git: 3c4f46b0d57b - main - riscv: Port improvements from arm64/amd64 pmaps, part 2

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=3c4f46b0d57b76d304f8a94862c6ba9be0273565

commit 3c4f46b0d57b76d304f8a94862c6ba9be0273565
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2023-11-02 18:33:55 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2023-11-02 18:33:55 +0000

    riscv: Port improvements from arm64/amd64 pmaps, part 2
    
    - Give pmap_promote_l2() a return value indicating whether or not
      promotion succeeded.
    - Check pmap_ps_enabled() in pmap_promote_l2() rather than making
      callers do it.
    - Annotate superpages_enabled with __read_frequently.
    
    Reviewed by:    kib
    MFC after:      1 month
    Differential Revision:  https://reviews.freebsd.org/D42289
---
 sys/riscv/riscv/pmap.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/sys/riscv/riscv/pmap.c b/sys/riscv/riscv/pmap.c
index 30bcf113628c..9b2866d7dd4d 100644
--- a/sys/riscv/riscv/pmap.c
+++ b/sys/riscv/riscv/pmap.c
@@ -256,7 +256,7 @@ CTASSERT(VM_EARLY_DTB_ADDRESS < (VM_MAX_KERNEL_ADDRESS - PMAP_MAPDEV_EARLY_SIZE)
 static struct rwlock_padalign pvh_global_lock;
 static struct mtx_padalign allpmaps_lock;
 
-static int superpages_enabled = 1;
+static int __read_frequently superpages_enabled = 1;
 SYSCTL_INT(_vm_pmap, OID_AUTO, superpages_enabled,
     CTLFLAG_RDTUN, &superpages_enabled, 0,
     "Enable support for transparent superpages");
@@ -2759,7 +2759,7 @@ pmap_demote_l2_locked(pmap_t pmap, pd_entry_t *l2, vm_offset_t va,
 }
 
 #if VM_NRESERVLEVEL > 0
-static void
+static bool
 pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
     struct rwlock **lockp)
 {
@@ -2767,6 +2767,8 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 	vm_paddr_t pa;
 
 	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+	if (!pmap_ps_enabled(pmap))
+		return (false);
 
 	KASSERT((pmap_load(l2) & PTE_RWX) == 0,
 	    ("pmap_promote_l2: invalid l2 entry %p", l2));
@@ -2783,7 +2785,7 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 		CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx pmap %p",
 		    va, pmap);
 		atomic_add_long(&pmap_l2_p_failures, 1);
-		return;
+		return (false);
 	}
 
 	/*
@@ -2817,7 +2819,7 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 			    "pmap_promote_l2: failure for va %#lx pmap %p",
 			    va, pmap);
 			atomic_add_long(&pmap_l2_p_failures, 1);
-			return;
+			return (false);
 		}
 		while ((l3e & (PTE_W | PTE_D)) == PTE_W) {
 			if (atomic_fcmpset_64(l3, &l3e, l3e & ~PTE_W)) {
@@ -2830,7 +2832,7 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 			    "pmap_promote_l2: failure for va %#lx pmap %p",
 			    va, pmap);
 			atomic_add_long(&pmap_l2_p_failures, 1);
-			return;
+			return (false);
 		}
 		all_l3e_PTE_A &= l3e;
 		pa -= PAGE_SIZE;
@@ -2857,7 +2859,7 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 		CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx pmap %p",
 		    va, pmap);
 		atomic_add_long(&pmap_l2_p_failures, 1);
-		return;
+		return (false);
 	}
 
 	if ((firstl3e & PTE_SW_MANAGED) != 0)
@@ -2868,6 +2870,7 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, vm_page_t ml3,
 	atomic_add_long(&pmap_l2_promotions, 1);
 	CTR2(KTR_PMAP, "pmap_promote_l2: success for va %#lx in pmap %p", va,
 	    pmap);
+	return (true);
 }
 #endif
 
@@ -3133,10 +3136,9 @@ validate:
 
 #if VM_NRESERVLEVEL > 0
 	if (mpte != NULL && mpte->ref_count == Ln_ENTRIES &&
-	    pmap_ps_enabled(pmap) &&
 	    (m->flags & PG_FICTITIOUS) == 0 &&
 	    vm_reserv_level_iffullpop(m) == 0)
-		pmap_promote_l2(pmap, l2, va, mpte, &lock);
+		(void)pmap_promote_l2(pmap, l2, va, mpte, &lock);
 #endif
 
 	rv = KERN_SUCCESS;