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authorMatthew R. Ochs <mrochs@linux.vnet.ibm.com>2015-08-14 04:47:43 +0200
committerJames Bottomley <JBottomley@Odin.com>2015-08-27 03:04:37 +0200
commit65be2c79acc3aa0f9c0e8d4871f5a451d854465a (patch)
tree44a0bcdad372238cdfcfbdeb2f47875c4f575509 /drivers/scsi/cxlflash/lunmgt.c
parentcxlflash: Base error recovery support (diff)
downloadlinux-65be2c79acc3aa0f9c0e8d4871f5a451d854465a.tar.xz
linux-65be2c79acc3aa0f9c0e8d4871f5a451d854465a.zip
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.c263
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 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;
+}