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: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Samuel Holland 2024-03-29 00:18:29 -07:00 committed by Andrew Morton
parent a28e4b672f
commit 9613736d85
4 changed files with 48 additions and 32 deletions

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@ -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).

8
lib/test_fpu.h Normal file
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@ -0,0 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef _LIB_TEST_FPU_H
#define _LIB_TEST_FPU_H
int test_fpu(void);
#endif

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@ -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)
{

37
lib/test_fpu_impl.c Normal file
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@ -0,0 +1,37 @@
// 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;
}