From 9439047657fe3a6f5ebcd81d5f8cf23c542f3b1c Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Thu, 1 Oct 2015 10:43:40 +0000 Subject: [PATCH] Use pmap_load more consistently. While here try to only load the data once when we reuse the same data. Obtained from: EuroBSDCon Devsummit Sponsored by: ABT Systems Ltd --- sys/arm64/arm64/pmap.c | 90 ++++++++++++++++++++++-------------------- 1 file changed, 48 insertions(+), 42 deletions(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index b558149b6917..004b4a7656af 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -243,6 +243,16 @@ static void _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free); static int pmap_unuse_l3(pmap_t, vm_offset_t, pd_entry_t, struct spglist *); +/* + * These load the old table data and store the new value. + * They need to be atomic as the System MMU may write to the table at + * the same time as the CPU. + */ +#define pmap_load_store(table, entry) atomic_swap_64(table, entry) +#define pmap_set(table, mask) atomic_set_64(table, mask) +#define pmap_load_clear(table) atomic_swap_64(table, 0) +#define pmap_load(table) (*table) + /********************/ /* Inline functions */ /********************/ @@ -277,7 +287,7 @@ pmap_l1_to_l2(pd_entry_t *l1, vm_offset_t va) { pd_entry_t *l2; - l2 = (pd_entry_t *)PHYS_TO_DMAP(*l1 & ~ATTR_MASK); + l2 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l1) & ~ATTR_MASK); return (&l2[pmap_l2_index(va)]); } @@ -287,7 +297,7 @@ pmap_l2(pmap_t pmap, vm_offset_t va) pd_entry_t *l1; l1 = pmap_l1(pmap, va); - if ((*l1 & ATTR_DESCR_MASK) != L1_TABLE) + if ((pmap_load(l1) & ATTR_DESCR_MASK) != L1_TABLE) return (NULL); return (pmap_l1_to_l2(l1, va)); @@ -298,7 +308,7 @@ pmap_l2_to_l3(pd_entry_t *l2, vm_offset_t va) { pt_entry_t *l3; - l3 = (pd_entry_t *)PHYS_TO_DMAP(*l2 & ~ATTR_MASK); + l3 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l2) & ~ATTR_MASK); return (&l3[pmap_l3_index(va)]); } @@ -308,7 +318,7 @@ pmap_l3(pmap_t pmap, vm_offset_t va) pd_entry_t *l2; l2 = pmap_l2(pmap, va); - if (l2 == NULL || (*l2 & ATTR_DESCR_MASK) != L2_TABLE) + if (l2 == NULL || (pmap_load(l2) & ATTR_DESCR_MASK) != L2_TABLE) return (NULL); return (pmap_l2_to_l3(l2, va)); @@ -326,19 +336,19 @@ pmap_get_tables(pmap_t pmap, vm_offset_t va, pd_entry_t **l1, pd_entry_t **l2, l1p = pmap_l1(pmap, va); *l1 = l1p; - if ((*l1p & ATTR_DESCR_MASK) == L1_BLOCK) { + if ((pmap_load(l1p) & ATTR_DESCR_MASK) == L1_BLOCK) { *l2 = NULL; *l3 = NULL; return (true); } - if ((*l1p & ATTR_DESCR_MASK) != L1_TABLE) + if ((pmap_load(l1p) & ATTR_DESCR_MASK) != L1_TABLE) return (false); l2p = pmap_l1_to_l2(l1p, va); *l2 = l2p; - if ((*l2p & ATTR_DESCR_MASK) == L2_BLOCK) { + if ((pmap_load(l2p) & ATTR_DESCR_MASK) == L2_BLOCK) { *l3 = NULL; return (true); } @@ -348,16 +358,6 @@ pmap_get_tables(pmap_t pmap, vm_offset_t va, pd_entry_t **l1, pd_entry_t **l2, return (true); } -/* - * These load the old table data and store the new value. - * They need to be atomic as the System MMU may write to the table at - * the same time as the CPU. - */ -#define pmap_load_store(table, entry) atomic_swap_64(table, entry) -#define pmap_set(table, mask) atomic_set_64(table, mask) -#define pmap_load_clear(table) atomic_swap_64(table, 0) -#define pmap_load(table) (*table) - static __inline int pmap_is_current(pmap_t pmap) { @@ -799,11 +799,11 @@ pmap_extract(pmap_t pmap, vm_offset_t va) */ l2p = pmap_l2(pmap, va); if (l2p != NULL) { - l2 = *l2p; + l2 = pmap_load(l2p); if ((l2 & ATTR_DESCR_MASK) == L2_TABLE) { l3p = pmap_l2_to_l3(l2p, va); if (l3p != NULL) { - l3 = *l3p; + l3 = pmap_load(l3p); if ((l3 & ATTR_DESCR_MASK) == L3_PAGE) pa = (l3 & ~ATTR_MASK) | @@ -852,23 +852,25 @@ pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot) vm_paddr_t pmap_kextract(vm_offset_t va) { - pd_entry_t *l2; + pd_entry_t *l2p, l2; pt_entry_t *l3; vm_paddr_t pa; if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) { pa = DMAP_TO_PHYS(va); } else { - l2 = pmap_l2(kernel_pmap, va); - if (l2 == NULL) + l2p = pmap_l2(kernel_pmap, va); + if (l2p == NULL) panic("pmap_kextract: No l2"); - if ((*l2 & ATTR_DESCR_MASK) == L2_BLOCK) - return ((*l2 & ~ATTR_MASK) | (va & L2_OFFSET)); + l2 = pmap_load(l2p); + if ((l2 & ATTR_DESCR_MASK) == L2_BLOCK) + return ((l2 & ~ATTR_MASK) | + (va & L2_OFFSET)); - l3 = pmap_l2_to_l3(l2, va); + l3 = pmap_l2_to_l3(l2p, va); if (l3 == NULL) panic("pmap_kextract: No l3..."); - pa = (*l3 & ~ATTR_MASK) | (va & PAGE_MASK); + pa = (pmap_load(l3) & ~ATTR_MASK) | (va & PAGE_MASK); } return (pa); } @@ -1242,11 +1244,11 @@ _pmap_alloc_l3(pmap_t pmap, vm_pindex_t ptepindex, struct rwlock **lockp) return (NULL); } } else { - pdpg = PHYS_TO_VM_PAGE(*l1 & ~ATTR_MASK); + pdpg = PHYS_TO_VM_PAGE(pmap_load(l1) & ~ATTR_MASK); pdpg->wire_count++; } - l2 = (pd_entry_t *)PHYS_TO_DMAP(*l1 & ~ATTR_MASK); + l2 = (pd_entry_t *)PHYS_TO_DMAP(pmap_load(l1) & ~ATTR_MASK); l2 = &l2[ptepindex & Ln_ADDR_MASK]; pmap_load_store(l2, VM_PAGE_TO_PHYS(m) | L2_TABLE); PTE_SYNC(l2); @@ -1738,7 +1740,7 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) if (l2 == NULL) continue; - l3_paddr = *l2; + l3_paddr = pmap_load(l2); /* * Weed out invalid mappings. @@ -1805,7 +1807,7 @@ pmap_remove_all(vm_page_t m) pv_entry_t pv; pmap_t pmap; pt_entry_t *l3, tl3; - pd_entry_t *l2; + pd_entry_t *l2, tl2; struct spglist free; KASSERT((m->oflags & VPO_UNMANAGED) == 0, @@ -1817,7 +1819,9 @@ pmap_remove_all(vm_page_t