanwin	! prevent unnecessary clean_window exceptions
 
	/*
	 * Switch to kernel stack. The old stack is
	 * automatically saved in the old window's %sp
	 * and the new window's %fp.

	/*
	 * If TSTATE.CWP + 1 == CWP, then we still do not have to fix CWP.
	 */
	and %g1, TSTATE_CWP_MASK, %l0
	inc %l0
	and %l0, NWINDOWS - 1, %l0	! %l0 mod NWINDOWS
	rdpr %cwp, %l1
	cmp %l0, %l1
	bz 0f				! CWP is ok
	nop
 

	 * Skip all OTHERWIN windows and descend to the first window
	 * in the userspace window buffer.
	 */
	sub %g1, %g2, %g3
	dec %g3
	and %g3, NWINDOWS - 1, %g3
	wrpr %g3, 0, %cwp
 
	/*
	 * CWP is now in the window last saved in the userspace window buffer.
	 * Fill all windows stored in the buffer.

	ldx [%g7 + I5_OFFSET], %i5
	ldx [%g7 + I6_OFFSET], %i6
	ldx [%g7 + I7_OFFSET], %i7
 
	dec %g3
	and %g3, NWINDOWS - 1, %g3
	wrpr %g3, 0, %cwp			! switch to the preceeding window
 
	ba 0b
	inc %g4
 

	 * Switch back to the proper current window and adjust
	 * OTHERWIN, CANRESTORE, CANSAVE and CLEANWIN.
	 */
	wrpr %g1, 0, %cwp
	add %g4, %g2, %g2
	cmp %g2, NWINDOWS - 2
	bg 2f					! fix the CANRESTORE=NWINDOWS-1 anomaly
	mov NWINDOWS - 2, %g1			! use dealy slot for both cases
	sub %g1, %g2, %g1
	
	wrpr %g0, 0, %otherwin
	wrpr %g1, 0, %cansave			! NWINDOWS - 2 - CANRESTORE
	wrpr %g2, 0, %canrestore		! OTHERWIN + windows in the buffer
	wrpr %g2, 0, %cleanwin			! avoid information leak
 
1:
	restore

	 * If the:
	 *
	 * 	save %g6, -PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE, %sp
	 *
	 * instruction trapped and spilled a register window into the userspace
	 * window buffer, we have just restored NWINDOWS - 1 register windows.
	 * However, CANRESTORE can be only NWINDOW - 2 at most.
	 *
	 * The solution is to manually switch to (CWP - 1) mod NWINDOWS
	 * and set the window state registers so that:
	 *
	 * 	CANRESTORE 	= NWINDOWS - 2
	 *	CLEANWIN	= NWINDOWS - 2
	 *	CANSAVE 	= 0
	 *	OTHERWIN	= 0
	 *
	 * The RESTORE instruction is therfore to be skipped.
	 */

