ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/s390/include/asm/fpu/api.h b/marvell/linux/arch/s390/include/asm/fpu/api.h
new file mode 100644
index 0000000..be16a6c
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+++ b/marvell/linux/arch/s390/include/asm/fpu/api.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * In-kernel FPU support functions
+ *
+ *
+ * Consider these guidelines before using in-kernel FPU functions:
+ *
+ * 1. Use kernel_fpu_begin() and kernel_fpu_end() to enclose all in-kernel
+ * use of floating-point or vector registers and instructions.
+ *
+ * 2. For kernel_fpu_begin(), specify the vector register range you want to
+ * use with the KERNEL_VXR_* constants. Consider these usage guidelines:
+ *
+ * a) If your function typically runs in process-context, use the lower
+ * half of the vector registers, for example, specify KERNEL_VXR_LOW.
+ * b) If your function typically runs in soft-irq or hard-irq context,
+ * prefer using the upper half of the vector registers, for example,
+ * specify KERNEL_VXR_HIGH.
+ *
+ * If you adhere to these guidelines, an interrupted process context
+ * does not require to save and restore vector registers because of
+ * disjoint register ranges.
+ *
+ * Also note that the __kernel_fpu_begin()/__kernel_fpu_end() functions
+ * includes logic to save and restore up to 16 vector registers at once.
+ *
+ * 3. You can nest kernel_fpu_begin()/kernel_fpu_end() by using different
+ * struct kernel_fpu states. Vector registers that are in use by outer
+ * levels are saved and restored. You can minimize the save and restore
+ * effort by choosing disjoint vector register ranges.
+ *
+ * 5. To use vector floating-point instructions, specify the KERNEL_FPC
+ * flag to save and restore floating-point controls in addition to any
+ * vector register range.
+ *
+ * 6. To use floating-point registers and instructions only, specify the
+ * KERNEL_FPR flag. This flag triggers a save and restore of vector
+ * registers V0 to V15 and floating-point controls.
+ *
+ * Copyright IBM Corp. 2015
+ * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ */
+
+#ifndef _ASM_S390_FPU_API_H
+#define _ASM_S390_FPU_API_H
+
+#include <linux/preempt.h>
+
+void save_fpu_regs(void);
+
+static inline int test_fp_ctl(u32 fpc)
+{
+ u32 orig_fpc;
+ int rc;
+
+ asm volatile(
+ " efpc %1\n"
+ " sfpc %2\n"
+ "0: sfpc %1\n"
+ " la %0,0\n"
+ "1:\n"
+ EX_TABLE(0b,1b)
+ : "=d" (rc), "=&d" (orig_fpc)
+ : "d" (fpc), "0" (-EINVAL));
+ return rc;
+}
+
+#define KERNEL_FPC 1
+#define KERNEL_VXR_V0V7 2
+#define KERNEL_VXR_V8V15 4
+#define KERNEL_VXR_V16V23 8
+#define KERNEL_VXR_V24V31 16
+
+#define KERNEL_VXR_LOW (KERNEL_VXR_V0V7|KERNEL_VXR_V8V15)
+#define KERNEL_VXR_MID (KERNEL_VXR_V8V15|KERNEL_VXR_V16V23)
+#define KERNEL_VXR_HIGH (KERNEL_VXR_V16V23|KERNEL_VXR_V24V31)
+
+#define KERNEL_VXR (KERNEL_VXR_LOW|KERNEL_VXR_HIGH)
+#define KERNEL_FPR (KERNEL_FPC|KERNEL_VXR_LOW)
+
+struct kernel_fpu;
+
+/*
+ * Note the functions below must be called with preemption disabled.
+ * Do not enable preemption before calling __kernel_fpu_end() to prevent
+ * an corruption of an existing kernel FPU state.
+ *
+ * Prefer using the kernel_fpu_begin()/kernel_fpu_end() pair of functions.
+ */
+void __kernel_fpu_begin(struct kernel_fpu *state, u32 flags);
+void __kernel_fpu_end(struct kernel_fpu *state, u32 flags);
+
+
+static inline void kernel_fpu_begin(struct kernel_fpu *state, u32 flags)
+{
+ preempt_disable();
+ state->mask = S390_lowcore.fpu_flags;
+ if (!test_cpu_flag(CIF_FPU))
+ /* Save user space FPU state and register contents */
+ save_fpu_regs();
+ else if (state->mask & flags)
+ /* Save FPU/vector register in-use by the kernel */
+ __kernel_fpu_begin(state, flags);
+ S390_lowcore.fpu_flags |= flags;
+}
+
+static inline void kernel_fpu_end(struct kernel_fpu *state, u32 flags)
+{
+ S390_lowcore.fpu_flags = state->mask;
+ if (state->mask & flags)
+ /* Restore FPU/vector register in-use by the kernel */
+ __kernel_fpu_end(state, flags);
+ preempt_enable();
+}
+
+#endif /* _ASM_S390_FPU_API_H */