From patchwork Tue Apr 13 16:01:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12200891 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C310DC433ED for ; Tue, 13 Apr 2021 16:03:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A752A61221 for ; Tue, 13 Apr 2021 16:03:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346710AbhDMQD1 (ORCPT ); Tue, 13 Apr 2021 12:03:27 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2843 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346652AbhDMQD0 (ORCPT ); Tue, 13 Apr 2021 12:03:26 -0400 Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FKVWJ2x2sz689HW; Tue, 13 Apr 2021 23:53:16 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml704-chm.china.huawei.com (10.206.15.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Tue, 13 Apr 2021 18:03:05 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 13 Apr 2021 17:03:04 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v2 1/4] PCI: Add vendor define ID for the PCI SIG Date: Wed, 14 Apr 2021 00:01:56 +0800 Message-ID: <20210413160159.935663-2-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> References: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml748-chm.china.huawei.com (10.201.108.198) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This ID is used in DOE headers to identify protocols that are defined within the PCI Express Base Specification. Signed-off-by: Jonathan Cameron --- Since V1: New Patch include/linux/pci_ids.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index a76ccb697bef..2c0459c23331 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -149,6 +149,7 @@ #define PCI_CLASS_OTHERS 0xff /* Vendors and devices. Sort key: vendor first, device next. */ +#define PCI_VENDOR_ID_PCI_SIG 0x0001 #define PCI_VENDOR_ID_LOONGSON 0x0014 From patchwork Tue Apr 13 16:01:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12200893 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C014FC433B4 for ; Tue, 13 Apr 2021 16:03:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9955161153 for ; Tue, 13 Apr 2021 16:03:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346749AbhDMQD5 (ORCPT ); Tue, 13 Apr 2021 12:03:57 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2844 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346652AbhDMQD5 (ORCPT ); Tue, 13 Apr 2021 12:03:57 -0400 Received: from fraeml703-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FKVZt0bv9z688Z4; Tue, 13 Apr 2021 23:56:22 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml703-chm.china.huawei.com (10.206.15.52) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Tue, 13 Apr 2021 18:03:35 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 13 Apr 2021 17:03:35 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v2 2/4] PCI/doe: Initial support PCI Data Object Exchange Date: Wed, 14 Apr 2021 00:01:57 +0800 Message-ID: <20210413160159.935663-3-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> References: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml748-chm.china.huawei.com (10.201.108.198) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Introduced in a PCI ECN [1], DOE provides a config space based mailbox with standard protocol discovery. Each mailbox is accessed through a DOE PCIE Extended Capability. A device may have 1 or more DOE mailboxes, each of which is allowed to support any number of protocols (some DOE protocols specifications apply additional restrictions). A given protocol may be supported on more than one DOE mailbox on a given function. If a driver wishes to access any number of DOE instances / protocols it makes a single call to pcie_doe_register_all() which will find available DOEs, create the required infrastructure and cache the protocols they support. pcie_doe_find() can then retrieve a pointer to an appropriate DOE instance. Testing conducted against QEMU using: https://lore.kernel.org/qemu-devel/1612900760-7361-1-git-send-email-cbrowy@avery-design.com/ + fix for interrupt flag mentioned in that thread and a whole load of hacks to exercise error paths etc. [1] https://members.pcisig.com/wg/PCI-SIG/document/14143 Signed-off-by: Jonathan Cameron --- Thanks to Dan Williams for reviewing v1. Note code has changed a lot, so I may well have missed stuff in this log. Details on approaches to the DOE serialization discussed in the cover letter. Changes since v1: Major stuff: * Rework the registration of DOE. DOE instances are added to a list in the struct pci_dev. A single call to pcie_doe_register_all() finds all DOEs present on a device and caches which protocols they support. The lifetime of these can then all be managed alongside the struct pci_dev avoiding need for reference counting etc whilst allowing a driver not to care if different protocols are using the same DOE instance, or different ones. The driver issues a call to pcie_doe_find() to get a pointer to the first appropriate DOE. Note, a side effect of minimizing impact of this on struct pci_dev is that we can't build DOE support as a module. * Instead of serializing on a mutex, move to a more complex state machine based scheme in which the DOE config space registers are only accessed from a single delayed work item. The state machine uses two states for normal operation, IDLE and WAITING. Two states also exist for ABORT to indicate if it was called in response to error, or at startup. Interrupts result in mod_delayed_work() to force an immediate check on the status register. Message queuing is implemented with a list of tasks and kicking the state machine work item as needed. * Decide, inside the core DOE code, whether to poll based on if the MSI/MSIX interrupts are enabled and the DOE instance advertises an interrupt. * Define a struct pcie_doe_exchange to encapsulate header info with payloads etc. Specific fields used for VID and protocol + lengths so the DOE header can be constructed inside the DOE functions