[src/trunk]: src/sys/external/bsd/drm2/linux Convert linux_kmap_lock to an ad...

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

details:   https://anonhg.NetBSD.org/src/rev/2732bdab8bc8
branches:  trunk
changeset: 802005:2732bdab8bc8
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Aug 27 16:05:38 2014 +0000

description:
Convert linux_kmap_lock to an adaptive lock.

kmap/kunmap can't be used in interrupt context anyway, so there is no
need for this to be a spin lock.

diffstat:

 sys/external/bsd/drm2/linux/linux_kmap.c |  16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diffs (65 lines):

diff -r a8bb753b5b8a -r 2732bdab8bc8 sys/external/bsd/drm2/linux/linux_kmap.c
--- a/sys/external/bsd/drm2/linux/linux_kmap.c  Wed Aug 27 15:31:08 2014 +0000
+++ b/sys/external/bsd/drm2/linux/linux_kmap.c  Wed Aug 27 16:05:38 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_kmap.c,v 1.4 2014/03/28 23:22:27 riastradh Exp $ */
+/*     $NetBSD: linux_kmap.c,v 1.5 2014/08/27 16:05:38 riastradh Exp $ */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_kmap.c,v 1.4 2014/03/28 23:22:27 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_kmap.c,v 1.5 2014/08/27 16:05:38 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/kmem.h>
@@ -106,7 +106,7 @@
 linux_kmap_init(void)
 {
 
-       /* IPL_VM is needed to block pmap_kenter_pa.  */
+       /* IPL_VM since interrupt handlers use kmap_atomic.  */
        mutex_init(&linux_kmap_atomic_lock, MUTEX_DEFAULT, IPL_VM);
 
        linux_kmap_atomic_vaddr = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
@@ -115,7 +115,7 @@
        KASSERT(linux_kmap_atomic_vaddr != 0);
        KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL));
 
-       mutex_init(&linux_kmap_lock, MUTEX_DEFAULT, IPL_VM);
+       mutex_init(&linux_kmap_lock, MUTEX_DEFAULT, IPL_NONE);
        rb_tree_init(&linux_kmap_entries, &linux_kmap_entry_ops);
 
        return 0;
@@ -188,11 +188,11 @@
        lke->lke_paddr = paddr;
        lke->lke_vaddr = vaddr;
 
-       mutex_spin_enter(&linux_kmap_lock);
+       mutex_enter(&linux_kmap_lock);
        struct linux_kmap_entry *const collision __unused =
            rb_tree_insert_node(&linux_kmap_entries, lke);
        KASSERT(collision == lke);
-       mutex_spin_exit(&linux_kmap_lock);
+       mutex_exit(&linux_kmap_lock);
 
        KASSERT(!pmap_extract(pmap_kernel(), vaddr, NULL));
        const int prot = (VM_PROT_READ | VM_PROT_WRITE);
@@ -208,12 +208,12 @@
 {
        const paddr_t paddr = VM_PAGE_TO_PHYS(&page->p_vmp);
 
-       mutex_spin_enter(&linux_kmap_lock);
+       mutex_enter(&linux_kmap_lock);
        struct linux_kmap_entry *const lke =
            rb_tree_find_node(&linux_kmap_entries, &paddr);
        KASSERT(lke != NULL);
        rb_tree_remove_node(&linux_kmap_entries, lke);
-       mutex_spin_exit(&linux_kmap_lock);
+       mutex_exit(&linux_kmap_lock);
 
        const vaddr_t vaddr = lke->lke_vaddr;
        kmem_free(lke, sizeof(*lke));