crypto: api - move crypto_simd_disabled_for_test to lib

Move crypto_simd_disabled_for_test to lib/ so that crypto_simd_usable()
can be used by library code.

This was discussed previously
(https://lore.kernel.org/linux-crypto/20220716062920.210381-4-ebiggers@kernel.org/)
but was not done because there was no use case yet.  However, this is
now needed for the arm64 CRC32 library code.

Tested with:
    export ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
    echo CONFIG_CRC32=y > .config
    echo CONFIG_MODULES=y >> .config
    echo CONFIG_CRYPTO=m >> .config
    echo CONFIG_DEBUG_KERNEL=y >> .config
    echo CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=n >> .config
    echo CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y >> .config
    make olddefconfig
    make -j$(nproc)

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: ebiggers

crypto/algapi.c

@@ -6,7 +6,6 @@
  */
 
 #include <crypto/algapi.h>
-#include <crypto/internal/simd.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/fips.h>
@@ -23,11 +22,6 @@
 
 static LIST_HEAD(crypto_template_list);
 
-#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
-DEFINE_PER_CPU(bool, crypto_simd_disabled_for_test);
-EXPORT_PER_CPU_SYMBOL_GPL(crypto_simd_disabled_for_test);
-#endif
-
 static inline void crypto_check_module_sig(struct module *mod)
 {
 	if (fips_enabled && mod && !module_sig_ok(mod))

lib/crypto/Makefile

@@ -58,3 +58,5 @@ libcurve25519-y					+= curve25519-selftest.o
 endif
 
 obj-$(CONFIG_MPILIB) += mpi/
+
+obj-$(CONFIG_CRYPTO_MANAGER_EXTRA_TESTS)	+= simd.o

lib/crypto/simd.c

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SIMD testing utility functions
+ *
+ * Copyright 2024 Google LLC
+ */
+
+#include <crypto/internal/simd.h>
+
+DEFINE_PER_CPU(bool, crypto_simd_disabled_for_test);
+EXPORT_PER_CPU_SYMBOL_GPL(crypto_simd_disabled_for_test);