rather than relying on callers to do that. * Don't hide away devm_ stuff in calls that don't make it obvious. Minor stuff: * pcie_doe_init() and pcie_doe_register separation to cover the bits that can fail in register() and the bits that can't in init() * Many typos * Rename cap_offset field to cap * Use new PCI_VENDOR_ID_PCI_SIG define to avoid open coding the value * Add defines for timeouts etc. * Missing EXPORT_SYMBOL_GPL() added to allow DOE access from modules. drivers/pci/pcie/Kconfig | 8 + drivers/pci/pcie/Makefile | 1 + drivers/pci/pcie/doe.c | 590 ++++++++++++++++++++++++++++++++++ include/linux/pci.h | 3 + include/linux/pcie-doe.h | 85 +++++ include/uapi/linux/pci_regs.h | 29 +- 6 files changed, 715 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig index 45a2ef702b45..1b566d08bfef 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -142,3 +142,11 @@ config PCIE_EDR the PCI Firmware Specification r3.2. Enable this if you want to support hybrid DPC model which uses both firmware and OS to implement DPC. + +config PCIE_DOE + bool + help + This enables library support PCI Data Object Exchange capability. + DOE provides a simple mailbox in PCI express config space that is + used by a number of different protocols. + It is defined in the Data Object Exchange ECN to PCI 5.0. diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile index b2980db88cc0..801fdd5fbfc1 100644 --- a/drivers/pci/pcie/Makefile +++ b/drivers/pci/pcie/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_PCIE_PME) += pme.o obj-$(CONFIG_PCIE_DPC) += dpc.o obj-$(CONFIG_PCIE_PTM) += ptm.o obj-$(CONFIG_PCIE_EDR) += edr.o +obj-$(CONFIG_PCIE_DOE) += doe.o diff --git a/drivers/pci/pcie/doe.c b/drivers/pci/pcie/doe.c new file mode 100644 index 000000000000..b8a27c744d09 --- /dev/null +++ b/drivers/pci/pcie/doe.c @@ -0,0 +1,590 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Data Object Exchange ECN + * https://members.pcisig.com/wg/PCI-SIG/document/14143 + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define PCI_DOE_PROTOCOL_DISCOVERY 0 + +#define PCI_DOE_BUSY_MAX_RETRIES 16 +#define PCI_DOE_POLL_INTERVAL (HZ / 128) + +/* Timeout of 1 second from 6.xx.1 ECN - Data Object Exchange */ +#define PCI_DOE_TIMEOUT HZ + +static irqreturn_t pcie_doe_irq(int irq, void *data) +{ + struct pcie_doe *doe = data; + struct pci_dev *pdev = doe->pdev; + u32 val; + + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_INT_STATUS, val)) { + pci_write_config_dword(pdev, doe->cap + PCI_DOE_STATUS, val); + mod_delayed_work(system_wq, &doe->statemachine, 0); + return IRQ_HANDLED; + } + /* Leave the error case to be handled outside irq */ + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) { + mod_delayed_work(system_wq, &doe->statemachine, 0); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +/* + * Only call when safe to directly access the DOE, either because no tasks + * yet queued, or called from doe_statemachine_work() which has exclusive + * access to the DOE config space. + */ +static void pcie_doe_abort_start(struct pcie_doe *doe) +{ + struct pci_dev *pdev = doe->pdev; + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, + PCI_DOE_CTRL_ABORT); + + doe->timeout_jiffies = jiffies + HZ; + schedule_delayed_work(&doe->statemachine, HZ); +} + +static int pcie_doe_send_req(struct pcie_doe *doe, struct pcie_doe_exchange *ex) +{ + struct pci_dev *pdev = doe->pdev; + u32 val; + int i; + + /* + * Check the DOE busy bit is not set. + * If it is set, this could indicate someone other than Linux is + * using the mailbox. + */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_BUSY, val)) + return -EBUSY; + + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) + return -EIO; + + /* Write DOE Header */ + val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, ex->vid) | + FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, ex->protocol); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, val); + /* Length is 2 DW of header + length of payload in DW */ + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, + FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, + 2 + ex->request_pl_sz / 4)); + for (i = 0; i < ex->request_pl_sz / 4; i++) + pci_write_config_dword(pdev, doe->cap + PCI_DOE_WRITE, + ex->request_pl[i]); + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, PCI_DOE_CTRL_GO); + /* Request is sent - now wait for poll or irq */ + return 0; +} + +static int pcie_doe_recv_resp(struct pcie_doe *doe, struct pcie_doe_exchange *ex) +{ + struct pci_dev *pdev = doe->pdev; + size_t length; + u32 val; + int i; + + /* Read the first two dwords to get the length and protocol */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != ex->vid) || + (FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != ex->protocol)) { + dev_err(&pdev->dev, "Expected [VID, Protocol] = [%x, %x], got [%x, %x]\n", + ex->vid, ex->protocol, + FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val), + FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val)); + return -EIO; + } + + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + + length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val); + if (length > SZ_1M) + return -EIO; + + /* Read the rest of the response payload */ + for (i = 0; i < min(length, ex->response_pl_sz / 4); i++) { + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, + &ex->response_pl[i]); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + } + + /* Flush excess length */ + for (; i < length; i++) { + pci_read_config_dword(pdev, doe->cap + PCI_DOE_READ, &val); + pci_write_config_dword(pdev, doe->cap + PCI_DOE_READ, 0); + } + /* Final error check to pick up on any since Data Object Ready */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) + return -EIO; + + return min(length, ex->response_pl_sz / 4) * 4; +} + +static void pcie_doe_task_complete(void *private) +{ + complete(private); +} + +/** + * struct pcie_doe_task - description of a query / response task + * @h: Head to add it to the list of outstanding tasks. + * @ex: The info details of the task to be done. + * @rv: Return value. Length of received response or error. + * @cb: Callback for completion of task. + * @private: Private data passed to callback on completion. + */ +struct pcie_doe_task { + struct list_head h; + struct pcie_doe_exchange *ex; + int rv; + void (*cb)(void *private); + void *private; +}; + +/** + * pcie_doe_sync() - Send a request, then wait for and receive response. + * @doe: DOE mailbox state structure + * @ex: Description of the buffers and vid, type used in this + * request/response pair + * + * Excess data will be discarded. + * + * Return: payload in bytes on success, < 0 on error + */ +int pcie_doe_sync(struct pcie_doe *doe, struct pcie_doe_exchange *ex) +{ + struct pcie_doe_task task; + DECLARE_COMPLETION_ONSTACK(c); + bool only_task; + + /* DOE requests must be a whole number of DW */ + if (ex->request_pl_sz % sizeof(u32)) + return -EINVAL; + + task.ex = ex; + task.cb = pcie_doe_task_complete; + task.private = &c; + + mutex_lock(&doe->tasks_lock); + if (doe->dead) { + mutex_unlock(&doe->tasks_lock); + return -EIO; + } + only_task = list_empty(&doe->tasks); + list_add_tail(&task.h, &doe->tasks); + if (only_task) + schedule_delayed_work(&doe->statemachine, 0); + mutex_unlock(&doe->tasks_lock); + wait_for_completion(&c); + + return task.rv; +} + +static void doe_statemachine_work(struct work_struct *work) +{ + struct delayed_work *w = to_delayed_work(work); + struct pcie_doe *doe = container_of(w, struct pcie_doe, statemachine); + struct pci_dev *pdev = doe->pdev; + struct pcie_doe_task *task; + bool abort; + u32 val; + int rc; + + mutex_lock(&doe->tasks_lock); + task = list_first_entry_or_null(&doe->tasks, struct pcie_doe_task, h); + abort = doe->abort; + doe->abort = false; + mutex_unlock(&doe->tasks_lock); + + if (abort) { + /* + * Currently only used during init - care needed if we want to generally + * expose pcie_doe_abort() as it would impact queries in flight. + */ + WARN_ON(task); + doe->state = DOE_WAIT_ABORT; + pcie_doe_abort_start(doe); + return; + } + + switch (doe->state) { + case DOE_IDLE: + if (task == NULL) + return; + + /* Nothing currently in flight so queue a task */ + rc = pcie_doe_send_req(doe, task->ex); + /* + * The specification does not provide any guidance on how long some other + * entity could keep the DOE busy, so try for 1 second then fail. + * Busy handling is best effort only, because there is not way of avoiding + * racing against another user of the DOE. + */ + if (rc == -EBUSY) { + doe->busy_retries++; + if (doe->busy_retries == PCI_DOE_BUSY_MAX_RETRIES) { + /* Long enough, fail this request */ + doe->busy_retries = 0; + goto busy; + } + schedule_delayed_work(w, HZ / PCI_DOE_BUSY_MAX_RETRIES); + return; + } + if (rc) + goto abort; + doe->busy_retries = 0; + + doe->state = DOE_WAIT_RESP; + doe->timeout_jiffies = jiffies + HZ; + /* Now poll or wait for IRQ with timeout */ + if (doe->irq > 0) + schedule_delayed_work(w, PCI_DOE_TIMEOUT); + else + schedule_delayed_work(w, PCI_DOE_POLL_INTERVAL); + return; + + case DOE_WAIT_RESP: + /* Not possible to get here with NULL task */ + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) { + rc = -EIO; + goto abort; + } + + if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) { + /* If not yet at timeout reschedule otherwise abort */ + if (time_after(jiffies, doe->timeout_jiffies)) { + rc = -ETIMEDOUT; + goto abort; + } + schedule_delayed_work(w, PCI_DOE_POLL_INTERVAL); + return; + } + + rc = pcie_doe_recv_resp(doe, task->ex); + if (rc < 0) + goto abort; + + doe->state = DOE_IDLE; + + mutex_lock(&doe->tasks_lock); + list_del(&task->h); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + + /* Set the return value to the length of received payload */ + task->rv = rc; + task->cb(task->private); + return; + + case DOE_WAIT_ABORT: + case DOE_WAIT_ABORT_ON_ERR: + pci_read_config_dword(pdev, doe->cap + PCI_DOE_STATUS, &val); + + if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) && + !FIELD_GET(PCI_DOE_STATUS_BUSY, val)) { + /* Back to normal state - carry on */ + mutex_lock(&doe->tasks_lock); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + + /* For deliberately triggered abort, someone is waiting */ + if (doe->state == DOE_WAIT_ABORT) + complete(&doe->abort_c); + doe->state = DOE_IDLE; + + return; + } + if (time_after(jiffies, doe->timeout_jiffies)) { + struct pcie_doe_task *t, *n; + + /* We are dead - abort all queued tasks */ + dev_err(&pdev->dev, "DOE ABORT timed out\n"); + mutex_lock(&doe->tasks_lock); + doe->dead = true; + list_for_each_entry_safe(t, n, &doe->tasks, h) { + t->rv = -EIO; + t->cb(t->private); + list_del(&t->h); + } + + mutex_unlock(&doe->tasks_lock); + if (doe->state == DOE_WAIT_ABORT) + complete(&doe->abort_c); + } + return; + } + +abort: + pcie_doe_abort_start(doe); + doe->state = DOE_WAIT_ABORT_ON_ERR; +busy: + mutex_lock(&doe->tasks_lock); + list_del(&task->h); + mutex_unlock(&doe->tasks_lock); + + task->rv = rc; + task->cb(task->private); + /* If we got here via busy, and the queue isn't empty then we need to go again */ + if (doe->state == DOE_IDLE) { + mutex_lock(&doe->tasks_lock); + if (!list_empty(&doe->tasks)) + schedule_delayed_work(w, 0); + mutex_unlock(&doe->tasks_lock); + } +} + +static int pcie_doe_discovery(struct pcie_doe *doe, u8 *index, u16 *vid, + u8 *protocol) +{ + u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX, *index); + u32 response_pl; + struct pcie_doe_exchange ex = { + .vid = PCI_VENDOR_ID_PCI_SIG, + .protocol = PCI_DOE_PROTOCOL_DISCOVERY, + .request_pl = &request_pl, + .request_pl_sz = sizeof(request_pl), + .response_pl = &response_pl, + .response_pl_sz = sizeof(response_pl), + }; + int ret; + + ret = pcie_doe_sync(doe, &ex); + if (ret < 0) + return ret; + + if (ret != sizeof(response_pl)) + return -EIO; + + *vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl); + *protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL, response_pl); + *index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX, response_pl); + + return 0; +} + +static int pcie_doe_cache_protocols(struct pcie_doe *doe) +{ + u8 index = 0; + int rc; + + /* Discovery protocol must always be supported and must report itself */ + doe->num_prots = 1; + doe->prots = kzalloc(sizeof(*doe->prots) * doe->num_prots, GFP_KERNEL); + if (doe->prots == NULL) + return -ENOMEM; + + do { + struct pcie_doe_prot *prot, *prot_new; + + prot = &doe->prots[doe->num_prots - 1]; + rc = pcie_doe_discovery(doe, &index, &prot->vid, &prot->type); + if (rc) + goto free_prots; + + if (index) { + prot_new = krealloc(doe->prots, + sizeof(*doe->prots) * doe->num_prots, + GFP_KERNEL); + if (prot_new == NULL) { + rc = -ENOMEM; + goto free_prots; + } + doe->prots = prot_new; + doe->num_prots++; + } + } while (index); + + return 0; + +free_prots: + kfree(doe->prots); + return rc; +} + +static void pcie_doe_init(struct pcie_doe *doe, struct pci_dev *pdev, int doe_offset) +{ + mutex_init(&doe->tasks_lock); + init_completion(&doe->abort_c); + doe->cap = doe_offset; + doe->pdev = pdev; + INIT_LIST_HEAD(&doe->tasks); + INIT_DELAYED_WORK(&doe->statemachine, doe_statemachine_work); +} + +static int pcie_doe_abort(struct pcie_doe *doe) +{ + reinit_completion(&doe->abort_c); + mutex_lock(&doe->tasks_lock); + doe->abort = true; + mutex_unlock(&doe->tasks_lock); + schedule_delayed_work(&doe->statemachine, 0); + wait_for_completion(&doe->abort_c); + + if (doe->dead) + return -EIO; + + return 0; +} + +static int pcie_doe_register(struct pcie_doe *doe) +{ + struct pci_dev *pdev = doe->pdev; + bool poll = !pci_dev_msi_enabled(pdev); + int rc, irq; + u32 val; + + pci_read_config_dword(pdev, doe->cap + PCI_DOE_CAP, &val); + + if (!poll && FIELD_GET(PCI_DOE_CAP_INT, val)) { + irq = pci_irq_vector(pdev, FIELD_GET(PCI_DOE_CAP_IRQ, val)); + if (irq < 0) + return irq; + + rc = request_irq(irq, pcie_doe_irq, 0, "DOE", doe); + if (rc) + return rc; + + doe->irq = irq; + pci_write_config_dword(pdev, doe->cap + PCI_DOE_CTRL, + FIELD_PREP(PCI_DOE_CTRL_INT_EN, 1)); + } + + /* Reset the mailbox by issuing an abort */ + rc = pcie_doe_abort(doe); + if (rc) + goto err_free_irqs; + + return 0; + +err_free_irqs: + if (doe->irq > 0) + free_irq(doe->irq, doe); + + return rc; +} + +static void pcie_doe_unregister(struct pcie_doe *doe) +{ + if (doe->irq > 0) + free_irq(doe->irq, doe); +} + +void pcie_doe_unregister_all(struct pci_dev *pdev) +{ + struct pcie_doe *doe, *next; + + list_for_each_entry_safe(doe, next, &pdev->doe_list, h) { + /* First halt the state machine */ + cancel_delayed_work_sync(&doe->statemachine); + kfree(doe->prots); + pcie_doe_unregister(doe); + kfree(doe); + } +} +EXPORT_SYMBOL_GPL(pcie_doe_unregister_all); + +/** + * pcie_doe_register_all() - Find and register all DOE mailboxes + * @pdev: PCI device whose DOE mailboxes we are finding. + * + * Will locate any DOE mailboxes present on the device and cache the + * protocols so that pcie_doe_find() can be used to retrieve a suitable DOE + * instance. + * DOE mailboxes are available until pcie_doe_unregister_all() + * is called. + * + * RETURNS: 0 on success, < 0 on error + */ +int pcie_doe_register_all(struct pci_dev *pdev) +{ + struct pcie_doe *doe; + int pos = 0; + int rc; + + INIT_LIST_HEAD(&pdev->doe_list); + + /* Walk the DOE extended capabilities and add to per pci_dev list */ + while (true) { + + pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DOE); + if (!pos) + return 0; + + doe = kzalloc(sizeof(*doe), GFP_KERNEL); + if (!doe) { + rc = -ENOMEM; + goto free_does; + } + + pcie_doe_init(doe, pdev, pos); + rc = pcie_doe_register(doe); + if (rc) { + kfree(doe); + goto free_does; + } + + rc = pcie_doe_cache_protocols(doe); + if (rc) { + pcie_doe_unregister(doe); + kfree(doe); + goto free_does; + } + + list_add(&doe->h, &pdev->doe_list); + } + +free_does: + pcie_doe_unregister_all(pdev); + + return rc; +} +EXPORT_SYMBOL_GPL(pcie_doe_register_all); + +/** + * pcie_doe_find() - Find the first DOE instance that supports a given protocol + * @pdev: Device on which to find the DOE instance. + * @vid: Vendor ID. + * @type: Specific protocol for this vendor. + * + * RETURNS: Pointer to DOE instance, or NULL if no suitable instance available. + */ +struct pcie_doe *pcie_doe_find(struct pci_dev *pdev, u16 vid, u8 type) +{ + struct pcie_doe *doe; + int i; + + list_for_each_entry(doe, &pdev->doe_list, h) { + for (i = 0; i < doe->num_prots; i++) + if ((doe->prots[i].vid == vid) && + (doe->prots[i].type == type)) + return doe; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(pcie_doe_find); diff --git a/include/linux/pci.h b/include/linux/pci.h index 86c799c97b77..5d958a63e8c7 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -332,6 +332,9 @@ struct pci_dev { #ifdef CONFIG_PCIEPORTBUS struct rcec_ea *rcec_ea; /* RCEC cached endpoint association */ struct pci_dev *rcec; /* Associated RCEC device */ +#endif +#ifdef CONFIG_PCIE_DOE + struct list_head doe_list; /* Data Object Exchange mailboxes */ #endif u8 pcie_cap; /* PCIe capability offset */ u8 msi_cap; /* MSI capability offset */ diff --git a/include/linux/pcie-doe.h b/include/linux/pcie-doe.h new file mode 100644 index 000000000000..794d6f090779 --- /dev/null +++ b/include/linux/pcie-doe.