Changeset 817d939 in mainline for kernel/arch/sparc32/src/trap_table.S

Timestamp:

2013-10-22T20:44:20Z (11 years ago)

Author:

Jakub Klama <jakub.klama@…>

Branches:

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

Children:

e6a3bfee

Parents:

d783145

Message:

Changes as follows:

• Implemented storing kernel stack pointer and userspace window buffer in invalid register window space
• Initialized IRQ routing

File:

• kernel/arch/sparc32/src/trap_table.S (modified) (10 diffs)

kernel/arch/sparc32/src/trap_table.S

@@ -34 +34 @@
 .global reset_trap
 .global preemptible_trap
+.global interrupt_trap
 .global syscall_trap
 .global window_overflow_trap
 .global window_underflow_trap
+.global write_to_invalid
+
+.macro get_wim_number reg
+        clr \reg
+        mov %wim, %g5
+1:      inc \reg
+        srl %g5, 1, %g5
+        andcc %g5, 1, %g0
+        bne 1b
+        nop
+.endm
+
+.macro get_cwp reg
+        mov %psr, \reg
+        and \reg, 0x7, \reg
+.endm
+
+.macro switch_to_invalid saved_wim, saved_psr
+        get_wim_number %g6
+        mov %wim, \saved_wim    ! save WIM
+        mov %g0, %wim           ! clear WIM
+        mov %psr, \saved_psr    ! read PSR
+        or \saved_psr, %g6, %g6 ! set CWP
+        mov %g6, %psr           ! write PSR
+        nop
+        nop
+        nop
+        nop                     ! wait for PSR to be effective
+.endm   
+
+.macro switch_back wim, psr
+        mov \wim, %wim          ! saved WIM
+        mov \psr, %psr          ! saved PSR
+        nop
+        nop
+        nop
+        nop
+.endm
+
+/* Save next window to kernel stack or UWB */
+.macro inline_save_kernel
+        save
+        std %l0, [%sp +  0]
+        std %l2, [%sp +  8]
+        std %l4, [%sp + 16]
+        std %l6, [%sp + 24]
+        std %i0, [%sp + 32]
+        std %i2, [%sp + 40]
+        std %i4, [%sp + 48]
+        std %i6, [%sp + 56]
+        restore
+.endm
+
+.macro inline_save_uspace uwb
+        save
+        ld [\uwb], %g1
+        std %l0, [%g1 +  0]
+        std %l2, [%g1 +  8]
+        std %l4, [%g1 + 16]
+        std %l6, [%g1 + 24]
+        std %i0, [%g1 + 32]
+        std %i2, [%g1 + 40]
+        std %i4, [%g1 + 48]
+        std %i6, [%g1 + 56]
+        add \uwb, 64, \uwb
+        restore
+.endm
+
+/* Restore window from kernel stack or UWB */
+.macro inline_restore_kernel
+        save
+        ldd [%sp +  0], %l0
+        ldd [%sp +  8], %l2
+        ldd [%sp + 16], %l4
+        ldd [%sp + 24], %l6
+        ldd [%sp + 32], %i0
+        ldd [%sp + 40], %i2
+        ldd [%sp + 48], %i4
+        ldd [%sp + 56], %i6
+        restore
+.endm
+
+.macro inline_restore_uspace uwb
+        save
+        ld [\uwb], %g1
+        std %l0, [%g1 +  0]
+        std %l2, [%g1 +  8]
+        std %l4, [%g1 + 16]
+        std %l6, [%g1 + 24]
+        std %i0, [%g1 + 32]
+        std %i2, [%g1 + 40]
+        std %i4, [%g1 + 48]
+        std %i6, [%g1 + 56]
+        sub \uwb, 64, \uwb
+        restore
+.endm
+
+.macro if_from_kernel label
+        mov %psr, %g2
+        and %g2, (1 << 6), %g2
+        cmp %g2, 0
+        bne \label
+        nop
+.endm
+
+write_to_invalid:
+        mov %o0, %g5
+        mov %o1, %g6
+        mov %o2, %g7
+        switch_to_invalid %g3, %g4
+        mov %g5, %l5
+        mov %g6, %l6
+        mov %g7, %l7
+        switch_back %g3, %g4
+        retl
+        nop
 
 reset_trap:
@@ -62 +179 @@
         beq 1f
         nop
+
+        /* Save invalid window data */
+        mov %l5, %g5            ! kernel stack pointer
+        mov %l6, %g6            ! kernel wbuf
+        mov %l7, %g7
 
