From patchwork Fri Jan 7 00:37:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12706037 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 D67D8C433F5 for ; Fri, 7 Jan 2022 00:38:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344302AbiAGAiM (ORCPT ); Thu, 6 Jan 2022 19:38:12 -0500 Received: from mga18.intel.com ([134.134.136.126]:59439 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344112AbiAGAiM (ORCPT ); Thu, 6 Jan 2022 19:38:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641515891; x=1673051891; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jRAGW40hm+eWujsirYaF4GKLwnQu9VufkUx+C2DxegU=; b=nU7q73BGqB3POhgnBLgluffT1SY1QQxg9TRCl6+ae3zjb1Cl1sP8/210 Se9zGb/Gf09yECoumo0ueZ2ez2rYhV+2h3CTXhoIrDRIQmpEvD0xyQyrK aO4kFsbhyq0nTORFZ1/xKGcvLfrCHekyyOPFfiaQhna68bsuL1SwlKT8T MczNmFwiVtdfvHlrFS1nxiouuH3j+zejyTWozCfqAhnZMH4vLSyd07aWK zV65I8WhQNURRIWe7QkVmWQpX+2A/333KZ4Lfs0SzTg4RQn8lzLsVJ47x aADjJWFFgn5EPgIKlHbD4YkmJPUfNolW9WrnDg4/YQgsaygfBeLbCP9Xa Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10217"; a="229582027" X-IronPort-AV: E=Sophos;i="5.88,268,1635231600"; d="scan'208";a="229582027" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jan 2022 16:38:11 -0800 X-IronPort-AV: E=Sophos;i="5.88,268,1635231600"; d="scan'208";a="471123212" Received: from elenawei-mobl2.amr.corp.intel.com (HELO localhost.localdomain) ([10.252.138.104]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jan 2022 16:38:11 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org Cc: patches@lists.linux.dev, Bjorn Helgaas , Ben Widawsky , Alison Schofield , Dan Williams , Ira Weiny , Jonathan Cameron , Vishal Verma Subject: [PATCH 06/13] cxl/region: Introduce a cxl_region driver Date: Thu, 6 Jan 2022 16:37:49 -0800 Message-Id: <20220107003756.806582-7-ben.widawsky@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220107003756.806582-1-ben.widawsky@intel.com> References: <20220107003756.806582-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The cxl_region driver is responsible for managing the HDM decoder programming in the CXL topology. Once a region is created it must be configured and bound to the driver in order to activate it. The following is a sample of how such controls might work: region=$(cat /sys/bus/cxl/devices/decoder0.0/create_region) echo $region > /sys/bus/cxl/devices/decoder0.0/create_region echo 2 > /sys/bus/cxl/devices/decoder0.0/region0.0:0/interleave echo $((256<<20)) > /sys/bus/cxl/devices/decoder0.0/region0.0:0/size echo mem0 > /sys/bus/cxl/devices/decoder0.0/region0.0:0/target0 echo mem1 > /sys/bus/cxl/devices/decoder0.0/region0.0:0/target1 echo region0.0:0 > /sys/bus/cxl/drivers/cxl_region/bind In order to handle the eventual rise in failure modes of binding a region, a new trace event is created to help track these failures for debug and reconfiguration paths in userspace. Signed-off-by: Ben Widawsky --- .../driver-api/cxl/memory-devices.rst | 3 + drivers/cxl/Makefile | 2 + drivers/cxl/core/core.h | 1 + drivers/cxl/core/port.c | 21 +- drivers/cxl/core/region.c | 25 +- drivers/cxl/cxl.h | 6 + drivers/cxl/region.c | 331 ++++++++++++++++++ drivers/cxl/region.h | 4 + drivers/cxl/trace.h | 45 +++ 9 files changed, 433 insertions(+), 5 deletions(-) create mode 100644 drivers/cxl/region.c create mode 100644 drivers/cxl/trace.h diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst index dc756ed23a3a..6734939b7136 100644 --- a/Documentation/driver-api/cxl/memory-devices.rst +++ b/Documentation/driver-api/cxl/memory-devices.rst @@ -73,6 +73,9 @@ CXL Core CXL Regions ----------- +.. kernel-doc:: drivers/cxl/region.c + :doc: cxl region + .. kernel-doc:: drivers/cxl/region.h :identifiers: diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index ce267ef11d93..677a04528b22 