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authorGustavo Padovan <gustavo.padovan@collabora.co.uk>2013-09-27 11:56:14 -0300
committerGustavo Padovan <gustavo.padovan@collabora.co.uk>2013-09-27 11:56:14 -0300
commit1025c04cecd19882e28f16c4004034b475c372c5 (patch)
tree2b7402887e86d54bff5a123228c9059eae5e32bd /arch/arm/include/asm/neon.h
parent4375f1037d52602413142e290608d0d84671ad36 (diff)
parent5bcecf325378218a8e248bb6bcae96ec7362f8ef (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth
Conflicts: net/bluetooth/hci_core.c
Diffstat (limited to 'arch/arm/include/asm/neon.h')
-rw-r--r--arch/arm/include/asm/neon.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm/include/asm/neon.h b/arch/arm/include/asm/neon.h
new file mode 100644
index 00000000000..8f730fe7009
--- /dev/null
+++ b/arch/arm/include/asm/neon.h
@@ -0,0 +1,36 @@
+/*
+ * linux/arch/arm/include/asm/neon.h
+ *
+ * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm/hwcap.h>
+
+#define cpu_has_neon() (!!(elf_hwcap & HWCAP_NEON))
+
+#ifdef __ARM_NEON__
+
+/*
+ * If you are affected by the BUILD_BUG below, it probably means that you are
+ * using NEON code /and/ calling the kernel_neon_begin() function from the same
+ * compilation unit. To prevent issues that may arise from GCC reordering or
+ * generating(1) NEON instructions outside of these begin/end functions, the
+ * only supported way of using NEON code in the kernel is by isolating it in a
+ * separate compilation unit, and calling it from another unit from inside a
+ * kernel_neon_begin/kernel_neon_end pair.
+ *
+ * (1) Current GCC (4.7) might generate NEON instructions at O3 level if
+ * -mpfu=neon is set.
+ */
+
+#define kernel_neon_begin() \
+ BUILD_BUG_ON_MSG(1, "kernel_neon_begin() called from NEON code")
+
+#else
+void kernel_neon_begin(void);
+#endif
+void kernel_neon_end(void);