diff options
| -rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 1 | ||||
| -rw-r--r-- | Documentation/powerpc/cxlflash.txt | 257 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/Makefile | 2 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/common.h | 19 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/lunmgt.c | 263 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/main.c | 38 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/sislite.h | 5 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.c | 2014 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.h | 132 | ||||
| -rw-r--r-- | include/uapi/scsi/Kbuild | 1 | ||||
| -rw-r--r-- | include/uapi/scsi/cxlflash_ioctl.h | 140 |
11 files changed, 2868 insertions, 4 deletions
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 611c52267d24..9bd118d26a8a 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -314,6 +314,7 @@ Code Seq#(hex) Include File Comments 0xB3 00 linux/mmc/ioctl.h 0xC0 00-0F linux/usb/iowarrior.h 0xCA 00-0F uapi/misc/cxl.h +0xCA 80-8F uapi/scsi/cxlflash_ioctl.h 0xCB 00-1F CBM serial IEC bus in development: <mailto:michael.klein@puffin.lb.shuttle.de> 0xCD 01 linux/reiserfs_fs.h diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.txt new file mode 100644 index 000000000000..f943967f90ce --- /dev/null +++ b/Documentation/powerpc/cxlflash.txt @@ -0,0 +1,257 @@ +Introduction +============ + + The IBM Power architecture provides support for CAPI (Coherent + Accelerator Power Interface), which is available to certain PCIe slots + on Power 8 systems. CAPI can be thought of as a special tunneling + protocol through PCIe that allow PCIe adapters to look like special + purpose co-processors which can read or write an application's + memory and generate page faults. As a result, the host interface to + an adapter running in CAPI mode does not require the data buffers to + be mapped to the device's memory (IOMMU bypass) nor does it require + memory to be pinned. + + On Linux, Coherent Accelerator (CXL) kernel services present CAPI + devices as a PCI device by implementing a virtual PCI host bridge. + This abstraction simplifies the infrastructure and programming + model, allowing for drivers to look similar to other native PCI + device drivers. + + CXL provides a mechanism by which user space applications can + directly talk to a device (network or storage) bypassing the typical + kernel/device driver stack. The CXL Flash Adapter Driver enables a + user space application direct access to Flash storage. + + The CXL Flash Adapter Driver is a kernel module that sits in the + SCSI stack as a low level device driver (below the SCSI disk and + protocol drivers) for the IBM CXL Flash Adapter. This driver is + responsible for the initialization of the adapter, setting up the + special path for user space access, and performing error recovery. It + communicates directly the Flash Accelerator Functional Unit (AFU) + as described in Documentation/powerpc/cxl.txt. + + The cxlflash driver supports two, mutually exclusive, modes of + operation at the device (LUN) level: + + - Any flash device (LUN) can be configured to be accessed as a + regular disk device (i.e.: /dev/sdc). This is the default mode. + + - Any flash device (LUN) can be configured to be accessed from + user space with a special block library. This mode further + specifies the means of accessing the device and provides for + either raw access to the entire LUN (referred to as direct + or physical LUN access) or access to a kernel/AFU-mediated + partition of the LUN (referred to as virtual LUN access). The + segmentation of a disk device into virtual LUNs is assisted + by special translation services provided by the Flash AFU. + +Overview +======== + + The Coherent Accelerator Interface Architecture (CAIA) introduces a + concept of a master context. A master typically has special privileges + granted to it by the kernel or hypervisor allowing it to perform AFU + wide management and control. The master