Commit 9613736d authored by Samuel Holland's avatar Samuel Holland Committed by Andrew Morton
Browse files

selftests/fpu: move FP code to a separate translation unit 

This ensures no compiler-generated floating-point code can appear outside
kernel_fpu_{begin,end}() sections, and some architectures enforce this
separation.

Link: https://lkml.kernel.org/r/20240329072441.591471-15-samuel.holland@sifive.com


Signed-off-by: default avatarSamuel Holland <samuel.holland@sifive.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: WANG Xuerui <git@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent a28e4b67

lib/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -133,7 +133,8 @@ FPU_CFLAGS += $(call cc-option,-msse -mpreferred-stack-boundary=3,-mpreferred-st 
endif



obj-$(CONFIG_TEST_FPU) += test_fpu.o

CFLAGS_test_fpu.o += $(FPU_CFLAGS)

test_fpu-y := test_fpu_glue.o test_fpu_impl.o

CFLAGS_test_fpu_impl.o += $(FPU_CFLAGS)



# Some KUnit files (hooks.o) need to be built-in even when KUnit is a module,

# so we can't just use obj-$(CONFIG_KUNIT).

lib/test_fpu.h

0 → 100644
+8 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0+ */



#ifndef _LIB_TEST_FPU_H

#define _LIB_TEST_FPU_H



int test_fpu(void);



#endif

lib/test_fpu.c→lib/test_fpu_glue.c

+1 −31
Original line number Diff line number Diff line
@@ -19,37 +19,7 @@ 
#include <linux/debugfs.h>

#include <asm/fpu/api.h>



static int test_fpu(void)

{

	/*

	 * This sequence of operations tests that rounding mode is

	 * to nearest and that denormal numbers are supported.

	 * Volatile variables are used to avoid compiler optimizing

	 * the calculations away.

	 */

	volatile double a, b, c, d, e, f, g;



	a = 4.0;

	b = 1e-15;

	c = 1e-310;



	/* Sets precision flag */

	d = a + b;



	/* Result depends on rounding mode */

	e = a + b / 2;



	/* Denormal and very large values */

	f = b / c;



	/* Depends on denormal support */

	g = a + c * f;



	if (d > a && e > a && g > a)

		return 0;

	else

		return -EINVAL;

}

#include "test_fpu.h"



static int test_fpu_get(void *data, u64 *val)

{

lib/test_fpu_impl.c

0 → 100644
+37 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+



#include <linux/errno.h>



#include "test_fpu.h"



int test_fpu(void)

{

	/*

	 * This sequence of operations tests that rounding mode is

	 * to nearest and that denormal numbers are supported.

	 * Volatile variables are used to avoid compiler optimizing

	 * the calculations away.

	 */

	volatile double a, b, c, d, e, f, g;



	a = 4.0;

	b = 1e-15;

	c = 1e-310;



	/* Sets precision flag */

	d = a + b;



	/* Result depends on rounding mode */

	e = a + b / 2;



	/* Denormal and very large values */

	f = b / c;



	/* Depends on denormal support */

	g = a + c * f;



	if (d > a && e > a && g > a)

		return 0;

	else

		return -EINVAL;

}