From patchwork Mon Jul 4 13:22:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Munsie X-Patchwork-Id: 644175 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rjp3W6Pldz9sXR for ; Mon, 4 Jul 2016 23:37:27 +1000 (AEST) Received: from ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3rjp3W5QQ2zDrLn for ; Mon, 4 Jul 2016 23:37:27 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rjnkz2cv0zDqps for ; Mon, 4 Jul 2016 23:23:07 +1000 (AEST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u64DIeYw069598 for ; Mon, 4 Jul 2016 09:23:05 -0400 Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) by mx0b-001b2d01.pphosted.com with ESMTP id 23x9rkmys4-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 04 Jul 2016 09:23:03 -0400 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 4 Jul 2016 23:22:59 +1000 X-IBM-Helo: d23dlp01.au.ibm.com X-IBM-MailFrom: imunsie@au1.ibm.com X-IBM-RcptTo: linuxppc-dev@lists.ozlabs.org Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id DB5982CE8054 for ; Mon, 4 Jul 2016 23:22:58 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u64DMw8613369638 for ; Mon, 4 Jul 2016 23:22:58 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u64DMw86001337 for ; Mon, 4 Jul 2016 23:22:58 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u64DMv1n001334; Mon, 4 Jul 2016 23:22:58 +1000 Received: from x230.au.ibm.com (unknown [9.192.161.209]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 71C7FA01E4; Mon, 4 Jul 2016 23:22:56 +1000 (AEST) From: "Ian Munsie" To: Michael Ellerman , Michael Neuling , Frederic Barrat , Andrew Donnellan , linuxppc-dev@lists.ozlabs.org, Huy Nguyen Subject: [PATCH 14/14] cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cards Date: Mon, 4 Jul 2016 23:22:12 +1000 X-Mailer: git-send-email 2.8.1 In-Reply-To: <1467638532-9250-1-git-send-email-imunsie@au.ibm.com> References: <1467638532-9250-1-git-send-email-imunsie@au.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16070413-1617-0000-0000-000001359CE7 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16070413-1618-0000-0000-0000463488DF Message-Id: <1467638532-9250-15-git-send-email-imunsie@au.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-07-04_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607040124 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gavin Shan MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Andrew Donnellan Add a new API, cxl_check_and_switch_mode() to allow for switching of bi-modal CAPI cards, such as the Mellanox CX-4 network card. When a driver requests to switch a card to CAPI mode, use PCI hotplug infrastructure to remove all PCI devices underneath the slot. We then write an updated mode control register to the CAPI VSEC, hot reset the card, and reprobe the card. As the card may present a different set of PCI devices after the mode switch, use the infrastructure provided by the pnv_php driver and the OPAL PCI slot management facilities to ensure that: * the old devices are removed from both the OPAL and Linux device trees * the new devices are probed by OPAL and added to the OPAL device tree * the new devices are added to the Linux device tree and probed through the regular PCI device probe path As such, introduce a new option, CONFIG_CXL_BIMODAL, with a dependency on the pnv_php driver. Refactor existing code that touches the mode control register in the regular single mode case into a new function, setup_cxl_protocol_area(). Co-authored-by: Ian Munsie Cc: Gavin Shan Signed-off-by: Andrew Donnellan Reviewed-by: Gavin Shan --- drivers/misc/cxl/Kconfig | 8 ++ drivers/misc/cxl/pci.c | 234 +++++++++++++++++++++++++++++++++++++++++++---- include/misc/cxl.h | 25 +++++ 3 files changed, 249 insertions(+), 18 deletions(-) diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig index 560412c..6859723 100644 --- a/drivers/misc/cxl/Kconfig +++ b/drivers/misc/cxl/Kconfig @@ -38,3 +38,11 @@ config CXL CAPI adapters are found in POWER8 based systems. If unsure, say N. + +config CXL_BIMODAL + bool "Support for bi-modal CAPI cards" + depends on HOTPLUG_PCI_POWERNV = y && CXL || HOTPLUG_PCI_POWERNV = m && CXL = m + default y + help + Select this option to enable support for bi-modal CAPI cards, such as + the Mellanox CX-4. \ No newline at end of file diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 090eee8..63abd26 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -55,6 +55,8 @@ pci_read_config_byte(dev, vsec + 0xa, dest) #define CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val) \ pci_write_config_byte(dev, vsec + 