1 files changed, 65 insertions, 0 deletions
diff --git a/src/compat/simd/include/linux/simd.h b/src/compat/simd/include/linux/simd.h
new file mode 100644
index 0000000..6adf0c3
--- /dev/null
+++ b/src/compat/simd/include/linux/simd.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef _WG_SIMD_H
+#define _WG_SIMD_H
+
+#include <linux/sched.h>
+#if defined(CONFIG_X86_64)
+#include <linux/version.h>
+#include <asm/fpu/api.h>
+#include <asm/simd.h>
+#elif IS_ENABLED(CONFIG_KERNEL_MODE_NEON)
+#include <asm/neon.h>
+#include <asm/simd.h>
+#endif
+
+typedef enum {
+	HAVE_NO_SIMD,
+	HAVE_FULL_SIMD
+} simd_context_t;
+
+static inline simd_context_t simd_get(void)
+{
+	bool have_simd = false;
+#if defined(CONFIG_X86_64) && !defined(CONFIG_UML) && !defined(CONFIG_PREEMPT_RT_BASE)
+	have_simd = irq_fpu_usable();
+	if (have_simd)
+		kernel_fpu_begin();
+#elif IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && !defined(CONFIG_PREEMPT_RT_BASE)
+#if defined(CONFIG_ARM64)
+	have_simd = true; /* ARM64 supports NEON in any context. */
+#elif defined(CONFIG_ARM)
+	have_simd = may_use_simd(); /* ARM doesn't support NEON in interrupt context. */
+#endif
+	if (have_simd)
+		kernel_neon_begin();
+#endif
+	return have_simd ? HAVE_FULL_SIMD : HAVE_NO_SIMD;
+}
+
+static inline void simd_put(simd_context_t prior_context)
+{
+#if defined(CONFIG_X86_64) && !defined(CONFIG_UML) && !defined(CONFIG_PREEMPT_RT_BASE)
+	if (prior_context != HAVE_NO_SIMD)
+		kernel_fpu_end();
+#elif IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && !defined(CONFIG_PREEMPT_RT_BASE)
+	if (prior_context != HAVE_NO_SIMD)
+		kernel_neon_end();
+#endif
+}
+
+static inline simd_context_t simd_relax(simd_context_t prior_context)
+{
+#ifdef CONFIG_PREEMPT
+	if (prior_context != HAVE_NO_SIMD && need_resched()) {
+		simd_put(prior_context);
+		return simd_get();
+	}
+#endif
+	return prior_context;
+}
+
+#endif /* _WG_SIMD_H */