Add arm64 support. On ARM write-combining translates into the normal uncached

memory attribute and uncached translates into device-nGnRnE memory.  This
complicates the mapping onto PMAP_WC, PMAP_NOCACHE and PMAP_DEVICE a bit
since the requirements of the drm(4) subsystem don't quite match the natural
definitions for these.

ok jsg@, mpi@, visa@

diff --git a/sys/dev/pci/drm/drm_linux.h b/sys/dev/pci/drm/drm_linux.h
index 40f0da1..ba24e5f 100644 (file)
--- a/sys/dev/pci/drm/drm_linux.h
+++ b/sys/dev/pci/drm/drm_linux.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: drm_linux.h,v 1.90 2018/07/27 21:11:31 kettenis Exp $ */
+/*     $OpenBSD: drm_linux.h,v 1.91 2018/08/20 19:33:31 kettenis Exp $ */
 /*
  * Copyright (c) 2013, 2014, 2015 Mark Kettenis
  * Copyright (c) 2017 Martin Pieuchot
@@ -2120,6 +2120,26 @@ typedef int pgprot_t;
 #define pgprot_val(v)  (v)
 #define PAGE_KERNEL    0
 
+static inline pgprot_t
+pgprot_writecombine(pgprot_t prot)
+{
+#ifdef PMAP_WC
+       return prot | PMAP_WC;
+#else
+       return prot | PMAP_NOCACHE;
+#endif
+}
+
+static inline pgprot_t
+pgprot_noncached(pgprot_t prot)
+{
+#ifdef PMAP_DEVICE
+       return prot | PMAP_DEVICE;
+#else
+       return prot | PMAP_NOCACHE;
+#endif
+}
+
 void   *kmap(struct vm_page *);
 void    kunmap(void *addr);
 void   *vmap(struct vm_page **, unsigned int, unsigned long, pgprot_t);

diff --git a/sys/dev/pci/drm/ttm/ttm_bo_util.c b/sys/dev/pci/drm/ttm/ttm_bo_util.c
index 13f408a..b065bba 100644 (file)
--- a/sys/dev/pci/drm/ttm/ttm_bo_util.c
+++ b/sys/dev/pci/drm/ttm/ttm_bo_util.c
@@ -517,12 +517,13 @@ pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
        /* Cached mappings need no adjustment */
        if (caching_flags & TTM_PL_FLAG_CACHED)
                return tmp;
-#ifdef PMAP_WC
+
        if (caching_flags & TTM_PL_FLAG_WC)
-               return PMAP_WC;
+               tmp = pgprot_writecombine(tmp);
        else
-#endif
-               return PMAP_NOCACHE;
+               tmp = pgprot_noncached(tmp);
+
+       return tmp;
 }
 
 static int ttm_bo_ioremap(struct ttm_buffer_object *bo,