From patchwork Wed Nov 16 23:37:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13045926 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35CC815C9A for ; Wed, 16 Nov 2022 23:41:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668642091; x=1700178091; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to; bh=453B5mw51T7IX+AXE0lYBsFPvcN1QxhgkLQ4Y5mYFRM=; b=KRYa9XGCWZ0eliOl0NrcdlqiW9fmdqoQfeu2YgsoiYhkQzJnQFJje5Em uF/LSITfYX0prLsqG4yj0L0C9+PENoSZYk9QeG6MUzEuHG5+44bg2u9oh NjiUU5fAkWISG8C2hZmTUPbPW9kZY6HwP3ut3MwN4a0btAPw4qoaOqlQE i83LeqBZiTrJVjaLxwZ6btHYSkISs407HZ34RE7A1X50L3ABrlHyBCFuH PTxNpweB9ejYyHd/r4PlRJrHyIoNfwbNwfw+ozko2nQivoKvxUWTdujlS +fNBUJr7PFuLjI4YFfPW9UEW3O9mLh79lQCTKwUA9l2ikqXTKvNbe/Lto w==; X-IronPort-AV: E=McAfee;i="6500,9779,10533"; a="339519706" X-IronPort-AV: E=Sophos;i="5.96,169,1665471600"; d="scan'208";a="339519706" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2022 15:41:28 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10533"; a="641848525" X-IronPort-AV: E=Sophos;i="5.96,169,1665471600"; d="scan'208";a="641848525" Received: from jjeyaram-mobl1.amr.corp.intel.com (HELO [192.168.1.28]) ([10.212.1.223]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2022 15:41:28 -0800 From: Vishal Verma Date: Wed, 16 Nov 2022 16:37:37 -0700 Subject: [PATCH v2 2/2] ACPI: HMAT: Fix initiator registration for single-initiator systems Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20221116-acpi_hmat_fix-v2-2-3712569be691@intel.com> References: <20221116-acpi_hmat_fix-v2-0-3712569be691@intel.com> In-Reply-To: <20221116-acpi_hmat_fix-v2-0-3712569be691@intel.com> To: "Rafael J. Wysocki" , Vishal Verma , linux-kernel@vger.kernel.org, Chris Piper , nvdimm@lists.linux.dev, linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , "Kirill A. Shutemov" , Dan Williams , Liu Shixin , stable@vger.kernel.org X-Mailer: b4 0.11.0-dev-d1636 X-Developer-Signature: v=1; a=openpgp-sha256; l=3352; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=453B5mw51T7IX+AXE0lYBsFPvcN1QxhgkLQ4Y5mYFRM=; b=owGbwMvMwCXGf25diOft7jLG02pJDMmlpeqsYdp2c6xeZyWxh7anfNhvw1H+WbRO+Ayz2zwZr7Sk i787SlkYxLgYZMUUWf7u+ch4TG57Pk9ggiPMHFYmkCEMXJwCMJFb0gz/U172aH6qFWVgmvjmX+DGCo 6b/u//7ddaqnris2xwmIJqOcM/s9eXn8WKzOXZu3v/G7uVJ4siwiUDNFq8lde3/XYJcs7nBgA= X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF In a system with a single initiator node, and one or more memory-only 'target' nodes, the memory-only node(s) would fail to register their initiator node correctly. i.e. in sysfs: # ls /sys/devices/system/node/node0/access0/targets/ node0 Where as the correct behavior should be: # ls /sys/devices/system/node/node0/access0/targets/ node0 node1 This happened because hmat_register_target_initiators() uses list_sort() to sort the initiator list, but the sort comparision function (initiator_cmp()) is overloaded to also set the node mask's bits. In a system with a single initiator, the list is singular, and list_sort elides the comparision helper call. Thus the node mask never gets set, and the subsequent search for the best initiator comes up empty. Add a new helper to consume the sorted initiator list, and generate the nodemask, decoupling it from the overloaded initiator_cmp() comparision callback. This prevents the singular list corner case naturally, and makes the code easier to follow as well. Cc: Cc: Rafael J. Wysocki Cc: Liu Shixin Cc: Dan Williams Cc: Kirill A. Shutemov Reported-by: Chris Piper Signed-off-by: Vishal Verma Acked-by: Kirill A. Shutemov Acked-by: Rafael J. Wysocki --- drivers/acpi/numa/hmat.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 144a84f429ed..6cceca64a6bc 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -562,17 +562,26 @@ static int initiator_cmp(void *priv, const struct list_head *a, { struct memory_initiator *ia; struct memory_initiator *ib; - unsigned long *p_nodes = priv; ia = list_entry(a, struct memory_initiator, node); ib = list_entry(b, struct memory_initiator, node); - set_bit(ia->processor_pxm, p_nodes); - set_bit(ib->processor_pxm, p_nodes); - return ia->processor_pxm - ib->processor_pxm; } +static int initiators_to_nodemask(unsigned long *p_nodes) +{ + struct memory_initiator *initiator; + + if (list_empty(&initiators)) + return -ENXIO; + + list_for_each_entry(initiator, &initiators, node) + set_bit(initiator->processor_pxm, p_nodes); + + return 0; +} + static void hmat_register_target_initiators(struct memory_target *target) { static DECLARE_BITMAP(p_nodes, MAX_NUMNODES); @@ -609,7 +618,10 @@ static void hmat_register_target_initiators(struct memory_target *target) * initiators. */ bitmap_zero(p_nodes, MAX_NUMNODES); - list_sort(p_nodes, &initiators, initiator_cmp); + list_sort(NULL, &initiators, initiator_cmp); + if (initiators_to_nodemask(p_nodes) < 0) + return; + if (!access0done) { for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { loc = localities_types[i]; @@ -643,7 +655,9 @@ static void hmat_register_target_initiators(struct memory_target *target) /* Access 1 ignores Generic Initiators */ bitmap_zero(p_nodes, MAX_NUMNODES); - list_sort(p_nodes, &initiators, initiator_cmp); + if (initiators_to_nodemask(p_nodes) < 0) + return; + for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { loc = localities_types[i]; if (!loc)