git: 4ccd6c137f5b - main - arm64: Implement final level only TLB invalidations
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Date: Mon, 03 Jan 2022 19:18:48 UTC
The branch main has been updated by alc:
URL: https://cgit.FreeBSD.org/src/commit/?id=4ccd6c137f5b53361efe54b78b815c7902258572
commit 4ccd6c137f5b53361efe54b78b815c7902258572
Author: Alan Cox <alc@FreeBSD.org>
AuthorDate: 2021-12-29 07:50:05 +0000
Commit: Alan Cox <alc@FreeBSD.org>
CommitDate: 2022-01-03 19:14:18 +0000
arm64: Implement final level only TLB invalidations
A feature of arm64's instruction for TLB invalidation is the ability
to determine whether cached intermediate entries, i.e., L{0,1,2}_TABLE
entries, are invalidated in addition to the final entry, e.g., an
L3_PAGE entry.
Update pmap_invalidate_{page,range}() to support both types of
invalidation, allowing the caller to determine which type of
invalidation is performed.
Update the callers to request the appropriate type of invalidation.
Eliminate redundant TLB invalidations in pmap_abort_ptp() and
pmap_remove_l3_range().
Add a comment to pmap_invalidate_all() making clear that it always
invalidates entries at all levels.
As expected, these changes result in a tiny yet measurable
performance improvement.
Reviewed by: kib, markj
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D33705
---
sys/arm64/arm64/pmap.c | 144 +++++++++++++++++++++++++++++++------------------
1 file changed, 92 insertions(+), 52 deletions(-)
diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 68164708dce9..130d4a255286 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -1223,10 +1223,35 @@ SYSCTL_ULONG(_vm_pmap_l2, OID_AUTO, promotions, CTLFLAG_RD,
&pmap_l2_promotions, 0, "2MB page promotions");
/*
- * Invalidate a single TLB entry.
+ * If the given value for "final_only" is false, then any cached intermediate-
+ * level entries, i.e., L{0,1,2}_TABLE entries, are invalidated in addition to
+ * any cached final-level entry, i.e., either an L{1,2}_BLOCK or L3_PAGE entry.
+ * Otherwise, just the cached final-level entry is invalidated.
*/
static __inline void
-pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
+pmap_invalidate_kernel(uint64_t r, bool final_only)
+{
+ if (final_only)
+ __asm __volatile("tlbi vaale1is, %0" : : "r" (r));
+ else
+ __asm __volatile("tlbi vaae1is, %0" : : "r" (r));
+}
+
+static __inline void
+pmap_invalidate_user(uint64_t r, bool final_only)
+{
+ if (final_only)
+ __asm __volatile("tlbi vale1is, %0" : : "r" (r));
+ else
+ __asm __volatile("tlbi vae1is, %0" : : "r" (r));
+}
+
+/*
+ * Invalidates any cached final- and optionally intermediate-level TLB entries
+ * for the specified virtual address in the given virtual address space.
+ */
+static __inline void
+pmap_invalidate_page(pmap_t pmap, vm_offset_t va, bool final_only)
{
uint64_t r;
@@ -1235,17 +1260,22 @@ pmap_invalidate_page(pmap_t pmap, vm_offset_t va)
dsb(ishst);
if (pmap == kernel_pmap) {
r = atop(va);
- __asm __volatile("tlbi vaae1is, %0" : : "r" (r));
+ pmap_invalidate_kernel(r, final_only);
} else {
r = ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie)) | atop(va);
- __asm __volatile("tlbi vae1is, %0" : : "r" (r));
+ pmap_invalidate_user(r, final_only);
}
dsb(ish);
isb();
}
+/*
+ * Invalidates any cached final- and optionally intermediate-level TLB entries
+ * for the specified virtual address range in the given virtual address space.
+ */
static __inline void
-pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
+pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva,
+ bool final_only)
{
uint64_t end, r, start;
@@ -1256,18 +1286,22 @@ pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
start = atop(sva);
end = atop(eva);
for (r = start; r < end; r++)
- __asm __volatile("tlbi vaae1is, %0" : : "r" (r));
+ pmap_invalidate_kernel(r, final_only);
} else {
start = end = ASID_TO_OPERAND(COOKIE_TO_ASID(pmap->pm_cookie));
start |= atop(sva);
end |= atop(eva);
for (r = start; r < end; r++)
- __asm __volatile("tlbi vae1is, %0" : : "r" (r));
+ pmap_invalidate_user(r, final_only);
}
dsb(ish);
isb();
}
+/*
+ * Invalidates all cached intermediate- and final-level TLB entries for the
+ * given virtual address space.