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -5,9 +5,11 @@ obj-$(CONFIG_CXL_MEM) += cxl_mem.o obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o obj-$(CONFIG_CXL_PORT) += cxl_port.o +obj-$(CONFIG_CXL_MEM) += cxl_region.o cxl_mem-y := mem.o cxl_pci-y := pci.o cxl_acpi-y := acpi.o cxl_pmem-y := pmem.o cxl_port-y := port.o +cxl_region-y := region.o diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 1d4d1699b479..bd47e1b59f8b 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -7,6 +7,7 @@ extern const struct device_type cxl_nvdimm_bridge_type; extern const struct device_type cxl_nvdimm_type; extern const struct device_type cxl_memdev_type; +extern const struct device_type cxl_region_type; extern struct attribute_group cxl_base_attribute_group; diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index ef3840c50e3e..67f3345d44ef 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include "core.h" @@ -29,6 +30,8 @@ static DEFINE_IDA(cxl_port_ida); static DEFINE_XARRAY(cxl_root_buses); +static void cxl_decoder_release(struct device *dev); + static bool is_cxl_decoder(struct device *dev); static int decoder_match(struct device *dev, void *data) @@ -732,6 +735,7 @@ struct cxl_port *find_cxl_root(struct cxl_memdev *cxlmd) } return NULL; } +EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL); static void cxl_remove_ep(void *data) { @@ -1276,6 +1280,8 @@ static int cxl_device_id(struct device *dev) } if (dev->type == &cxl_memdev_type) return CXL_DEVICE_MEMORY_EXPANDER; + if (dev->type == &cxl_region_type) + return CXL_DEVICE_REGION; return 0; } @@ -1292,10 +1298,21 @@ static int cxl_bus_match(struct device *dev, struct device_driver *drv) static int cxl_bus_probe(struct device *dev) { - int rc; + int id = cxl_device_id(dev); + int rc = -ENODEV; + + if (id == CXL_DEVICE_REGION) { + /* Regions cannot bind until parameters are set */ + struct cxl_region *region = to_cxl_region(dev); + + if (is_cxl_region_configured(region)) + rc = to_cxl_drv(dev->driver)->probe(dev); + } else { + rc = to_cxl_drv(dev->driver)->probe(dev); + } - rc = to_cxl_drv(dev->driver)->probe(dev); dev_dbg(dev, "probe: %d\n", rc); + return rc; } diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 26b5ad389cd2..de0514a85cf1 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -12,6 +12,8 @@ #include #include "core.h" +#include "core.h" + /** * DOC: cxl core region * @@ -26,10 +28,27 @@ static const struct attribute_group region_interleave_group; static bool is_region_active(struct cxl_region *region) { - /* TODO: Regions can't be activated yet. */ - return false; + return region->active; } +/* + * Most sanity checking is left up to region binding. This does the most basic + * check to determine whether or not the core should try probing the driver. + */ +bool is_cxl_region_configured(const struct cxl_region *region) +{ + /* zero sized regions aren't a thing. */ + if (region->config.size <= 0) + return false; + + /* all regions have at least 1 target */ + if (!region->config.targets[0]) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(is_cxl_region_configured); + static void remove_target(struct cxl_region *region, int target) { struct cxl_memdev *cxlmd; @@ -311,7 +330,7 @@ static const struct attribute_group *region_groups[] = { static void cxl_region_release(struct device *dev); -static const struct device_type cxl_region_type = { +const struct device_type cxl_region_type = { .name = "cxl_region", .release = cxl_region_release, .groups = region_groups diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 79c5781b6173..b318cabfc4a2 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -181,6 +181,10 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, #define CXL_DECODER_F_ENABLE BIT(5) #define CXL_DECODER_F_MASK GENMASK(5, 