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Message-ID: <20230814085114.122486064@linutronix.de>
From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     x86@kernel.org, Tom Lendacky <thomas.lendacky@amd.com>,
        Andrew Cooper <andrew.cooper3@citrix.com>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Huang Rui <ray.huang@amd.com>, Juergen Gross <jgross@suse.com>,
        Dimitri Sivanich <dimitri.sivanich@hpe.com>,
        Michael Kelley <mikelley@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Pu Wen <puwen@hygon.cn>,
        Qiuxu Zhuo <qiuxu.zhuo@intel.com>,
        Sohil Mehta <sohil.mehta@intel.com>
Subject: [patch V4 35/41] x86/mm/numa: Use core domain size on AMD
References: <20230814085006.593997112@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date:   Mon, 14 Aug 2023 10:54:29 +0200 (CEST)
Precedence: bulk

cpuinfo::topo::x86_coreid_bits is about to be phased out. Use the core
domain size from the topology information.

Add a comment why the early MPTABLE parsing is required and decrapify the
loop which sets the APIC ID to node map.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mikelley@microsoft.com>

---
 arch/x86/mm/amdtopology.c |   35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

--- a/arch/x86/mm/amdtopology.c
+++ b/arch/x86/mm/amdtopology.c
@@ -54,13 +54,11 @@ static __init int find_northbridge(void)
 
 int __init amd_numa_init(void)
 {
-	u64 start = PFN_PHYS(0);
+	unsigned int numnodes, cores, apicid;
+	u64 prevbase, start = PFN_PHYS(0);
 	u64 end = PFN_PHYS(max_pfn);
-	unsigned numnodes;
-	u64 prevbase;
-	int i, j, nb;
 	u32 nodeid, reg;
-	unsigned int bits, cores, apicid_base;
+	int i, j, nb;
 
 	if (!early_pci_allowed())
 		return -EINVAL;
@@ -158,26 +156,25 @@ int __init amd_numa_init(void)
 		return -ENOENT;
 
 	/*
-	 * We seem to have valid NUMA configuration.  Map apicids to nodes
-	 * using the coreid bits from early_identify_cpu.
+	 * We seem to have valid NUMA configuration. Map apicids to nodes
+	 * using the size of the core domain in the APIC space.
 	 */
-	bits = boot_cpu_data.x86_coreid_bits;
-	cores = 1 << bits;
-	apicid_base = 0;
+	cores = topology_get_domain_size(TOPO_CORE_DOMAIN);
 
 	/*
-	 * get boot-time SMP configuration:
+	 * Scan MPTABLE to map the local APIC and ensure that the boot CPU
+	 * APIC ID is valid. This is required because on pre ACPI/SRAT
+	 * systems IO-APICs are mapped before the boot CPU.
 	 */
 	early_get_smp_config();
 
-	if (boot_cpu_physical_apicid > 0) {
-		pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
-		apicid_base = boot_cpu_physical_apicid;
+	apicid = boot_cpu_physical_apicid;
+	if (apicid > 0)
+		pr_info("BSP APIC ID: %02x\n", apicid);
+
+	for_each_node_mask(i, numa_nodes_parsed) {
+		for (j = 0; j < cores; j++, apicid++)
+			set_apicid_to_node(apicid, i);
 	}
-
-	for_each_node_mask(i, numa_nodes_parsed)
-		for (j = apicid_base; j < cores + apicid_base; j++)
-			set_apicid_to_node((i << bits) + j, i);
-
 	return 0;
 }