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author | jeff <jeff@FreeBSD.org> | 2013-08-05 00:28:03 +0000 |
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committer | jeff <jeff@FreeBSD.org> | 2013-08-05 00:28:03 +0000 |
commit | baea70e2d240e48edbd021981532b9d16f16589b (patch) | |
tree | 198c60f2a696d008cea3389a370600c5aecf6df2 /sys/i386/i386 | |
parent | 598e23d2ea39e4526a2c2ba5e99a952645a9e3b0 (diff) | |
download | FreeBSD-src-baea70e2d240e48edbd021981532b9d16f16589b.zip FreeBSD-src-baea70e2d240e48edbd021981532b9d16f16589b.tar.gz |
- Introduce a specific function, pmap_remove_kernel_pde, for removing
huge pages in the kernel's address space. This works around several
asserts from pmap_demote_pde_locked that did not apply and gave false
warnings.
Discovered by: pho
Reviewed by: alc
Sponsored by: EMC / Isilon Storage Division
Diffstat (limited to 'sys/i386/i386')
-rw-r--r-- | sys/i386/i386/pmap.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index 9556458..77b0235 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -2773,6 +2773,44 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va) } /* + * Removes a 2- or 4MB page mapping from the kernel pmap. + */ +static void +pmap_remove_kernel_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va) +{ + pd_entry_t newpde; + vm_paddr_t mptepa; + vm_page_t mpte; + + PMAP_LOCK_ASSERT(pmap, MA_OWNED); + mpte = pmap_lookup_pt_page(pmap, va); + if (mpte == NULL) + panic("pmap_remove_kernel_pde: Missing pt page."); + + pmap_remove_pt_page(pmap, mpte); + mptepa = VM_PAGE_TO_PHYS(mpte); + newpde = mptepa | PG_M | PG_A | PG_RW | PG_V; + + /* + * Initialize the page table page. + */ + pagezero((void *)&KPTmap[i386_btop(trunc_4mpage(va))]); + + /* + * Remove the mapping. + */ + if (workaround_erratum383) + pmap_update_pde(pmap, va, pde, newpde); + else + pmap_kenter_pde(va, newpde); + + /* + * Invalidate the recursive mapping of the page table page. + */ + pmap_invalidate_page(pmap, (vm_offset_t)vtopte(va)); +} + +/* * pmap_remove_pde: do the things to unmap a superpage in a process */ static void @@ -2814,8 +2852,7 @@ pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva, } } if (pmap == kernel_pmap) { - if (!pmap_demote_pde(pmap, pdq, sva)) - panic("pmap_remove_pde: failed demotion"); + pmap_remove_kernel_pde(pmap, pdq, sva); } else { mpte = pmap_lookup_pt_page(pmap, sva); if (mpte != NULL) { |