git: 841cf52595b6 - main - arm64 pmap: Add ATTR_CONTIGUOUS support [Part 2]
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Tue, 09 Apr 2024 16:21:53 UTC
The branch main has been updated by alc:
URL: https://cgit.FreeBSD.org/src/commit/?id=841cf52595b6a6b98e266b63e54a7cf6fb6ca73e
commit 841cf52595b6a6b98e266b63e54a7cf6fb6ca73e
Author: Alan Cox <alc@FreeBSD.org>
AuthorDate: 2024-04-08 05:05:54 +0000
Commit: Alan Cox <alc@FreeBSD.org>
CommitDate: 2024-04-09 16:21:08 +0000
arm64 pmap: Add ATTR_CONTIGUOUS support [Part 2]
Create ATTR_CONTIGUOUS mappings in pmap_enter_object(). As a result,
when the base page size is 4 KB, the read-only data and text sections
of large (2 MB+) executables, e.g., clang, can be mapped using 64 KB
pages. Similarly, when the base page size is 16 KB, the read-only
data section of large executables can be mapped using 2 MB pages.
Rename pmap_enter_2mpage(). Given that we have grown support for 16 KB
base pages, we should no longer include page sizes that may vary, e.g.,
2mpage, in pmap function names. Requested by: andrew
Co-authored-by: Eliot Solomon <ehs3@rice.edu>
Differential Revision: https://reviews.freebsd.org/D44575
---
sys/arm64/arm64/pmap.c | 252 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 245 insertions(+), 7 deletions(-)
diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 258aa141653b..ea7ff18971e4 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -472,6 +472,8 @@ static vm_page_t pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va,
vm_page_t m, vm_prot_t prot, vm_page_t mpte, struct rwlock **lockp);
static int pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2,
u_int flags, vm_page_t m, struct rwlock **lockp);
+static int pmap_enter_l3c(pmap_t pmap, vm_offset_t va, pt_entry_t l3e, u_int flags,
+ vm_page_t m, vm_page_t *ml3p, struct rwlock **lockp);
static bool pmap_every_pte_zero(vm_paddr_t pa);
static int pmap_insert_pt_page(pmap_t pmap, vm_page_t mpte, bool promoted,
bool all_l3e_AF_set);
@@ -5177,13 +5179,13 @@ out:
}
/*
- * Tries to create a read- and/or execute-only 2MB page mapping. Returns
+ * Tries to create a read- and/or execute-only L2 page mapping. Returns
* KERN_SUCCESS if the mapping was created. Otherwise, returns an error
* value. See pmap_enter_l2() for the possible error values when "no sleep",
* "no replace", and "no reclaim" are specified.
*/
static int
-pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
+pmap_enter_l2_rx(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
struct rwlock **lockp)
{
pd_entry_t new_l2;
@@ -5233,13 +5235,13 @@ pmap_every_pte_zero(vm_paddr_t pa)
}
/*
- * Tries to create the specified 2MB page mapping. Returns KERN_SUCCESS if
+ * Tries to create the specified L2 page mapping. Returns KERN_SUCCESS if
* the mapping was created, and one of KERN_FAILURE, KERN_NO_SPACE, or
* KERN_RESOURCE_SHORTAGE otherwise. Returns KERN_FAILURE if
- * PMAP_ENTER_NOREPLACE was specified and a 4KB page mapping already exists
- * within the 2MB virtual address range starting at the specified virtual
+ * PMAP_ENTER_NOREPLACE was specified and a base page mapping already exists
+ * within the L2 virtual address range starting at the specified virtual
* address. Returns KERN_NO_SPACE if PMAP_ENTER_NOREPLACE was specified and a
- * 2MB page mapping already exists at the specified virtual address. Returns
+ * L2 page mapping already exists at the specified virtual address. Returns
* KERN_RESOURCE_SHORTAGE if either (1) PMAP_ENTER_NOSLEEP was specified and a
* page table page allocation failed or (2) PMAP_ENTER_NORECLAIM was specified
* and a PV entry allocation failed.
@@ -5405,6 +5407,235 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags,
return (KERN_SUCCESS);
}
+/*
+ * Tries to create a read- and/or execute-only L3C page mapping. Returns
+ * KERN_SUCCESS if the mapping was created. Otherwise, returns an error
+ * value.
