git: 3499df29c2a1 - main - arm64 pmap: Convert PC_IS_FREE into an inline function.

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=3499df29c2a1bbd6755f4ebe4b4a0083fda7a666

commit 3499df29c2a1bbd6755f4ebe4b4a0083fda7a666
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2022-08-17 19:10:35 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2022-08-17 19:10:35 +0000

    arm64 pmap: Convert PC_IS_FREE into an inline function.
    
    This permits inlining the comparisons even in the 16K page case.
    Note that since PC_FREEN is -1, values can be compared efficiently
    without having to fetch words of pc_freemask from memory via the
    'cmn <reg>, #0x1' instruction.
    
    Reviewed by:    markj
    Sponsored by:   DARPA
    Differential Revision:  https://reviews.freebsd.org/D36218
---
 sys/arm64/arm64/pmap.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 9c47c043d251..deea00bc5d13 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -2462,14 +2462,6 @@ pv_to_chunk(pv_entry_t pv)
 #define	PC_FREEN	0xfffffffffffffffful
 #define	PC_FREEL	((1ul << (_NPCPV % 64)) - 1)
 
-#if _NPCM == 3
-#define	PC_IS_FREE(pc)	((pc)->pc_map[0] == PC_FREEN &&			\
-    (pc)->pc_map[1] == PC_FREEN && (pc)->pc_map[2] == PC_FREEL)
-#else
-#define	PC_IS_FREE(pc)							\
-    (memcmp((pc)->pc_map, pc_freemask, sizeof(pc_freemask)) == 0)
-#endif
-
 static const uint64_t pc_freemask[] = { PC_FREEN, PC_FREEN,
 #if _NPCM > 3
     PC_FREEN, PC_FREEN, PC_FREEN, PC_FREEN, PC_FREEN, PC_FREEN, PC_FREEN,
@@ -2489,6 +2481,15 @@ pc_is_full(struct pv_chunk *pc)
 	return (true);
 }
 
+static __inline bool
+pc_is_free(struct pv_chunk *pc)
+{
+	for (u_int i = 0; i < _NPCM - 1; i++)
+		if (pc->pc_map[i] != PC_FREEN)
+			return (false);
+	return (pc->pc_map[_NPCM - 1] == PC_FREEL);
+}
+
 #ifdef PV_STATS
 static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail;
 
@@ -2653,7 +2654,7 @@ reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp)
 		PV_STAT(atomic_add_int(&pv_entry_spare, freed));
 		PV_STAT(atomic_subtract_long(&pv_entry_count, freed));
 		TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
-		if (PC_IS_FREE(pc)) {
+		if (pc_is_free(pc)) {
 			PV_STAT(atomic_subtract_int(&pv_entry_spare, _NPCPV));
 			PV_STAT(atomic_subtract_int(&pc_chunk_count, 1));
 			PV_STAT(atomic_add_int(&pc_chunk_frees, 1));
@@ -2722,7 +2723,7 @@ free_pv_entry(pmap_t pmap, pv_entry_t pv)
 	field = idx / 64;
 	bit = idx % 64;
 	pc->pc_map[field] |= 1ul << bit;
-	if (!PC_IS_FREE(pc)) {
+	if (!pc_is_free(pc)) {
 		/* 98% of the time, pc is already at the head of the list. */
 		if (__predict_false(pc != TAILQ_FIRST(&pmap->pm_pvchunk))) {
 			TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);