[PATCH AUTOSEL 4.19 12/15] arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=n

[Sasha Levin]

From: Will Deacon <will at kernel.org>

[ Upstream commit e575fb9e76c8e33440fb859572a8b7d430f053d6 ]

When I squashed the 'allnoconfig' compiler warning about the
set_sve_default_vl() function being defined but not used in commit
1e570f512cbd ("arm64/sve: Eliminate data races on sve_default_vl"), I
accidentally broke the build for configs where ARM64_SVE is enabled, but
SYSCTL is not.

Fix this by only compiling the SVE sysctl support if both CONFIG_SVE=y
and CONFIG_SYSCTL=y.

Cc: Dave Martin <Dave.Martin at arm.com>
Reported-by: Qian Cai <cai at lca.pw>
Link: https://lore.kernel.org/r/20200616131808.GA1040@lca.pw
Signed-off-by: Will Deacon <will at kernel.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 arch/arm64/kernel/fpsimd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index af59b42973141..177363abbd3e3 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -315,7 +315,7 @@ static unsigned int find_supported_vector_length(unsigned int vl)
 	return sve_vl_from_vq(bit_to_vq(bit));
 }
 
-#ifdef CONFIG_SYSCTL
+#if defined(CONFIG_ARM64_SVE) && defined(CONFIG_SYSCTL)
 
 static int sve_proc_do_default_vl(struct ctl_table *table, int write,
 				  void __user *buffer, size_t *lenp,
@@ -361,9 +361,9 @@ static int __init sve_sysctl_init(void)
 	return 0;
 }
 
-#else /* ! CONFIG_SYSCTL */
+#else /* ! (CONFIG_ARM64_SVE && CONFIG_SYSCTL) */
 static int __init sve_sysctl_init(void) { return 0; }
-#endif /* ! CONFIG_SYSCTL */
+#endif /* ! (CONFIG_ARM64_SVE && CONFIG_SYSCTL) */
 
 #define ZREG(sve_state, vq, n) ((char *)(sve_state) +		\
 	(SVE_SIG_ZREG_OFFSET(vq, n) - SVE_SIG_REGS_OFFSET))
-- 
2.25.1