From patchwork Fri Apr 16 19:20:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stuart Hayes X-Patchwork-Id: 12208625 X-Patchwork-Delegate: bhelgaas@google.com 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 ADAD3C433ED for ; Fri, 16 Apr 2021 19:20:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7974E613B4 for ; Fri, 16 Apr 2021 19:20:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237789AbhDPTUq (ORCPT ); Fri, 16 Apr 2021 15:20:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235122AbhDPTUp (ORCPT ); Fri, 16 Apr 2021 15:20:45 -0400 Received: from mail-oi1-x235.google.com (mail-oi1-x235.google.com [IPv6:2607:f8b0:4864:20::235]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3435FC061574 for ; Fri, 16 Apr 2021 12:20:19 -0700 (PDT) Received: by mail-oi1-x235.google.com with SMTP id b3so14147668oie.5 for ; Fri, 16 Apr 2021 12:20:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=NlbO91rwmb9BUR79UPP3pIDiPt8WOBgxLLZHVYBmyiM=; b=U/Qh5a0b5VI/8r2jxqpH+fmasiqkwovJnfRIDyMRk88jWcVJuC0zu9dU9MncBTAT9a XIYPE3Mg7a9HIKrgIybPwCM71NS4F/QqSf1IMPYt9KOU1MSDn0xndLb1uPD7dCRlxYvA k35n7aNCpw5FCNPjFED0y4RH73XQEy8WKFKk4JUa035s9Wm5dGWo+l1CLXPHS/To5DIb Cl6HC0sCImcMVSFRQieTPhI5wcxLkwkF+MrEyJhCDySxkDjEET7iUIjZ74Rr+5Bw8ym2 SJK/eqXD/tkKDwoxrafdYrBc8oaurDTwuj/ad3jiC048t3VwZeoonIfo+llkbU9zHWDS E1qw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=NlbO91rwmb9BUR79UPP3pIDiPt8WOBgxLLZHVYBmyiM=; b=rPOuzVbfR49174AjIyiuUe2iuklyFMVm72jrrdPXXapbxUPgvzjEHL+d/ZcZwNCU0x kg5y1Hr9aBMiWoXBpIL0bgyUIKA+RtzldU/Gs6Y7FGpP792drXa+Mo1CWbWuNnYY2/F+ YbVSxvnjgZ6Rbfn4B5Ky8jPhNMiJDEGsM3SHRcydXWJI3wtxg2A6JPCI1Yj8Tr6ddsmE rqcZ0jiQ9/8UPVmQZzxpiN1RrmAEEQrdrdJIahSd6bXqCGfD1DeHZsosDQV9lEGKI6s2 t8iYMuun+YuUSBqHTWK4hifI9/0uXp2Prb5ZLFR/yrAZE/dn7Adu+2YSYMiaF8qa6jy5 L4eQ== X-Gm-Message-State: AOAM532e1X38bBeurpGKYEgDHGA8anA1sVGSatcmM4cSkWxBqtqFDP+a o/nozNQGMSkTwR2Oyzf4K54= X-Google-Smtp-Source: ABdhPJwbAPQpH4JxKe9HBbHpK95DX1BTtWXJ/uAOOuJrppldMQl95hrvQLjX4yqXUbnX9M+eiN164g== X-Received: by 2002:aca:4487:: with SMTP id r129mr7817454oia.106.1618600818569; Fri, 16 Apr 2021 12:20:18 -0700 (PDT) Received: from localhost.localdomain ([143.166.81.254]) by smtp.gmail.com with ESMTPSA id q130sm1538601oif.40.2021.04.16.12.20.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Apr 2021 12:20:17 -0700 (PDT) From: Stuart Hayes To: Bjorn Helgaas , linux-pci@vger.kernel.org Cc: Stuart Hayes Subject: [PATCH] Add support for PCIe SSD status LED management Date: Fri, 16 Apr 2021 15:20:10 -0400 Message-Id: <20210416192010.3197-1-stuart.w.hayes@gmail.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This patch adds support for the PCIe SSD Status LED Management interface, as described in the "_DSM Additions for PCIe SSD Status LED Management" ECN to the PCI Firmware Specification revision 3.2. It will add a single (led_classdev) LED for any PCIe device that has the relevant _DSM. The ten possible status states are exposed using attributes current_states and supported_states. Reading current_states (and supported_states) will show the definition and value of each bit: >cat /sys/class/leds/0000:88:00.0::pcie_ssd_status/supported_states ok 0x0004 [ ] locate 0x0008 [*] fail 0x0010 [ ] rebuild 0x0020 [ ] pfa 0x0040 [ ] hotspare 0x0080 [ ] criticalarray 