0xa, val) +#define CXL_WRITE_VSEC_MODE_CONTROL_BUS(bus, devfn, vsec, val) \ + pci_bus_write_config_byte(bus, devfn, vsec + 0xa, val) #define CXL_VSEC_PROTOCOL_MASK 0xe0 #define CXL_VSEC_PROTOCOL_1024TB 0x80 #define CXL_VSEC_PROTOCOL_512TB 0x40 @@ -614,36 +616,232 @@ static int setup_cxl_bars(struct pci_dev *dev) return 0; } -/* pciex node: ibm,opal-m64-window = <0x3d058 0x0 0x3d058 0x0 0x8 0x0>; */ -static int switch_card_to_cxl(struct pci_dev *dev) -{ +#ifdef CONFIG_CXL_BIMODAL + +struct cxl_switch_work { + struct pci_dev *dev; + struct work_struct work; int vsec; + int mode; +}; + +static void switch_card_to_cxl(struct work_struct *work) +{ + struct cxl_switch_work *switch_work = + container_of(work, struct cxl_switch_work, work); + struct pci_dev *dev = switch_work->dev; + struct pci_bus *bus = dev->bus; + struct pci_controller *hose = pci_bus_to_host(bus); + struct pci_dev *bridge; + struct pnv_php_slot *php_slot; + unsigned int devfn; u8 val; int rc; - dev_info(&dev->dev, "switch card to CXL\n"); + dev_info(&bus->dev, "cxl: Preparing for mode switch...\n"); + bridge = list_first_entry_or_null(&hose->bus->devices, struct pci_dev, + bus_list); + if (!bridge) { + dev_WARN(&bus->dev, "cxl: Couldn't find root port!\n"); + goto err_free_work; + } - if (!(vsec = find_cxl_vsec(dev))) { - dev_err(&dev->dev, "ABORTING: CXL VSEC not found!\n"); + php_slot = pnv_php_find_slot(pci_device_to_OF_node(bridge)); + if (!php_slot) { + dev_err(&bus->dev, "cxl: Failed to find slot hotplug " + "information. You may need to upgrade " + "skiboot. Aborting.\n"); + pci_dev_put(dev); + goto err_free_work; + } + + rc = CXL_READ_VSEC_MODE_CONTROL(dev, switch_work->vsec, &val); + if (rc) { + dev_err(&bus->dev, "cxl: Failed to read CAPI mode control: %i\n", rc); + pci_dev_put(dev); + goto err_free_work; + } + devfn = dev->devfn; + pci_dev_put(dev); + + dev_dbg(&bus->dev, "cxl: Removing PCI devices from kernel\n"); + pci_lock_rescan_remove(); + pci_hp_remove_devices(bridge->subordinate); + pci_unlock_rescan_remove(); + + /* Switch the CXL protocol on the card */ + if (switch_work->mode == CXL_BIMODE_CXL) { + dev_info(&bus->dev, "cxl: Switching card to CXL mode\n"); + val &= ~CXL_VSEC_PROTOCOL_MASK; + val |= CXL_VSEC_PROTOCOL_256TB | CXL_VSEC_PROTOCOL_ENABLE; + rc = pnv_cxl_enable_phb_kernel_api(hose, true); + if (rc) { + dev_err(&bus->dev, "cxl: Failed to enable kernel API" + " on real PHB, aborting\n"); + goto err_free_work; + } + } else { + dev_WARN(&bus->dev, "cxl: Switching card to PCI mode not supported!\n"); + goto err_free_work; + } + + rc = CXL_WRITE_VSEC_MODE_CONTROL_BUS(bus, devfn, switch_work->vsec, val); + if (rc) { + dev_err(&bus->dev, "cxl: Failed to configure CXL protocol: %i\n", rc); + goto err_free_work; + } + + /* + * The CAIA spec (v1.1, Section 10.6 Bi-modal Device Support) states + * we must wait 100ms after this mode switch before touching PCIe config + * space. + */ + msleep(100); + + /* + * Hot reset to cause the card to come back in cxl mode. A + * OPAL_RESET_PCI_LINK would be sufficient, but currently lacks support + * in skiboot, so we use a hot reset instead. + * + * We call pci_set_pcie_reset_state() on the bridge, as a CAPI card is + * guaranteed to sit directly under the root port, and setting the reset + * state on a device directly under the root port is equivalent to doing + * it on the root port iself. + */ + dev_info(&bus->dev, "cxl: Configuration write complete, resetting card\n"); + pci_set_pcie_reset_state(bridge, pcie_hot_reset); + pci_set_pcie_reset_state(bridge, pcie_deassert_reset); + + dev_dbg(&bus->dev, "cxl: Offlining slot\n"); + rc = pnv_php_set_slot_power_state(&php_slot->slot, OPAL_PCI_SLOT_OFFLINE); + if (rc) { + dev_err(&bus->dev, "cxl: OPAL offlining call failed: %i\n", rc); + goto err_free_work; + } + + dev_dbg(&bus->dev, "cxl: Onlining and probing slot\n"); + rc = pnv_php_set_slot_power_state(&php_slot->slot, OPAL_PCI_SLOT_ONLINE); + if (rc) { + dev_err(&bus->dev, "cxl: OPAL onlining call failed: %i\n", rc); + goto err_free_work; + } + + pci_lock_rescan_remove(); + pci_hp_add_devices(bridge->subordinate); + pci_unlock_rescan_remove(); + + dev_info(&bus->dev, "cxl: CAPI mode switch completed\n"); + kfree(switch_work); + return; + +err_free_work: + kfree(switch_work); +} + +int cxl_check_and_switch_mode(struct pci_dev *dev, int mode, int vsec) +{ + struct cxl_switch_work *work; + u8 val; + int rc; + + if (!cpu_has_feature(CPU_FTR_HVMODE)) return -ENODEV; + + if (!vsec) { + vsec = find_cxl_vsec(dev); + if (!vsec) { + dev_info(&dev->dev, "CXL VSEC not found\n"); + return -ENODEV; + } } - if ((rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val))) { - dev_err(&dev->dev, "failed to read current mode control: %i", rc); + rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val); + if (rc) { + dev_err(&dev->dev, "Failed to read current mode control: %i", rc); return rc; } - val &= ~CXL_VSEC_PROTOCOL_MASK; - val |= CXL_VSEC_PROTOCOL_256TB | CXL_VSEC_PROTOCOL_ENABLE; - if ((rc = CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val))) { - dev_err(&dev->dev, "failed to enable CXL protocol: %i", rc); - return rc; + + if (mode == CXL_BIMODE_PCI) { + if (!