0) +#define cxl_is_pmem_t3(flags) \ + (((flags) & (CXL_DECODER_F_TYPE3 | CXL_DECODER_F_PMEM)) == \ + (CXL_DECODER_F_TYPE3 | CXL_DECODER_F_PMEM)) + enum cxl_decoder_type { CXL_DECODER_ACCELERATOR = 2, CXL_DECODER_EXPANDER = 3, @@ -348,6 +352,7 @@ int devm_cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, resource_size_t component_reg_phys); struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dev); +struct cxl_port *ep_find_cxl_port(struct cxl_memdev *cxlmd, unsigned int depth); struct cxl_decoder *to_cxl_decoder(struct device *dev); bool is_root_decoder(struct device *dev); @@ -388,6 +393,7 @@ void cxl_driver_unregister(struct cxl_driver *cxl_drv); #define CXL_DEVICE_PORT 3 #define CXL_DEVICE_MEMORY_EXPANDER 4 #define CXL_DEVICE_ROOT 5 +#define CXL_DEVICE_REGION 6 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") #define CXL_MODALIAS_FMT "cxl:t%d" diff --git a/drivers/cxl/region.c b/drivers/cxl/region.c new file mode 100644 index 000000000000..9174925b67e3 --- /dev/null +++ b/drivers/cxl/region.c @@ -0,0 +1,331 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include +#include +#include +#include +#include "cxlmem.h" +#include "region.h" +#include "cxl.h" + +#define CREATE_TRACE_POINTS +#include "trace.h" + +/** + * DOC: cxl region + * + * This module implements a region driver that is capable of programming CXL + * hardware to setup regions. + * + * A CXL region encompasses a chunk of host physical address space that may be + * consumed by a single device (x1 interleave aka linear) or across multiple + * devices (xN interleaved). A region is a child device of a &struct + * cxl_decoder. There may be multiple active regions under a single &struct + * cxl_decoder. The common case for multiple regions would be several linear, + * contiguous regions under a single decoder. Generally, there will be a 1:1 + * relationship between decoder and region when the region is interleaved. + */ + +#define region_ways(region) ((region)->config.eniw) + +static struct cxl_decoder *rootd_from_region(struct cxl_region *r) +{ + struct device *d = r->dev.parent; + + if (WARN_ONCE(!is_root_decoder(d), "Corrupt topology for root region\n")) + return NULL; + + return to_cxl_decoder(d); +} + +static struct cxl_port *get_hostbridge(const struct cxl_memdev *ep) +{ + struct cxl_port *port = ep->port; + + while (!is_cxl_root(port)) { + port = to_cxl_port(port->dev.parent); + if (port->depth == 1) + return port; + } + + BUG(); + return NULL; +} + +static struct cxl_port *get_root_decoder(const struct cxl_memdev *endpoint) +{ + struct cxl_port *hostbridge = get_hostbridge(endpoint); + + if (hostbridge) + return to_cxl_port(hostbridge->dev.parent); + + return NULL; +} + +/** + * sanitize_region() - Check is region is reasonably configured + * @region: The region to check + * + * Determination as to whether or not a region can possibly be configured is + * described in CXL Memory Device SW Guide. In order to implement the algorithms + * described there, certain more basic configuration parameters must first need + * to be validated. That is accomplished by this function. + * + * Returns 0 if the region is reasonably configured, else returns a negative + * error code. + */ +static int sanitize_region(const struct cxl_region *region) +{ + int i; + + if (dev_WARN_ONCE(®ion->dev, !is_cxl_region_configured(region), + "unconfigured regions can't be probed (race?)