+ */
+static int
+pmap_enter_l3c_rx(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_page_t *ml3p,
+ vm_prot_t prot, struct rwlock **lockp)
+{
+ pt_entry_t l3e;
+
+ PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+ PMAP_ASSERT_STAGE1(pmap);
+ KASSERT(ADDR_IS_CANONICAL(va),
+ ("%s: Address not in canonical form: %lx", __func__, va));
+
+ l3e = PHYS_TO_PTE(VM_PAGE_TO_PHYS(m)) | ATTR_DEFAULT |
+ ATTR_S1_IDX(m->md.pv_memattr) | ATTR_S1_AP(ATTR_S1_AP_RO) |
+ ATTR_CONTIGUOUS | L3_PAGE;
+ l3e |= pmap_pte_bti(pmap, va);
+ if ((m->oflags & VPO_UNMANAGED) == 0) {
+ l3e |= ATTR_SW_MANAGED;
+ l3e &= ~ATTR_AF;
+ }
+ if ((prot & VM_PROT_EXECUTE) == 0 ||
+ m->md.pv_memattr == VM_MEMATTR_DEVICE)
+ l3e |= ATTR_S1_XN;
+ if (!ADDR_IS_KERNEL(va))
+ l3e |= ATTR_S1_AP(ATTR_S1_AP_USER) | ATTR_S1_PXN;
+ else
+ l3e |= ATTR_S1_UXN;
+ if (pmap != kernel_pmap)
+ l3e |= ATTR_S1_nG;
+ return (pmap_enter_l3c(pmap, va, l3e, PMAP_ENTER_NOSLEEP |
+ PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, m, ml3p, lockp));
+}
+
+static int
+pmap_enter_l3c(pmap_t pmap, vm_offset_t va, pt_entry_t l3e, u_int flags,
+ vm_page_t m, vm_page_t *ml3p, struct rwlock **lockp)
+{
+ pd_entry_t *l2p, *pde;
+ pt_entry_t *l3p, *tl3p;
+ vm_page_t mt;
+ vm_paddr_t pa;
+ vm_pindex_t l2pindex;
+ int lvl;
+
+ PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+ KASSERT((va & L3C_OFFSET) == 0,
+ ("pmap_enter_l3c: va is not aligned"));
+ KASSERT(!VA_IS_CLEANMAP(va) || (l3e & ATTR_SW_MANAGED) == 0,
+ ("pmap_enter_l3c: managed mapping within the clean submap"));
+
+ /*
+ * If the L3 PTP is not resident, we attempt to create it here.
+ */
+ if (!ADDR_IS_KERNEL(va)) {
+ /*
+ * Were we given the correct L3 PTP? If so, we can simply
+ * increment its ref count.
+ */
+ l2pindex = pmap_l2_pindex(va);
+ if (*ml3p != NULL && (*ml3p)->pindex == l2pindex) {
+ (*ml3p)->ref_count += L3C_ENTRIES;
+ } else {
+retry:
+ /*
+ * Get the L2 entry.
+ */
+ pde = pmap_pde(pmap, va, &lvl);
+
+ /*
+ * If the L2 entry is a superpage, we either abort or
+ * demote depending on the given flags.
+ */
+ if (lvl == 1) {
+ l2p = pmap_l1_to_l2(pde, va);
+ if ((pmap_load(l2p) & ATTR_DESCR_MASK) ==
+ L2_BLOCK) {
+ if ((flags & PMAP_ENTER_NOREPLACE) != 0)
+ return (KERN_FAILURE);
+ l3p = pmap_demote_l2_locked(pmap, l2p,
+ va, lockp);
+ if (l3p != NULL) {
+ *ml3p = PHYS_TO_VM_PAGE(
+ PTE_TO_PHYS(pmap_load(
+ l2p)));
+ (*ml3p)->ref_count +=
+ L3C_ENTRIES;
+ goto have_l3p;
+ }
+ }
+ /* We need to allocate an L3 PTP. */
+ }
+
+ /*
+ * If the L3 PTP is mapped, we just increment its ref
+ * count. Otherwise, we attempt to allocate it.
+ */
+ if (lvl == 2 && pmap_load(pde) != 0) {
+ *ml3p = PHYS_TO_VM_PAGE(PTE_TO_PHYS(
+ pmap_load(pde)));
+ (*ml3p)->ref_count += L3C_ENTRIES;
+ } else {
+ *ml3p = _pmap_alloc_l3(pmap, l2pindex, (flags &
+ PMAP_ENTER_NOSLEEP) != 0 ? NULL : lockp);
+ if (*ml3p == NULL) {
+ if ((flags & PMAP_ENTER_NOSLEEP) != 0)
+ return (KERN_FAILURE);
+
+ /*
+ * The page table may have changed
+ * while we slept.
+ */
+ goto retry;
+ }
+ (*ml3p)->ref_count += L3C_ENTRIES - 1;
+ }
+ }
+ l3p = (pt_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(*ml3p));
+ } else {
+ *ml3p = NULL;
+
+ /*
+ * If the L2 entry is a superpage, we either abort or demote
+ * depending on the given flags.
+ */
+ pde = pmap_pde(kernel_pmap, va, &lvl);
+ if (lvl == 1) {
+ l2p = pmap_l1_to_l2(pde, va);
+ KASSERT((pmap_load(l2p) & ATTR_DESCR_MASK) == L2_BLOCK,
+ ("pmap_enter_l3c: missing L2 block"));
+ if ((flags & PMAP_ENTER_NOREPLACE) != 0)
+ return (KERN_FAILURE);
+ l3p = pmap_demote_l2_locked(pmap, l2p, va, lockp);
+ } else {
+ KASSERT(lvl == 2,
+ ("pmap_enter_l3c: Invalid level %d", lvl));
+ l3p = (pt_entry_t *)PHYS_TO_DMAP(PTE_TO_PHYS(
+ pmap_load(pde)));
+ }
+ }
+have_l3p:
+ l3p = &l3p[pmap_l3_index(va)];
+
+ /*
+ * If bti is not the same for the whole L3C range, return failure
+ * and let vm_fault() cope. Check after L3 allocation, since
+ * it could sleep.
