Author: alc
Date: Thu Sep 13 06:16:49 2012
New Revision: 240442
URL: http://svn.freebsd.org/changeset/base/240442
Log:
Simplify the kernel pmap locking in pmap_enter_pv(). While I'm here, tidy
up the comments and whitespace.
Tested by: cognet
Modified:
head/sys/arm/arm/pmap.c
Modified: head/sys/arm/arm/pmap.c
==============================================================================
--- head/sys/arm/arm/pmap.c Thu Sep 13 01:05:30 2012 (r240441)
+++ head/sys/arm/arm/pmap.c Thu Sep 13 06:16:49 2012 (r240442)
@@ -1588,11 +1588,11 @@ pmap_clearbit(struct vm_page *pg, u_int
*/
/*
- * pmap_enter_pv: enter a mapping onto a vm_page lst
+ * pmap_enter_pv: enter a mapping onto a vm_page's PV list
*
* => caller should hold the proper lock on pvh_global_lock
* => caller should have pmap locked
- * => we will gain the lock on the vm_page and allocate the new pv_entry
+ * => we will (someday) gain the lock on the vm_page's PV list
* => caller should adjust ptp's wire_count before calling
* => caller should not adjust pmap's wire_count
*/
@@ -1600,33 +1600,26 @@ static void
pmap_enter_pv(struct vm_page *pg, struct pv_entry *pve, pmap_t pm,
vm_offset_t va, u_int flags)
{
- int km;
rw_assert(&pvh_global_lock, RA_WLOCKED);
-
+ PMAP_ASSERT_LOCKED(pm);
if (pg->md.pv_kva != 0) {
- /* PMAP_ASSERT_LOCKED(pmap_kernel()); */
- pve->pv_pmap = pmap_kernel();
+ pve->pv_pmap = kernel_pmap;
pve->pv_va = pg->md.pv_kva;
pve->pv_flags = PVF_WRITE | PVF_UNMAN;
- pg->md.pv_kva = 0;
-
- if (!(km = PMAP_OWNED(pmap_kernel())))
- PMAP_LOCK(pmap_kernel());
+ if (pm != kernel_pmap)
+ PMAP_LOCK(kernel_pmap);
TAILQ_INSERT_HEAD(&pg->md.pv_list, pve, pv_list);
- TAILQ_INSERT_HEAD(&pve->pv_pmap->pm_pvlist, pve, pv_plist);
- PMAP_UNLOCK(pmap_kernel());
+ TAILQ_INSERT_HEAD(&kernel_pmap->pm_pvlist, pve, pv_plist);
+ if (pm != kernel_pmap)
+ PMAP_UNLOCK(kernel_pmap);
+ pg->md.pv_kva = 0;
if ((pve = pmap_get_pv_entry()) == NULL)
panic("pmap_kenter_pv: no pv entries");
- if (km)
- PMAP_LOCK(pmap_kernel());
}
-
- PMAP_ASSERT_LOCKED(pm);
pve->pv_pmap = pm;
pve->pv_va = va;
pve->pv_flags = flags;
-
TAILQ_INSERT_HEAD(&pg->md.pv_list, pve, pv_list);
TAILQ_INSERT_HEAD(&pm->pm_pvlist, pve, pv_plist);
pg->md.pvh_attrs |= flags & (PVF_REF | PVF_MOD);
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