This patch adds a new driver "nvme-debug". It uses memory as a backing
store and it is used to test the copy offload functionality.

Signed-off-by: Mikulas Patocka <[email protected]>

---
 drivers/nvme/host/Kconfig      |   13 
 drivers/nvme/host/Makefile     |    1 
 drivers/nvme/host/nvme-debug.c |  838 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 852 insertions(+)

Index: linux-2.6/drivers/nvme/host/Kconfig
===================================================================
--- linux-2.6.orig/drivers/nvme/host/Kconfig    2022-02-01 18:34:22.000000000 
+0100
+++ linux-2.6/drivers/nvme/host/Kconfig 2022-02-01 18:34:22.000000000 +0100
@@ -83,3 +83,16 @@ config NVME_TCP
          from https://github.com/linux-nvme/nvme-cli.
 
          If unsure, say N.
+
+config NVME_DEBUG
+       tristate "NVM Express debug"
+       depends on INET
+       depends on BLOCK
+       select NVME_CORE
+       select NVME_FABRICS
+       select CRYPTO
+       select CRYPTO_CRC32C
+       help
+         This pseudo driver simulates a NVMe adapter.
+
+         If unsure, say N.
Index: linux-2.6/drivers/nvme/host/Makefile
===================================================================
--- linux-2.6.orig/drivers/nvme/host/Makefile   2022-02-01 18:34:22.000000000 
+0100
+++ linux-2.6/drivers/nvme/host/Makefile        2022-02-01 18:34:22.000000000 
+0100
@@ -8,6 +8,7 @@ obj-$(CONFIG_NVME_FABRICS)              += nvme-fabr
 obj-$(CONFIG_NVME_RDMA)                        += nvme-rdma.o
 obj-$(CONFIG_NVME_FC)                  += nvme-fc.o
 obj-$(CONFIG_NVME_TCP)                 += nvme-tcp.o
+obj-$(CONFIG_NVME_DEBUG)               += nvme-debug.o
 
 nvme-core-y                            := core.o ioctl.o
 nvme-core-$(CONFIG_TRACING)            += trace.o
Index: linux-2.6/drivers/nvme/host/nvme-debug.c
===================================================================
--- /dev/null   1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/drivers/nvme/host/nvme-debug.c    2022-02-01 18:34:22.000000000 
+0100
@@ -0,0 +1,838 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe debug
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/blk-mq.h>
+#include <linux/sort.h>
+#include <linux/version.h>
+
+#include "nvme.h"
+#include "fabrics.h"
+
+static ulong dev_size_mb = 16;
+module_param_named(dev_size_mb, dev_size_mb, ulong, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dev_size_mb, "size in MiB of the namespace(def=8)");
+
+static unsigned sector_size = 512;
+module_param_named(sector_size, sector_size, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(sector_size, "logical block size in bytes (def=512)");
+
+struct nvme_debug_ctrl {
+       struct nvme_ctrl ctrl;
+       uint32_t reg_cc;
+       struct blk_mq_tag_set admin_tag_set;
+       struct blk_mq_tag_set io_tag_set;
+       struct workqueue_struct *admin_wq;
+       struct workqueue_struct *io_wq;
+       struct list_head namespaces;
+       struct list_head list;
+};
+
+struct nvme_debug_namespace {
+       struct list_head list;
+       uint32_t nsid;
+       unsigned char sector_size_bits;
+       size_t n_sectors;
+       void *space;
+       char uuid[16];
+};
+
+struct nvme_debug_request {
+       struct nvme_request req;
+       struct nvme_command cmd;
+       struct work_struct work;
+};
+
+static LIST_HEAD(nvme_debug_ctrl_list);
+static DEFINE_MUTEX(nvme_debug_ctrl_mutex);
+
+DEFINE_STATIC_PERCPU_RWSEM(nvme_debug_sem);
+
+static inline struct nvme_debug_ctrl *to_debug_ctrl(struct nvme_ctrl *nctrl)
+{
+       return container_of(nctrl, struct nvme_debug_ctrl, ctrl);
+}
+
+static struct nvme_debug_namespace *nvme_debug_find_namespace(struct 
