From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 ADDE2157462; Tue, 9 Apr 2024 19:15:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712690153; cv=none; b=SzzP21ETR5J4Ixq3XwTMI4VHNgMpFMegvHbJ8H8BOhSU+UCkcsE/tbJ1vWjyRb+nZ+nZIteEUqDulUgJX40JsV1zRUzsAT5vSMAfGykmisEKHaPpGzPLGKjEox2TeOSxAr8opJCvaZCAUJHreVzoRwHqPL/Qxc18bdCasAS8jgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712690153; c=relaxed/simple; bh=P3Z0Rgecbqy5GMoJK4XNHZXEK5RvpqeukRb0HOaJO/8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nX20V7l4k7vAySZINJJt6RTUVMNkdqUhuM2KXw96HYN3hSVzHX7xDmCDRXCZltQKZta17imEwFYBXrD1RJ7fbzNQYpYkPXPU7qQC2/PuNWhM0a+hWHqLrEdCmYLOmELeGeV89qF75zMwxn40xcsNs1W7b+IN2s6YQKfL39cHKrw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=dSsRxTrL; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="dSsRxTrL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712690151; x=1744226151; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=P3Z0Rgecbqy5GMoJK4XNHZXEK5RvpqeukRb0HOaJO/8=; b=dSsRxTrL4TlKGZeRIs0v4Q5uex9CkZEjXRYuKuCD0Qsc1mNMbApmoL+p MwbdX1ejrcwM5Bew0yIpbUdL2/I88FeTTwREpPncwCP0ttZe4ACHGF5wi MDfSdCiMMIeueYO6G6RlZS8pluC2G5GS94w00mhb3KrvdSubP0a+rk104 zv50Ogh3QYy1yaNqhJpuaPfsb15L3rQXjAK0ugsCT8mp5LiyqO+TqzuKP +oIY3xjCr95173VPl51xeXyOhHODIpbYycF0+W9vvdMz79/PAF5iVbt/X Joz8RueHXjOYqyzj2kPcSDqlM/AcK/VOX93oh0vbRCYeI3+IYilzh6Nwx Q==; X-CSE-ConnectionGUID: 98rE46KKS/qLZsRYigUARw== X-CSE-MsgGUID: I/SV1O94SIOWwyy/qe7Ung== X-IronPort-AV: E=McAfee;i="6600,9927,11039"; a="7881509" X-IronPort-AV: E=Sophos;i="6.07,190,1708416000"; d="scan'208";a="7881509" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Apr 2024 12:15:51 -0700 X-CSE-ConnectionGUID: VVzvsBA/Q8SPNaJnk07HcQ== X-CSE-MsgGUID: wOsuXYO9RDOj0ZYquYcTMg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,190,1708416000"; d="scan'208";a="24814231" Received: from djiang5-mobl3.amr.corp.intel.com (HELO [10.213.183.123]) ([10.213.183.123]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Apr 2024 12:15:51 -0700 Message-ID: <519bf934-840b-496d-9a5e-7b183c5be258@intel.com> Date: Tue, 9 Apr 2024 12:15:50 -0700 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/3] cxl/core/regs: Add rcd_regs initialization at __rcrb_to_component() To: "Kobayashi,Daisuke" , kobayashi.da-06@jp.fujitsu.com, linux-cxl@vger.kernel.org Cc: y-goto@fujitsu.com, linux-pci@vger.kernel.org, mj@ucw.cz, dan.j.williams@intel.com References: <20240409073528.13214-1-kobayashi.da-06@fujitsu.com> <20240409073528.13214-3-kobayashi.da-06@fujitsu.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <20240409073528.13214-3-kobayashi.da-06@fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/9/24 12:35 AM, Kobayashi,Daisuke wrote: > Add rcd_regs initialization at __rcrb_to_component() to cache the cxl1.1 > device link status information. Reduce access to the memory map area > where the RCRB is located by caching the cxl1.1 device link status information. > > Signed-off-by: "Kobayashi,Daisuke" > --- > drivers/cxl/core/regs.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c > index 372786f80955..308eb951613e 100644 > --- a/drivers/cxl/core/regs.c > +++ b/drivers/cxl/core/regs.c > @@ -514,6 +514,8 @@ resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri > u32 bar0, bar1; > u16 cmd; > u32 id; > + u16 offset; > + u32 cap_hdr; > > if (which == CXL_RCRB_UPSTREAM) > rcrb += SZ_4K; > @@ -537,6 +539,22 @@ resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri > cmd = readw(addr + PCI_COMMAND); > bar0 = readl(addr + PCI_BASE_ADDRESS_0); > bar1 = readl(addr + PCI_BASE_ADDRESS_1); > + > + offset = readw(addr + PCI_CAPABILITY_LIST); > + offset &= 0x00ff; GENMASK(7,0) is preferred to 0x00ff. Although a properly defined mask would be nice. Also please consider using FIELD_GET(). > + cap_hdr = readl(addr + offset); > + while ((cap_hdr & 0x000000ff) != PCI_CAP_ID_EXP) { Same comment as above > + offset = (cap_hdr >> 8) & 0x000000ff; Also here > + if (offset == 0) // End of capability list Please use /* */ instead of // for Linux kernel code > + break; > + cap_hdr = readl(addr + offset); > + } > + if (offset) { > + ri->rcd_lnkcap = readl(addr + offset + PCI_EXP_LNKCAP); > + ri->rcd_lnkctrl = readl(addr + offset + PCI_EXP_LNKCTL); > + ri->rcd_lnkstatus = readl(addr + offset + PCI_EXP_LNKSTA); > + } > + > iounmap(addr); > release_mem_region(rcrb, SZ_4K); >