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Data Object Exchange was added to the PCI spec as an ECN to 5.0. + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron + */ + +#include +#include +#include + +#ifndef LINUX_PCIE_DOE_H +#define LINUX_PCIE_DOE_H + +struct pcie_doe_prot { + u16 vid; + u8 type; +}; + +struct workqueue_struct; + +enum pcie_doe_state { + DOE_IDLE, + DOE_WAIT_RESP, + DOE_WAIT_ABORT, + DOE_WAIT_ABORT_ON_ERR, +}; + +struct pcie_doe_exchange { + u16 vid; + u8 protocol; + u32 *request_pl; + size_t request_pl_sz; + u32 *response_pl; + size_t response_pl_sz; +}; + +/** + * struct pcie_doe - State to support use of DOE mailbox + * @cap: Config space offset to base of DOE capability. + * @pdev: PCI device that hosts this DOE. + * @abort_c: Completion used for initial abort handling. + * @irq: Interrupt used for signaling DOE ready or abort. + * @prots: Cache of identifiers for protocols supported. + * @num_prots: Size of prots cache. + * @h: Used for DOE instance lifetime management. + * @wq: Workqueue used to handle state machine and polling / timeouts + * @tasks: List of task in flight + pending. + * @tasks_lock: Protect the tasks list. + * @statemachine: Work item for the DOE statemachine + * @state: Current state of this DOE. + * @timeout_jiffies: 1 second after GO set. + * @busy_retries: Count of retry attempts + * @abort: Request a manual abort (e.g. on init) + * @dead: Used to mark a DOE for which an ABORT has timed out. + * Further messages will immediately be aborted with error. + */ +struct pcie_doe { + int cap; + struct pci_dev *pdev; + struct completion abort_c; + int irq; + struct pcie_doe_prot *prots; + int num_prots; + struct list_head h; + + struct workqueue_struct *wq; + struct list_head tasks; + struct mutex tasks_lock; + struct delayed_work statemachine; + enum pcie_doe_state state; + unsigned long timeout_jiffies; + unsigned int busy_retries; + bool abort; + bool dead; +}; + +int pcie_doe_register_all(struct pci_dev *pdev); +void pcie_doe_unregister_all(struct pci_dev *pdev); +struct pcie_doe *pcie_doe_find(struct pci_dev *pdev, u16 vid, u8 type); + +int pcie_doe_sync(struct pcie_doe *doe, struct pcie_doe_exchange *ex); + +#endif diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index e709ae8235e7..4d8a5fee2cdf 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -730,7 +730,8 @@ #define PCI_EXT_CAP_ID_DVSEC 0x23 /* Designated Vendor-Specific */ #define PCI_EXT_CAP_ID_DLF 0x25 /* Data Link Feature */ #define PCI_EXT_CAP_ID_PL_16GT 0x26 /* Physical Layer 16.0 GT/s */ -#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_PL_16GT +#define PCI_EXT_CAP_ID_DOE 0x2E /* Data Object Exchange */ +#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_DOE #define PCI_EXT_CAP_DSN_SIZEOF 12 #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40 @@ -1092,4 +1093,30 @@ #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_MASK 0x000000F0 #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_SHIFT 4 +/* Data Object Exchange */ +#define PCI_DOE_CAP 0x04 /* DOE Capabilities Register */ +#define PCI_DOE_CAP_INT 0x00000001 /* Interrupt Support */ +#define PCI_DOE_CAP_IRQ 0x00000ffe /* Interrupt Message Number */ +#define PCI_DOE_CTRL 0x08 /* DOE Control Register */ +#define PCI_DOE_CTRL_ABORT 0x00000001 /* DOE Abort */ +#define PCI_DOE_CTRL_INT_EN 0x00000002 /* DOE Interrupt Enable */ +#define PCI_DOE_CTRL_GO 0x80000000 /* DOE Go */ +#define PCI_DOE_STATUS 0x0C /* DOE Status Register */ +#define PCI_DOE_STATUS_BUSY 0x00000001 /* DOE Busy */ +#define PCI_DOE_STATUS_INT_STATUS 0x00000002 /* DOE Interrupt Status */ +#define PCI_DOE_STATUS_ERROR 0x00000004 /* DOE Error */ +#define PCI_DOE_STATUS_DATA_OBJECT_READY 0x80000000 /* Data Object Ready */ +#define PCI_DOE_WRITE 0x10 /* DOE Write Data Mailbox Register */ +#define PCI_DOE_READ 0x14 /* DOE Read Data Mailbox Register */ + +/* DOE Data Object - note not actually registers */ +#define PCI_DOE_DATA_OBJECT_HEADER_1_VID 0x0000FFFF +#define PCI_DOE_DATA_OBJECT_HEADER_1_TYPE 0x00FF0000 +#define PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH 0x0003FFFF + +#define PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX 0x000000FF +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID 0x0000FFFF +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00FF0000 +#define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX 0xFF000000 + #endif /* LINUX_PCI_REGS_H */ From patchwork Tue Apr 13 16:01:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12200895 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13999C433B4 for ; Tue, 13 Apr 2021 16:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0F7A61153 for ; Tue, 13 Apr 2021 16:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346775AbhDMQEc (ORCPT ); Tue, 13 Apr 2021 12:04:32 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2845 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346772AbhDMQE2 (ORCPT ); Tue, 13 Apr 2021 12:04:28 -0400 Received: from fraeml702-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FKVbS4jWQz688Rd; Tue, 13 Apr 2021 23:56:52 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml702-chm.china.huawei.com (10.206.15.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Tue, 13 Apr 2021 18:04:05 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 13 Apr 2021 17:04:05 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v2 3/4] cxl/mem: Add CDAT table reading from DOE Date: Wed, 14 Apr 2021 00:01:58 +0800 Message-ID: <20210413160159.935663-4-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> References: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml748-chm.china.huawei.com (10.201.108.198) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This patch provides a sysfs binary attribute to allow dumping of the whole table. Binary dumping is modeled on /sys/firmware/ACPI/tables/ The ability to dump this table will be very useful for emulation of real devices once they become available as QEMU CXL type 3 device emulation will be able to load this file in. Access to that file is restricted to root. Open questions: * No support here for table updates via the binary attribute. You get whatever was there when it was first cached. Worth including these from the start, or leave that complexity for later? We could read directly from the DOE every time, but need to check we get a coherent table. Let's figure this out once we are making 'real' use