0x0100 [ ] failedarray 0x0200 [ ] invaliddevice 0x0400 [ ] disabled 0x0800 [ ] --- supported_states = 0x0008 >cat /sys/class/leds/0000:88:00.0::pcie_ssd_status/current_states locate 0x0008 [ ] -- current_states = 0x0000 Signed-off-by: Stuart Hayes --- .../sysfs-class-led-driver-pcie-ssd-leds | 30 ++ drivers/pci/Kconfig | 12 + drivers/pci/Makefile | 1 + drivers/pci/pcie-ssd-leds.c | 421 ++++++++++++++++++ 4 files changed, 464 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-pcie-ssd-leds create mode 100644 drivers/pci/pcie-ssd-leds.c diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-pcie-ssd-leds b/Documentation/ABI/testing/sysfs-class-led-driver-pcie-ssd-leds new file mode 100644 index 000000000000..856f5a078568 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-driver-pcie-ssd-leds @@ -0,0 +1,30 @@ +What: /sys/class/leds//supported_states +Date: April 2021 +Contact: linux-pci@vger.kernel.org +Description: + This attribute indicates the status states supported by this + display. Reading will show a verbose output with the value on + the final line (example below), writing only takes a single + numerical value. + + >cat /sys/class/leds/0000:88:00.0::pcie_ssd_status/supported_states + ok 0x0004 [ ] + locate 0x0008 [*] + fail 0x0010 [ ] + rebuild 0x0020 [ ] + pfa 0x0040 [ ] + hotspare 0x0080 [ ] + criticalarray 0x0100 [ ] + failedarray 0x0200 [ ] + invaliddevice 0x0400 [ ] + disabled 0x0800 [ ] + -- + supported_states = 0x0008 + +What: /sys/class/leds//current_states +Date: April 2021 +Contact: linux-pci@vger.kernel.org +Description: + This attribute indicates the currently active status states on + this display. Reading will show a verbose output with the value + the final line, writing only takes a single numerical value. diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 0c473d75e625..f4acf1ad0fb5 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -190,6 +190,18 @@ config PCI_HYPERV The PCI device frontend driver allows the kernel to import arbitrary PCI devices from a PCI backend to support PCI driver domains. +config PCIE_SSD_LEDS + tristate "PCIe SSD status LED support" + depends on ACPI && NEW_LEDS + help + Driver for PCIe SSD status LED management as described in a PCI + Firmware Specification, Revision 3.2 ECN. + + When enabled, an LED interface will be created for each PCIe device + that has the ACPI method described in the referenced specification, + to allow the device status LEDs for that PCIe device (presumably a + solid state storage device or its slot) to be seen and controlled. + choice prompt "PCI Express hierarchy optimization setting" default PCIE_BUS_DEFAULT diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index d62c4ac4ae1b..ea0a0f351ad2 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_PCI_PF_STUB) += pci-pf-stub.o obj-$(CONFIG_PCI_ECAM) += ecam.o obj-$(CONFIG_PCI_P2PDMA) += p2pdma.o obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o +obj-$(CONFIG_PCIE_SSD_LEDS) += pcie-ssd-leds.o # Endpoint library must be initialized before its users obj-$(CONFIG_PCI_ENDPOINT) += endpoint/ diff --git a/drivers/pci/pcie-ssd-leds.c b/drivers/pci/pcie-ssd-leds.c new file mode 100644 index 000000000000..cd00b7dd1a8e --- /dev/null +++ b/drivers/pci/pcie-ssd-leds.c @@ -0,0 +1,421 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Module to expose interface to control PCIe SSD LEDs as defined in the + * "_DSM additions for PCIe SSD Status LED Management" ECN to the PCI + * Firmware Specification Revision 3.2, dated 12 February 2020. + * + * Copyright (c) 2021 Dell Inc. