Use DEVICE memory instead of UNCACHEABLE on aarch64 in ioremap() in the LinuxKPI.

This fixes system hangs on reading device registers on aarch64.

Tested with:	Marvell MACCHIATObin (Armada8k) + mlx4en, amdgpu
Submitted by:	Greg V <greg@unrelenting.technology>
Differential Revision:	https://reviews.freebsd.org/D20789
MFC after:	1 week
Sponsored by:	Mellanox Technologies

diff --git a/sys/compat/linuxkpi/common/include/linux/io.h b/sys/compat/linuxkpi/common/include/linux/io.h
index 8dc0308a5e7dcb0acd550893cf8f983a49ea14ac..5cffe9b080e344bab0e27332d56fbdb3ccfd845c 100644 (file)
--- a/sys/compat/linuxkpi/common/include/linux/io.h
+++ b/sys/compat/linuxkpi/common/include/linux/io.h
@@ -396,16 +396,25 @@ void *_ioremap_attr(vm_paddr_t phys_addr, unsigned long size, int attr);
 #define        _ioremap_attr(...) NULL
 #endif
 
+#ifdef VM_MEMATTR_DEVICE
+#define        ioremap_nocache(addr, size)                                     \
+    _ioremap_attr((addr), (size), VM_MEMATTR_DEVICE)
+#define        ioremap_wt(addr, size)                                          \
+    _ioremap_attr((addr), (size), VM_MEMATTR_DEVICE)
+#define        ioremap(addr, size)                                             \
+    _ioremap_attr((addr), (size), VM_MEMATTR_DEVICE)
+#else
 #define        ioremap_nocache(addr, size)                                     \
     _ioremap_attr((addr), (size), VM_MEMATTR_UNCACHEABLE)
-#define        ioremap_wc(addr, size)                                          \
-    _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_COMBINING)
-#define        ioremap_wb(addr, size)                                          \
-    _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_BACK)
 #define        ioremap_wt(addr, size)                                          \
     _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_THROUGH)
 #define        ioremap(addr, size)                                             \
     _ioremap_attr((addr), (size), VM_MEMATTR_UNCACHEABLE)
+#endif
+#define        ioremap_wc(addr, size)                                          \
+    _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_COMBINING)
+#define        ioremap_wb(addr, size)                                          \
+    _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_BACK)
 void iounmap(void *addr);
 
 #define        memset_io(a, b, c)      memset((a), (b), (c))