[src/riastradh-drm2]: src/sys/external/bsd/drm2 Implement non-`atomic' kmap/k...

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

details:   https://anonhg.NetBSD.org/src/rev/6c9d5e81da73
branches:  riastradh-drm2
changeset: 788432:6c9d5e81da73
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jul 24 03:46:22 2013 +0000

description:
Implement non-`atomic' kmap/kunmap in drm2 Linux shims.

Uses uvm_km_alloc and pmap_kenter_pa.  Does not use direct mappings
on architectures that support this (e.g., amd64).

diffstat:

 sys/external/bsd/drm2/include/linux/highmem.h |   5 ++-
 sys/external/bsd/drm2/linux/linux_kmap.c      |  50 +++++++++++++++++++++++++-
 2 files changed, 52 insertions(+), 3 deletions(-)

diffs (99 lines):

diff -r edcd79778df8 -r 6c9d5e81da73 sys/external/bsd/drm2/include/linux/highmem.h
--- a/sys/external/bsd/drm2/include/linux/highmem.h     Wed Jul 24 03:46:07 2013 +0000
+++ b/sys/external/bsd/drm2/include/linux/highmem.h     Wed Jul 24 03:46:22 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: highmem.h,v 1.1.2.2 2013/07/24 03:31:12 riastradh Exp $        */
+/*     $NetBSD: highmem.h,v 1.1.2.3 2013/07/24 03:46:22 riastradh Exp $        */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -50,4 +50,7 @@
 void * kmap_atomic(struct page *);
 void   kunmap_atomic(void *);
 
+void * kmap(struct page *);
+void   kunmap(void *);
+
 #endif  /* _LINUX_HIGHMEM_H_ */
diff -r edcd79778df8 -r 6c9d5e81da73 sys/external/bsd/drm2/linux/linux_kmap.c
--- a/sys/external/bsd/drm2/linux/linux_kmap.c  Wed Jul 24 03:46:07 2013 +0000
+++ b/sys/external/bsd/drm2/linux/linux_kmap.c  Wed Jul 24 03:46:22 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_kmap.c,v 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $     */
+/*     $NetBSD: linux_kmap.c,v 1.1.2.2 2013/07/24 03:46:22 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 1.1.2.1 2013/07/24 03:31:12 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_kmap.c,v 1.1.2.2 2013/07/24 03:46:22 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/mutex.h>
@@ -46,6 +46,12 @@
  * use at a time.
  */
 
+/*
+ * XXX Use direct-mapped physical pages where available, e.g. amd64.
+ *
+ * XXX ...or add an abstraction to uvm for this.  (uvm_emap?)
+ */
+
 static kmutex_t linux_kmap_atomic_lock;
 static vaddr_t linux_kmap_atomic_vaddr;
 
@@ -102,6 +108,7 @@
 {
        const vaddr_t vaddr = (vaddr_t)addr;
 
+       KASSERT(mutex_owned(&linux_kmap_atomic_lock));
        KASSERT(linux_kmap_atomic_vaddr == vaddr);
        KASSERT(pmap_extract(pmap_kernel(), vaddr, NULL));
 
@@ -110,3 +117,42 @@
 
        mutex_spin_exit(&linux_kmap_atomic_lock);
 }
+
+void *
+kmap(struct page *page)
+{
+       int s;
+
+       const vaddr_t vaddr = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
+           (UVM_KMF_VAONLY | UVM_KMF_WAITVA));
+       KASSERT(vaddr != 0);
+
+       s = splvm();
+
+       KASSERT(!pmap_extract(pmap_kernel(), vaddr, NULL));
+       const paddr_t paddr = uvm_vm_page_to_phys(&page->p_vmp);
+       const int prot = (VM_PROT_READ | VM_PROT_WRITE);
+       const int flags = 0;
+       pmap_kenter_pa(vaddr, paddr, prot, flags);
+       pmap_update(pmap_kernel());
+
+       splx(s);
+
+       return (void *)vaddr;
+}
+
+void
+kunmap(void *addr)
+{
+       const vaddr_t vaddr = (vaddr_t)addr;
+       int s;
+
+       s = splvm();
+
+       KASSERT(pmap_extract(pmap_kernel(), vaddr, NULL));
+
+       pmap_kremove(vaddr, PAGE_SIZE);
+       pmap_update(pmap_kernel());
+
+       splx(s);
+}