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "pcie-ssd-leds" +#define DRIVER_VERSION "v1.0" + +struct led_state { + char *name; + u32 mask; +}; + +static struct led_state led_states[] = { + { .name = "ok", .mask = 1 << 2 }, + { .name = "locate", .mask = 1 << 3 }, + { .name = "fail", .mask = 1 << 4 }, + { .name = "rebuild", .mask = 1 << 5 }, + { .name = "pfa", .mask = 1 << 6 }, + { .name = "hotspare", .mask = 1 << 7 }, + { .name = "criticalarray", .mask = 1 << 8 }, + { .name = "failedarray", .mask = 1 << 9 }, + { .name = "invaliddevice", .mask = 1 << 10 }, + { .name = "disabled", .mask = 1 << 11 }, +}; + +/* + * ssd_status_dev could be the SSD's PCIe dev or its hotplug slot + */ +struct ssd_status_dev { + struct list_head ssd_list; + struct pci_dev *pdev; + u32 supported_states; + struct led_classdev led_cdev; + enum led_brightness brightness; +}; + +struct mutex ssd_list_lock; +struct list_head ssd_list; + +const guid_t pcie_ssdleds_dsm_guid = + GUID_INIT(0x5d524d9d, 0xfff9, 0x4d4b, + 0x8c, 0xb7, 0x74, 0x7e, 0xd5, 0x1e, 0x19, 0x4d); + +#define GET_SUPPORTED_STATES_DSM 0x01 +#define GET_STATE_DSM 0x02 +#define SET_STATE_DSM 0x03 + +struct pci_ssdleds_dsm_output { + u16 status; + u8 function_specific_err; + u8 vendor_specific_err; + u32 state; +}; + +static void dsm_status_err_print(struct device *dev, + struct pci_ssdleds_dsm_output *output) +{ + switch (output->status) { + case 0: + break; + case 1: + dev_dbg(dev, "_DSM not supported\n"); + break; + case 2: + dev_dbg(dev, "_DSM invalid input parameters\n"); + break; + case 3: + dev_dbg(dev, "_DSM communication error\n"); + break; + case 4: + dev_dbg(dev, "_DSM function-specific error 0x%x\n", + output->function_specific_err); + break; + case 5: + dev_dbg(dev, "_DSM vendor-specific error 0x%x\n", + output->vendor_specific_err); + break; + default: + dev_dbg(dev, "_DSM returned unknown status 0x%x\n", + output->status); + } +} + +static int dsm_set(struct device *dev, u32 value) +{ + acpi_handle handle; + union acpi_object *out_obj, arg3[2]; + struct pci_ssdleds_dsm_output *dsm_output; + + handle = ACPI_HANDLE(dev); + if (!handle) + return -ENODEV; + + arg3[0].type = ACPI_TYPE_PACKAGE; + arg3[0].package.count = 1; + arg3[0].package.elements = &arg3[1]; + + arg3[1].type = ACPI_TYPE_BUFFER; + arg3[1].buffer.length = 4; + arg3[1].buffer.pointer = (u8 *)&value; + + out_obj = acpi_evaluate_dsm_typed(handle, &pcie_ssdleds_dsm_guid, + 1, SET_STATE_DSM, &arg3[0], ACPI_TYPE_BUFFER); + if (!out_obj) + return -EIO; + + if (out_obj->buffer.length < 8) { + ACPI_FREE(out_obj); + return -EIO; + } + + dsm_output = (struct pci_ssdleds_dsm_output *)out_obj->buffer.pointer; + + if (dsm_output->status != 0) { + dsm_status_err_print(dev, dsm_output); + ACPI_FREE(out_obj); + return -EIO; + } + ACPI_FREE(out_obj); + return 0; +} + +static int dsm_get(struct device *dev, u64 dsm_func, u32 *output) +{ + acpi_handle handle; + union acpi_object *out_obj; + struct