+ */
static __inline void
pmap_invalidate_all(pmap_t pmap)
{
@@ -1513,7 +1547,7 @@ pmap_kenter(vm_offset_t sva, vm_size_t size, vm_paddr_t pa, int mode)
pa += PAGE_SIZE;
size -= PAGE_SIZE;
}
- pmap_invalidate_range(kernel_pmap, sva, va);
+ pmap_invalidate_range(kernel_pmap, sva, va, true);
}
void
@@ -1533,7 +1567,7 @@ pmap_kremove(vm_offset_t va)
pte = pmap_pte_exists(kernel_pmap, va, 3, __func__);
pmap_clear(pte);
- pmap_invalidate_page(kernel_pmap, va);
+ pmap_invalidate_page(kernel_pmap, va, true);
}
void
@@ -1555,7 +1589,7 @@ pmap_kremove_device(vm_offset_t sva, vm_size_t size)
va += PAGE_SIZE;
size -= PAGE_SIZE;
}
- pmap_invalidate_range(kernel_pmap, sva, va);
+ pmap_invalidate_range(kernel_pmap, sva, va, true);
}
/*
@@ -1611,7 +1645,7 @@ pmap_qenter(vm_offset_t sva, vm_page_t *ma, int count)
va += L3_SIZE;
}
- pmap_invalidate_range(kernel_pmap, sva, va);
+ pmap_invalidate_range(kernel_pmap, sva, va, true);
}
/*
@@ -1637,7 +1671,7 @@ pmap_qremove(vm_offset_t sva, int count)
va += PAGE_SIZE;
}
- pmap_invalidate_range(kernel_pmap, sva, va);
+ pmap_invalidate_range(kernel_pmap, sva, va, true);
}
/***************************************************
@@ -1725,7 +1759,7 @@ _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free)
l1pg = PHYS_TO_VM_PAGE(tl0 & ~ATTR_MASK);
pmap_unwire_l3(pmap, va, l1pg, free);
}
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, false);
/*
* Put page on a list so that it is released after
@@ -1763,17 +1797,8 @@ pmap_abort_ptp(pmap_t pmap, vm_offset_t va, vm_page_t mpte)
struct spglist free;
SLIST_INIT(&free);
- if (pmap_unwire_l3(pmap, va, mpte, &free)) {
- /*
- * Although "va" was never mapped, the TLB could nonetheless
- * have intermediate entries that refer to the freed page
- * table pages. Invalidate those entries.
- *
- * XXX redundant invalidation (See _pmap_unwire_l3().)
- */
- pmap_invalidate_page(pmap, va);
+ if (pmap_unwire_l3(pmap, va, mpte, &free))
vm_page_free_pages_toq(&free, true);
- }
}
void
@@ -2417,7 +2442,7 @@ reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp)
if (pmap_pte_dirty(pmap, tpte))
vm_page_dirty(m);
if ((tpte & ATTR_AF) != 0) {
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
vm_page_aflag_set(m, PGA_REFERENCED);
}
CHANGE_PV_LIST_LOCK_TO_VM_PAGE(lockp, m);
@@ -2898,7 +2923,7 @@ pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
* Since a promotion must break the 4KB page mappings before making
* the 2MB page mapping, a pmap_invalidate_page() suffices.
