Massive cleanup of SPARC kernel entry code

[akaros.git] / kern / arch / sparc / entry.S

diff --git a/kern/arch/sparc/entry.S b/kern/arch/sparc/entry.S
index 6e831a1..371214f 100644 (file)
--- a/kern/arch/sparc/entry.S
+++ b/kern/arch/sparc/entry.S
@@ -35,16 +35,14 @@ _start:
 
        // compute NWINDOWS
 
-       mov     -1,%wim                 ! mark all windows invalid.
-       mov     (PSR_S|PSR_PS),%psr
-       nop                             ! 3 insns between wrwim/rdwim
-       mov     0,%g2           ! g2 will contain NWINDOWS-1
-       mov     %wim,%g1        ! get wim. nonexistent windows set to 0
-
-1:     srl     %g1,1,%g1
-       tst     %g1
-       bne,a   1b
-        inc    %g2
+       mov     0,%wim                          ! mark all windows valid
+       mov (PSR_PIL|PSR_S|PSR_PS),%psr ! CWP = 0
+       nop; nop; nop                   ! 3 insns between write -> read state reg
+       save                                    ! CWP = (CWP-1) % NWINDOWS = NWINDOWS-1
+       mov     %psr,%g2
+       and     %g2,PSR_CWP,%g2         ! g2 = NWINDOWS-1
+       restore                                 ! CWP = 0
+       mov     1<<1,%wim                       ! mark window 1 invalid (trap on restore)
 
        // now g2 = NWINDOWS - 1.  Patch the window spill trap handler.
        set     RELOC(spill_patchme),%g1
@@ -60,15 +58,18 @@ _start:
        st      %g3,[%g1]
        flush   %g1
 
+       // and patch the trap entry point.
+       set     RELOC(trap_patchme),%g1
+       ld      [%g1],%g3
+       or      %g2,%g3,%g3
+       st      %g3,[%g1]
+       flush   %g1
+
        // store NWINDOWS away for safekeeping
        set     RELOC(NWINDOWS),%g1
        inc     %g2
        st      %g2,[%g1]
 
-       // PSR.CWP (current window pointer) == 0.
-       // Set WIM so we'll trap on the next save instruction.
-       mov     1 << 1,%wim
-
        // set up the TBR (trap base register)
        set     RELOC(trap_table),%g1
        mov     %g1,%tbr
@@ -80,11 +81,28 @@ _start:
        // sp = bootstacktop - core_id*KSTKSIZE - 64
        set     RELOC(bootstacktop)-64,%sp
        mov     CORE_ID_REG,%g1
-       sll     %g1,KSTKSHIFT,%g1
-       sub     %sp,%g1,%sp
+       sll     %g1,KSTKSHIFT,%g2
+       sub     %sp,%g2,%sp
 
        // set up a virtual->physical mapping
-       call    mmu_boot
+       tst     %g1
+       set     RELOC(pagetable_init_done),%l0
+       bne pagetable_init_wait
+        nop
+
+       // core 0 initializes the pagetable
+       call    pagetable_init
+        nop
+       mov     1,%g2
+       st      %g2,[%l0]
+
+pagetable_init_wait:
+       ld      [%l0],%g1
+       tst     %g1
+       be      pagetable_init_wait
+        nop
+
+       call    mmu_init
         nop
 
        // relocate
@@ -95,9 +113,26 @@ _start:
        jmp     %g1
         add    %g2,%sp,%sp
 reloc:
+       call    mmu_boot_cleanup_all
+        nop
 
-       // finish mmu_boot
-       call    mmu_boot_finish
+       mov     1,%g1
+       set     cores_relocated,%g2
+       set     cores_relocated_lock,%g3
+       swap    [%g3],%g1
+       tst     %g1
+       bne     reloc
+        nop
+       ld      [%g2],%g1
+       inc     %g1
+       st      %g1,[%g2]
+       st      %g0,[%g3]
+
+wait_for_reloc:
+       ld      [%g2],%g1
+       mov     NUM_CORES_REG,%g3
+       cmp     %g1,%g3
+       bl      wait_for_reloc
         nop
 
        // now it's safe to enable traps
@@ -112,6 +147,9 @@ reloc:
         nop
 
        // only core 0 gets here
+       call    mmu_boot_cleanup_core0
+        nop
+
        // set num_cpus
        set     num_cpus,%l0
        mov     NUM_CORES_REG,%l1
@@ -120,6 +158,10 @@ reloc:
        cmp     %l1,MAX_NUM_CPUS
        tg      0x7f
 
+       // use a stack in the data section (as opposed to bss) here,
+       // since kernel_init will zero the stack
+       set     core0_bootstacktop-64,%sp
+
        sub     %sp,64,%sp              ! 64 >= sizeof(multiboot_header_t)
        call    build_multiboot_info
         add    %sp,64,%o0
@@ -153,6 +195,15 @@ reloc:
 ///////////////////////////////////////////////////////////////////
 // various data
 ///////////////////////////////////////////////////////////////////
+.data
+
+pagetable_init_done:
+       .word 0
+
+cores_relocated:
+       .word 0
+cores_relocated_lock:
+       .word 0
 
        .global         time_for_smp_init
 time_for_smp_init:
@@ -170,13 +221,18 @@ num_cpus:
 // boot stack
 ///////////////////////////////////////////////////////////////////
 
-       .align          PGSIZE          ! force page alignment
-       .global         bootstack
-bootstack:
+.section ".bss"
+       .align          PGSIZE
        .space          KSTKSIZE*MAX_NUM_CPUS
        .global         bootstacktop   
 bootstacktop:
 
+.data
+       .align          PGSIZE
+       .space          KSTKSIZE
+       .global         core0_bootstacktop
+core0_bootstacktop:
+
 ///////////////////////////////////////////////////////////////////
 // page tables
 ///////////////////////////////////////////////////////////////////