linux-kernel - [PATCH 07/16] x86/amd_nb: Use topology info to get AMD node count

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241023172150.659002-8-yazen.ghannam@amd.com>
Date: Wed, 23 Oct 2024 17:21:41 +0000
From: Yazen Ghannam <yazen.ghannam@....com>
To: <linux-edac@...r.kernel.org>
CC: <linux-kernel@...r.kernel.org>, <tony.luck@...el.com>, <x86@...nel.org>,
	<avadhut.naik@....com>, <john.allen@....com>, <mario.limonciello@....com>,
	<bhelgaas@...gle.com>, <Shyam-sundar.S-k@....com>, <richard.gong@....com>,
	<jdelvare@...e.com>, <linux@...ck-us.net>, <clemens@...isch.de>,
	<hdegoede@...hat.com>, <ilpo.jarvinen@...ux.intel.com>,
	<linux-pci@...r.kernel.org>, <linux-hwmon@...r.kernel.org>,
	<platform-driver-x86@...r.kernel.org>, <naveenkrishna.chatradhi@....com>,
	<carlos.bilbao.osdev@...il.com>, Yazen Ghannam <yazen.ghannam@....com>
Subject: [PATCH 07/16] x86/amd_nb: Use topology info to get AMD node count

Currently, the total AMD node count is determined by searching and
counting CPU/node devices using PCI IDs.

However, AMD node information is already available through topology
CPUID/MSRs. The recent topology rework has made this info easier to
access.

Replace the node counting code with a simple product of topology info.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---
 arch/x86/include/asm/amd_node.h |  5 +++++
 arch/x86/kernel/amd_nb.c        | 11 ++---------
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/amd_node.h b/arch/x86/include/asm/amd_node.h
index 3f097dd479f8..419a0ad13ef2 100644
--- a/arch/x86/include/asm/amd_node.h
+++ b/arch/x86/include/asm/amd_node.h
@@ -25,4 +25,9 @@
 struct pci_dev *amd_node_get_func(u16 node, u8 func);
 struct pci_dev *amd_node_get_root(u16 node);
 
+static inline u16 amd_num_nodes(void)
+{
+	return topology_amd_nodes_per_pkg() * topology_max_packages();
+}
+
 #endif /*_ASM_X86_AMD_NODE_H_*/
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 135ecc0a0166..7ccd769f9c5e 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -186,7 +186,6 @@ static int amd_cache_northbridges(void)
 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
 	struct pci_dev *misc;
 	struct amd_northbridge *nb;
-	u16 misc_count = 0;
 	u16 i;
 
 	if (amd_northbridges.num)
@@ -196,19 +195,13 @@ static int amd_cache_northbridges(void)
 		misc_ids = hygon_nb_misc_ids;
 	}
 
-	misc = NULL;
-	while ((misc = next_northbridge(misc, misc_ids)))
-		misc_count++;
-
-	if (!misc_count)
-		return -ENODEV;
+	amd_northbridges.num = amd_num_nodes();
 
-	nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);
+	nb = kcalloc(amd_northbridges.num, sizeof(struct amd_northbridge), GFP_KERNEL);
 	if (!nb)
 		return -ENOMEM;
 
 	amd_northbridges.nb = nb;
-	amd_northbridges.num = misc_count;
 
 	misc = NULL;
 	for (i = 0; i < amd_northbridges.num; i++) {
-- 
2.43.0