nvme_debug_ctrl *ctrl, unsigned nsid)
+{
+       struct nvme_debug_namespace *ns;
+       list_for_each_entry(ns, &ctrl->namespaces, list) {
+               if (ns->nsid == nsid)
+                       return ns;
+       }
+       return NULL;
+}
+
+static bool nvme_debug_alloc_namespace(struct nvme_debug_ctrl *ctrl)
+{
+       struct nvme_debug_namespace *ns;
+       unsigned s;
+       size_t dsm;
+
+       ns = kmalloc(sizeof(struct nvme_debug_namespace), GFP_KERNEL);
+       if (!ns)
+               goto fail0;
+
+       ns->nsid = 1;
+       while (nvme_debug_find_namespace(ctrl, ns->nsid))
+               ns->nsid++;
+
+       s = READ_ONCE(sector_size);
+       if (s < 512 || s > PAGE_SIZE || !is_power_of_2(s))
+               goto fail1;
+       ns->sector_size_bits = __ffs(s);
+       dsm = READ_ONCE(dev_size_mb);
+       ns->n_sectors = dsm << (20 - ns->sector_size_bits);
+       if (ns->n_sectors >> (20 - ns->sector_size_bits) != dsm)
+               goto fail1;
+
+       if (ns->n_sectors << ns->sector_size_bits >> ns->sector_size_bits != 
ns->n_sectors)
+               goto fail1;
+
+       ns->space = vzalloc(ns->n_sectors << ns->sector_size_bits);
+       if (!ns->space)
+               goto fail1;
+
+       generate_random_uuid(ns->uuid);
+
+       list_add(&ns->list, &ctrl->namespaces);
+       return true;
+
+fail1:
+       kfree(ns);
+fail0:
+       return false;
+}
+
+static void nvme_debug_free_namespace(struct nvme_debug_namespace *ns)
+{
+       vfree(ns->space);
+       list_del(&ns->list);
+       kfree(ns);
+}
+
+static int nvme_debug_reg_read32(struct nvme_ctrl *nctrl, u32 off, u32 *val)
+{
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(nctrl);
+       switch (off) {
+               case NVME_REG_VS: {
+                       *val = 0x20000;
+                       break;
+               }
+               case NVME_REG_CC: {
+                       *val = ctrl->reg_cc;
+                       break;
+               }
+               case NVME_REG_CSTS: {
+                       *val = 0;
+                       if (ctrl->reg_cc & NVME_CC_ENABLE)
+                               *val |= NVME_CSTS_RDY;
+                       if (ctrl->reg_cc & NVME_CC_SHN_MASK)
+                               *val |= NVME_CSTS_SHST_CMPLT;
+                       break;
+               }
+               default: {
+                       printk("nvme_debug_reg_read32: %x\n", off);
+                       return -ENOSYS;
+               }
+       }
+       return 0;
+}
+
+int nvme_debug_reg_read64(struct nvme_ctrl *nctrl, u32 off, u64 *val)
+{
+       switch (off) {
+               case NVME_REG_CAP: {
+                       *val = (1ULL << 0) | (1ULL << 37);
+                       break;
+               }
+               default: {
+                       printk("nvme_debug_reg_read64: %x\n", off);
+                       return -ENOSYS;
+               }
+       }
+       return 0;
+}
+
+int nvme_debug_reg_write32(struct nvme_ctrl *nctrl, u32 off, u32 val)
+{
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(nctrl);
+       switch (off) {
+               case NVME_REG_CC: {
+                       ctrl->reg_cc = val;
+                       break;
+               }
+               default: {
+                       printk("nvme_debug_reg_write32: %x, %x\n", off, val);
+                       return -ENOSYS;
+               }
+       }
+       return 0;
+}
+
+static void nvme_debug_submit_async_event(struct nvme_ctrl *nctrl)
+{
+       printk("nvme_debug_submit_async_event\n");
+}
+
+static void nvme_debug_delete_ctrl(struct nvme_ctrl *nctrl)
