Changeset ee454eb in mainline for kernel/arch/sparc64/src/trap/trap_table.S

Timestamp:

2006-08-30T15:50:29Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

beb3926a

Parents:

e11ae91

Message:

sparc64 work.
More bits needed to reach the userspace milestone were added.
The preemptible_handler(), still a prototype, now contains all functionality it needs.
Some sanitation was added to functions expecting page-aligned pointers to
userspace window buffer.

File:

• kernel/arch/sparc64/src/trap/trap_table.S (modified) (6 diffs)

kernel/arch/sparc64/src/trap/trap_table.S

@@ -41 +41 @@
 #include <arch/trap/exception.h>
 #include <arch/trap/mmu.h>
+#include <arch/mm/page.h>
 #include <arch/stack.h>
 #include <arch/regdef.h>
@@ -330 +331 @@
 
         /*
+         * Normal window spills will go to the userspace window buffer.
+         */
+        wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(2), %wstate
+
+        /*
          * Switch to kernel stack. The old stack is
          * automatically saved in the old window's %sp
@@ -364 +370 @@
          */
 1:
-
+        
+        /*
+         * Other window spills will go to the userspace window buffer
+         * and normal spills will go to the kernel stack.
+         */
+        wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(0), %wstate
+        
         /*
          * Copy arguments.
@@ -450 +462 @@
          */
         flushw
-        mov %sp, %g1
+        mov %sp, %g2
         stx %i0, [%sp + PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE + STACK_BIAS + SAVED_I0]
         stx %i1, [%sp + PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE + STACK_BIAS + SAVED_I1]
@@ -460 +472 @@
         stx %i7, [%sp + PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE + STACK_BIAS + SAVED_I7]
         wrpr %l0, 0, %cwp
-        mov %g1, %sp
+        mov %g2, %sp
         ldx [%sp + PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE + STACK_BIAS + SAVED_I0], %i0
         ldx [%sp + PREEMPTIBLE_HANDLER_STACK_FRAME_SIZE + STACK_BIAS + SAVED_I1], %i1
@@ -472 +484 @@
         /*
          * OTHERWIN != 0 or fall-through from the OTHERWIN == 0 case.
+         * The CWP has already been restored to the value it had prior to the SAVE
+         * at the beginning of this function.
          */
 0:
-        ! TODO: restore register windows from register window memory buffer
-
+        rdpr %tstate, %g1
+        andcc %g1, TSTATE_PRIV_BIT, %g0         ! if we are not returning to userspace...,
+        bnz 1f                                  ! ...skip restoring userspace windows
+        nop
+        
+        rdpr %cwp, %g1
+        rdpr %otherwin, %g2
+
+        /*
+         * Skip all OTHERWIN windows and descend to the first window
+         * in the userspace window buffer.
+         */
+        sub %g1, %g2, %g3
+        dec %g3
+        and %g3, NWINDOW - 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.
+         */
+        clr %g4
+0:      andcc %g7, PAGE_WIDTH - 1, %g0          ! PAGE_SIZE alignment check
+        bz 0f                                   ! %g7 is page-aligned, no more windows to refill
+        nop
+
+        add %g7, -STACK_WINDOW_SAVE_AREA_SIZE, %g7
+        ldx [%g7 + L0_OFFSET], %l0
+        ldx [%g7 + L1_OFFSET], %l1
+        ldx [%g7 + L2_OFFSET], %l2
+        ldx [%g7 + L3_OFFSET], %l3
+        ldx [%g7 + L4_OFFSET], %l4
+        ldx [%g7 + L5_OFFSET], %l5
+        ldx [%g7 + L6_OFFSET], %l6
+        ldx [%g7 + L7_OFFSET], %l7
+        ldx [%g7 + I0_OFFSET], %i0
+        ldx [%g7 + I1_OFFSET], %i1
+        ldx [%g7 + I2_OFFSET], %i2
+        ldx [%g7 + I3_OFFSET], %i3
+        ldx [%g7 + I4_OFFSET], %i4
+        ldx [%g7 + I5_OFFSET], %i5
+        ldx [%g7 + I6_OFFSET], %i6
+        ldx [%g7 + I7_OFFSET], %i7
+
+        dec %g3
+        and %g3, NWINDOW - 1, %g3
+        wrpr %g3, 0, %cwp                       ! switch to the preceeding window
+
+        ba 0b
+        inc %g4
+
+0:
+        /*
+         * Switch back to the proper current window and adjust
+         * OTHERWIN, CANRESTORE, CANSAVE and CLEANWIN.
+         */
+        wrpr %g1, 0, %cwp
+        add %g4, %g2, %g2
+        mov NWINDOW - 2, %g1
+        sub %g1, %g2, %g1
+        
+        wrpr %g0, 0, %otherwin
+        wrpr %g1, 0, %cansave                   ! NWINDOW - 2 - CANRESTORE
+        wrpr %g2, 0, %canrestore                ! OTHERWIN + windows in the buffer
+        wrpr %g2, 0, %cleanwin                  ! avoid information leak
+
+        /*
+         * Spills and fills will be processed by the {spill,fill}_1_normal
+         * handlers.
+         */
+        wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(1), %wstate
+
+1:
         restore
         retry