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author | Matthew R. Ochs <mrochs@linux.vnet.ibm.com> | 2015-08-14 02:47:43 (GMT) |
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committer | James Bottomley <JBottomley@Odin.com> | 2015-08-27 01:04:37 (GMT) |
commit | 65be2c79acc3aa0f9c0e8d4871f5a451d854465a (patch) | |
tree | 44a0bcdad372238cdfcfbdeb2f47875c4f575509 /drivers/scsi/cxlflash/lunmgt.c | |
parent | 5cdac81a870f3bb65c50d3f5566a86fb086118d2 (diff) | |
download | linux-65be2c79acc3aa0f9c0e8d4871f5a451d854465a.tar.xz |
cxlflash: Superpipe support
Add superpipe supporting infrastructure to device driver for the IBM CXL
Flash adapter. This patch allows userspace applications to take advantage
of the accelerated I/O features that this adapter provides and bypass the
traditional filesystem stack.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Diffstat (limited to 'drivers/scsi/cxlflash/lunmgt.c')
-rw-r--r-- | drivers/scsi/cxlflash/lunmgt.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/lunmgt.c b/drivers/scsi/cxlflash/lunmgt.c new file mode 100644 index 0000000..66d5bef --- /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; +} |