From patchwork Thu Oct 27 04:07:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alison Schofield X-Patchwork-Id: 13021567 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4A8AFA3740 for ; Thu, 27 Oct 2022 04:08:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234434AbiJ0EIA (ORCPT ); Thu, 27 Oct 2022 00:08:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234437AbiJ0EH6 (ORCPT ); Thu, 27 Oct 2022 00:07:58 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C08B4156244 for ; Wed, 26 Oct 2022 21:07:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666843673; x=1698379673; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8JSXwemUR97hfN7bebzAsiPRQIeTRXeVA85tL5XAYBg=; b=LEZM7U8F12wpf8aMl8xdt37p+2OWiRbuLY2NMEZ0wOcfU9HKh6/X4nfU US7wchn4pLfyOFY7ZfEBXgcJ9n2yiSIAGxX5difyOYSz/4n4fcCUrGPEI q92U0xr+aB3jvAS19KnGIevBwQaQv4jhUasfS6Q5DlIyGks0FXBYV9EaT gJ++J3NiW6F2zY6mqPdF93+TmSaaA/O05j304NxAWNuLWF5COtlzwjaYv 60wtQyCMMiZi01mFffauwXJrrxrLEvvqMh5yKl6xyv9RNQ59pKKgabzEc 81EDXJVfmmbqOvBf+275XgdtTzoJ3wqBoCelAPm2e4NVrgFMTLXjrC9iV A==; X-IronPort-AV: E=McAfee;i="6500,9779,10512"; a="295533033" X-IronPort-AV: E=Sophos;i="5.95,215,1661842800"; d="scan'208";a="295533033" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2022 21:07:52 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10512"; a="961475581" X-IronPort-AV: E=Sophos;i="5.95,215,1661842800"; d="scan'208";a="961475581" Received: from aschofie-mobl2.amr.corp.intel.com (HELO localhost) ([10.209.1.141]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2022 21:07:52 -0700 From: alison.schofield@intel.com To: Dan Williams , Ira Weiny , Vishal Verma , Ben Widawsky , Dave Jiang Cc: Alison Schofield , linux-cxl@vger.kernel.org Subject: [PATCH v5 2/3] cxl/acpi: Support CXL XOR Interleave Math (CXIMS) Date: Wed, 26 Oct 2022 21:07:42 -0700 Message-Id: <83476d7728d87ff276c19664d096cba708a0c143.1666841669.git.alison.schofield@intel.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Alison Schofield When the CFMWS is using XOR math, parse the corresponding CXIMS structure and store the xormaps in the root decoder structure. Use the xormaps in a new lookup, cxl_hb_xor(), to find a targets entry in the host bridge interleave target list. Defined in CXL Specfication 3.0 Section: 9.17.1 Signed-off-by: Alison Schofield --- drivers/cxl/acpi.c | 129 +++++++++++++++++++++++++++++++++++++++++++-- drivers/cxl/cxl.h | 2 + 2 files changed, 126 insertions(+), 5 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index fb649683dd3a..1211c31c29d2 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -6,9 +6,106 @@ #include #include #include +#include #include "cxlpci.h" #include "cxl.h" +struct cxims_data { + int nr_maps; + u64 xormaps[]; +}; + +/* + * Find a targets entry (n) in the host bridge interleave list. + * CXL Specfication 3.0 Table 9-22 + */ +static struct cxl_dport *cxl_hb_xor(struct cxl_root_decoder *cxlrd, int pos) +{ + struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd; + struct cxims_data *cximsd = cxlrd->platform_data; + struct cxl_decoder *cxld = &cxlsd->cxld; + int ig = cxld->interleave_granularity; + int iw = cxld->interleave_ways; + int eiw, i = 0, n = 0; + u64 hpa; + + if (dev_WARN_ONCE(&cxld->dev, + cxld->interleave_ways != cxlsd->nr_targets, + "misconfigured root decoder\n")) + return NULL; + + if (iw == 1) + /* Entry is always 0 for no interleave */ + return cxlrd->cxlsd.target[0]; + + hpa = cxlrd->res->start + pos * ig; + + if (iw == 3) + goto no_map; + + /* IW: 2,4,6,8,12,16 begin building 'n' using xormaps */ + for (i = 0; i < cximsd->nr_maps; i++) + n |= (hweight64(hpa & cximsd->xormaps[i]) & 1) << i; + +no_map: + /* IW: 3,6,12 add a modulo calculation to 'n' */ + if (!is_power_of_2(iw)) { + eiw = ilog2(iw / 3) + 8; + hpa &= GENMASK_ULL(51, eiw + ig); + n |= do_div(hpa, 3) << i; + } + return cxlrd->cxlsd.target[n]; +} + +struct cxl_cxims_context { + struct device *dev; + struct cxl_root_decoder *cxlrd; +}; + +static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg, + const unsigned long end) +{ + struct acpi_cedt_cxims *cxims = (struct acpi_cedt_cxims *)header; + struct cxl_cxims_context *ctx = arg; + struct cxl_root_decoder *cxlrd = ctx->cxlrd; + struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld; + struct device *dev = ctx->dev; + struct cxims_data *cximsd; + unsigned int hbig, nr_maps; + int rc; + + rc = cxl_to_granularity(cxims->hbig, &hbig); + if (rc) + return rc; + + if (hbig == cxld->interleave_granularity) { + /* IW 1,3 do not use xormaps and skip this parsing entirely */ + + if (is_power_of_2(cxld->interleave_ways)) + /* 2, 4, 8, 16 way */ + nr_maps = ilog2(cxld->interleave_ways); + else + /* 6, 12 way */ + nr_maps = ilog2(cxld->interleave_ways / 3); + + if (cxims->nr_xormaps < nr_maps) { + dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n", + cxims->nr_xormaps, nr_maps); + return -ENXIO; + } + + cximsd = devm_kzalloc(dev, + struct_size(cximsd, xormaps, nr_maps), + GFP_KERNEL); + memcpy(cximsd->xormaps, cxims->xormap_list, + nr_maps * sizeof(*cximsd->xormaps)); + cximsd->nr_maps = nr_maps; + cxlrd->platform_data = cximsd; + cxlrd->calc_hb = cxl_hb_xor; + } + return 0; +} + static unsigned long cfmws_to_decoder_flags(int restrictions) { unsigned long flags = CXL_DECODER_F_ENABLE; @@ -33,11 +130,6 @@ static int cxl_acpi_cfmws_verify(struct device *dev, int rc, expected_len; unsigned int ways; - if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) { - dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n"); - return -EINVAL; - } - if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) { dev_err(dev, "CFMWS Base HPA not 256MB aligned\n"); return -EINVAL; @@ -84,6 +176,7 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, struct cxl_cfmws_context *ctx = arg; struct cxl_port *root_port = ctx->root_port; struct resource *cxl_res = ctx->cxl_res; + struct cxl_cxims_context cxims_ctx; struct cxl_root_decoder *cxlrd; struct device *dev = ctx->dev; struct acpi_cedt_cfmws *cfmws; @@ -148,7 +241,33 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, ig = CXL_DECODER_MIN_GRANULARITY; cxld->interleave_granularity = ig; + if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) { + if (ways == 1 || ways == 3) { + /* Skip CXIMS parsing for IW 1 or 3. No xormaps used */ + cxlrd->calc_hb = cxl_hb_xor; + goto decoder_add; + } + + cxims_ctx = (struct cxl_cxims_context) { + .dev = dev, + .cxlrd = cxlrd, + }; + + rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS, + cxl_parse_cxims, &cxims_ctx); + if (rc < 0) + goto err_xormap; + + if (cxlrd->calc_hb != cxl_hb_xor) { + rc = -ENXIO; + goto err_xormap; + } + } + +decoder_add: rc = cxl_decoder_add(cxld, target_map); + +err_xormap: if (rc) put_device(&cxld->dev); else diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index f680450f0b16..0a17a7007bff 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -330,12 +330,14 @@ struct cxl_switch_decoder { * @res: host / parent resource for region allocations * @region_id: region id for next region provisioning event * @calc_hb: which host bridge covers the n'th position by granularity + * @platform_data: platform specific configuration data * @cxlsd: base cxl switch decoder */ struct cxl_root_decoder { struct resource *res; atomic_t region_id; struct cxl_dport *(*calc_hb)(struct cxl_root_decoder *cxlrd, int pos); + void *platform_data; struct cxl_switch_decoder cxlsd; };