may or may not be involved + directly in each user I/O, but at the minimum is involved in the + initial setup before the user application is allowed to send requests + directly to the AFU. + + The CXL Flash Adapter Driver establishes a master context with the + AFU. It uses memory mapped I/O (MMIO) for this control and setup. The + Adapter Problem Space Memory Map looks like this: + + +-------------------------------+ + | 512 * 64 KB User MMIO | + | (per context) | + | User Accessible | + +-------------------------------+ + | 512 * 128 B per context | + | Provisioning and Control | + | Trusted Process accessible | + +-------------------------------+ + | 64 KB Global | + | Trusted Process accessible | + +-------------------------------+ + + This driver configures itself into the SCSI software stack as an + adapter driver. The driver is the only entity that is considered a + Trusted Process to program the Provisioning and Control and Global + areas in the MMIO Space shown above. The master context driver + discovers all LUNs attached to the CXL Flash adapter and instantiates + scsi block devices (/dev/sdb, /dev/sdc etc.) for each unique LUN + seen from each path. + + Once these scsi block devices are instantiated, an application + written to a specification provided by the block library may get + access to the Flash from user space (without requiring a system call). + + This master context driver also provides a series of ioctls for this + block library to enable this user space access. The driver supports + two modes for accessing the block device. + + The first mode is called a virtual mode. In this mode a single scsi + block device (/dev/sdb) may be carved up into any number of distinct + virtual LUNs. The virtual LUNs may be resized as long as the sum of + the sizes of all the virtual LUNs, along with the meta-data associated + with it does not exceed the physical capacity. + + The second mode is called the physical mode. In this mode a single + block device (/dev/sdb) may be opened directly by the block library + and the entire space for the LUN is available to the application. + + Only the physical mode provides persistence of the data. i.e. The + data written to the block device will survive application exit and + restart and also reboot. The virtual LUNs do not persist (i.e. do + not survive after the application terminates or the system reboots). + + +Block library API +================= + + Applications intending to get access to the CXL Flash from user + space should use the block library, as it abstracts the details of + interfacing directly with the cxlflash driver that are necessary for + performing administrative actions (i.e.: setup, tear down, resize). + The block library can be thought of as a 'user' of services, + implemented as IOCTLs, that are provided by the cxlflash driver + specifically for devices (LUNs) operating in user space access + mode. While it is not a requirement that applications understand + the interface between the block library and the cxlflash driver, + a high-level overview of each supported service (IOCTL) is provided + below. + + The block library can be found on GitHub: + http://www.github.com/mikehollinger/ibmcapikv + + +CXL Flash Driver IOCTLs +======================= + + Users, such as the block library, that wish to interface with a flash + device (LUN) via user space access need to use the services provided + by the cxlflash driver. As these services are implemented as ioctls, + a file descriptor handle must first be obtained in order to establish + the communication channel between a user and the kernel. This file + descriptor is obtained by opening the device special file associated + with the scsi disk device (/dev/sdb) that was created during LUN + discovery. As per the location of the cxlflash driver within the + SCSI protocol stack, this open is actually not seen by the cxlflash + driver. Upon successful open, the user receives a file descriptor + (herein referred to as fd1) that should be