\n")) { + return -ENXIO; + } + + if (region->config.size % (SZ_256M * region_ways(region))) { + trace_sanitize_failed(region, + "Invalid size. Must be multiple of NIW"); + return -ENXIO; + } + + for (i = 0; i < region_ways(region); i++) { + if (!region->config.targets[i]) { + trace_sanitize_failed(region, + "Missing memory device target"); + return -ENXIO; + } + if (!region->config.targets[i]->dev.driver) { + trace_sanitize_failed(region, + "Target isn't CXL.mem capable"); + return -ENODEV; + } + } + + return 0; +} + +/** + * allocate_address_space() - Gets address space for the region. + * @region: The region that will consume the address space + */ +static int allocate_address_space(struct cxl_region *region) +{ + /* TODO */ + return 0; +} + +/** + * find_cdat_dsmas() - Find a valid DSMAS for the region + * @region: The region + */ +static bool find_cdat_dsmas(const struct cxl_region *region) +{ + return true; +} + +/** + * qtg_match() - Does this CFMWS have desirable QTG for the endpoint + * @cfmws: The CFMWS for the region + * @endpoint: Endpoint whose QTG is being compared + * + * Prior to calling this function, the caller should verify that all endpoints + * in the region have the same QTG ID. + * + * Returns true if the QTG ID of the CFMWS matches the endpoint + */ +static bool qtg_match(const struct cxl_decoder *cfmws, + const struct cxl_memdev *endpoint) +{ + /* TODO: */ + return true; +} + +/** + * region_xhb_config_valid() - determine cross host bridge validity + * @cfmws: The CFMWS to check against + * @region: The region being programmed + * + * The algorithm is outlined in 2.13.14 "Verify XHB configuration sequence" of + * the CXL Memory Device SW Guide (Rev1p0). + * + * Returns true if the configuration is valid. + */ +static bool region_xhb_config_valid(const struct cxl_region *region, + const struct cxl_decoder *cfmws) +{ + /* TODO: */ + return true; +} + +/** + * region_hb_rp_config_valid() - determine root port ordering is correct + * @cfmws: CFMWS decoder for this @region + * @region: Region to validate + * + * The algorithm is outlined in 2.13.15 "Verify HB root port configuration + * sequence" of the CXL Memory Device SW Guide (Rev1p0). + * + * Returns true if the configuration is valid. + */ +static bool region_hb_rp_config_valid(const struct cxl_region *region, + const struct cxl_decoder *cfmws) +{ + /* TODO: */ + return true; +} + +/** + * rootd_contains() - determine if this region can exist in the root decoder + * @rootd: CFMWS that potentially decodes to this region + * @region: region to be routed by the @rootd + */ +static bool rootd_contains(const struct cxl_region *region, + const struct cxl_decoder *rootd) +{ + /* TODO: */ + return true; +} + +static bool rootd_valid(const struct cxl_region *region, + const struct cxl_decoder *rootd) +{ + const struct cxl_memdev *endpoint = region->config.targets[0]; + + if (!qtg_match(rootd, endpoint)) + return false; + + if (!cxl_is_pmem_t3(rootd->flags)) + return false; + + if (!region_xhb_config_valid(region, rootd)) + return false; + + if (!region_hb_rp_config_valid(region, rootd)) + return false; + + if (!rootd_contains(region, rootd)) + return false; + + return true; +} + +struct rootd_context { + const struct cxl_region *region; + struct cxl_port *hbs[CXL_DECODER_MAX_INTERLEAVE]; + int count; +}; + +static int rootd_match(struct device *dev, void *data) +{ + struct rootd_context *ctx = (struct rootd_context *)data; + const struct cxl_region *region = ctx->region; + + if (!is_root_decoder(dev)) + return 0; + + return !!rootd_valid(region, to_cxl_decoder(dev)); +} + +/* + * This is a roughly equivalent implementation to "Figure 45 - High-level + * sequence: Finding CFMWS for region" from the CXL Memory Device SW Guide + * Rev1p0. + */ +static struct cxl_decoder *find_rootd(const struct cxl_region *region, + const struct cxl_port *root) +{ + struct rootd_context ctx; + struct device *ret; + + ctx.region = region; + + ret = device_find_child((struct device *)&root->dev, &ctx, rootd_match); + if (ret) + return to_cxl_decoder(ret); + + return NULL; +} + +static int collect_ep_decoders(const struct cxl_region *region) +{ + /* TODO: */ + return 0; +} + +static int bind_region(const struct cxl_region *region) +{ + /* TODO: */ + return 0; +} + +static int cxl_region_probe(struct device *dev) +{ + struct cxl_region *region = to_cxl_region(dev); + struct cxl_port *root_port; + struct cxl_decoder *rootd, *ours; + int ret; + + device_lock_assert(®ion->dev); + + if (region->active) + return 0; + + if (uuid_is_null(®ion->config.uuid)) + uuid_gen(®ion->config.uuid); + + /* TODO: What about volatile, and LSA generated regions? */ + + ret = sanitize_region(region); + if (ret) + return ret; + + ret = allocate_address_space(region); + if (ret) + return ret; + + if (!find_cdat_dsmas(region)) + return -ENXIO; + + rootd = rootd_from_region(region); + if (!rootd) { + dev_err(dev, "Couldn't find root decoder\n"); + return -ENXIO; + } + + if (!rootd_valid(region, rootd)) { + dev_err(dev, "Picked invalid rootd\n"); + return -ENXIO; + } + + root_port = get_root_decoder(region->config.targets[0]); + ours = find_rootd(region, root_port); + if (ours != rootd) + dev_warn(dev, "Picked different rootd %s %s\n", + dev_name(&rootd->dev), dev_name(&ours->dev)); + if (ours) + put_device(&ours->dev); + + ret = collect_ep_decoders(region); + if (ret) + return ret; + + ret = bind_region(region); + if (!ret) { + region->active = true; + trace_region_activated(region, ""); + } + + return ret; +} + +static struct cxl_driver cxl_region_driver = { + .name = "cxl_region", + .probe = cxl_region_probe, + .id = CXL_DEVICE_REGION, +}; +module_cxl_driver(cxl_region_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(CXL); +MODULE_ALIAS_CXL(CXL_DEVICE_REGION); diff --git a/drivers/cxl/region.h b/drivers/cxl/region.h index 3e6e5fb35822..97bb3f12f2fc 100644 --- a/drivers/cxl/region.h +++ b/drivers/cxl/region.h @@ -13,6 +13,7 @@ * @id: This regions id. Id is globally unique across all regions. * @list: Node in decoder's region list. * @res: Resource this region carves out of the platform decode range. + * @active: If the region has been activated. * @config: HDM decoder program config * @config.size: Size of the region determined from LSA or userspace. * @config.uuid: The UUID for this region. @@ -25,6 +26,7 @@ struct cxl_region { int id; struct list_head list; struct resource *res; + bool active; struct { u64 size; @@ -35,4 +37,6 @@ struct cxl_region { } config; }; +bool is_cxl_region_configured(const struct cxl_region *region); + #endif diff --git a/drivers/cxl/trace.h b/drivers/cxl/trace.h new file mode 100644 index 000000000000..8f7f471e15b8 --- /dev/null +++ b/drivers/cxl/trace.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM cxl + +#if !defined(__CXL_TRACE_H__) || defined(TRACE_HEADER_MULTI_READ) +#define __CXL_TRACE_H__ + +#include + +DECLARE_EVENT_CLASS(cxl_region_template, + + TP_PROTO(const struct cxl_region *region, char *status), + + TP_ARGS(region, status), + + TP_STRUCT__entry( + __string(dev_name, dev_name(®ion->dev)) + __field(const struct cxl_region *, region) + __string(status, status) + ), + + TP_fast_assign( + __assign_str(dev_name, dev_name(®ion->dev)); + __entry->region = (const struct cxl_region *)region; + __assign_str(status, status); + ), + + TP_printk("%s: (%s)\n", __get_str(dev_name), __get_str(status)) +); + +DEFINE_EVENT(cxl_region_template, region_activated, + TP_PROTO(const struct cxl_region *region, char *status), + TP_ARGS(region, status)); +DEFINE_EVENT(cxl_region_template, sanitize_failed, + TP_PROTO(const struct cxl_region *region, char *status), + TP_ARGS(region, status)); + +#endif /* if !defined (__CXL_TRACE_H__) || defined(TRACE_HEADER_MULTI_READ) */ + +/* This part must be outside protection */ +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH ../../../drivers/cxl +#define TRACE_INCLUDE_FILE trace +#include