pci_ssdleds_dsm_output *dsm_output; + + handle = ACPI_HANDLE(dev); + if (!handle) + return -ENODEV; + + out_obj = acpi_evaluate_dsm_typed(handle, &pcie_ssdleds_dsm_guid, 0x1, + dsm_func, NULL, ACPI_TYPE_BUFFER); + if (!out_obj) + return -EIO; + + if (out_obj->buffer.length < 8) { + ACPI_FREE(out_obj); + return -EIO; + } + + dsm_output = (struct pci_ssdleds_dsm_output *)out_obj->buffer.pointer; + if (dsm_output->status != 0) { + dsm_status_err_print(dev, dsm_output); + ACPI_FREE(out_obj); + return -EIO; + } + + *output = dsm_output->state; + ACPI_FREE(out_obj); + return 0; +} + +static bool pdev_has_dsm(struct pci_dev *pdev) +{ + acpi_handle handle; + + handle = ACPI_HANDLE(&pdev->dev); + if (!handle) + return false; + + return !!acpi_check_dsm(handle, &pcie_ssdleds_dsm_guid, 0x1, + 1 << GET_SUPPORTED_STATES_DSM || + 1 << GET_STATE_DSM || + 1 << SET_STATE_DSM); +} + +static ssize_t current_states_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct device *dsm_dev = led_cdev->dev->parent; + struct ssd_status_dev *ssd; + u32 val; + int err, i, result = 0; + + ssd = container_of(led_cdev, struct ssd_status_dev, led_cdev); + + err = dsm_get(dsm_dev, GET_STATE_DSM, &val); + if (err < 0) + return err; + for (i = 0; i < ARRAY_SIZE(led_states); i++) + if (led_states[i].mask & ssd->supported_states) + result += sprintf(buf + result, "%-25s\t0x%04X [%c]\n", + led_states[i].name, + led_states[i].mask, + (val & led_states[i].mask) + ? '*' : ' '); + + result += sprintf(buf + result, "--\ncurrent_states = 0x%04X\n", val); + return result; +} + +static ssize_t current_states_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct device *dsm_dev = led_cdev->dev->parent; + struct ssd_status_dev *ssd; + u32 val; + int err; + + ssd = container_of(led_cdev, struct ssd_status_dev, led_cdev); + + err = kstrtou32(buf, 10, &val); + if (err) + return err; + + val &= ssd->supported_states; + if (val) + ssd->brightness = LED_ON; + err = dsm_set(dsm_dev, val); + if (err < 0) + return err; + + return size; +} + +static ssize_t supported_states_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct ssd_status_dev *ssd; + int i, result = 0; + + ssd = container_of(led_cdev, struct ssd_status_dev, led_cdev); + + for (i = 0; i < ARRAY_SIZE(led_states); i++) + result += sprintf(buf + result, "%-25s\t0x%04X [%c]\n", + led_states[i].name, + led_states[i].mask, + (ssd->supported_states & led_states[i].mask) + ? '*' : ' '); + + result += sprintf(buf + result, "--\nsupported_states = 0x%04X\n", + ssd->supported_states); + return result; +} + +static DEVICE_ATTR_RW(current_states); +static DEVICE_ATTR_RO(supported_states); + +static struct attribute *pcie_ssd_status_attrs[] = { + &dev_attr_current_states.attr, + &dev_attr_supported_states.attr, + NULL +}; + +ATTRIBUTE_GROUPS(pcie_ssd_status); + +static int ssdleds_set_brightness(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + struct device *dsm_dev = led_cdev->dev->parent; + struct ssd_status_dev *ssd; + int err; + + ssd = container_of(led_cdev, struct ssd_status_dev, led_cdev); + ssd->brightness = brightness; + + if (brightness == LED_OFF) { + err = dsm_set(dsm_dev, 0); + if (err < 0) + return err; + } + return 0; +} + +static enum led_brightness ssdleds_get_brightness(struct