m) PMAP_LOCK(pmap); pmap_resident_count_dec(pmap, 1); l2 = pmap_l2(pmap, pv->pv_va); - KASSERT((*l2 & ATTR_DESCR_MASK) == L2_TABLE, + KASSERT(l2 != NULL, ("pmap_remove_all: no l2 table found")); + tl2 = pmap_load(l2); + KASSERT((tl2 & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_remove_all: found a table when expecting " "a block in %p's pv list", m)); l3 = pmap_l2_to_l3(l2, pv->pv_va); @@ -1837,7 +1841,7 @@ pmap_remove_all(vm_page_t m) */ if (pmap_page_dirty(tl3)) vm_page_dirty(m); - pmap_unuse_l3(pmap, pv->pv_va, *l2, &free); + pmap_unuse_l3(pmap, pv->pv_va, tl2, &free); TAILQ_REMOVE(&m->md.pv_list, pv, pv_next); m->md.pv_gen++; free_pv_entry(pmap, pv); @@ -1883,7 +1887,7 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) va_next = eva; l2 = pmap_l1_to_l2(l1, sva); - if (l2 == NULL || (*l2 & ATTR_DESCR_MASK) != L2_TABLE) + if (l2 == NULL || (pmap_load(l2) & ATTR_DESCR_MASK) != L2_TABLE) continue; if (va_next > eva) @@ -2345,7 +2349,7 @@ pmap_unwire(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) continue; if ((pmap_load(l3) & ATTR_SW_WIRED) == 0) panic("pmap_unwire: l3 %#jx is missing " - "ATTR_SW_WIRED", (uintmax_t)*l3); + "ATTR_SW_WIRED", (uintmax_t)pmap_load(l3)); /* * PG_W must be cleared atomically. Although the pmap @@ -2836,7 +2840,7 @@ pmap_remove_write(vm_page_t m) } l3 = pmap_l3(pmap, pv->pv_va); retry: - oldl3 = *l3; + oldl3 = pmap_load(l3); if ((oldl3 & ATTR_AP_RW_BIT) == ATTR_AP(ATTR_AP_RW)) { if (!atomic_cmpset_long(l3, oldl3, oldl3 | ATTR_AP(ATTR_AP_RO))) @@ -2879,7 +2883,7 @@ pmap_ts_referenced(vm_page_t m) pv_entry_t pv, pvf; pmap_t pmap; struct rwlock *lock; - pd_entry_t *l2; + pd_entry_t *l2p, l2; pt_entry_t *l3; vm_paddr_t pa; int cleared, md_gen, not_cleared; @@ -2912,12 +2916,14 @@ pmap_ts_referenced(vm_page_t m) goto retry; } } - l2 = pmap_l2(pmap, pv->pv_va); - KASSERT((*l2 & ATTR_DESCR_MASK) == L2_TABLE, + l2p = pmap_l2(pmap, pv->pv_va); + KASSERT(l2p != NULL, ("pmap_ts_referenced: no l2 table found")); + l2 = pmap_load(l2p); + KASSERT((l2 & ATTR_DESCR_MASK) == L2_TABLE, ("pmap_ts_referenced: found an invalid l2 table")); - l3 = pmap_l2_to_l3(l2, pv->pv_va); + l3 = pmap_l2_to_l3(l2p, pv->pv_va); if ((pmap_load(l3) & ATTR_AF) != 0) { - if (safe_to_clear_referenced(pmap, *l3)) { + if (safe_to_clear_referenced(pmap, pmap_load(l3))) { /* * TODO: We don't handle the access flag * at all. We need to be able to set it in @@ -2931,8 +2937,8 @@ pmap_ts_referenced(vm_page_t m) * them is wasted effort. We do the * hard work for unwired pages only. */ - pmap_remove_l3(pmap, l3, pv->pv_va, - *l2, &free, &lock); + pmap_remove_l3(pmap, l3, pv->pv_va, l2, + &free, &lock); pmap_invalidate_page(pmap, pv->pv_va); cleared++; if (pvf == pv)