*/
- pmap_invalidate_page(pmap, sva);
+ pmap_invalidate_page(pmap, sva, true);
if (old_l2 & ATTR_SW_WIRED)
pmap->pm_stats.wired_count -= L2_SIZE / PAGE_SIZE;
@@ -2948,7 +2973,7 @@ pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t va,
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
old_l3 = pmap_load_clear(l3);
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
if (old_l3 & ATTR_SW_WIRED)
pmap->pm_stats.wired_count -= 1;
pmap_resident_count_dec(pmap, 1);
@@ -2997,7 +3022,7 @@ pmap_remove_l3_range(pmap_t pmap, pd_entry_t l2e, vm_offset_t sva,
for (l3 = pmap_l2_to_l3(&l2e, sva); sva != eva; l3++, sva += L3_SIZE) {
if (!pmap_l3_valid(pmap_load(l3))) {
if (va != eva) {
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva, true);
va = eva;
}
continue;
@@ -3025,7 +3050,7 @@ pmap_remove_l3_range(pmap_t pmap, pd_entry_t l2e, vm_offset_t sva,
*/
if (va != eva) {
pmap_invalidate_range(pmap, va,
- sva);
+ sva, true);
va = eva;
}
rw_wunlock(*lockp);
@@ -3041,15 +3066,21 @@ pmap_remove_l3_range(pmap_t pmap, pd_entry_t l2e, vm_offset_t sva,
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
}
- if (va == eva)
- va = sva;
if (l3pg != NULL && pmap_unwire_l3(pmap, sva, l3pg, free)) {
- sva += L3_SIZE;
+ /*
+ * _pmap_unwire_l3() has already invalidated the TLB
+ * entries at all levels for "sva". So, we need not
+ * perform "sva += L3_SIZE;" here. Moreover, we need
+ * not perform "va = sva;" if "sva" is at the start
+ * of a new valid range consisting of a single page.
+ */
break;
}
+ if (va == eva)
+ va = sva;
}
if (va != eva)
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva, true);
}
/*
@@ -3104,7 +3135,7 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
MPASS(pmap != kernel_pmap);
MPASS((pmap_load(l1) & ATTR_SW_MANAGED) == 0);
pmap_clear(l1);
- pmap_invalidate_page(pmap, sva);
+ pmap_invalidate_page(pmap, sva, true);
pmap_resident_count_dec(pmap, L1_SIZE / PAGE_SIZE);
pmap_unuse_pt(pmap, sva, pmap_load(l0), &free);
continue;
@@ -3235,7 +3266,7 @@ retry:
if (tpte & ATTR_SW_WIRED)
pmap->pm_stats.wired_count--;
if ((tpte & ATTR_AF) != 0) {
- pmap_invalidate_page(pmap, pv->pv_va);
+ pmap_invalidate_page(pmap, pv->pv_va, true);
vm_page_aflag_set(m, PGA_REFERENCED);
}
@@ -3300,7 +3331,7 @@ pmap_protect_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva, pt_entry_t mask,
* Since a promotion must break the 4KB page mappings before making
* the 2MB page mapping, a pmap_invalidate_page() suffices.
*/
- pmap_invalidate_page(pmap, sva);
+ pmap_invalidate_page(pmap, sva, true);
}
/*
@@ -3357,7 +3388,7 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
MPASS((pmap_load(l1) & ATTR_SW_MANAGED) == 0);
if ((pmap_load(l1) & mask) != nbits) {
pmap_store(l1, (pmap_load(l1) & ~mask) | nbits);
- pmap_invalidate_page(pmap, sva);
+ pmap_invalidate_page(pmap, sva, true);
}
continue;
}
@@ -3398,7 +3429,8 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
*/
if (!pmap_l3_valid(l3) || (l3 & mask) == nbits) {
if (va != va_next) {
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva,
+ true);
va = va_next;
}
continue;
@@ -3421,7 +3453,7 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
va = sva;
}
if (va != va_next)
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva, true);
}
PMAP_UNLOCK(pmap);
}
@@ -3483,7 +3515,13 @@ pmap_update_entry(pmap_t pmap, pd_entry_t *pte, pd_entry_t newpte,
* lookup the physical address.
*/
pmap_clear_bits(pte, ATTR_DESCR_VALID);
- pmap_invalidate_range(pmap, va, va + size);
+
+ /*
+ * When promoting, the L{1,2}_TABLE entry that is being replaced might
+ * be cached, so we invalidate intermediate entries as well as final
+ * entries.