	wrpr %g1, 0, %canrestore
	wrpr %g1, 0, %cleanwin
 
	rdpr %cwp, %g1
	dec %g1
	and %g1, NWINDOWS - 1, %g1
	wrpr %g1, 0, %cwp			! CWP--
	
.if \is_syscall
	done
.else

Rev 1916	Rev 1917
Line 671...	Line 671...
671	/*	671	/*
672	* Normal window spills will go to the userspace window buffer.	672	* Normal window spills will go to the userspace window buffer.
673	*/	673	*/
674	wrpr %g0, WSTATE_OTHER(0) \| WSTATE_NORMAL(2), %wstate	674	wrpr %g0, WSTATE_OTHER(0) \| WSTATE_NORMAL(2), %wstate
675		675
676	wrpr %g0, NWINDOW - 1, %cleanwin ! prevent unnecessary clean_window exceptions	676	wrpr %g0, NWINDOWS - 1, %cleanwin ! prevent unnecessary clean_window exceptions
677		677
678	/*	678	/*
679	* Switch to kernel stack. The old stack is	679	* Switch to kernel stack. The old stack is
680	* automatically saved in the old window's %sp	680	* automatically saved in the old window's %sp
681	* and the new window's %fp.	681	* and the new window's %fp.
Line 828...	Line 828...
828	/*	828	/*
829	* If TSTATE.CWP + 1 == CWP, then we still do not have to fix CWP.	829	* If TSTATE.CWP + 1 == CWP, then we still do not have to fix CWP.
830	*/	830	*/
831	and %g1, TSTATE_CWP_MASK, %l0	831	and %g1, TSTATE_CWP_MASK, %l0
832	inc %l0	832	inc %l0
833	and %l0, NWINDOW - 1, %l0 ! %l0 mod NWINDOW	833	and %l0, NWINDOWS - 1, %l0 ! %l0 mod NWINDOWS
834	rdpr %cwp, %l1	834	rdpr %cwp, %l1
835	cmp %l0, %l1	835	cmp %l0, %l1
836	bz 0f ! CWP is ok	836	bz 0f ! CWP is ok
837	nop	837	nop
838		838
Line 899...	Line 899...
899	* Skip all OTHERWIN windows and descend to the first window	899	* Skip all OTHERWIN windows and descend to the first window
900	* in the userspace window buffer.	900	* in the userspace window buffer.
901	*/	901	*/
902	sub %g1, %g2, %g3	902	sub %g1, %g2, %g3
903	dec %g3	903	dec %g3
904	and %g3, NWINDOW - 1, %g3	904	and %g3, NWINDOWS - 1, %g3
905	wrpr %g3, 0, %cwp	905	wrpr %g3, 0, %cwp
906		906
907	/*	907	/*
908	* CWP is now in the window last saved in the userspace window buffer.	908	* CWP is now in the window last saved in the userspace window buffer.
909	* Fill all windows stored in the buffer.	909	* Fill all windows stored in the buffer.
Line 931...	Line 931...
931	ldx [%g7 + I5_OFFSET], %i5	931	ldx [%g7 + I5_OFFSET], %i5
932	ldx [%g7 + I6_OFFSET], %i6	932	ldx [%g7 + I6_OFFSET], %i6
933	ldx [%g7 + I7_OFFSET], %i7	933	ldx [%g7 + I7_OFFSET], %i7
934		934
935	dec %g3	935	dec %g3
936	and %g3, NWINDOW - 1, %g3	936	and %g3, NWINDOWS - 1, %g3
937	wrpr %g3, 0, %cwp ! switch to the preceeding window	937	wrpr %g3, 0, %cwp ! switch to the preceeding window
938		938
939	ba 0b	939	ba 0b
940	inc %g4	940	inc %g4
941		941
Line 944...	Line 944...
944	* Switch back to the proper current window and adjust	944	* Switch back to the proper current window and adjust
945	* OTHERWIN, CANRESTORE, CANSAVE and CLEANWIN.	945	* OTHERWIN, CANRESTORE, CANSAVE and CLEANWIN.
946	*/	946	*/
947	wrpr %g1, 0, %cwp	947	wrpr %g1, 0, %cwp
948	add %g4, %g2, %g2	948	add %g4, %g2, %g2
949	cmp %g2, NWINDOW - 2	949	cmp %g2, NWINDOWS - 2
950	bg 2f ! fix the CANRESTORE=NWINDOW-1 anomaly	950	bg 2f ! fix the CANRESTORE=NWINDOWS-1 anomaly
951	mov NWINDOW - 2, %g1 ! use dealy slot for both cases	951	mov NWINDOWS - 2, %g1 ! use dealy slot for both cases
952	sub %g1, %g2, %g1	952	sub %g1, %g2, %g1
953		953
954	wrpr %g0, 0, %otherwin	954	wrpr %g0, 0, %otherwin
955	wrpr %g1, 0, %cansave ! NWINDOW - 2 - CANRESTORE	955	wrpr %g1, 0, %cansave ! NWINDOWS - 2 - CANRESTORE
956	wrpr %g2, 0, %canrestore ! OTHERWIN + windows in the buffer	956	wrpr %g2, 0, %canrestore ! OTHERWIN + windows in the buffer
957	wrpr %g2, 0, %cleanwin ! avoid information leak	957	wrpr %g2, 0, %cleanwin ! avoid information leak
958		958
959	1:	959	1:
960	restore	960	restore
Line 970...	Line 970...
970	* If the:	970	* If the:
971	*	971	*
972	* save %g6, -PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE, %sp	972	* save %g6, -PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE, %sp
973	*	973	*
974	* instruction trapped and spilled a register window into the userspace	974	* instruction trapped and spilled a register window into the userspace
975	* window buffer, we have just restored NWINDOW - 1 register windows.	975	* window buffer, we have just restored NWINDOWS - 1 register windows.
976	* However, CANRESTORE can be only NWINDOW - 2 at most.	976	* However, CANRESTORE can be only NWINDOW - 2 at most.
977	*	977	*
978	* The solution is to manually switch to (CWP - 1) mod NWINDOW	978	* The solution is to manually switch to (CWP - 1) mod NWINDOWS
979	* and set the window state registers so that:	979	* and set the window state registers so that:
980	*	980	*
981	* CANRESTORE = NWINDOW - 2	981	* CANRESTORE = NWINDOWS - 2
982	* CLEANWIN = NWINDOW - 2	982	* CLEANWIN = NWINDOWS - 2
983	* CANSAVE = 0	983	* CANSAVE = 0
984	* OTHERWIN = 0	984	* OTHERWIN = 0
985	*	985	*
986	* The RESTORE instruction is therfore to be skipped.	986	* The RESTORE instruction is therfore to be skipped.
987	*/	987	*/
Line 991...	Line 991...
991	wrpr %g1, 0, %canrestore	991	wrpr %g1, 0, %canrestore
992	wrpr %g1, 0, %cleanwin	992	wrpr %g1, 0, %cleanwin
993		993
994	rdpr %cwp, %g1	994	rdpr %cwp, %g1
995	dec %g1	995	dec %g1
996	and %g1, NWINDOW - 1, %g1	996	and %g1, NWINDOWS - 1, %g1
997	wrpr %g1, 0, %cwp ! CWP--	997	wrpr %g1, 0, %cwp ! CWP--
998		998
999	.if \is_syscall	999	.if \is_syscall
1000	done	1000	done
1001	.else	1001	.else

Subversion Repositories HelenOS

(root)/trunk/kernel/arch/sparc64/src/trap/trap_table.S – Rev 1916 → 1917