         /* dump registers to stack */
@@ -78 +200 @@
         /* dump registers to uwb */
 1:      save
-        set uspace_wbuf, %g2
-        ld [%g1], %g1
-        std %l0, [%g1 +  0]
-        std %l2, [%g1 +  8]
-        std %l4, [%g1 + 16]
-        std %l6, [%g1 + 24]
-        std %i0, [%g1 + 32]
-        std %i2, [%g1 + 40]
-        std %i4, [%g1 + 48]
-        std %i6, [%g1 + 56]
-        add %g1, 64, %g1
-        st %g1, [%g2]
-
-        /* back to where we should be */
-2:      restore
+        std %l0, [%g4 +  0]
+        std %l2, [%g4 +  8]
+        std %l4, [%g4 + 16]
+        std %l6, [%g4 + 24]
+        std %i0, [%g4 + 32]
+        std %i2, [%g4 + 40]
+        std %i4, [%g4 + 48]
+        std %i6, [%g4 + 56]
+        add %g4, 64, %g4
+
+2:      /* back to where we should be */
+        mov %g5, %l5
+        mov %g6, %l6
+        mov %g7, %l7
+        restore
 
         /* set new value of window */
@@ -120 +242 @@
         beq 1f
         nop
+
+        /* Save invalid window data */
+        mov %l5, %g5            ! kernel stack pointer
+        mov %l6, %g6            ! kernel wbuf
+        mov %l7, %g7
 
         /* load registers from stack */
@@ -151 +278 @@
         st %g1, [%g2]
 
-        /* back to where we should be */
-2:      save
+2:      /* back to where we should be */
+        mov %g5, %l5
+        mov %g6, %l6
+        mov %g7, %l7
+        save
         save
 
@@ -164 +294 @@
 
 preemptible_trap:
+        /* Check whether we landed in invalid window */
+        get_wim_number %g6
+        get_cwp %g7
+        cmp %g6, %g7
+        bne 4f
+        nop
+
+        /* We are in invalid window. Check whether previous mode was usermode */
+        if_from_kernel 3f
+
+        /* Kernel stack pointer is at %l5, uwb is at %l6 */
+        inline_save_uspace %l6
+3:      inline_save_kernel 
+
+4:      /* Check whether previous mode was usermode */
+        if_from_kernel 5f
+
+        /* Load kernel stack pointer from invalid window */
+        switch_to_invalid %g5, %g6
+        mov %l5, %g7            ! stack pointer
+        switch_back %g5, %g6
+        mov %g7, %sp
+        mov %sp, %fp
+5:      sub %sp, 112, %sp
+
+        /* Save trap data on stack */
+        mov %psr, %l0
+        st %l1, [%fp - 4]
+        st %l2, [%fp - 8]
+        st %l0, [%fp - 12]
+
+        /* Enable traps */
+        mov %psr, %l0
+        or %l0, (1 << 5), %l0
+        mov %l0, %psr
+        nop
+        nop
+        nop
+        nop
+
+        /* Jump to actual subroutine */
+        call %o2
+        sub %fp, 12, %o1
+
+        /* Return from handler */
+        ld [%fp - 4], %l1
+        ld [%fp - 8], %l2
+        ld [%fp - 12], %l0
+        mov %l0, %psr
+        nop
+        nop
+        nop
+        nop
+        nop
+        jmp %l1
+        rett %l2
+
+interrupt_trap:
         mov %psr, %l0
 
@@ -195 +383 @@
         /* Jump to actual subroutine */
         mov %g2, %o0
-        call %g1
+        call exc_dispatch
         sub %fp, 12, %o1
 
@@ -268 +456 @@
 #define TRAP(_vector, _handler) \
         .org trap_table + _vector * TRAP_ENTRY_SIZE; \
-        set _vector, %g2 ; \
-        sethi %hi(_handler), %g1 ; \
+        set _vector, %o0 ; \
+        sethi %hi(_handler), %o2 ; \
         b preemptible_trap ; \
-        or %g1, %lo(_handler), %g1 ;
+        or %o2, %lo(_handler), %o2 ;
 
 #define SYSCALL(_vector) \
@@ -283 +471 @@
         mov %psr, %l0 ; \
         mov _priority, %g2 ; \
-        call exc_dispatch ; \
+        b interrupt_trap ; \
         nop ;
 
@@ -292 +480 @@
 .align TRAP_TABLE_SIZE
 trap_table:
-        TRAP(0x0, reset_trap)
+        STRAP(0x0, reset_trap)
         TRAP(0x1, instruction_access_exception)
         TRAP(0x2, illegal_instruction)