[PATCH 1/3] x86/cpuid: Make cpuinfo_x86.x86_vendor_id global
From: Borislav Petkov
Date: Wed Nov 14 2018 - 16:29:02 EST
From: Borislav Petkov <bp@xxxxxxx>
Make x86_vendor_id __ro_after_init and global as it is not needed
per-CPU. Thus, save 16 bytes of per-CPU memory. Remove the vendor ID
readout early in head_32.S because it is not needed that early either.
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/include/asm/processor.h | 4 ++--
arch/x86/kernel/asm-offsets_32.c | 1 -
arch/x86/kernel/cpu/common.c | 15 +++++++--------
arch/x86/kernel/cpu/cyrix.c | 2 +-
arch/x86/kernel/cpu/proc.c | 2 +-
arch/x86/kernel/head_32.S | 5 -----
arch/x86/kernel/setup.c | 1 +
7 files changed, 12 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 071b2a6fff85..2f6f7939dfe0 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -69,12 +69,13 @@ extern u16 __read_mostly tlb_lld_2m[NR_INFO];
extern u16 __read_mostly tlb_lld_4m[NR_INFO];
extern u16 __read_mostly tlb_lld_1g[NR_INFO];
+extern char x86_vendor_id[16];
+
/*
* CPU type and hardware bug flags. Kept separately for each CPU.
* Members of this structure are referenced in head_32.S, so think twice
* before touching them. [mj]
*/
-
struct cpuinfo_x86 {
__u8 x86; /* CPU family */
__u8 x86_vendor; /* CPU vendor */
@@ -94,7 +95,6 @@ struct cpuinfo_x86 {
/* Maximum supported CPUID level, -1=no CPUID: */
int cpuid_level;
__u32 x86_capability[NCAPINTS + NBUGINTS];
- char x86_vendor_id[16];
char x86_model_id[64];
/* in KB - valid for CPUS which support this call: */
unsigned int x86_cache_size;
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c
index 82826f2275cc..0b577c40c710 100644
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -21,7 +21,6 @@ void foo(void)
OFFSET(CPUINFO_x86_stepping, cpuinfo_x86, x86_stepping);
OFFSET(CPUINFO_cpuid_level, cpuinfo_x86, cpuid_level);
OFFSET(CPUINFO_x86_capability, cpuinfo_x86, x86_capability);
- OFFSET(CPUINFO_x86_vendor_id, cpuinfo_x86, x86_vendor_id);
BLANK();
OFFSET(PT_EBX, pt_regs, bx);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index ffb181f959d2..8a6071614652 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -708,7 +708,7 @@ void detect_ht(struct cpuinfo_x86 *c)
static void get_cpu_vendor(struct cpuinfo_x86 *c)
{
- char *v = c->x86_vendor_id;
+ char *v = x86_vendor_id;
int i;
for (i = 0; i < X86_VENDOR_NUM; i++) {
@@ -736,9 +736,9 @@ void cpu_detect(struct cpuinfo_x86 *c)
{
/* Get vendor name */
cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
- (unsigned int *)&c->x86_vendor_id[0],
- (unsigned int *)&c->x86_vendor_id[8],
- (unsigned int *)&c->x86_vendor_id[4]);
+ (unsigned int *)&x86_vendor_id[0],
+ (unsigned int *)&x86_vendor_id[8],
+ (unsigned int *)&x86_vendor_id[4]);
c->x86 = 4;
/* Intel-defined flags: level 0x00000001 */
@@ -938,9 +938,9 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
for (i = 0; i < X86_VENDOR_NUM; i++)
if (cpu_devs[i] && cpu_devs[i]->c_identify) {
- c->x86_vendor_id[0] = 0;
+ x86_vendor_id[0] = 0;
cpu_devs[i]->c_identify(c);
- if (c->x86_vendor_id[0]) {
+ if (x86_vendor_id[0]) {
get_cpu_vendor(c);
break;
}
@@ -1301,7 +1301,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
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 */
c->x86_model_id[0] = '\0'; /* Unset */
c->x86_max_cores = 1;
c->x86_coreid_bits = 0;
@@ -1480,7 +1479,7 @@ void print_cpu_info(struct cpuinfo_x86 *c)
vendor = this_cpu->c_vendor;
} else {
if (c->cpuid_level >= 0)
- vendor = c->x86_vendor_id;
+ vendor = x86_vendor_id;
}
if (vendor && !strstr(c->x86_model_id, vendor))
diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index d12226f60168..1f1f724dd4c3 100644
--- a/arch/x86/kernel/cpu/cyrix.c
+++ b/arch/x86/kernel/cpu/cyrix.c
@@ -415,7 +415,7 @@ static void cyrix_identify(struct cpuinfo_x86 *c)
if (c->x86 == 4 && test_cyrix_52div()) {
unsigned char dir0, dir1;
- strcpy(c->x86_vendor_id, "CyrixInstead");
+ strcpy(x86_vendor_id, "CyrixInstead");
c->x86_vendor = X86_VENDOR_CYRIX;
/* Actually enable cpuid on the older cyrix */
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 2c8522a39ed5..999371ddfedb 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -67,7 +67,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
"model\t\t: %u\n"
"model name\t: %s\n",
cpu,
- c->x86_vendor_id[0] ? c->x86_vendor_id : "unknown",
+ x86_vendor_id[0] ? x86_vendor_id : "unknown",
c->x86,
c->x86_model,
c->x86_model_id[0] ? c->x86_model_id : "unknown");
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 30f9cb2c0b55..7ee8a1325abe 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -41,8 +41,6 @@
#define X86_HARD_MATH new_cpu_data+CPUINFO_hard_math
#define X86_CPUID new_cpu_data+CPUINFO_cpuid_level
#define X86_CAPABILITY new_cpu_data+CPUINFO_x86_capability
-#define X86_VENDOR_ID new_cpu_data+CPUINFO_x86_vendor_id
-
#define SIZEOF_PTREGS 17*4
@@ -316,9 +314,6 @@ ENTRY(startup_32_smp)
xorl %eax,%eax # call CPUID with 0 -> return vendor ID
cpuid
movl %eax,X86_CPUID # save CPUID level
- movl %ebx,X86_VENDOR_ID # lo 4 chars
- movl %edx,X86_VENDOR_ID+4 # next 4 chars
- movl %ecx,X86_VENDOR_ID+8 # last 4 chars
orl %eax,%eax # do we have processor info as well?
je .Lis486
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b74e7bfed6ab..9f21f595f0de 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -161,6 +161,7 @@ static struct resource bss_resource = {
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};
+char x86_vendor_id[16] __ro_after_init;
#ifdef CONFIG_X86_32
/* cpu data as detected by the assembly code in head_32.S */
--
2.19.1