[Dri-devel] PPC Lockup (ati-pcigart-branch)

[Roman Zippel]

Hi,

On Mon, 22 Jan 2001, Dan Malek wrote:

> I do this:
>
> 		pgd = pgd_offset_k(i);
> 		if (pgd) {
> 			pmd = pmd_offset(pgd, i);
> 			if (pmd && pmd_present(*pmd)) {
> 				pte = pte_offset(pmd, i);
> 				if (pte && pte_present(*pte)) {
> 					/* Do your stuff */
> 				}
> 			}
> 		}

There is no need to test the pointers and you forgot a pgd_present(),
otherwise you might get a problem on architectures with 3-level mmus.
Anyway to get to the page struct, this should do it:

        pgd = pgd_offset_k(addr);
        if (!pgd_present(*pgd))
                return NULL;
        pmd = pmd_offset(pgd, addr);
        if (!pmd_present(*pmd))
                return NULL;
        pte = pte_offset(pmd, addr);
        if (!pte_present(*pte))
                return NULL;
        return pte_page(*pte);

bye, Roman


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