used for issuing the + subsequent ioctls listed below. + + The structure definitions for these IOCTLs are available in: + uapi/scsi/cxlflash_ioctl.h + +DK_CXLFLASH_ATTACH +------------------ + + This ioctl obtains, initializes, and starts a context using the CXL + kernel services. These services specify a context id (u16) by which + to uniquely identify the context and its allocated resources. The + services additionally provide a second file descriptor (herein + referred to as fd2) that is used by the block library to initiate + memory mapped I/O (via mmap()) to the CXL flash device and poll for + completion events. This file descriptor is intentionally installed by + this driver and not the CXL kernel services to allow for intermediary + notification and access in the event of a non-user-initiated close(), + such as a killed process. This design point is described in further + detail in the description for the DK_CXLFLASH_DETACH ioctl. + + There are a few important aspects regarding the "tokens" (context id + and fd2) that are provided back to the user: + + - These tokens are only valid for the process under which they + were created. The child of a forked process cannot continue + to use the context id or file descriptor created by its parent. + + - These tokens are only valid for the lifetime of the context and + the process under which they were created. Once either is + destroyed, the tokens are to be considered stale and subsequent + usage will result in errors. + + - When a context is no longer needed, the user shall detach from + the context via the DK_CXLFLASH_DETACH ioctl. + + - A close on fd2 will invalidate the tokens. This operation is not + required by the user. + +DK_CXLFLASH_USER_DIRECT +----------------------- + This ioctl is responsible for transitioning the LUN to direct + (physical) mode access and configuring the AFU for direct access from + user space on a per-context basis. Additionally, the block size and + last logical block address (LBA) are returned to the user. + + As mentioned previously, when operating in user space access mode, + LUNs may be accessed in whole or in part. Only one mode is allowed + at a time and if one mode is active (outstanding references exist), + requests to use the LUN in a different mode are denied. + + The AFU is configured for direct access from user space by adding an + entry to the AFU's resource handle table. The index of the entry is + treated as a resource handle that is returned to the user. The user + is then able to use the handle to reference the LUN during I/O. + +DK_CXLFLASH_RELEASE +------------------- + This ioctl is responsible for releasing a previously obtained + reference to either a physical or virtual LUN. This can be + thought of as the inverse of the DK_CXLFLASH_USER_DIRECT or + DK_CXLFLASH_USER_VIRTUAL ioctls. Upon success, the resource handle + is no longer valid and the entry in the resource handle table is + made available to be used again. + + As part of the release process for virtual LUNs, the virtual LUN + is first resized to 0 to clear out and free the translation tables + associated with the virtual LUN reference. + +DK_CXLFLASH_DETACH +------------------ + This ioctl is responsible for unregistering a context with the + cxlflash driver and release outstanding resources that were + not explicitly released via the DK_CXLFLASH_RELEASE ioctl. Upon + success, all "tokens" which had been provided to the user from the + DK_CXLFLASH_ATTACH onward are no longer valid. + +DK_CXLFLASH_VERIFY +------------------ + This ioctl is used to detect various changes such as the capacity of + the disk changing, the number of LUNs visible changing, etc. In cases + where the changes affect the application (such as a LUN resize), the + cxlflash driver will report the changed state to the application. + + The user calls in when they want to validate that a LUN hasn't been + changed in response to a check condition. As the user is operating out + of band from the kernel, they will