[PATCH 4.15 086/163] x86/cpu: Change type of x86_cache_size variable to unsigned int

Greg Kroah-Hartman
2018-02-21T12:48:35Z

From: Gustavo A. R. Silva <garsilva@embeddedor.com>

commit 24dbc6000f4b9b0ef5a9daecb161f1907733765a upstream.

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.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Addresses-Coverity-ID: 1464429
Link: http://lkml.kernel.org/r/20180213192208.GA26414@embeddedor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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(-)

--- 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 */
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1184,7 +1184,7 @@ static void identify_cpu(struct cpuinfo_
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_stepping = 0; /* So far unknown... */
c->x86_vendor_id[0] = '\0'; /* Unset */
--- 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_in

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);

--- 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
}

/* 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);