+ */
+ pmap_invalidate_range(pmap, va, va + size, false);
/* Create the new mapping */
pmap_store(pte, newpte);
@@ -3937,7 +3975,7 @@ havel3:
if (pmap_pte_dirty(pmap, orig_l3))
vm_page_dirty(om);
if ((orig_l3 & ATTR_AF) != 0) {
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
vm_page_aflag_set(om, PGA_REFERENCED);
}
CHANGE_PV_LIST_LOCK_TO_PHYS(&lock, opa);
@@ -3952,7 +3990,7 @@ havel3:
} else {
KASSERT((orig_l3 & ATTR_AF) != 0,
("pmap_enter: unmanaged mapping lacks ATTR_AF"));
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
}
orig_l3 = 0;
} else {
@@ -4010,7 +4048,7 @@ validate:
if ((orig_l3 & ~ATTR_AF) != (new_l3 & ~ATTR_AF)) {
/* same PA, different attributes */
orig_l3 = pmap_load_store(l3, new_l3);
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
if ((orig_l3 & ATTR_SW_MANAGED) != 0 &&
pmap_pte_dirty(pmap, orig_l3))
vm_page_dirty(m);
@@ -4179,13 +4217,15 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags,
* Both pmap_remove_l2() and pmap_remove_l3_range()
* will leave the kernel page table page zero filled.
* Nonetheless, the TLB could have an intermediate
- * entry for the kernel page table page.
+ * entry for the kernel page table page, so request
+ * an invalidation at all levels after clearing
+ * the L2_TABLE entry.
*/
mt = PHYS_TO_VM_PAGE(pmap_load(l2) & ~ATTR_MASK);
if (pmap_insert_pt_page(pmap, mt, false))
panic("pmap_enter_l2: trie insert failed");
pmap_clear(l2);
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, false);
}
}
@@ -5358,7 +5398,7 @@ retry:
if ((oldpte & ATTR_S1_AP_RW_BIT) ==
ATTR_S1_AP(ATTR_S1_AP_RW))
vm_page_dirty(m);
- pmap_invalidate_page(pmap, pv->pv_va);
+ pmap_invalidate_page(pmap, pv->pv_va, true);
}
PMAP_UNLOCK(pmap);
}
@@ -5456,7 +5496,7 @@ retry:
(uintptr_t)pmap) & (Ln_ENTRIES - 1)) == 0 &&
(tpte & ATTR_SW_WIRED) == 0) {
pmap_clear_bits(pte, ATTR_AF);
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
cleared++;
} else
not_cleared++;
@@ -5497,7 +5537,7 @@ small_mappings:
if ((tpte & ATTR_AF) != 0) {
if ((tpte & ATTR_SW_WIRED) == 0) {
pmap_clear_bits(pte, ATTR_AF);
- pmap_invalidate_page(pmap, pv->pv_va);
+ pmap_invalidate_page(pmap, pv->pv_va, true);
cleared++;
} else
not_cleared++;
@@ -5640,12 +5680,12 @@ pmap_advise(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, int advice)
continue;
maybe_invlrng:
if (va != va_next) {
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva, true);
va = va_next;
}
}
if (va != va_next)
- pmap_invalidate_range(pmap, va, sva);
+ pmap_invalidate_range(pmap, va, sva, true);
}
PMAP_UNLOCK(pmap);
}
@@ -5706,7 +5746,7 @@ restart:
(oldl3 & ~ATTR_SW_DBM) | ATTR_S1_AP(ATTR_S1_AP_RO)))
cpu_spinwait();
vm_page_dirty(m);
- pmap_invalidate_page(pmap, va);
+ pmap_invalidate_page(pmap, va, true);
}
PMAP_UNLOCK(pmap);
}
@@ -5729,7 +5769,7 @@ restart:
oldl3 = pmap_load(l3);
if ((oldl3 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == ATTR_SW_DBM){
pmap_set_bits(l3, ATTR_S1_AP(ATTR_S1_AP_RO));
- pmap_invalidate_page(pmap, pv->pv_va);
+ pmap_invalidate_page(pmap, pv->pv_va, true);
}
PMAP_UNLOCK(pmap);
}
@@ -6825,7 +6865,7 @@ pmap_fault(pmap_t pmap, uint64_t esr, uint64_t far)
if ((pte & ATTR_S1_AP_RW_BIT) ==
ATTR_S1_AP(ATTR_S1_AP_RO)) {
pmap_clear_bits(ptep, ATTR_S1_AP_RW_BIT);
- pmap_invalidate_page(pmap, far);
+ pmap_invalidate_page(pmap, far, true);
}
rv = KERN_SUCCESS;
}