see these types of events without + the kernel's knowledge. When encountered, the user's architected + behavior is to call in to this ioctl, indicating what they want to + verify and passing along any appropriate information. For now, only + verifying a LUN change (ie: size different) with sense data is + supported. + +DK_CXLFLASH_RECOVER_AFU +----------------------- + This ioctl is used to drive recovery (if such an action is warranted) + of a specified user context. Any state associated with the user context + is re-established upon successful recovery. + + User contexts are put into an error condition when the device needs to + be reset or is terminating. Users are notified of this error condition + by seeing all 0xF's on an MMIO read. Upon encountering this, the + architected behavior for a user is to call into this ioctl to recover + their context. A user may also call into this ioctl at any time to + check if the device is operating normally. If a failure is returned + from this ioctl, the user is expected to gracefully clean up their + context via release/detach ioctls. Until they do, the context they + hold is not relinquished. The user may also optionally exit the process + at which time the context/resources they held will be freed as part of + the release fop. + +DK_CXLFLASH_MANAGE_LUN +---------------------- + This ioctl is used to switch a LUN from a mode where it is available + for file-system access (legacy), to a mode where it is set aside for + exclusive user space access (superpipe). In case a LUN is visible + across multiple ports and adapters, this ioctl is used to uniquely + identify each LUN by its World Wide Node Name (WWNN). diff --git a/drivers/scsi/cxlflash/Makefile b/drivers/scsi/cxlflash/Makefile index dc95e203e3af..c14d24c720d6 100644 --- a/drivers/scsi/cxlflash/Makefile +++ b/drivers/scsi/cxlflash/Makefile @@ -1,2 +1,2 @@ obj-$(CONFIG_CXLFLASH) += cxlflash.o -cxlflash-y += main.o +cxlflash-y += main.o superpipe.o lunmgt.o diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h index ffdbc572d180..d3e54e61c7a5 100644 --- a/drivers/scsi/cxlflash/common.h +++ b/drivers/scsi/cxlflash/common.h @@ -107,6 +107,17 @@ struct cxlflash_cfg { struct pci_pool *cxlflash_cmd_pool; struct pci_dev *parent_dev; + atomic_t recovery_threads; + struct mutex ctx_recovery_mutex; + struct mutex ctx_tbl_list_mutex; + struct ctx_info *ctx_tbl[MAX_CONTEXT]; + struct list_head ctx_err_recovery; /* contexts w/ recovery pending */ + struct file_operations cxl_fops; + + atomic_t num_user_contexts; + + struct list_head lluns; /* list of llun_info structs */ + wait_queue_head_t tmf_waitq; bool tmf_active; wait_queue_head_t limbo_waitq; @@ -182,4 +193,12 @@ int cxlflash_afu_reset(struct cxlflash_cfg *); struct afu_cmd *cxlflash_cmd_checkout(struct afu *); void cxlflash_cmd_checkin(struct afu_cmd *); int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8); +void cxlflash_list_init(void); +void cxlflash_term_global_luns(void); +void cxlflash_free_errpage(void); +int cxlflash_ioctl(struct scsi_device *, int, void __user *); +void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *); +int cxlflash_mark_contexts_error(struct cxlflash_cfg *); +void cxlflash_term_local_luns(struct cxlflash_cfg *); + #endif /* ifndef _CXLFLASH_COMMON_H */ diff --git a/drivers/scsi/cxlflash/lunmgt.c b/drivers/scsi/cxlflash/lunmgt.c new file mode 100644 index 000000000000..66d5bef11ee6 --- /dev/null +++ b/drivers/scsi/cxlflash/lunmgt.c @@ -0,0 +1,263 @@ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation + * Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <misc/cxl.h> +#include <asm/unaligned.h> + +#include <scsi/scsi_host.h> +#include <uapi/scsi/cxlflash_ioctl.h> + +#include "sislite.h" +#include "common.h" +#include "superpipe.h" + +/** + * create_local() - allocate and initialize a local LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: World Wide Node Name for LUN. + * + * Return: Allocated local llun_info structure on success, NULL on failure + */ +static struct llun_info *create_local(struct scsi_device *sdev, u8 *wwid) +{ + struct llun_info *lli = NULL; + + lli = kzalloc(sizeof(*lli), GFP_KERNEL); + if (unlikely(!lli)) { + pr_err("%s: could not allocate lli\n", __func__); + goto out; + } + + lli->sdev = sdev; + lli->newly_created = true; + lli->host_no = sdev->host->host_no; + + memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN); +out: + return lli; +} + +/** + * create_global() - allocate and initialize a global LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: World Wide Node Name for LUN. + * + * Return: Allocated global glun_info structure on success, NULL on failure + */ +static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid) +{ + struct glun_info *gli = NULL; + + gli = kzalloc(sizeof(*gli), GFP_KERNEL); + if (unlikely(!gli)) { + pr_err("%s: could not allocate gli\n", __func__); + goto out; + } + + mutex_init(&gli->mutex); + memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN); +out: + return gli; +} + +/** + * refresh_local() - find and update local LUN information structure by WWID + * @cfg: Internal structure associated with the host. + * @wwid: WWID associated with LUN. + * + * When the LUN is found, mark it by updating it's newly_created field. + * + * Return: Found local lun_info structure on success, NULL on failure + * If a LUN with the WWID is found in the list, refresh it's state. + */ +static struct llun_info *refresh_local(struct cxlflash_cfg *cfg, u8 *wwid) +{ + struct llun_info *lli, *temp; + + list_for_each_entry_safe(lli, temp, &cfg->lluns, list) + if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN)) { + lli->newly_created = false; + return lli; + } + + return NULL; +} + +/** + * lookup_global() - find a global LUN information structure by WWID + * @wwid: WWID associated with LUN. + * + * Return: Found global lun_info structure on success, NULL on failure + */ +static struct glun_info *lookup_global(u8 *wwid) +{ + struct glun_info *gli, *temp; + + list_for_each_entry_safe(gli, temp, &global.gluns, list) + if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN)) + return gli; + + return NULL; +} + +/** + * find_and_create_lun() - find or create a local LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: WWID associated with LUN. + * + * The LUN is kept both in a local list (per adapter) and in a global list + * (across all adapters). Certain attributes of the LUN are local to the + * adapter (such as index, port selection mask etc.). + * The block allocation map is shared across all adapters (i.e. associated + * wih the global list). Since different attributes are associated with + * the per adapter and global entries, allocate two separate structures for each + * LUN (one local, one global). + * + * Keep a pointer back from the local to the global entry. + * + * Return: Found/Allocated local lun_info structure on success, NULL on failure + */ +static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid) +{ + struct llun_info *lli = NULL; + struct glun_info *gli = NULL; + struct Scsi_Host *shost = sdev->host; + struct cxlflash_cfg *cfg = shost_priv(shost); + + mutex_lock(&global.mutex); + if (unlikely(!wwid)) + goto out; + + lli = refresh_local(cfg, wwid); + if (lli) + goto out; + + lli = create_local(sdev, wwid); + if (unlikely(!lli)) + goto out; + + gli = lookup_global(wwid); + if (gli) { + lli->parent = gli; + list_add(&lli->list, &cfg->lluns); + goto out; + } + + gli = create_global(sdev, wwid); + if (unlikely(!gli)) { + kfree(lli); + lli = NULL; + goto out; + } + + lli->parent = gli; + list_add(&lli->list, &cfg->lluns); + + list_add(&gli->list, &global.gluns); + +out: + mutex_unlock(&global.mutex); + pr_debug("%s: returning %p\n", __func__, lli); + return lli; +} + +/** + * cxlflash_term_local_luns() - Delete all entries from local LUN list, free. + * @cfg: Internal structure associated with the host. + */ +void cxlflash_term_local_luns(struct cxlflash_cfg *cfg) +{ + struct llun_info *lli, *temp; + + mutex_lock(&global.mutex); + list_for_each_entry_safe(lli, temp, &cfg->lluns, list) { + list_del(&lli->list); + kfree(lli); + } + mutex_unlock(&global.mutex); +} + +/** + * cxlflash_list_init() - initializes the global LUN list + */ +void cxlflash_list_init(void) +{ + INIT_LIST_HEAD(&global.gluns); + mutex_init(&global.mutex); + global.err_page = NULL; +} + +/** + * cxlflash_term_global_luns() - frees resources associated with global LUN list + */ +void cxlflash_term_global_luns(void) +{ + struct glun_info *gli, *temp; + + mutex_lock(&global.mutex); + list_for_each_entry_safe(gli, temp, &global.gluns, list) { + list_del(&gli->list); + kfree(gli); + } + mutex_unlock(&global.mutex); +} + +/** + * cxlflash_manage_lun() - handles LUN management activities + * @sdev: SCSI device associated with LUN. + * @manage: Manage ioctl data structure. + * + * This routine is used to notify the driver about a LUN's WWID and associate + * SCSI devices (sdev) with a global LUN instance. Additionally it serves to + * change a LUN's operating mode: legacy or superpipe. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_manage_lun(struct scsi_device *sdev, + struct dk_cxlflash_manage_lun *manage) +{ + int rc = 0; + struct llun_info *lli = NULL; + u64 flags = manage->hdr.flags; + u32 chan = sdev->channel; + + lli = find_and_create_lun(sdev, manage->wwid); + pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n", + __func__, get_unaligned_le64(&manage->wwid[0]), + get_unaligned_le64(&manage->wwid[8]), + manage->hdr.flags, lli); + if (unlikely(!lli)) { + rc = -ENOMEM; + goto out; + } + + if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) { + if (lli->newly_created) + lli->port_sel = CHAN2PORT(chan); + else + lli->port_sel = BOTH_PORTS; + /* Store off lun in unpacked, AFU-friendly format */ + lli->lun_id[chan] = lun_to_lunid(sdev->lun); + sdev->hostdata = lli; + } else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) { + if (lli->parent->mode != MODE_NONE) + rc = -EBUSY; + else + sdev->hostdata = NULL; + } + +out: + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; +} diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 3ae8dca236ef..02d464f41b7f 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -23,6 +23,7 @@ #include <scsi/scsi_cmnd.h> #include <scsi/scsi_host.h> +#include <uapi/scsi/cxlflash_ioctl.h> #include "main.h" #include "sislite.h" @@ -519,7 +520,7 @@ static int cxlflash_eh_host_reset_handler(struct scsi_cmnd *scp) case STATE_NORMAL: cfg->state = STATE_LIMBO; scsi_block_requests(cfg->host); - + cxlflash_mark_contexts_error(cfg); rcr = cxlflash_afu_reset(cfg); if (rcr) { rc = FAILED; @@ -663,6 +664,21 @@ static ssize_t cxlflash_store_lun_mode(struct device *dev, } /** + * cxlflash_show_ioctl_version() - presents the current ioctl version of the host + * @dev: Generic device associated with the host. + * @attr: Device attribute representing the ioctl version. + * @buf: Buffer of length PAGE_SIZE to report back the ioctl version. + * + * Return: The size of the ASCII string returned in @buf. + */ +static ssize_t cxlflash_show_ioctl_version(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return scnprintf(buf, PAGE_SIZE, "%u\n", DK_CXLFLASH_VERSION_0); +} + +/** * cxlflash_show_dev_mode() - presents the current mode of the device * @dev: Generic device associated with the device. * @attr: Device attribute representing the device mode. @@ -700,11 +716,13 @@ static DEVICE_ATTR(port0, S_IRUGO, cxlflash_show_port_status, NULL); static DEVICE_ATTR(port1, S_IRUGO, cxlflash_show_port_status, NULL); static DEVICE_ATTR(lun_mode, S_IRUGO | S_IWUSR, cxlflash_show_lun_mode, cxlflash_store_lun_mode); +static DEVICE_ATTR(ioctl_version, S_IRUGO, cxlflash_show_ioctl_version, NULL); static struct device_attribute *cxlflash_host_attrs[] = { &dev_attr_port0, &dev_attr_port1, &dev_attr_lun_mode, + &dev_attr_ioctl_version, NULL }; @@ -725,6 +743,7 @@ static struct scsi_host_template driver_template = { .module = THIS_MODULE, .name = CXLFLASH_ADAPTER_NAME, .info = cxlflash_driver_info, + .ioctl = cxlflash_ioctl, .proc_name = CXLFLASH_NAME, .queuecommand = cxlflash_queuecommand, .eh_device_reset_handler = cxlflash_eh_device_reset_handler, @@ -872,9 +891,11 @@ static void cxlflash_remove(struct pci_dev *pdev) spin_unlock_irqrestore(&cfg->tmf_waitq.lock, lock_flags); cfg->state = STATE_FAILTERM; + cxlflash_stop_term_user_contexts(cfg); switch (cfg->init_state) { case INIT_STATE_SCSI: + cxlflash_term_local_luns(cfg); scsi_remove_host(cfg->host); scsi_host_put(cfg->host); /* Fall through */ @@ -2274,6 +2295,10 @@ static int cxlflash_probe(struct pci_dev *pdev, INIT_WORK(&cfg->work_q, cxlflash_worker_thread); cfg->lr_state = LINK_RESET_INVALID; cfg->lr_port = -1; + mutex_init(&cfg->ctx_tbl_list_mutex); + mutex_init(&cfg->ctx_recovery_mutex); + INIT_LIST_HEAD(&cfg->ctx_err_recovery); + INIT_LIST_HEAD(&cfg->lluns); pci_set_drvdata(pdev, cfg); @@ -2335,6 +2360,7 @@ out_remove: static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev, pci_channel_state_t state) { + int rc = 0; struct cxlflash_cfg *cfg = pci_get_drvdata(pdev); struct device *dev = &cfg->dev->dev; @@ -2346,7 +2372,10 @@ static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev, /* Turn off legacy I/O */ scsi_block_requests(cfg->host); - + rc = cxlflash_mark_contexts_error(cfg); + if (unlikely(rc)) + dev_err(dev, "%s: Failed to mark user contexts!(%d)\n", + __func__, rc); term_mc(cfg, UNDO_START); stop_afu(cfg); @@ -2431,6 +2460,8 @@ static int __init init_cxlflash(void) pr_info("%s: IBM Power CXL Flash Adapter: %s\n", __func__, CXLFLASH_DRIVER_DATE); + cxlflash_list_init(); + return pci_register_driver(&cxlflash_driver); } @@ -2439,6 +2470,9 @@ static int __init init_cxlflash(void) */ static void __exit exit_cxlflash(void) { + cxlflash_term_global_luns(); + cxlflash_free_errpage(); + pci_unregister_driver(&cxlflash_driver); } diff --git a/drivers/scsi/cxlflash/sislite.h b/drivers/scsi/cxlflash/sislite.h index bf5d39978630..66b889151a4c 100644 --- a/drivers/scsi/cxlflash/sislite.h +++ b/drivers/scsi/cxlflash/sislite.h @@ -409,7 +409,10 @@ struct sisl_lxt_entry { }; -/* Per the SISlite spec, RHT entries are to be 16-byte aligned */ +/* + * RHT - Resource Handle Table + * Per the SISlite spec, RHT entries are to be 16-byte aligned + */ struct sisl_rht_entry { struct sisl_lxt_entry *lxt_start; u32 lxt_cnt; diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c new file mode 100644 index 000000000000..3c8bce8bbb0b --- /dev/null +++ b/drivers/scsi/cxlflash/superpipe.c @@ -0,0 +1,2014 @@ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation + * Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/delay.h> +#include <linux/file.h> +#include <linux/syscalls.h> +#include <misc/cxl.h> +#include <asm/unaligned.h> + +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_eh.h> +#include <uapi/scsi/cxlflash_ioctl.h> + +#include "sislite.h" +#include "common.h" +#include "superpipe.h" + +struct cxlflash_global global; + +/** + * marshal_det_to_rele() - translate detach to release structure + * @detach: Destination structure for the translate/copy. + * @rele: Source structure from which to translate/copy. + */ +static void marshal_det_to_rele(struct dk_cxlflash_detach *detach, + struct dk_cxlflash_release *release) +{ + release->hdr = detach->hdr; + release->context_id = detach->context_id; +} + +/** + * cxlflash_free_errpage() - frees resources associated with global error page + */ +void cxlflash_free_errpage(void) +{ + + mutex_lock(&global.mutex); + if (global.err_page) { + __free_page(global.err_page); + global.err_page = NULL; + } + mutex_unlock(&global.mutex); +} + +/** + * cxlflash_stop_term_user_contexts() - stops/terminates known user contexts + * @cfg: Internal structure associated with the host. + * + * When the host needs to go down, all users must be quiesced and their + * memory freed. This is accomplished by putting the contexts in error + * state which will notify the user and let them 'drive' the tear-down. + * Meanwhile, this routine camps until all user contexts have been removed. + */ +void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg) +{ + struct device *dev = &cfg->dev->dev; + int i, found; + + cxlflash_mark_contexts_error(cfg); + + while (true) { + found = false; + + for (i = 0; i < MAX_CONTEXT; i++) + if (cfg->ctx_tbl[i]) { + found = true; + break; + } + + if (!found && list_empty(&cfg->ctx_err_recovery)) + return; + + dev_dbg(dev, "%s: Wait for user contexts to quiesce...