From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com (pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com [34.218.115.239]) (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 36B6837D108; Sun, 3 May 2026 15:51:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=34.218.115.239 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777823486; cv=none; b=PKCC4x766dCjtfMddeLnn68+M0+H/RyCWkX54/jo6Omw5YrP8JU+ldLrOIaZAx+syygV8KPhStnan1+RKdw/KLsaTIMeLRLIRvyQffONf/BtXwerIpDslcxf++7UQ7wJjWybGrRXDOZ2t4ImU5UnQuMYdmlku7Gaz1Gsf+PHxUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777823486; c=relaxed/simple; bh=pS76ZkZ9Bly89nkb5ej1x/6GyNi/bcPjv1fXxUb+xxU=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=WfOT2dqXb8cGRYDkg+Xtu2/xadr7dGI74gablvyuUYjsCmP6imQWq6vJxN3Jeb6bU1b7DcvkFcG+Nfv9SBjYUyQFPJsTFEd4h2yQQ7MuWT8qMBoEz4u61Lm+kAIjCVgw5RQuA0ZZe1o+8fPndwjmVwLuyCOOSJwrhYnv4f6N+GA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b=VpWxR2TU; arc=none smtp.client-ip=34.218.115.239 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b="VpWxR2TU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazoncorp2; t=1777823485; x=1809359485; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=wlNemilBuw39SThyFRPcSL8dn9W2ob2b25XcfmRbzNo=; b=VpWxR2TUDlormpr71cWCJdLCyWjMoH8vkV8CuhuETVwFzTjzc1b2QQyJ 6FmWjC5iIp8TzkHDtEoEeyeiHL5GsPBqAvN/0vSdqOKPP8k70LJX+NyST ioQx+8gEfQCTifBS7/HnQ+ie31D64We4Tf3KMut1ER6eaF+5Po51Xx8qS ZpF5cqM7BDdCWqUfyZ8LS2NJzGZ8PTBOuV0z55JCO/jh9GYbyAlMTWmWR q/SZ0//qXabON1+9eIOh0N0mFb0lWwThTF6mCwK3KWBA+j/MZPX6oISY6 U8tsjhNI699FtoSk3XP5VSFNPmWd2IE4lIdk976Ked8DjarDDq6Y5XdG5 w==; X-CSE-ConnectionGUID: 1C1iU2exQciPINPU8IOI/Q== X-CSE-MsgGUID: NLApcGvNT6aePF+J5pBjJw== X-IronPort-AV: E=Sophos;i="6.23,213,1770595200"; d="scan'208";a="18543697" Received: from ip-10-5-0-115.us-west-2.compute.internal (HELO smtpout.naws.us-west-2.prod.farcaster.email.amazon.dev) ([10.5.0.115]) by internal-pdx-out-013.esa.us-west-2.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 May 2026 15:51:22 +0000 Received: from EX19MTAUWB001.ant.amazon.com [205.251.233.51:1245] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.27.2:2525] with esmtp (Farcaster) id 7c33e460-31d7-4c8f-835e-d3e23c625257; Sun, 3 May 2026 15:51:22 +0000 (UTC) X-Farcaster-Flow-ID: 7c33e460-31d7-4c8f-835e-d3e23c625257 Received: from EX19D001UWA001.ant.amazon.com (10.13.138.214) by EX19MTAUWB001.ant.amazon.com (10.250.64.248) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Sun, 3 May 2026 15:51:22 +0000 Received: from dev-dsk-avivb-1b-e28f450e.eu-west-1.amazon.com (10.15.33.9) by EX19D001UWA001.ant.amazon.com (10.13.138.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Sun, 3 May 2026 15:51:20 +0000 From: Aviv Bakal To: , , CC: , , , , , Subject: [PATCH] perf/arm-cmn: Add workarounds for CMN-S3 on Graviton5 Date: Sun, 3 May 2026 18:51:18 +0300 Message-ID: <20260503155118.16191-1-avivb@amazon.com> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D031UWA001.ant.amazon.com (10.13.139.88) To EX19D001UWA001.ant.amazon.com (10.13.138.214) Graviton5 uses a customised CMN-S3 implementation where certain discovery registers report zeroed fields. Add the following workarounds: - Introduce a dedicated ACPI HID to identify the Graviton5 CMN variant. - Derive the DTC domain from the XP node ID, since the unit info register reports it as zero. - Set the DTC logical ID from the XP's logical ID, since the node info register's logical ID field is also zeroed. Signed-off-by: Aviv Bakal --- drivers/perf/arm-cmn.