From 0b35b54b4dd615b49183189078e9fb380a6870b7 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 13 Sep 2012 06:16:49 +0000 Subject: [PATCH] Simplify the kernel pmap locking in pmap_enter_pv(). While I'm here, tidy up the comments and whitespace. Tested by: cognet --- sys/arm/arm/pmap.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/sys/arm/arm/pmap.c b/sys/arm/arm/pmap.c index 635f0fe081fe..47d2c16e9795 100644 --- a/sys/arm/arm/pmap.c +++ b/sys/arm/arm/pmap.c @@ -1588,11 +1588,11 @@ pmap_clearbit(struct vm_page *pg, u_int maskbits) */ /* - * 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);