[tip: x86/cpu] x86/cpu: Simplify TLB entry count storage

tip-bot2 for Ahmed S. Darwish
2025-03-04T09:37:21Z

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: 849c0e9cea1a80003258fce2a5fe541574aefc38
Gitweb: https://git.kernel.org/tip/849c0e9cea1a80003258fce2a5fe541574aefc38
Author: Ahmed S. Darwish <darwi@linutronix.de>
AuthorDate: Tue, 04 Mar 2025 09:51:18 +01:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 04 Mar 2025 10:15:24 +01:00

x86/cpu: Simplify TLB entry count storage

Commit:

e0ba94f14f74 ("x86/tlb_info: get last level TLB entry number of CPU")

introduced u16 "info" arrays for each TLB type.

Since 2012 and each array stores just one type of information: the
number of TLB entries for its respective TLB type.

Replace such arrays with simple variables.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250304085152.51092-8-darwi@linutronix.de
---
arch/x86/include/asm/processor.h | 19 ++++--------
arch/x86/kernel/cpu/amd.c | 18 ++++++------
arch/x86/kernel/cpu/common.c | 20 +++++--------
arch/x86/kernel/cpu/hygon.c | 16 +++++-----
arch/x86/kernel/cpu/intel.c | 48 +++++++++++++++----------------
5 files changed, 57 insertions(+), 64 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c0cd101..0ea227f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -60,18 +60,13 @@ struct vm86;
# define ARCH_MIN_MMSTRUCT_ALIGN 0
#endif

-enum tlb_infos {
- ENTRIES,
- NR_INFO
-};
-
-extern u16 __read_mostly tlb_lli_4k[NR_INFO];
-extern u16 __read_mostly tlb_lli_2m[NR_INFO];
-extern u16 __read_mostly tlb_lli_4m[NR_INFO];
-extern u16 __read_mostly tlb_lld_4k[NR_INFO];
-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 u16 __read_mostly tlb_lli_4k;
+extern u16 __read_mostly tlb_lli_2m;
+extern u16 __read_mostly tlb_lli_4m;
+extern u16 __read_mostly tlb_lld_4k;
+extern u16 __read_mostly tlb_lld_2m;
+extern u16 __read_mostly tlb_lld_4m;
+extern u16 __read_mostly tlb_lld_1g;

/*
* CPU type and hardware bug flags. Kept separately for each CPU.
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index d747515..3157664 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1105,8 +1105,8 @@ static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)

cpuid(0x80000006, &eax, &ebx, &ecx, &edx);

- tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
- tlb_lli_4k[ENTRIES] = ebx & mask;
+ tlb_lld_4k = (ebx >> 16) & mask;
+ tlb_lli_4k = ebx & mask;

/*
* K8 doesn't have 2M/4M entries in the L2 TLB so read out the L1 TLB
@@ -1119,26 +1119,26 @@ static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)

/* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
if (!((eax >> 16) & mask))
- tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
+ tlb_lld_2m = (cpuid_eax(0x80000005) >> 16) & 0xff;
else
- tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
+ tlb_lld_2m = (eax >> 16) & mask;

/* a 4M entry uses two 2M entries */
- tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
+ tlb_lld_4m = tlb_lld_2m >> 1;

/* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
if (!(eax & mask)) {
/* Erratum 658 */
if (c->x86 == 0x15 && c->x86_model <= 0x1f) {
- tlb_lli_2m[ENTRIES] = 1024;
+ tlb_lli_2m = 1024;
} else {
cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
- tlb_lli_2m[ENTRIES] = eax & 0xff;
+ tlb_lli_2m = eax & 0xff;
}
} else
- tlb_lli_2m[ENTRIES] = eax & mask;
+ tlb_lli_2m = eax & mask;

- tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+ tlb_lli_4m = tlb_lli_2m >> 1;
}

static const struct cpu_dev amd_cpu_dev = {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8eba9ca..3a1a957 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -846,13 +846,13 @@ void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
c->x86_cache_size = l2size;
}

-u16 __read_mostly tlb_lli_4k[NR_INFO];
-u16 __read_mostly tlb_lli_2m[NR_INFO];
-u16 __read_mostly tlb_lli_4m[NR_INFO];
-u16 __read_mostly tlb_lld_4k[NR_INFO];
-u16 __read_mostly tlb_lld_2m[NR_INFO];
-u16 __read_mostly tlb_lld_4m[NR_INFO];
-u16 __read_mostly tlb_lld_1g[NR_INFO];
+u16 __read_mostly tlb_lli_4k;
+u16 __read_mostly tlb_lli_2m;
+u16 __read_mostly tlb_lli_4m;
+u16 __read_mostly tlb_lld_4k;
+u16 __read_mostly tlb_lld_2m;
+u16 __read_mostly tlb_lld_4m;
+u16 __read_mostly tlb_lld_1g;

static void cpu_detect_tlb(struct cpuinfo_x86 *c)
{
@@ -860,12 +860,10 @@ static void cpu_detect_tlb(struct cpuinfo_x86 *c)
this_cpu->c_detect_tlb(c);

pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
- tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
- tlb_lli_4m[ENTRIES]);
+ tlb_lli_4k, tlb_lli_2m, tlb_lli_4m);

pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
- tlb_lld_4k[ENTRIES], tlb_lld_2m[ENTRIES],
- tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
+ tlb_lld_4k, tlb_lld_2m, tlb_lld_4m, tlb_lld_1g);
}

void get_cpu_vendor(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
index c5191b0..6af4a4a 100644
--- a/arch/x86/kernel/cpu/hygon.c
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -240,26 +240,26 @@ static void cpu_detect_tlb_hygon(struct cpuinfo_x86 *c)

cpuid(0x80000006, &eax, &ebx, &ecx, &edx);

- tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
- tlb_lli_4k[ENTRIES] = ebx & mask;
+ tlb_lld_4k = (ebx >> 16) & mask;
+ tlb_lli_4k = ebx & mask;

/* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
if (!((eax >> 16) & mask))
- tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
+ tlb_lld_2m = (cpuid_eax(0x80000005) >> 16) & 0xff;
else
- tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
+ tlb_lld_2m = (eax >> 16) & mask;

/* a 4M entry uses two 2M entries */
- tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
+ tlb_lld_4m = tlb_lld_2m >> 1;

/* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
if (!(eax & mask)) {
cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
- tlb_lli_2m[ENTRIES] = eax & 0xff;
+ tlb_lli_2m = eax & 0xff;
} else
- tlb_lli_2m[ENTRIES] = eax & mask;
+ tlb_lli_2m = eax & mask;

- tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+ tlb_lli_4m = tlb_lli_2m >> 1;
}

static const struct cpu_dev hygon_cpu_dev = {
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 42a57b8..61d3fd3 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -718,55 +718,55 @@ static void intel_tlb_lookup(const unsigned char desc)
entries = intel_tlb_table[k].entries;
switch (intel_tlb_table[k].tlb_type) {
case STLB_4K:
- tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
- tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
+ tlb_lli_4k = max(tlb_lli_4k, entries);
+ tlb_lld_4k = max(tlb_lld_4k, entries);
break;
case STLB_4K_2M:
- tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
- tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
- tlb_lli_2m[ENTRIES] = max(tlb_lli_2m[ENTRIES], entries);
- tlb_lld_2m[ENTRIES] = max(tlb_lld_2m[ENTRIES], entries);
- tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
- tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
+ tlb_lli_4k = max(tlb_lli_4k, entries);
+ tlb_lld_4k = max(tlb_lld_4k, entries);
+ tlb_lli_2m = max(tlb_lli_2m, entries);
+ tlb_lld_2m = max(tlb_lld_2m, entries);
+ tlb_lli_4m = max(tlb_lli_4m, entries);
+ tlb_lld_4m = max(tlb_lld_4m, entries);
break;
case TLB_INST_ALL:
- tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
- tlb_lli_2m[ENTRIES] = max(tlb_lli_2m[ENTRIES], entries);
- tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
+ tlb_lli_4k = max(tlb_lli_4k, entries);
+ tlb_lli_2m = max(tlb_lli_2m, entries);
+ tlb_lli_4m = max(tlb_lli_4m, entries);
break;
case TLB_INST_4K:
- tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
+ tlb_lli_4k = max(tlb_lli_4k, entries);
break;
case TLB_INST_4M:
- tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
+ tlb_lli_4m = max(tlb_lli_4m, entries);
break;
case TLB_INST_2M_4M:
- tlb_lli_2m[ENTRIES] = max(tlb_lli_2m[ENTRIES], entries);
- tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
+ tlb_lli_2m = max(tlb_lli_2m, entries);
+ tlb_lli_4m = max(tlb_lli_4m, entries);
break;
case TLB_DATA_4K:
case TLB_DATA0_4K:
- tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
+ tlb_lld_4k = max(tlb_lld_4k, entries);
break;
case TLB_DATA_4M:
case TLB_DATA0_4M:
- tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
+ tlb_lld_4m = max(tlb_lld_4m, entries);
break;
case TLB_DATA_2M_4M:
case TLB_DATA0_2M_4M:
- tlb_lld_2m[ENTRIES] = max(tlb_lld_2m[ENTRIES], entries);
- tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
+ tlb_lld_2m = max(tlb_lld_2m, entries);
+ tlb_lld_4m = max(tlb_lld_4m, entries);
break;
case TLB_DATA_4K_4M:
- tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
- tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
+ tlb_lld_4k = max(tlb_lld_4k, entries);
+ tlb_lld_4m = max(tlb_lld_4m, entries);
break;
case TLB_DATA_1G_2M_4M:
- tlb_lld_2m[ENTRIES] = max(tlb_lld_2m[ENTRIES], TLB_0x63_2M_4M_ENTRIES);
- tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], TLB_0x63_2M_4M_ENTRIES);
+ tlb_lld_2m = max(tlb_lld_2m, TLB_0x63_2M_4M_ENTRIES);
+ tlb_lld_4m = max(tlb_lld_4m, TLB_0x63_2M_4M_ENTRIES);
fallthrough;
case TLB_DATA_1G:
- tlb_lld_1g[ENTRIES] = max(tlb_lld_1g[ENTRIES], entries);
+ tlb_lld_1g = max(tlb_lld_1g, entries);
break;
}
}