A question about map_page

kang shuo blackfin.kang at gmail.com
Sat Jun 30 13:31:36 EST 2007


hi:
     I had read some ppc code in linux-2.6.20. There is a question
about map_page function. map_page seems to implement the map between
virtual address and physical address. But I can not understand how the
tlb entry operation is done in the code in map_page. The map_page is
as the following:

int
map_page(unsigned long va, phys_addr_t pa, int flags)
{
        pmd_t *pd;
        pte_t *pg;
        int err = -ENOMEM;

        /* Use upper 10 bits of VA to index the first level map */
        pd = pmd_offset(pgd_offset_k(va), va);
        /* Use middle 10 bits of VA to index the second-level map */
        pg = pte_alloc_kernel(pd, va);
        if (pg != 0) {
                err = 0;
                set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
                if (mem_init_done)
                        flush_HPTE(0, va, pmd_val(*pd));
        }
        return err;
}

        Could anyone give me some hints about where and when tlb entry
is setup according to map_page function. That is very appreciate.

-- Thanks
-- Michael.Kang



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