led_classdev *led_cdev) +{ + struct ssd_status_dev *ssd; + + ssd = container_of(led_cdev, struct ssd_status_dev, led_cdev); + return ssd->brightness; +} + +static void remove_ssd(struct ssd_status_dev *ssd) +{ + mutex_lock(&ssd_list_lock); + list_del(&ssd->ssd_list); + mutex_unlock(&ssd_list_lock); + led_classdev_unregister(&ssd->led_cdev); + kfree(ssd); +} + +static struct ssd_status_dev *pci_dev_to_ssd_status_dev(struct pci_dev *pdev) +{ + struct ssd_status_dev *ssd; + + mutex_lock(&ssd_list_lock); + list_for_each_entry(ssd, &ssd_list, ssd_list) + if (pdev == ssd->pdev) { + mutex_unlock(&ssd_list_lock); + return ssd; + } + mutex_unlock(&ssd_list_lock); + return NULL; +} + +static void remove_ssd_for_pdev(struct pci_dev *pdev) +{ + struct ssd_status_dev *ssd = pci_dev_to_ssd_status_dev(pdev); + + if (ssd) + remove_ssd(ssd); +} + +static void add_ssd(struct pci_dev *pdev) +{ + u32 supported_states; + int ret; + struct ssd_status_dev *ssd; + char name[LED_MAX_NAME_SIZE]; + + if (dsm_get(&pdev->dev, GET_SUPPORTED_STATES_DSM, &supported_states) < 0) + return; + + ssd = kzalloc(sizeof(*ssd), GFP_KERNEL); + if (!ssd) + return; + + ssd->pdev = pdev; + ssd->supported_states = supported_states; + ssd->brightness = LED_ON; + snprintf(name, sizeof(name), "%s::%s", + dev_name(&pdev->dev), "pcie_ssd_status"); + ssd->led_cdev.name = name; + ssd->led_cdev.max_brightness = LED_ON; + ssd->led_cdev.brightness_set_blocking = ssdleds_set_brightness; + ssd->led_cdev.brightness_get = ssdleds_get_brightness; + ssd->led_cdev.groups = pcie_ssd_status_groups; + + ret = led_classdev_register(&pdev->dev, &ssd->led_cdev); + if (ret) { + pr_warn("Failed to register LED %s\n", ssd->led_cdev.name); + remove_ssd(ssd); + return; + } + mutex_lock(&ssd_list_lock); + list_add_tail(&ssd->ssd_list, &ssd_list); + mutex_unlock(&ssd_list_lock); +} + +static void probe_pdev(struct pci_dev *pdev) +{ + if (pci_dev_to_ssd_status_dev(pdev)) + /* + * leds have already been added for this pdev + */ + return; + + if (pdev_has_dsm(pdev)) + add_ssd(pdev); +} + +static int pciessdleds_pci_bus_notifier_cb(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pci_dev *pdev = to_pci_dev(data); + + if (action == BUS_NOTIFY_ADD_DEVICE) + probe_pdev(pdev); + else if (action == BUS_NOTIFY_REMOVED_DEVICE) + remove_ssd_for_pdev(pdev); + return NOTIFY_DONE; +} + +static struct notifier_block pciessdleds_pci_bus_nb = { + .notifier_call = pciessdleds_pci_bus_notifier_cb, + .priority = INT_MIN, +}; + +static void initial_scan_for_leds(void) +{ + struct pci_dev *pdev = NULL; + + for_each_pci_dev(pdev) + probe_pdev(pdev); +} + +static int __init pciessdleds_init(void) +{ + mutex_init(&ssd_list_lock); + INIT_LIST_HEAD(&ssd_list); + + bus_register_notifier(&pci_bus_type, &pciessdleds_pci_bus_nb); + initial_scan_for_leds(); + return 0; +} + +static void __exit pciessdleds_exit(void) +{ + struct ssd_status_dev *ssd, *temp; + + bus_unregister_notifier(&pci_bus_type, &pciessdleds_pci_bus_nb); + list_for_each_entry_safe(ssd, temp, &ssd_list, ssd_list) + remove_ssd(ssd); +} + +module_init(pciessdleds_init); +module_exit(pciessdleds_exit); + +MODULE_AUTHOR("Stuart Hayes "); +MODULE_DESCRIPTION("Support for PCIe SSD Status LED Management _DSM"); +MODULE_LICENSE("GPL");