Date: Mon, 22 Apr 2013 18:38:29 +0000 (UTC) From: "Cherry G. Mathew" <cherry@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r249773 - projects/amd64_xen_pv/sys/amd64/xen Message-ID: <201304221838.r3MIcTHU055114@svn.freebsd.org>
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Author: cherry Date: Mon Apr 22 18:38:29 2013 New Revision: 249773 URL: http://svnweb.freebsd.org/changeset/base/249773 Log: Add pmap_zero_page_area() and pmap_remove_pages() Approved by: gibbs(implicit) Modified: projects/amd64_xen_pv/sys/amd64/xen/pmap.c Modified: projects/amd64_xen_pv/sys/amd64/xen/pmap.c ============================================================================== --- projects/amd64_xen_pv/sys/amd64/xen/pmap.c Mon Apr 22 18:35:04 2013 (r249772) +++ projects/amd64_xen_pv/sys/amd64/xen/pmap.c Mon Apr 22 18:38:29 2013 (r249773) @@ -1450,6 +1450,8 @@ pv_remove(pmap_t pmap, vm_offset_t va, v mmu_map_t tptr = tbuf; + KASSERT(m != NULL, ("%s: passed NULL page!", __func__)); + PMAP_LOCK(pmap); pte = pmap_vtopte_inspect(pmap, va, &tptr); @@ -1929,10 +1931,23 @@ pmap_zero_page(vm_page_t m) pmap_kremove(zerova); } +/* + * pmap_zero_page_area zeros the specified hardware page by mapping + * the page into KVM and using bzero to clear its contents. + * + * off and size may not cover an area beyond a single hardware page. + */ + void pmap_zero_page_area(vm_page_t m, int off, int size) { - KASSERT(0, ("XXX: %s: TODO\n", __func__)); + if (off == 0 && size == PAGE_SIZE) + pmap_zero_page(m); + else { + pmap_kenter(zerova, VM_PAGE_TO_PHYS(m)); + bzero((char *)zerova + off, size); + pmap_kremove(zerova); + } } void @@ -1972,10 +1987,88 @@ pmap_activate(struct thread *td) critical_exit(); } +/* This is subtly different from pv_remove(). We don't defer removal + * of pv entries until the end. + * XXX: the pmap_pv.[ch] needs review for performance and use cases. + */ +static bool +pv_map_remove(pmap_t pmap, vm_offset_t va, vm_page_t m) +{ + pt_entry_t *pte, tpte; + + char tbuf[tsz]; /* Safe to do this on the stack since tsz is + * effectively const. + */ + + mmu_map_t tptr = tbuf; + + PMAP_LOCK_ASSERT(pmap, MA_OWNED); + + pte = pmap_vtopte_inspect(pmap, va, &tptr); + + KASSERT(pte != NULL, ("pte has no backing page tables!")); + + tpte = pte_load(pte); + + if ((tpte & PG_V) == 0) { + panic("bad pte va %lx pte %lx", va, tpte); + } + + /* + * We cannot remove wired pages from a process' mapping at this time + */ + if (tpte & PG_W) { + return false; /* Continue iteration */ + } + + if (m == NULL) { + m = MACH_TO_VM_PAGE(tpte & PG_FRAME); + } + + PT_CLEAR_VA(pte, TRUE); + + /* + * Update the vm_page_t clean/reference bits. + */ + if ((tpte & (PG_M | PG_RW)) == (PG_M | PG_RW)) { + vm_page_dirty(m); + } + + /* XXX: Tell mmu_xxx about backing page */ + pmap_vtopte_release(pmap, va, &tptr); + + pmap_resident_count_dec(pmap, 1); + + if (!pmap_free_pv_entry(pmap, va, m)) { /* XXX: This is very slow */ + panic("%s: pv 0x%lx: 0x%lx, unknown on managed page!", + __func__, VM_PAGE_TO_PHYS(m), va); + } + + return false; +} + +/* + * Remove all pages from specified address space + * this aids process exit speeds. Also, this code + * is special cased for current process only, but + * can have the more generic (and slightly slower) + * mode enabled. This is much faster than pmap_remove + * in the case of running down an entire address space. + */ + void pmap_remove_pages(pmap_t pmap) { - KASSERT(0, ("XXX: %s: TODO\n", __func__)); + if (pmap != PCPU_GET(curpmap)) { + printf("warning: pmap_remove_pages called with non-current pmap\n"); + return; + } + PMAP_LOCK(pmap); + + pmap_pv_iterate_map(pmap, pv_map_remove); + + pmap_invalidate_all(pmap); + PMAP_UNLOCK(pmap); } void @@ -2093,6 +2186,7 @@ pv_remove_write(pmap_t pmap, vm_offset_t mmu_map_t tptr = tbuf; + KASSERT(m != NULL, ("%s: passed NULL page!", __func__)); PMAP_LOCK(pmap); pte = pmap_vtopte_inspect(pmap, va, &tptr);
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