10 files changed, 43 insertions, 29 deletions
diff --git a/arch/nds32/include/uapi/asm/Kbuild b/arch/nds32/include/uapi/asm/Kbuild
index 1c72f04ff75d..e78470141932 100644
--- a/arch/nds32/include/uapi/asm/Kbuild
+++ b/arch/nds32/include/uapi/asm/Kbuild
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h
diff --git a/arch/nds32/include/uapi/asm/auxvec.h b/arch/nds32/include/uapi/asm/auxvec.h
index 2d3213f5e595..b5d58ea8decb 100644
--- a/arch/nds32/include/uapi/asm/auxvec.h
+++ b/arch/nds32/include/uapi/asm/auxvec.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef __ASM_AUXVEC_H
diff --git a/arch/nds32/include/uapi/asm/byteorder.h b/arch/nds32/include/uapi/asm/byteorder.h
index a23f6f3a2468..511e653c709d 100644
--- a/arch/nds32/include/uapi/asm/byteorder.h
+++ b/arch/nds32/include/uapi/asm/byteorder.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef __NDS32_BYTEORDER_H__
diff --git a/arch/nds32/include/uapi/asm/cachectl.h b/arch/nds32/include/uapi/asm/cachectl.h
index 4cdca9b23974..73793662815c 100644
--- a/arch/nds32/include/uapi/asm/cachectl.h
+++ b/arch/nds32/include/uapi/asm/cachectl.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 1994, 1995, 1996 by Ralf Baechle
 // Copyright (C) 2005-2017 Andes Technology Corporation
 #ifndef	_ASM_CACHECTL
diff --git a/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h b/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h
new file mode 100644
index 000000000000..d54a5d6c6538
--- /dev/null
+++ b/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2005-2019 Andes Technology Corporation */
+#ifndef	_FP_UDF_IEX_CRTL_H
+#define	_FP_UDF_IEX_CRTL_H
+
+/*
+ * The cmd list of sys_fp_udfiex_crtl()
+ */
+/* Disable UDF or IEX trap based on the content of parameter act */
+#define DISABLE_UDF_IEX_TRAP	0
+/* Enable UDF or IEX trap based on the content of parameter act */
+#define ENABLE_UDF_IEX_TRAP	1
+/* Get current status of UDF and IEX trap */
+#define GET_UDF_IEX_TRAP	2
+
+#endif /* _FP_UDF_IEX_CRTL_H */
diff --git a/arch/nds32/include/uapi/asm/param.h b/arch/nds32/include/uapi/asm/param.h
index e3fb723ee362..2977534a6bd3 100644
--- a/arch/nds32/include/uapi/asm/param.h
+++ b/arch/nds32/include/uapi/asm/param.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef __ASM_NDS32_PARAM_H
diff --git a/arch/nds32/include/uapi/asm/ptrace.h b/arch/nds32/include/uapi/asm/ptrace.h
index 358c99e399d0..1a6e01c00e6f 100644
--- a/arch/nds32/include/uapi/asm/ptrace.h
+++ b/arch/nds32/include/uapi/asm/ptrace.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef __UAPI_ASM_NDS32_PTRACE_H
diff --git a/arch/nds32/include/uapi/asm/sigcontext.h b/arch/nds32/include/uapi/asm/sigcontext.h
index 58afc416473e..dc89af7ddcc3 100644
--- a/arch/nds32/include/uapi/asm/sigcontext.h
+++ b/arch/nds32/include/uapi/asm/sigcontext.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef _ASMNDS32_SIGCONTEXT_H
@@ -13,14 +13,24 @@ struct fpu_struct {
 	unsigned long long fd_regs[32];
 	unsigned long fpcsr;
 	/*
-	 * UDF_trap is used to recognize whether underflow trap is enabled
-	 * or not. When UDF_trap == 1, this process will be traped and then
-	 * get a SIGFPE signal when encountering an underflow exception.
-	 * UDF_trap is only modified through setfputrap syscall. Therefore,
-	 * UDF_trap needn't be saved or loaded to context in each context
-	 * switch.
+	 * When CONFIG_SUPPORT_DENORMAL_ARITHMETIC is defined, kernel prevents
+	 * hardware from treating the denormalized output as an underflow case
+	 * and rounding it to a normal number. Hence kernel enables the UDF and
+	 * IEX trap in the fpcsr register to step in the calculation.
+	 * However, the UDF and IEX trap enable bit in $fpcsr also lose
+	 * their use.
+	 *
+	 * UDF_IEX_trap replaces the feature of UDF and IEX trap enable bit in
+	 * $fpcsr to control the trap of underflow and inexact. The bit filed
+	 * of UDF_IEX_trap is the same as $fpcsr, 10th bit is used to enable UDF
+	 * exception trapping and 11th bit is used to enable IEX exception
+	 * trapping.
+	 *
+	 * UDF_IEX_trap is only modified through fp_udfiex_crtl syscall.
+	 * Therefore, UDF_IEX_trap needn't be saved and restored in each
+	 * context switch.
 	 */
-	unsigned long UDF_trap;
+	unsigned long UDF_IEX_trap;
 };
 
 struct zol_struct {
diff --git a/arch/nds32/include/uapi/asm/udftrap.h b/arch/nds32/include/uapi/asm/udftrap.h
deleted file mode 100644
index 433f79d679c0..000000000000
--- a/arch/nds32/include/uapi/asm/udftrap.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* Copyright (C) 2005-2018 Andes Technology Corporation */
-#ifndef	_ASM_SETFPUTRAP
-#define	_ASM_SETFPUTRAP
-
-/*
- * Options for setfputrap system call
- */
-#define	DISABLE_UDFTRAP	0	/* disable underflow exception trap */
-#define	ENABLE_UDFTRAP	1	/* enable undeflos exception trap */
-#define	GET_UDFTRAP	2	/* only get undeflos exception trap status */
-
-#endif /* _ASM_CACHECTL */
diff --git a/arch/nds32/include/uapi/asm/unistd.h b/arch/nds32/include/uapi/asm/unistd.h
index 4ec8f543103f..a0b2f7b9c0f2 100644
--- a/arch/nds32/include/uapi/asm/unistd.h
+++ b/arch/nds32/include/uapi/asm/unistd.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #define __ARCH_WANT_STAT64
@@ -11,6 +11,6 @@
 
 /* Additional NDS32 specific syscalls. */
 #define __NR_cacheflush		(__NR_arch_specific_syscall)
-#define __NR_udftrap		(__NR_arch_specific_syscall + 1)
+#define __NR_fp_udfiex_crtl	(__NR_arch_specific_syscall + 1)
 __SYSCALL(__NR_cacheflush, sys_cacheflush)
-__SYSCALL(__NR_udftrap, sys_udftrap)
+__SYSCALL(__NR_fp_udfiex_crtl, sys_fp_udfiex_crtl)