of the table. * What is maximum size of the SSLBIS entry - I haven't quite managed to figure that out and this is the record with largest size. We could support dynamic allocation of the record size, but it would add complexity that seems unnecessary. It would not be compliant with the specification for a type 3 memory device to report this record anyway so I'm not that worried about this for now. It will become relevant once we have support for reading CDAT from CXL switches. * cdat.h is formatted in a similar style to pci_regs.h on basis that it may well be helpful to share this header with userspace tools. * Move the generic parts of this out to driver/cxl/cdat.c or leave that until we have other CXL drivers wishing to use this? Signed-off-by: Jonathan Cameron --- Thanks to Dan William's for review Changes since v1: * static creation of the binary attribute * moved the debug print to separate patch to make it easy to drop later. * select PCIE_DOE * Changes due to interface changes in previous patch. drivers/cxl/Kconfig | 1 + drivers/cxl/cdat.h | 79 ++++++++++++++++++++ drivers/cxl/cxl.h | 13 ++++ drivers/cxl/mem.c | 177 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 270 insertions(+) diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 3eec9276e586..afc65d594d6b 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -15,6 +15,7 @@ if CXL_BUS config CXL_MEM tristate "CXL.mem: Memory Devices" + select PCIE_DOE help The CXL.mem protocol allows a device to act as a provider of "System RAM" and/or "Persistent Memory" that is fully coherent diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h new file mode 100644 index 000000000000..e67b18e02c35 --- /dev/null +++ b/drivers/cxl/cdat.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Coherent Device Attribute table (CDAT) + * + * Specification available from UEFI.org + * + * Whilst CDAT is defined as a single table, the access via DOE maiboxes is + * done one entry at a time, where the first entry is the header. + */ + +#define CXL_DOE_TABLE_ACCESS_REQ_CODE 0x000000ff +#define CXL_DOE_TABLE_ACCESS_REQ_CODE_READ 0 +#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE 0x0000ff00 +#define CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA 0 +#define CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE 0xffff0000 + + +/* + * CDAT entries are little endian and are read from PCI config space which + * is also little endian. + * As such, on a big endian system these will have been reversed. + * This prevents us from making easy use of packed structures. + * Style form pci_regs.h + */ + +#define CDAT_HEADER_LENGTH_DW 3 +#define CDAT_HEADER_DW0_LENGTH 0xFFFFFFFF +#define CDAT_HEADER_DW1_REVISION 0x000000FF +#define CDAT_HEADER_DW1_CHECKSUM 0x0000FF00 +#define CDAT_HEADER_DW2_SEQUENCE 0xFFFFFFFF + +/* All structures have a common first DW */ +#define CDAT_STRUCTURE_DW0_TYPE 0x000000FF +#define CDAT_STRUCTURE_DW0_TYPE_DSMAS 0 +#define CDAT_STRUCTURE_DW0_TYPE_DSLBIS 1 +#define CDAT_STRUCTURE_DW0_TYPE_DSMSCIS 2 +#define CDAT_STRUCTURE_DW0_TYPE_DSIS 3 +#define CDAT_STRUCTURE_DW0_TYPE_DSEMTS 4 +#define CDAT_STRUCTURE_DW0_TYPE_SSLBIS 5 + +#define CDAT_STRUCTURE_DW0_LENGTH 0xFFFF0000 + +/* Device Scoped Memory Affinity Structure */ +#define CDAT_DSMAS_DW1_DSMAD_HANDLE 0x000000ff +#define CDAT_DSMAS_DW1_FLAGS 0x0000ff00 +#define CDAT_DSMAS_DPA_OFFSET(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSMAS_DPA_LEN(entry) ((u64)((entry)[5]) << 32 | (entry)[4]) + +/* Device Scoped Latency and Bandwidth Information Structure */ +#define CDAT_DSLBIS_DW1_HANDLE 0x000000ff +#define CDAT_DSLBIS_DW1_FLAGS 0x0000ff00 +#define CDAT_DSLBIS_DW1_DATA_TYPE 0x00ff0000 +#define CDAT_DSLBIS_BASE_UNIT(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSLBIS_DW4_ENTRY_0 0x0000ffff +#define CDAT_DSLBIS_DW4_ENTRY_1 0xffff0000 +#define CDAT_DSLBIS_DW5_ENTRY_2 0x0000ffff + +/* Device Scoped Memory Side Cache Information Structure */ +#define CDAT_DSMSCIS_DW1_HANDLE 0x000000ff +#define CDAT_DSMSCIS_MEMORY_SIDE_CACHE_SIZE(entry) \ + ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSMSCIS_DW4_MEMORY_SIDE_CACHE_ATTRS 0xffffffff + +/* Device Scoped Initiator Structure */ +#define CDAT_DSIS_DW1_FLAGS 0x000000ff +#define CDAT_DSIS_DW1_HANDLE 0x0000ff00 + +/* Device Scoped EFI Memory Type Structure */ +#define CDAT_DSEMTS_DW1_HANDLE 0x000000ff +#define CDAT_DSEMTS_DW1_EFI_MEMORY_TYPE_ATTR 0x0000ff00 +#define CDAT_DSEMTS_DPA_OFFSET(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_DSEMTS_DPA_LENGTH(entry) ((u64)((entry)[5]) << 32 | (entry)[4]) + +/* Switch Scoped Latency and Bandwidth Information Structure */ +#define CDAT_SSLBIS_DW1_DATA_TYPE 0x000000ff +#define CDAT_SSLBIS_BASE_UNIT(entry) ((u64)((entry)[3]) << 32 | (entry)[2]) +#define CDAT_SSLBIS_ENTRY_PORT_X(entry, i) ((entry)[4 + (i) * 2] & 0x0000ffff) +#define CDAT_SSLBIS_ENTRY_PORT_Y(entry, i) (((entry)[4 + (i) * 2] & 0xffff0000) >> 16) +#define CDAT_SSLBIS_ENTRY_LAT_OR_BW(entry, i) ((entry)[4 + (i) * 2 + 1] & 0x0000ffff) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 6f14838c2d25..cd80f589fff7 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -7,6 +7,7 @@ #include #include #include +#include /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ #define CXLDEV_CAP_ARRAY_OFFSET 0x0 @@ -57,10 +58,21 @@ (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \ CXLMDEV_RESET_NEEDED_NOT) +#define CXL_DOE_PROTOCOL_COMPLIANCE 0 +#define CXL_DOE_PROTOCOL_TABLE_ACCESS 2 + +/* Common to request and response */ +#define CXL_DOE_TABLE_ACCESS_3_CODE GENMASK(7, 0) +#define CXL_DOE_TABLE_ACCESS_3_CODE_READ 0 +#define CXL_DOE_TABLE_ACCESS_3_TYPE GENMASK(15, 8) +#define CXL_DOE_TABLE_ACCESS_3_TYPE_CDAT 0 +#define CXL_DOE_TABLE_ACCESS_3_ENTRY_HANDLE GENMASK(31, 16) + struct cxl_memdev; /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. + * @table_doe: Data exchange object mailbox used to read tables. * @regs: IO mappings to the