+{
+       nvme_shutdown_ctrl(nctrl);
+}
+
+static void nvme_debug_free_namespaces(struct nvme_debug_ctrl *ctrl)
+{
+       if (!list_empty(&ctrl->namespaces)) {
+               struct nvme_debug_namespace *ns = 
container_of(ctrl->namespaces.next, struct nvme_debug_namespace, list);
+               nvme_debug_free_namespace(ns);
+       }
+}
+
+static void nvme_debug_free_ctrl(struct nvme_ctrl *nctrl)
+{
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(nctrl);
+
+       flush_workqueue(ctrl->admin_wq);
+       flush_workqueue(ctrl->io_wq);
+
+       nvme_debug_free_namespaces(ctrl);
+
+       if (list_empty(&ctrl->list))
+               goto free_ctrl;
+
+       mutex_lock(&nvme_debug_ctrl_mutex);
+       list_del(&ctrl->list);
+       mutex_unlock(&nvme_debug_ctrl_mutex);
+
+       nvmf_free_options(nctrl->opts);
+free_ctrl:
+       destroy_workqueue(ctrl->admin_wq);
+       destroy_workqueue(ctrl->io_wq);
+       kfree(ctrl);
+}
+
+static int nvme_debug_get_address(struct nvme_ctrl *nctrl, char *buf, int size)
+{
+       int len = 0;
+       len += snprintf(buf, size, "debug");
+       return len;
+}
+
+static void nvme_debug_reset_ctrl_work(struct work_struct *work)
+{
+       printk("nvme_reset_ctrl_work\n");
+}
+
+static void copy_data_request(struct request *req, void *data, size_t size, 
bool to_req)
+{
+       if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
+               void *addr;
+               struct bio_vec bv = req->special_vec;
+               addr = kmap_atomic(bv.bv_page);
+               if (to_req) {
+                       memcpy(addr + bv.bv_offset, data, bv.bv_len);
+                       flush_dcache_page(bv.bv_page);
+               } else {
+                       flush_dcache_page(bv.bv_page);
+                       memcpy(data, addr + bv.bv_offset, bv.bv_len);
+               }
+               kunmap_atomic(addr);
+               data += bv.bv_len;
+               size -= bv.bv_len;
+       } else {
+               struct req_iterator bi;
+               struct bio_vec bv;
+               rq_for_each_segment(bv, req, bi) {
+                       void *addr;
+                       addr = kmap_atomic(bv.bv_page);
+                       if (to_req) {
+                               memcpy(addr + bv.bv_offset, data, bv.bv_len);
+                               flush_dcache_page(bv.bv_page);
+                       } else {
+                               flush_dcache_page(bv.bv_page);
+                               memcpy(data, addr + bv.bv_offset, bv.bv_len);
+                       }
+                       kunmap_atomic(addr);
+                       data += bv.bv_len;
+                       size -= bv.bv_len;
+               }
+       }
+       if (size)
+               printk("size mismatch: %lx\n", (unsigned long)size);
+}
+
+static void nvme_debug_identify_ns(struct nvme_debug_ctrl *ctrl, struct 
request *req)
+{
+       struct nvme_id_ns *id;
+       struct nvme_debug_namespace *ns;
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+
+       id = kzalloc(sizeof(struct nvme_id_ns), GFP_NOIO);
+       if (!id) {
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       ns = nvme_debug_find_namespace(ctrl, 
le32_to_cpu(ndr->cmd.identify.nsid));
+       if (!ns) {
+               nvme_req(req)->status = cpu_to_le16(NVME_SC_INVALID_NS);
+               goto free_ret;
+       }
+
+       id->nsze = cpu_to_le64(ns->n_sectors);
+       id->ncap = id->nsze;
+       id->nuse = id->nsze;
+       /*id->nlbaf = 0;*/
+       id->dlfeat = 0x01;
+       id->lbaf[0].ds = ns->sector_size_bits;
+
