linux-kernel - [patch V6 19/19] x86/apic/uv: Remove the private leaf 0xb parser

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Date: Tue, 13 Feb 2024 22:04:25 +0100 (CET)
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: x86@...nel.org,
 Tom Lendacky <thomas.lendacky@....com>,
 Andrew Cooper <andrew.cooper3@...rix.com>,
 Arjan van de Ven <arjan@...ux.intel.com>,
 Huang Rui <ray.huang@....com>,
 Juergen Gross <jgross@...e.com>,
 Dimitri Sivanich <dimitri.sivanich@....com>,
 Sohil Mehta <sohil.mehta@...el.com>,
 K Prateek Nayak <kprateek.nayak@....com>,
 Kan Liang <kan.liang@...ux.intel.com>,
 Zhang Rui <rui.zhang@...el.com>,
 "Paul E. McKenney" <paulmck@...nel.org>,
 Feng Tang <feng.tang@...el.com>,
 Andy Shevchenko <andy@...radead.org>,
 Michael Kelley <mhklinux@...look.com>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 Wang Wendy <wendy.wang@...el.com>
Subject: [patch V6 19/19] x86/apic/uv: Remove the private leaf 0xb parser

From: Thomas Gleixner <tglx@...utronix.de>

The package shift has been already evaluated by the early CPU init.

Put the mindless copy right next to the original leaf 0xb parser.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Tested-by: Juergen Gross <jgross@...e.com>
Tested-by: Sohil Mehta <sohil.mehta@...el.com>
Tested-by: Michael Kelley <mhklinux@...look.com>
Tested-by: Zhang Rui <rui.zhang@...el.com>
Tested-by: Wang Wendy <wendy.wang@...el.com>



---
 arch/x86/include/asm/topology.h    |    5 +++
 arch/x86/kernel/apic/x2apic_uv_x.c |   52 ++++++-------------------------------
 2 files changed, 14 insertions(+), 43 deletions(-)
---

--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -126,6 +126,11 @@ static inline unsigned int topology_get_
 	return x86_topo_system.dom_size[dom];
 }
 
+static inline unsigned int topology_get_domain_shift(enum x86_topology_domains dom)
+{
+	return dom == TOPO_SMT_DOMAIN ? 0 : x86_topo_system.dom_shifts[dom - 1];
+}
+
 extern const struct cpumask *cpu_coregroup_mask(int cpu);
 extern const struct cpumask *cpu_clustergroup_mask(int cpu);
 
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -241,54 +241,20 @@ static void __init uv_tsc_check_sync(voi
 	is_uv(UV3) ? sname.s3.field :		\
 	undef)
 
-/* [Copied from arch/x86/kernel/cpu/topology.c:detect_extended_topology()] */
-
-#define SMT_LEVEL			0	/* Leaf 0xb SMT level */
-#define INVALID_TYPE			0	/* Leaf 0xb sub-leaf types */
-#define SMT_TYPE			1
-#define CORE_TYPE			2
-#define LEAFB_SUBTYPE(ecx)		(((ecx) >> 8) & 0xff)
-#define BITS_SHIFT_NEXT_LEVEL(eax)	((eax) & 0x1f)
-
-static void set_x2apic_bits(void)
-{
-	unsigned int eax, ebx, ecx, edx, sub_index;
-	unsigned int sid_shift;
-
-	cpuid(0, &eax, &ebx, &ecx, &edx);
-	if (eax < 0xb) {
-		pr_info("UV: CPU does not have CPUID.11\n");
-		return;
-	}
-
-	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
-	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE)) {
-		pr_info("UV: CPUID.11 not implemented\n");
-		return;
-	}
-
-	sid_shift = BITS_SHIFT_NEXT_LEVEL(eax);
-	sub_index = 1;
-	do {
-		cpuid_count(0xb, sub_index, &eax, &ebx, &ecx, &edx);
-		if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
-			sid_shift = BITS_SHIFT_NEXT_LEVEL(eax);
-			break;
-		}
-		sub_index++;
-	} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
-
-	uv_cpuid.apicid_shift	= 0;
-	uv_cpuid.apicid_mask	= (~(-1 << sid_shift));
-	uv_cpuid.socketid_shift = sid_shift;
-}
-
 static void __init early_get_apic_socketid_shift(void)
 {
+	unsigned int sid_shift = topology_get_domain_shift(TOPO_PKG_DOMAIN);
+
 	if (is_uv2_hub() || is_uv3_hub())
 		uvh_apicid.v = uv_early_read_mmr(UVH_APICID);
 
-	set_x2apic_bits();
+	if (sid_shift) {
+		uv_cpuid.apicid_shift	= 0;
+		uv_cpuid.apicid_mask	= (~(-1 << sid_shift));
+		uv_cpuid.socketid_shift = sid_shift;
+	} else {
+		pr_info("UV: CPU does not have valid CPUID.11\n");
+	}
 
 	pr_info("UV: apicid_shift:%d apicid_mask:0x%x\n", uv_cpuid.apicid_shift, uv_cpuid.apicid_mask);
 	pr_info("UV: socketid_shift:%d pnode_mask:0x%x\n", uv_cpuid.socketid_shift, uv_cpuid.pnode_mask);