[tip: x86/cpu] x86/cpu: Use max() for CPUID leaf 0x2 TLB descriptors parsing
From: tip-bot2 for Ahmed S. Darwish
Date: Tue Mar 04 2025 - 04:41:20 EST
The following commit has been merged into the x86/cpu branch of tip:
Commit-ID: 581616f5254333d510886ebb2206f0bff85778ff
Gitweb: https://git.kernel.org/tip/581616f5254333d510886ebb2206f0bff85778ff
Author: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx>
AuthorDate: Tue, 04 Mar 2025 09:51:17 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 04 Mar 2025 10:15:24 +01:00
x86/cpu: Use max() for CPUID leaf 0x2 TLB descriptors parsing
The conditional statement "if (x < y) { x = y; }" appears 22 times at
the Intel leaf 0x2 descriptors parsing logic.
Replace each of such instances with a max() expression to simplify
the code.
Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250304085152.51092-7-darwi@xxxxxxxxxxxxx
---
arch/x86/kernel/cpu/intel.c | 76 +++++++++++++-----------------------
1 file changed, 28 insertions(+), 48 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 60b58b1..42a57b8 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -3,6 +3,7 @@
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/minmax.h>
#include <linux/smp.h>
#include <linux/string.h>
@@ -700,7 +701,9 @@ static const struct _tlb_table intel_tlb_table[] = {
static void intel_tlb_lookup(const unsigned char desc)
{
+ unsigned int entries;
unsigned char k;
+
if (desc == 0)
return;
@@ -712,81 +715,58 @@ static void intel_tlb_lookup(const unsigned char desc)
if (intel_tlb_table[k].tlb_type == 0)
return;
+ entries = intel_tlb_table[k].entries;
switch (intel_tlb_table[k].tlb_type) {
case STLB_4K:
- if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
+ tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
break;
case STLB_4K_2M:
- if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
+ 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);
break;
case TLB_INST_ALL:
- if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
+ 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);
break;
case TLB_INST_4K:
- if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lli_4k[ENTRIES] = max(tlb_lli_4k[ENTRIES], entries);
break;
case TLB_INST_4M:
- if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
break;
case TLB_INST_2M_4M:
- if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lli_2m[ENTRIES] = max(tlb_lli_2m[ENTRIES], entries);
+ tlb_lli_4m[ENTRIES] = max(tlb_lli_4m[ENTRIES], entries);
break;
case TLB_DATA_4K:
case TLB_DATA0_4K:
- if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
break;
case TLB_DATA_4M:
case TLB_DATA0_4M:
- if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
break;
case TLB_DATA_2M_4M:
case TLB_DATA0_2M_4M:
- if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lld_2m[ENTRIES] = max(tlb_lld_2m[ENTRIES], entries);
+ tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
break;
case TLB_DATA_4K_4M:
- if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
- if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lld_4k[ENTRIES] = max(tlb_lld_4k[ENTRIES], entries);
+ tlb_lld_4m[ENTRIES] = max(tlb_lld_4m[ENTRIES], entries);
break;
case TLB_DATA_1G_2M_4M:
- if (tlb_lld_2m[ENTRIES] < TLB_0x63_2M_4M_ENTRIES)
- tlb_lld_2m[ENTRIES] = TLB_0x63_2M_4M_ENTRIES;
- if (tlb_lld_4m[ENTRIES] < TLB_0x63_2M_4M_ENTRIES)
- tlb_lld_4m[ENTRIES] = TLB_0x63_2M_4M_ENTRIES;
+ 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);
fallthrough;
case TLB_DATA_1G:
- if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
- tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
+ tlb_lld_1g[ENTRIES] = max(tlb_lld_1g[ENTRIES], entries);
break;
}
}