+       copy_data_request(req, id, sizeof(struct nvme_id_ns), true);
+
+free_ret:
+       kfree(id);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static void nvme_debug_identify_ctrl(struct nvme_debug_ctrl *ctrl, struct 
request *req)
+{
+       struct nvme_debug_namespace *ns;
+       struct nvme_id_ctrl *id;
+       char ver[9];
+       size_t ver_len;
+
+       id = kzalloc(sizeof(struct nvme_id_ctrl), GFP_NOIO);
+       if (!id) {
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       id->vid = cpu_to_le16(PCI_VENDOR_ID_REDHAT);
+       id->ssvid = cpu_to_le16(PCI_VENDOR_ID_REDHAT);
+       memset(id->sn, ' ', sizeof id->sn);
+       memset(id->mn, ' ', sizeof id->mn);
+       memcpy(id->mn, "nvme-debug", 10);
+       snprintf(ver, sizeof ver, "%X", LINUX_VERSION_CODE);
+       ver_len = min(strlen(ver), sizeof id->fr);
+       memset(id->fr, ' ', sizeof id->fr);
+       memcpy(id->fr, ver, ver_len);
+       memcpy(id->ieee, "\xe9\xf2\x40", sizeof id->ieee);
+       id->ver = cpu_to_le32(0x20000);
+       id->kas = cpu_to_le16(100);
+       id->sqes = 0x66;
+       id->cqes = 0x44;
+       id->maxcmd = cpu_to_le16(1);
+       mutex_lock(&nvme_debug_ctrl_mutex);
+       list_for_each_entry(ns, &ctrl->namespaces, list) {
+               if (ns->nsid > le32_to_cpu(id->nn))
+                       id->nn = cpu_to_le32(ns->nsid);
+       }
+       mutex_unlock(&nvme_debug_ctrl_mutex);
+       id->oncs = cpu_to_le16(NVME_CTRL_ONCS_COPY);
+       id->vwc = 0x6;
+       id->mnan = cpu_to_le32(0xffffffff);
+       strcpy(id->subnqn, "nqn.2021-09.com.redhat:nvme-debug");
+       id->ioccsz = cpu_to_le32(4);
+       id->iorcsz = cpu_to_le32(1);
+
+       copy_data_request(req, id, sizeof(struct nvme_id_ctrl), true);
+
+       kfree(id);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static int cmp_ns(const void *a1, const void *a2)
+{
+       __u32 v1 = le32_to_cpu(*(__u32 *)a1);
+       __u32 v2 = le32_to_cpu(*(__u32 *)a2);
+       if (!v1)
+               v1 = 0xffffffffU;
+       if (!v2)
+               v2 = 0xffffffffU;
+       if (v1 < v2)
+               return -1;
+       if (v1 > v2)
+               return 1;
+       return 0;
+}
+
+static void nvme_debug_identify_active_ns(struct nvme_debug_ctrl *ctrl, struct 
request *req)
+{
+       struct nvme_debug_namespace *ns;
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       unsigned size;
+       __u32 *id;
+       unsigned idp;
+
+       if (le32_to_cpu(ndr->cmd.identify.nsid) >= 0xFFFFFFFE) {
+               nvme_req(req)->status = cpu_to_le16(NVME_SC_INVALID_NS);
+               blk_mq_end_request(req, BLK_STS_OK);
+               return;
+       }
+
+       mutex_lock(&nvme_debug_ctrl_mutex);
+       size = 0;
+       list_for_each_entry(ns, &ctrl->namespaces, list) {
+               size++;
+       }
+       size = min(size, 1024U);
+
+       id = kzalloc(sizeof(__u32) * size, GFP_NOIO);
+       if (!id) {
+               mutex_unlock(&nvme_debug_ctrl_mutex);
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       idp = 0;
+       list_for_each_entry(ns, &ctrl->namespaces, list) {
+               if (ns->nsid > le32_to_cpu(ndr->cmd.identify.nsid))
+                       id[idp++] = cpu_to_le32(ns->nsid);
+       }
+       mutex_unlock(&nvme_debug_ctrl_mutex);
+       sort(id, idp, sizeof(__u32), cmp_ns, NULL);
+
+       copy_data_request(req, id, sizeof(__u32) * 1024, true);
+
+       kfree(id);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static void nvme_debug_identify_ns_desc_list(struct nvme_debug_ctrl *ctrl, 
struct request *req)
+{
+       struct nvme_ns_id_desc *id;
+       struct nvme_debug_namespace *ns;
