--- Arjan van de Ven <[EMAIL PROTECTED]> wrote:
> you forgot to attach your source code or provide a URL to it.....
Sorry, my bad. I'm just diving into Linux for the first time and wasn't
aware of the protocols. Here's the code fragment I'm currently using:
address = skb_vaddr(skb) & PAGE_MASK;
end = PAGE_ALIGN(skb_vaddr(skb) + len);
down_read(¤t->mm->mmap_sem);
vma = find_vma(current->mm, skb_vaddr(skb));
spin_lock(¤t->mm->page_table_lock);
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, address += PAGE_SIZE) {
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep;
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
/*
* If we're looking at the ZERO_PAGE() then we don't have to
* do anything. It's never going to be modified. See also
* where we avoid the ZERO_PAGE() in skb_dma_complete().
*/
if (frag->page == ZERO_PAGE(address))
continue;
atomic_inc(&frag->page->_mapcount);
/*
* If we're not dealing with the ZERO_PAGE() then it should
* not be possible to end up without a mapping to the page.
* But just in case we check here and issue a BUG() if the
* mapping is missing ...
*/
if (unlikely((pgd = pgd_offset(current->mm, address),
pgd_none(*pgd)) ||
(pud = pud_offset(pgd, address),
pud_none(*pud)) ||
(pmd = pmd_offset(pud, address),
pmd_none(*pmd)) ||
(ptep = pte_offset_map(pmd, address),
pte_none(*ptep)))) {
printk("skb_dma_pending: missing %s page mapping"
" for vaddr=%#lx, page=%p\n",
pgd_none(*pgd) ? "pgd"
: pud_none(*pud) ? "pud"
: pmd_none(*pmd) ? "pmd"
: "pte",
address, frag->page);
BUG();
}
ptep_set_wrprotect(current->mm, address, ptep);
pte_unmap(ptep);
}
spin_unlock(¤t->mm->page_table_lock);
flush_tlb_range(vma, address, end);
I hope that isn't too large but I wanted to provide sufficient context.
Casey
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