[src/trunk]: src/sys/kern Prepare the removal of the 'ioff' argument: add a K...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0c62a8a245a6
branches:  trunk
changeset: 997636:0c62a8a245a6
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sun Mar 17 06:55:06 2019 +0000

description:
Prepare the removal of the 'ioff' argument: add a KASSERT to ensure it is
zero, and remove the internal logic. The pool code is simpler now.

diffstat:

 sys/kern/subr_pool.c |  40 +++++++++++++---------------------------
 1 files changed, 13 insertions(+), 27 deletions(-)

diffs (124 lines):

diff -r 2ef3bc101ec4 -r 0c62a8a245a6 sys/kern/subr_pool.c
--- a/sys/kern/subr_pool.c      Sun Mar 17 06:36:22 2019 +0000
+++ b/sys/kern/subr_pool.c      Sun Mar 17 06:55:06 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_pool.c,v 1.237 2019/03/16 13:33:10 maxv Exp $     */
+/*     $NetBSD: subr_pool.c,v 1.238 2019/03/17 06:55:06 maxv Exp $     */
 
 /*
  * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015, 2018
@@ -33,7 +33,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.237 2019/03/16 13:33:10 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.238 2019/03/17 06:55:06 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -580,6 +580,9 @@
        size_t trysize, phsize, prsize;
        int itemspace, slack;
 
+       /* XXX ioff will be removed. */
+       KASSERT(ioff == 0);
+
 #ifdef DEBUG
        if (__predict_true(!cold))
                mutex_enter(&pool_head_lock);
@@ -665,9 +668,6 @@
        pp->pr_freecheck = NULL;
        pool_redzone_init(pp, size);
 
-       /* Silently enforce '0 <= ioff < align'. */
-       ioff %= align;
-
        /*
         * Decide whether to put the page header off page to avoid wasting too
         * large a part of the page or too big item. Off-page page headers go
@@ -678,8 +678,8 @@
         * However, we'll put the header into the page if we can put it without
         * wasting any items.
         */
-       pp->pr_itemoffset = ioff;
-       trysize = palloc->pa_pagesz - ((align - ioff) % align);
+       pp->pr_itemoffset = 0;
+       trysize = palloc->pa_pagesz;
        phsize = ALIGN(sizeof(struct pool_item_header));
        if (pp->pr_roflags & PR_PHINPAGE ||
            ((pp->pr_roflags & (PR_NOTOUCH | PR_NOALIGN)) == 0 &&
@@ -696,13 +696,7 @@
                SPLAY_INIT(&pp->pr_phtree);
        }
 
-       /*
-        * Alignment is to take place at `ioff' within the item. This means
-        * we must reserve up to `align - 1' bytes on the page to allow
-        * appropriate positioning of each item.
-        */
-       pp->pr_itemsperpage =
-           (itemspace - ((align - ioff) % align)) / pp->pr_size;
+       pp->pr_itemsperpage = itemspace / pp->pr_size;
        KASSERT(pp->pr_itemsperpage != 0);
        if ((pp->pr_roflags & PR_NOTOUCH)) {
                int idx;
@@ -1012,7 +1006,7 @@
        }
 
        mutex_exit(&pp->pr_lock);
-       KASSERT((((vaddr_t)v + pp->pr_itemoffset) & (pp->pr_align - 1)) == 0);
+       KASSERT((((vaddr_t)v) & (pp->pr_align - 1)) == 0);
        FREECHECK_OUT(&pp->pr_freecheck, v);
        pool_redzone_fill(pp, v);
        if (flags & PR_ZERO)
@@ -1243,7 +1237,6 @@
 pool_prime_page(struct pool *pp, void *storage, struct pool_item_header *ph)
 {
        const unsigned int align = pp->pr_align;
-       const unsigned int ioff = pp->pr_itemoffset;
        struct pool_item *pi;
        void *cp = storage;
        int n;
@@ -1274,13 +1267,7 @@
        if ((pp->pr_curcolor += align) > pp->pr_maxcolor)
                pp->pr_curcolor = 0;
 
-       /*
-        * Adjust storage to apply alignment to `pr_itemoffset' in each item.
-        */
-       if (ioff != 0)
-               cp = (char *)cp + align - ioff;
-
-       KASSERT((((vaddr_t)cp + ioff) & (align - 1)) == 0);
+       KASSERT((((vaddr_t)cp) & (align - 1)) == 0);
 
        /*
         * Insert remaining chunks on the bucket list.
@@ -1294,7 +1281,7 @@
                while (n--) {
                        pi = (struct pool_item *)cp;
 
-                       KASSERT(((((vaddr_t)pi) + ioff) & (align - 1)) == 0);
+                       KASSERT((((vaddr_t)pi) & (align - 1)) == 0);
 
                        /* Insert on page list */
                        LIST_INSERT_HEAD(&ph->ph_itemlist, pi, pi_list);
@@ -1303,7 +1290,7 @@
 #endif
                        cp = (char *)cp + pp->pr_size;
 
-                       KASSERT((((vaddr_t)cp + ioff) & (align - 1)) == 0);
+                       KASSERT((((vaddr_t)cp) & (align - 1)) == 0);
                }
        }
 
@@ -2323,8 +2310,7 @@
                return false;
        }
 
-       KASSERT((((vaddr_t)object + pc->pc_pool.pr_itemoffset) &
-           (pc->pc_pool.pr_align - 1)) == 0);
+       KASSERT((((vaddr_t)object) & (pc->pc_pool.pr_align - 1)) == 0);
 
        if (pap != NULL) {
 #ifdef POOL_VTOPHYS