device's MMIO * @status_regs: CXL 2.0 8.2.8.3 Device Status Registers * @mbox_regs: CXL 2.0 8.2.8.4 Mailbox Registers @@ -75,6 +87,7 @@ struct cxl_memdev; */ struct cxl_mem { struct pci_dev *pdev; + struct pcie_doe *table_doe; void __iomem *regs; struct cxl_memdev *cxlmd; diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 4597b28aeb3f..29b3054adf1c 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -12,6 +12,7 @@ #include #include "pci.h" #include "cxl.h" +#include "cdat.h" /** * DOC: cxl mem @@ -99,6 +100,8 @@ struct mbox_cmd { * @ops_active: active user of @cxlm in ops handlers * @ops_dead: completion when all @cxlm ops users have exited * @id: id number of this memdev instance. + * @cdat_table: cache of CDAT table + * @cdat_length: length of cached CDAT table */ struct cxl_memdev { struct device dev; @@ -107,6 +110,8 @@ struct cxl_memdev { struct percpu_ref ops_active; struct completion ops_dead; int id; + void *cdat_table; + size_t cdat_length; }; static int cxl_mem_major; @@ -976,6 +981,85 @@ static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm) return 0; } +#define CDAT_DOE_REQ(entry_handle) \ + (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \ + CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \ + FIELD_PREP(CXL_DOE_TABLE_ACCESS_TABLE_TYPE, \ + CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) | \ + FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle))) + +static ssize_t cdat_get_length(struct pcie_doe *doe) +{ + u32 cdat_request_pl = CDAT_DOE_REQ(0); + u32 cdat_response_pl[32]; + struct pcie_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + + ssize_t rc; + + rc = pcie_doe_sync(doe, &ex); + if (rc < 0) + return rc; + if (rc < 1) + return -EIO; + + return cdat_response_pl[1]; +} + +static int cdat_to_buffer(struct pcie_doe *doe, u32 *buffer, size_t length) +{ + int entry_handle = 0; + int rc; + + do { + u32 cdat_request_pl = CDAT_DOE_REQ(entry_handle); + u32 cdat_response_pl[32]; + struct pcie_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + size_t entry_dw; + u32 *entry; + + rc = pcie_doe_sync(doe, &ex); + if (rc < 0) + return rc; + + entry = cdat_response_pl + 1; + entry_dw = rc / sizeof(u32); + /* Skip Header */ + entry_dw -= 1; + entry_dw = min(length / 4, entry_dw); + memcpy(buffer, entry, entry_dw * sizeof(u32)); + length -= entry_dw * sizeof(u32); + buffer += entry_dw; + entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, cdat_response_pl[0]); + + } while (entry_handle != 0xFFFF); + + return 0; +} + +static void cxl_mem_free_irq_vectors(void *data) +{ + pci_free_irq_vectors(data); +} + +static void cxl_mem_doe_unregister_all(void *data) +{ + pcie_doe_unregister_all(data); +} + static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi) { @@ -983,6 +1067,7 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, struct cxl_mem *cxlm; void __iomem *regs; u64 offset; + int irqs; u8 bar; int rc; @@ -1021,6 +1106,44 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, return NULL; } + /* + * An implementation of a cxl type3 device may support an unknown + * number of interrupts. Assume that number is not that large and + * request them all. + */ + irqs = pci_msix_vec_count(pdev); + rc = pci_alloc_irq_vectors(pdev, irqs, irqs, PCI_IRQ_MSIX); + if (rc != irqs) { + /* No interrupt available - carry on */ + dev_dbg(dev, "No interrupts available for DOE\n"); + } else { + /* + * Enabling bus mastering could be done within the DOE + * initialization, but as it potentially has other impacts + * keep it within the driver. + */ + pci_set_master(pdev); + rc = devm_add_action_or_reset(dev, cxl_mem_free_irq_vectors, + pdev); + if (rc) + return NULL; + } + + /* + * Find a DOE mailbox that supports CDAT. + * Supporting other DOE protocols will require more complexity. + */ + rc = pcie_doe_register_all(pdev); + if (rc < 0) + return NULL; + + rc = devm_add_action_or_reset(dev, cxl_mem_doe_unregister_all, pdev); + if (rc) + return NULL; + + cxlm->table_doe = pcie_doe_find(pdev, PCI_DVSEC_VENDOR_ID_CXL, + CXL_DOE_PROTOCOL_TABLE_ACCESS); + dev_dbg(dev, "Mapped CXL Memory Device resource\n"); return cxlm; } @@ -1111,6 +1234,31 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%#llx\n", len); } +static ssize_t CDAT_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t offset, size_t count) +{ + struct device *dev = kobj_to_dev(kobj); + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + return memory_read_from_buffer(buf, count, &offset, cxlmd->cdat_table, + cxlmd->cdat_length); +} + +static BIN_ATTR_RO(CDAT, 0); + +static umode_t cxl_memdev_bin_attr_is_visible(struct kobject *kobj, + struct bin_attribute *attr, int i) +{ + struct device *dev = kobj_to_dev(kobj); + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + if ((attr == &bin_attr_CDAT) && cxlmd->cdat_table) + return 0400; + + return 0; +} + static struct device_attribute dev_attr_pmem_size = __ATTR(size, 0444, pmem_size_show, NULL); @@ -1120,6 +1268,11 @@ static struct attribute *cxl_memdev_attributes[] = { NULL, }; +static struct bin_attribute *cxl_memdev_bin_attributes[] = { + &bin_attr_CDAT, + NULL, +}; + static struct attribute *cxl_memdev_pmem_attributes[] = { &dev_attr_pmem_size.attr, NULL, @@ -1132,6 +1285,8 @@ static struct attribute *cxl_memdev_ram_attributes[] = { static struct attribute_group cxl_memdev_attribute_group = { .attrs = cxl_memdev_attributes, + .bin_attrs = cxl_memdev_bin_attributes, + .is_bin_visible = cxl_memdev_bin_attr_is_visible, }; static struct attribute_group cxl_memdev_ram_attribute_group = { @@ -1178,6 +1333,25 @@ static void cxlmdev_ops_active_release(struct percpu_ref *ref) complete(&cxlmd->ops_dead); } +static int cxl_cache_cdat_table(struct cxl_memdev *cxlmd) +{ + struct cxl_mem *cxlm = cxlmd->cxlm; + struct device *dev = &cxlmd->dev; + ssize_t cdat_length; + + if (cxlm->table_doe == NULL) + return 0; + + cdat_length = cdat_get_length(cxlm->table_doe); + if (cdat_length < 