[PATCH v2] arm64: avoid -Woverride-init warning

From: Arnd Bergmann
Date: Mon Oct 26 2020 - 15:38:15 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

The icache_policy_str[] definition causes a warning when extra
warning flags are enabled:

arch/arm64/kernel/cpuinfo.c:38:26: warning: initialized field overwritten [-Woverride-init]
38 | [ICACHE_POLICY_VIPT] = "VIPT",
| ^~~~~~
arch/arm64/kernel/cpuinfo.c:38:26: note: (near initialization for 'icache_policy_str[2]')
arch/arm64/kernel/cpuinfo.c:39:26: warning: initialized field overwritten [-Woverride-init]
39 | [ICACHE_POLICY_PIPT] = "PIPT",
| ^~~~~~
arch/arm64/kernel/cpuinfo.c:39:26: note: (near initialization for 'icache_policy_str[3]')
arch/arm64/kernel/cpuinfo.c:40:27: warning: initialized field overwritten [-Woverride-init]
40 | [ICACHE_POLICY_VPIPT] = "VPIPT",
| ^~~~~~~
arch/arm64/kernel/cpuinfo.c:40:27: note: (near initialization for 'icache_policy_str[0]')

There is no real need for the default initializer here, as printing a
NULL string is harmless. Rewrite the logic to have an explicit
reserved value for the only one that uses the default value.

This partially reverts the commit that removed ICACHE_POLICY_AIVIVT.

Fixes: 155433cb365e ("arm64: cache: Remove support for ASID-tagged VIVT I-caches")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arm64/include/asm/cache.h | 1 +
arch/arm64/kernel/cpuinfo.c | 7 ++++---
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index a4d1b5f771f6..16e1e16e7e61 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -24,6 +24,7 @@
#define CTR_L1IP(ctr) (((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)

#define ICACHE_POLICY_VPIPT 0
+#define ICACHE_POLICY_RESERVED 1
#define ICACHE_POLICY_VIPT 2
#define ICACHE_POLICY_PIPT 3

diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 6a7bb3729d60..77605aec25fe 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -34,10 +34,10 @@ DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
static struct cpuinfo_arm64 boot_cpu_data;

static const char *icache_policy_str[] = {
- [0 ... ICACHE_POLICY_PIPT] = "RESERVED/UNKNOWN",
+ [ICACHE_POLICY_VPIPT] = "VPIPT",
+ [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
[ICACHE_POLICY_VIPT] = "VIPT",
[ICACHE_POLICY_PIPT] = "PIPT",
- [ICACHE_POLICY_VPIPT] = "VPIPT",
};

unsigned long __icache_flags;
@@ -334,10 +334,11 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
case ICACHE_POLICY_VPIPT:
set_bit(ICACHEF_VPIPT, &__icache_flags);
break;
- default:
+ case ICACHE_POLICY_RESERVED:
case ICACHE_POLICY_VIPT:
/* Assume aliasing */
set_bit(ICACHEF_ALIASING, &__icache_flags);
+ break;
}

pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
--
2.27.0