On Mar 26, 2005, at 2:39 AM, Izumi Tsutsui wrote:

> Precisely, is it worth to pass VM_PROT_READ (and VM_PROT_WRITE on  
> B_READ)
> to pmap_enter(9) flags in vmapbuf() on mips?

The pmap_enter() flags argument must always have at least the  
permissions that are in the prot argument if flags also has PMAP_WIRED.


> And should we pass VM_PROT_WRITE in pmap_enter() prot arg only
> on B_READ too?
> ---
> Izumi Tsutsui
>
>
> Index: mips/vm_machdep.c
> ===================================================================
> RCS file: /cvsroot/src/sys/arch/mips/mips/vm_machdep.c,v
> retrieving revision 1.105
> diff -u -r1.105 vm_machdep.c
> --- mips/vm_machdep.c    1 Jan 2005 03:25:46 -0000    1.105
> +++ mips/vm_machdep.c    26 Mar 2005 02:40:27 -0000
> @@ -318,6 +306,7 @@
>      vaddr_t kva;    /* Kernel VA (new to) */
>      paddr_t pa;    /* physical address */
>      vsize_t off;
> +    int prot;
>
>      if ((bp->b_flags & B_PHYS) == 0)
>          panic("vmapbuf");
> @@ -329,11 +318,12 @@
>      bp->b_data = (caddr_t)(kva + off);
>
>      upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map);
> +    prot = VM_PROT_READ | ((bp->b_flags & B_READ) ?  
> VM_PROT_WRITE : 0);
>      do {
>          if (pmap_extract(upmap, uva, &pa) == FALSE)
>              panic("vmapbuf: null page frame");
>          pmap_enter(vm_map_pmap(phys_map), kva, pa,
> -            VM_PROT_READ | VM_PROT_WRITE, PMAP_WIRED);
> +            prot, prot | PMAP_WIRED);
>          uva += PAGE_SIZE;
>          kva += PAGE_SIZE;
>          len -= PAGE_SIZE;
>

-- thorpej