Re: [PATCH] HPET driver

From: Andrew Morton
Date: Thu May 13 2004 - 18:43:38 EST


Jeff Garzik <jgarzik@xxxxxxxxx> wrote:
>
> > + vma->vm_flags |= (VM_IO | VM_SHM | VM_LOCKED);
> > + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> > + addr = __pa(addr);
>
> where did these flags come from? don't you just want VM_RESERVED?

VM_IO is the way to mark mmapped I/O devices.

vma->vm_flags |= VM_IO;

should be sufficient here.

hm, I'm trying to decrypt how the driver accesses the hardware. It's
taking copies of kernel virtual addresses based off hpet_virt_address, but
there are no readl's or writel's in there. Is the actual device access
done over in time_hpet.c?

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