\n", + __func__); + wake_up_all(&cfg->limbo_waitq); + ssleep(1); + } +} + +/** + * find_error_context() - locates a context by cookie on the error recovery list + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context by id. + * @file: Desired context by file. + * + * Return: Found context on success, NULL on failure + */ +static struct ctx_info *find_error_context(struct cxlflash_cfg *cfg, u64 rctxid, + struct file *file) +{ + struct ctx_info *ctxi; + + list_for_each_entry(ctxi, &cfg->ctx_err_recovery, list) + if ((ctxi->ctxid == rctxid) || (ctxi->file == file)) + return ctxi; + + return NULL; +} + +/** + * get_context() - obtains a validated and locked context reference + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context (raw, un-decoded format). + * @arg: LUN information or file associated with request. + * @ctx_ctrl: Control information to 'steer' desired lookup. + * + * NOTE: despite the name pid, in linux, current->pid actually refers + * to the lightweight process id (tid) and can change if the process is + * multi threaded. The tgid remains constant for the process and only changes + * when the process of fork. For all intents and purposes, think of tgid + * as a pid in the traditional sense. + * + * Return: Validated context on success, NULL on failure + */ +struct ctx_info *get_context(struct cxlflash_cfg *cfg, u64 rctxid, + void *arg, enum ctx_ctrl ctx_ctrl) +{ + struct device *dev = &cfg->dev->dev; + struct ctx_info *ctxi = NULL; + struct lun_access *lun_access = NULL; + struct file *file = NULL; + struct llun_info *lli = arg; + u64 ctxid = DECODE_CTXID(rctxid); + int rc; + pid_t pid = current->tgid, ctxpid = 0; + + if (ctx_ctrl & CTX_CTRL_FILE) { + lli = NULL; + file = (struct file *)arg; + } + + if (ctx_ctrl & CTX_CTRL_CLONE) + pid = current->parent->tgid; + + if (likely(ctxid < MAX_CONTEXT)) { + while (true) { + rc = mutex_lock_interruptible(&cfg->ctx_tbl_list_mutex); + if (rc) + goto out; + + ctxi = cfg->ctx_tbl[ctxid]; + if (ctxi) + if ((file && (ctxi->file != file)) || + (!file && (ctxi->ctxid != rctxid))) + ctxi = NULL; + + if ((ctx_ctrl & CTX_CTRL_ERR) || + (!ctxi && (ctx_ctrl & CTX_CTRL_ERR_FALLBACK))) + ctxi = find_error_context(cfg, rctxid, file); + if (!ctxi) { + mutex_unlock(&cfg->ctx_tbl_list_mutex); + goto out; + } + + /* + * Need to acquire ownership of the context while still + * under the table/list lock to serialize with a remove + * thread. Use the 'try' to avoid stalling the + * table/list lock for a single context. + * + * Note that the lock order is: + * + * cfg->ctx_tbl_list_mutex -> ctxi->mutex + * + * Therefore release ctx_tbl_list_mutex before retrying. + */ + rc = mutex_trylock(&ctxi->mutex); + mutex_unlock(&cfg->ctx_tbl_list_mutex); + if (rc) + break; /* got the context's lock! */ + } + + if (ctxi->unavail) + goto denied; + + ctxpid = ctxi->pid; + if (likely(!(ctx_ctrl & CTX_CTRL_NOPID))) + if (pid != ctxpid) + goto denied; + + if (lli) { + list_for_each_entry(lun_access, &ctxi->luns, list) + if (lun_access->lli == lli) + goto out; + goto denied; + } + } + +out: + dev_dbg(dev, "%s: rctxid=%016llX ctxinfo=%p ctxpid=%u pid=%u " + "ctx_ctrl=%u\n", __func__, rctxid, ctxi, ctxpid, pid, + ctx_ctrl); + + return ctxi; + +denied: + mutex_unlock(&ctxi->mutex); + ctxi = NULL; + goto out; +} + +/** + * put_context() - release a context that was retrieved from get_context() + * @ctxi: Context to release. + * + * For now, releasing the context equates to unlocking it's mutex. + */ +void put_context(struct ctx_info *ctxi) +{ + mutex_unlock(&ctxi->mu |