0) + return cdat_length; + + cxlmd->cdat_length = cdat_length; + cxlmd->cdat_table = devm_kzalloc(dev->parent, cdat_length, GFP_KERNEL); + + return cdat_to_buffer(cxlm->table_doe, cxlmd->cdat_table, cxlmd->cdat_length); +} + static int cxl_mem_add_memdev(struct cxl_mem *cxlm) { struct pci_dev *pdev = cxlm->pdev; @@ -1216,6 +1390,9 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) cdev = &cxlmd->cdev; cdev_init(cdev, &cxl_memdev_fops); + rc = cxl_cache_cdat_table(cxlmd); + if (rc) + goto err_add; rc = cdev_device_add(cdev, dev); if (rc) From patchwork Tue Apr 13 16:01:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12200897 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AD95C433ED for ; Tue, 13 Apr 2021 16:04:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DBD56124B for ; Tue, 13 Apr 2021 16:04:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346796AbhDMQE6 (ORCPT ); Tue, 13 Apr 2021 12:04:58 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2846 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346794AbhDMQE5 (ORCPT ); Tue, 13 Apr 2021 12:04:57 -0400 Received: from fraeml701-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FKVfK0v5jz67ywp; Tue, 13 Apr 2021 23:59:21 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml701-chm.china.huawei.com (10.206.15.50) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Tue, 13 Apr 2021 18:04:36 +0200 Received: from localhost.localdomain (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 13 Apr 2021 17:04:35 +0100 From: Jonathan Cameron To: , , Dan Williams , Bjorn Helgaas , "Lorenzo Pieralisi" CC: Ben Widawsky , Chris Browy , , , , , , Fangjian , Jonathan Cameron Subject: [RFC PATCH v2 4/4] cxl/mem: Add a debug parser for CDAT commands. Date: Wed, 14 Apr 2021 00:01:59 +0800 Message-ID: <20210413160159.935663-5-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> References: <20210413160159.935663-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml748-chm.china.huawei.com (10.201.108.198) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Logs a pretty printed version of the CDAT table entries at driver load. I find this helpful for development, so including as an extra patch that I would suggest is never merged. Signed-off-by: Jonathan Cameron --- Changes since v1: Split out as separate patch so we can drop it easily before merging the rest. drivers/cxl/mem.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 29b3054adf1c..d3f40894f3df 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -1050,6 +1050,104 @@ static int cdat_to_buffer(struct pcie_doe *doe, u32 *buffer, size_t length) return 0; } +static int cdat_dump(struct pcie_doe *doe) +{ + struct pci_dev *dev = doe->pdev; + int entry_handle = 0; + int rc; + + if (doe == NULL) + return 0; + + dev = doe->pdev; + do { + /* Table access is available */ + u32 cdat_request_pl = CDAT_DOE_REQ(entry_handle); + u32 cdat_response_pl[32]; + struct pcie_doe_exchange ex = { + .vid = PCI_DVSEC_VENDOR_ID_CXL, + .protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS, + .request_pl = &cdat_request_pl, + .request_pl_sz = sizeof(cdat_request_pl), + .response_pl = cdat_response_pl, + .response_pl_sz = sizeof(cdat_response_pl), + }; + u32 *entry; + + rc = pcie_doe_sync(doe, &ex); + if (rc < 0) + return rc; + + /* Skip past table response header */ + entry = cdat_response_pl + 1; + if (entry_handle == 0) { + pci_info(dev, + "CDAT Header (Length=%u, Revision=%u, Checksum=0x%x, Sequence=%u\n", + entry[0], + FIELD_GET(CDAT_HEADER_DW1_REVISION, entry[1]), + FIELD_GET(CDAT_HEADER_DW1_CHECKSUM, entry[1]), + entry[2]); + } else { + u8 entry_type = FIELD_GET(CDAT_STRUCTURE_DW0_TYPE, entry[0]); + + switch (entry_type) { + case CDAT_STRUCTURE_DW0_TYPE_DSMAS: + pci_info(dev, + "CDAT DSMAS (handle=%u flags=0x%x, dpa(0x%llx 0x%llx)\n", + FIELD_GET(CDAT_DSMAS_DW1_DSMAD_HANDLE, entry[1]), + FIELD_GET(CDAT_DSMAS_DW1_FLAGS, entry[1]), + CDAT_DSMAS_DPA_OFFSET(entry), + CDAT_DSMAS_DPA_LEN(entry)); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSLBIS: + pci_info(dev, + "CDAT DSLBIS (handle=%u flags=0x%x, ent_base=0x%llx, entry[%u %u %u])\n", + FIELD_GET(CDAT_DSLBIS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSLBIS_DW1_FLAGS, entry[1]), + CDAT_DSLBIS_BASE_UNIT(entry), + FIELD_GET(CDAT_DSLBIS_DW4_ENTRY_0, entry[4]), + FIELD_GET(CDAT_DSLBIS_DW4_ENTRY_1, entry[4]), + FIELD_GET(CDAT_DSLBIS_DW5_ENTRY_2, entry[5])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSMSCIS: + pci_info(dev, + "CDAT DSMSCIS (handle=%u sc_size=0x%llx attrs=0x%x)\n", + FIELD_GET(CDAT_DSMSCIS_DW1_HANDLE, entry[1]), + CDAT_DSMSCIS_MEMORY_SIDE_CACHE_SIZE(entry), + FIELD_GET(CDAT_DSMSCIS_DW4_MEMORY_SIDE_CACHE_ATTRS, + entry[4])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSIS: + pci_info(dev, + "CDAT DSIS (handle=%u flags=0x%x)\n", + FIELD_GET(CDAT_DSIS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSIS_DW1_FLAGS, entry[1])); + break; + case CDAT_STRUCTURE_DW0_TYPE_DSEMTS: + pci_info(dev, + "CDAT DSEMTS (handle=%u EFI=0x%x dpa(0x%llx 0x%llx)\n", + FIELD_GET(CDAT_DSEMTS_DW1_HANDLE, entry[1]), + FIELD_GET(CDAT_DSEMTS_DW1_EFI_MEMORY_TYPE_ATTR, + entry[1]), + CDAT_DSEMTS_DPA_OFFSET(entry), + CDAT_DSEMTS_DPA_LENGTH(entry)); + break; + case CDAT_STRUCTURE_DW0_TYPE_SSLBIS: + pci_info(dev, + "CDAT SSLBIS (type%u ent_base=%llu...)\n", + FIELD_GET(CDAT_SSLBIS_DW1_DATA_TYPE, + entry[1]), + CDAT_SSLBIS_BASE_UNIT(entry)); + break; + } + } + entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, + cdat_response_pl[0]); + } while (entry_handle != 0xFFFF); + + return 0; +} + static void cxl_mem_free_irq_vectors(void *data) { pci_free_irq_vectors(data); @@ -1144,6 +1242,10 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, cxlm->table_doe = pcie_doe_find(pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS); + rc = cdat_dump(cxlm->table_doe); + if (rc) + return NULL; + dev_dbg(dev, "Mapped CXL Memory Device resource\n"); return cxlm; }