+ */
+ if (!pmap_bti_same(pmap, va, va + L3C_SIZE)) {
+ KASSERT(*ml3p != NULL, ("pmap_enter_l3c: missing L3 PTP"));
+ (*ml3p)->ref_count -= L3C_ENTRIES - 1;
+ pmap_abort_ptp(pmap, va, *ml3p);
+ *ml3p = NULL;
+ return (KERN_PROTECTION_FAILURE);
+ }
+
+ /*
+ * If there are existing mappings, either abort or remove them.
+ */
+ if ((flags & PMAP_ENTER_NOREPLACE) != 0) {
+ for (tl3p = l3p; tl3p < &l3p[L3C_ENTRIES]; tl3p++) {
+ if (pmap_load(tl3p) != 0) {
+ if (*ml3p != NULL)
+ (*ml3p)->ref_count -= L3C_ENTRIES;
+ return (KERN_FAILURE);
+ }
+ }
+ } else {
+ /*
+ * Because we increment the L3 page's reference count above,
+ * it is guaranteed not to be freed here and we can pass NULL
+ * instead of a valid free list.
+ */
+ pmap_remove_l3_range(pmap, pmap_load(pmap_l2(pmap, va)), va,
+ va + L3C_SIZE, NULL, lockp);
+ }
+
+ /*
+ * Enter on the PV list if part of our managed memory.
+ */
+ if ((l3e & ATTR_SW_MANAGED) != 0) {
+ if (!pmap_pv_insert_l3c(pmap, va, m, lockp)) {
+ if (*ml3p != NULL) {
+ (*ml3p)->ref_count -= L3C_ENTRIES - 1;
+ pmap_abort_ptp(pmap, va, *ml3p);
+ *ml3p = NULL;
+ }
+ return (KERN_RESOURCE_SHORTAGE);
+ }
+ if ((l3e & ATTR_SW_DBM) != 0)
+ for (mt = m; mt < &m[L3C_ENTRIES]; mt++)
+ vm_page_aflag_set(mt, PGA_WRITEABLE);
+ }
+
+ /*
+ * Increment counters.
+ */
+ if ((l3e & ATTR_SW_WIRED) != 0)
+ pmap->pm_stats.wired_count += L3C_ENTRIES;
+ pmap_resident_count_inc(pmap, L3C_ENTRIES);
+
+ pa = VM_PAGE_TO_PHYS(m);
+ KASSERT((pa & L3C_OFFSET) == 0, ("pmap_enter_l3c: pa is not aligned"));
+
+ /*
+ * Sync the icache before the mapping is stored.
+ */
+ if ((l3e & ATTR_S1_XN) == 0 && pmap != kernel_pmap &&
+ m->md.pv_memattr == VM_MEMATTR_WRITE_BACK)
+ cpu_icache_sync_range((void *)PHYS_TO_DMAP(pa), L3C_SIZE);
+
+ /*
+ * Map the superpage.
+ */
+ for (tl3p = l3p; tl3p < &l3p[L3C_ENTRIES]; tl3p++) {
+ pmap_store(tl3p, l3e);
+ l3e += L3_SIZE;
+ }
+ dsb(ishst);
+
+ atomic_add_long(&pmap_l3c_mappings, 1);
+ CTR2(KTR_PMAP, "pmap_enter_l3c: success for va %#lx in pmap %p",
+ va, pmap);
+ return (KERN_SUCCESS);
+}
+
/*
* Maps a sequence of resident pages belonging to the same object.
* The sequence begins with the given page m_start. This page is
@@ -5438,9 +5669,16 @@ pmap_enter_object(pmap_t pmap, vm_offset_t start, vm_offset_t end,
va = start + ptoa(diff);
if ((va & L2_OFFSET) == 0 && va + L2_SIZE <= end &&
m->psind == 1 && pmap_ps_enabled(pmap) &&
- ((rv = pmap_enter_2mpage(pmap, va, m, prot, &lock)) ==
+ ((rv = pmap_enter_l2_rx(pmap, va, m, prot, &lock)) ==
KERN_SUCCESS || rv == KERN_NO_SPACE))
m = &m[L2_SIZE / PAGE_SIZE - 1];
+ else if ((va & L3C_OFFSET) == 0 && va + L3C_SIZE <= end &&
+ (VM_PAGE_TO_PHYS(m) & L3C_OFFSET) == 0 &&
+ vm_reserv_is_populated(m, L3C_ENTRIES) &&
+ pmap_ps_enabled(pmap) &&
+ ((rv = pmap_enter_l3c_rx(pmap, va, m, &mpte, prot,
+ &lock)) == KERN_SUCCESS || rv == KERN_NO_SPACE))
+ m = &m[L3C_ENTRIES - 1];
else
mpte = pmap_enter_quick_locked(pmap, va, m, prot, mpte,
&lock);