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index f5305c8fdca4..368fe1a86bfb 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -31,7 +31,8 @@ #define CMN_CHILD_NODE_ADDR GENMASK(29, 0) #define CMN_CHILD_NODE_EXTERNAL BIT(31) -#define CMN_MAX_DIMENSION 12 +/* Some implementations use a mesh larger than the architectural max of 12 */ +#define CMN_MAX_DIMENSION 14 #define CMN_MAX_XPS (CMN_MAX_DIMENSION * CMN_MAX_DIMENSION) #define CMN_MAX_DTMS (CMN_MAX_XPS + (CMN_MAX_DIMENSION - 1) * 4) @@ -214,6 +215,8 @@ enum cmn_part { PART_CMN700 = 0x43c, PART_CI700 = 0x43a, PART_CMN_S3 = 0x43e, + /* Synthetic part number, overridden to PART_CMN_S3 during discovery */ + PART_GRAVITON5 = 0xa5, }; /* CMN-600 r0px shouldn't exist in silicon, thankfully */ @@ -2221,6 +2224,18 @@ static unsigned int arm_cmn_dtc_domain(struct arm_cmn *cmn, void __iomem *xp_reg return FIELD_GET(CMN_DTM_UNIT_INFO_DTC_DOMAIN, readl_relaxed(xp_region + offset)); } +static unsigned int arm_cmn_graviton5_dtc_domain(u16 xp_id) +{ + unsigned int x = (xp_id >> 7) & 0xf; + unsigned int y = (xp_id >> 3) & 0xf; + + /* + * The unit info register reads as zero; derive the DTC domain from + * the XP's mesh coordinates over the 10x14 mesh. + */ + return (x / 5) + (y / 7) * 2; +} + static void arm_cmn_init_node_info(struct arm_cmn *cmn, u32 offset, struct arm_cmn_node *node) { int level; @@ -2266,6 +2281,7 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) u64 reg; int i, j; size_t sz; + bool graviton5_workaround = false; arm_cmn_init_node_info(cmn, rgn_offset, &cfg); if (cfg.type != CMN_TYPE_CFG) @@ -2276,6 +2292,13 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) reg = readq_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_01); part = FIELD_GET(CMN_CFGM_PID0_PART_0, reg); part |= FIELD_GET(CMN_CFGM_PID1_PART_1, reg) << 8; + + /* Graviton5 has a customised CMN-S3 which needs some fixups */ + if (cmn->part == PART_GRAVITON5) { + cmn->part = PART_CMN_S3; + graviton5_workaround = true; + } + /* 600AE is close enough that it's not really worth more complexity */ if (part == PART_CMN600AE) part = PART_CMN600; @@ -2365,6 +2388,8 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) if (cmn->part == PART_CMN600) xp->dtc = -1; + else if (graviton5_workaround) + xp->dtc = arm_cmn_graviton5_dtc_domain(xp->id); else xp->dtc = arm_cmn_dtc_domain(cmn, xp_region); @@ -2443,6 +2468,10 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) switch (dn->type) { case CMN_TYPE_DTC: + if (graviton5_workaround) { + /* Node info logical ID is zeroed; use the XP's */ + dn->logid = xp->logid; + } cmn->num_dtcs++; dn++; break; @@ -2658,6 +2687,7 @@ static const struct acpi_device_id arm_cmn_acpi_match[] = { { "ARMHC650" }, { "ARMHC700" }, { "ARMHC003" }, + { "AMZN0070", PART_GRAVITON5 }, {} }; MODULE_DEVICE_TABLE(acpi, arm_cmn_acpi_match); -- 2.47.3