Date: Mon, 5 Aug 2013 00:28:03 +0000 (UTC) From: Jeff Roberson <jeff@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r253949 - in head/sys: amd64/amd64 i386/i386 Message-ID: <201308050028.r750S3fY056021@svn.freebsd.org>
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Author: jeff Date: Mon Aug 5 00:28:03 2013 New Revision: 253949 URL: http://svnweb.freebsd.org/changeset/base/253949 Log: - 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 Modified: head/sys/amd64/amd64/pmap.c head/sys/i386/i386/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Sun Aug 4 23:45:04 2013 (r253948) +++ head/sys/amd64/amd64/pmap.c Mon Aug 5 00:28:03 2013 (r253949) @@ -2795,6 +2795,44 @@ pmap_demote_pde_locked(pmap_t pmap, pd_e } /* + * pmap_remove_kernel_pde: Remove a kernel superpage mapping. + */ +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 *)PHYS_TO_DMAP(mptepa)); + + /* + * Demote the mapping. + */ + if (workaround_erratum383) + pmap_update_pde(pmap, va, pde, newpde); + else + pde_store(pde, newpde); + + /* + * Invalidate a stale 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 int @@ -2837,8 +2875,7 @@ pmap_remove_pde(pmap_t pmap, pd_entry_t } } if (pmap == kernel_pmap) { - if (!pmap_demote_pde_locked(pmap, pdq, sva, lockp)) - panic("pmap_remove_pde: failed demotion"); + pmap_remove_kernel_pde(pmap, pdq, sva); } else { mpte = pmap_lookup_pt_page(pmap, sva); if (mpte != NULL) { Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Sun Aug 4 23:45:04 2013 (r253948) +++ head/sys/i386/i386/pmap.c Mon Aug 5 00:28:03 2013 (r253949) @@ -2773,6 +2773,44 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t } /* + * 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 } } 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) {
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