[PATCH] x86/kernel/cpu: Change type of x86_cache_size variable to unsigned int

From: Gustavo A. R. Silva
Date: Tue Feb 13 2018 - 14:22:20 EST


Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So instead of
initializing this variable to -1, it can perfectly be initialized to 0
and use it as an unsigned variable instead.

Addresses-Coverity-ID: 1464429
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 2 +-
arch/x86/kernel/cpu/common.c | 2 +-
arch/x86/kernel/cpu/microcode/intel.c | 2 +-
arch/x86/kernel/cpu/proc.c | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 23fdaf4..c4d66aa 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -109,7 +109,7 @@ struct cpuinfo_x86 {
char x86_vendor_id[16];
char x86_model_id[64];
/* in KB - valid for CPUS which support this call: */
- int x86_cache_size;
+ unsigned int x86_cache_size;
int x86_cache_alignment; /* In bytes */
/* Cache QoS architectural values: */
int x86_cache_max_rmid; /* max index */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index d63f4b57..a37fd00 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1184,7 +1184,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
int i;

c->loops_per_jiffy = loops_per_jiffy;
- c->x86_cache_size = -1;
+ c->x86_cache_size = 0;
c->x86_vendor = X86_VENDOR_UNKNOWN;
c->x86_model = c->x86_mask = 0; /* So far unknown... */
c->x86_vendor_id[0] = '\0'; /* Unset */
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index f7c55b0..e5edb92 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -982,7 +982,7 @@ static struct microcode_ops microcode_intel_ops = {

static int __init calc_llc_size_per_core(struct cpuinfo_x86 *c)
{
- u64 llc_size = c->x86_cache_size * 1024;
+ u64 llc_size = c->x86_cache_size * 1024ULL;

do_div(llc_size, c->x86_max_cores);

diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index e7eceda..f3da3bb 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -91,8 +91,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
}

/* Cache size */
- if (c->x86_cache_size >= 0)
- seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);
+ if (c->x86_cache_size)
+ seq_printf(m, "cache size\t: %u KB\n", c->x86_cache_size);

show_cpuinfo_core(m, c, cpu);
show_cpuinfo_misc(m, c);
--
2.7.4