(val & CXL_VSEC_PROTOCOL_ENABLE)) { + dev_info(&dev->dev, "Card is already in PCI mode\n"); + return 0; + } + /* + * TODO: Before it's safe to switch the card back to PCI mode + * we need to disable the CAPP and make sure any cachelines the + * card holds have been flushed out. Needs skiboot support. + */ + dev_WARN(&dev->dev, "CXL mode switch to PCI unsupported!\n"); + return -EIO; } + + if (val & CXL_VSEC_PROTOCOL_ENABLE) { + dev_info(&dev->dev, "Card is already in CXL mode\n"); + return 0; + } + + dev_info(&dev->dev, "Card is in PCI mode, scheduling kernel thread " + "to switch to CXL mode\n"); + + work = kmalloc(sizeof(struct cxl_switch_work), GFP_KERNEL); + if (!work) + return -ENOMEM; + + pci_dev_get(dev); + work->dev = dev; + work->vsec = vsec; + work->mode = mode; + INIT_WORK(&work->work, switch_card_to_cxl); + + schedule_work(&work->work); + /* - * The CAIA spec (v0.12 11.6 Bi-modal Device Support) states - * we must wait 100ms after this mode switch before touching - * PCIe config space. + * We return a failure now to abort the driver init. Once the + * link has been cycled and the card is in cxl mode we will + * come back (possibly using the generic cxl driver), but + * return success as the card should then be in cxl mode. + * + * TODO: What if the card comes back in PCI mode even after + * the switch? Don't want to spin endlessly. */ - msleep(100); + return -EBUSY; +} +EXPORT_SYMBOL_GPL(cxl_check_and_switch_mode); + +#endif /* CONFIG_CXL_BIMODAL */ + +static int setup_cxl_protocol_area(struct pci_dev *dev) +{ + u8 val; + int rc; + int vsec = find_cxl_vsec(dev); + + if (!vsec) { + dev_info(&dev->dev, "CXL VSEC not found\n"); + return -ENODEV; + } + + rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val); + if (rc) { + dev_err(&dev->dev, "Failed to read current mode control: %i\n", rc); + return rc; + } + + if (!(val & CXL_VSEC_PROTOCOL_ENABLE)) { + dev_err(&dev->dev, "Card not in CAPI mode!\n"); + return -EIO; + } + + /* Still configure the protocol area for single mode cards */ + if ((val & CXL_VSEC_PROTOCOL_MASK) != CXL_VSEC_PROTOCOL_256TB) { + val &= ~CXL_VSEC_PROTOCOL_MASK; + val |= CXL_VSEC_PROTOCOL_256TB; + rc = CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val); + if (rc) { + dev_err(&dev->dev, "Failed to set CXL protocol area: %i\n", rc); + return rc; + } + } return 0; } @@ -1249,7 +1447,7 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev) if ((rc = setup_cxl_bars(dev))) return rc; - if ((rc = switch_card_to_cxl(dev))) + if ((rc = setup_cxl_protocol_area(dev))) return rc; if ((rc = cxl_update_image_control(adapter))) diff --git a/include/misc/cxl.h b/include/misc/cxl.h index ed81a17..e5e17ed 100644 --- a/include/misc/cxl.h +++ b/include/misc/cxl.h @@ -39,6 +39,31 @@ bool cxl_slot_is_supported(struct pci_dev *dev, int flags); +#define CXL_BIMODE_CXL 1 +#define CXL_BIMODE_PCI 2 + +/* + * Check the mode that the given bi-modal CXL adapter is currently in and + * change it if necessary. This does not apply to AFU drivers. + * + * If the mode matches the requested mode this function will return 0 - if the + * driver was expecting the generic CXL driver to have bound to the adapter and + * it gets this return value it should fail the probe function to give the CXL + * driver a chance to probe it. + * + * If the mode does not match it will start a background task to unplug the + * device from Linux and switch its mode, and will return -EBUSY. At this + * point the calling driver should make sure it has released the device and + * fail its probe function. + * + * The offset of the CXL VSEC can be provided to this function. If 0 is passed, + * this function will search for a CXL VSEC with ID 0x1280 and return -ENODEV + * if it is not found. + */ +#ifdef CONFIG_CXL_BIMODAL +int cxl_check_and_switch_mode(struct pci_dev *dev, int mode, int vsec); +#endif + /* Get the AFU associated with a pci_dev */ struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);