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       id = kzalloc(4096, GFP_NOIO);
+       if (!id) {
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       ns = nvme_debug_find_namespace(ctrl, 
le32_to_cpu(ndr->cmd.identify.nsid));
+       if (!ns) {
+               nvme_req(req)->status = cpu_to_le16(NVME_SC_INVALID_NS);
+               goto free_ret;
+       }
+
+       id->nidt = NVME_NIDT_UUID;
+       id->nidl = NVME_NIDT_UUID_LEN;
+       memcpy((char *)(id + 1), ns->uuid, NVME_NIDT_UUID_LEN);
+
+       copy_data_request(req, id, 4096, true);
+
+free_ret:
+       kfree(id);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static void nvme_debug_identify_ctrl_cs(struct request *req)
+{
+       struct nvme_id_ctrl_nvm *id;
+       id = kzalloc(sizeof(struct nvme_id_ctrl_nvm), GFP_NOIO);
+       if (!id) {
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       copy_data_request(req, id, sizeof(struct nvme_id_ctrl_nvm), true);
+
+       kfree(id);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static void nvme_debug_admin_rq(struct work_struct *w)
+{
+       struct nvme_debug_request *ndr = container_of(w, struct 
nvme_debug_request, work);
+       struct request *req = (struct request *)ndr - 1;
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(ndr->req.ctrl);
+
+       switch (ndr->cmd.common.opcode) {
+               case nvme_admin_identify: {
+                       switch (ndr->cmd.identify.cns) {
+                               case NVME_ID_CNS_NS: {
+                                       percpu_down_read(&nvme_debug_sem);
+                                       nvme_debug_identify_ns(ctrl, req);
+                                       percpu_up_read(&nvme_debug_sem);
+                                       return;
+                               };
+                               case NVME_ID_CNS_CTRL: {
+                                       percpu_down_read(&nvme_debug_sem);
+                                       nvme_debug_identify_ctrl(ctrl, req);
+                                       percpu_up_read(&nvme_debug_sem);
+                                       return;
+                               }
+                               case NVME_ID_CNS_NS_ACTIVE_LIST: {
+                                       percpu_down_read(&nvme_debug_sem);
+                                       nvme_debug_identify_active_ns(ctrl, 
req);
+                                       percpu_up_read(&nvme_debug_sem);
+                                       return;
+                               }
+                               case NVME_ID_CNS_NS_DESC_LIST: {
+                                       percpu_down_read(&nvme_debug_sem);
+                                       nvme_debug_identify_ns_desc_list(ctrl, 
req);
+                                       percpu_up_read(&nvme_debug_sem);
+                                       return;
+                               }
+                               case NVME_ID_CNS_CS_CTRL: {
+                                       percpu_down_read(&nvme_debug_sem);
+                                       nvme_debug_identify_ctrl_cs(req);
+                                       percpu_up_read(&nvme_debug_sem);
+                                       return;
+                               }
+                               default: {
+                                       printk("nvme_admin_identify: %x\n", 
ndr->cmd.identify.cns);
+                                       break;
+                               }
+                       }
+                       break;
+               }
+               default: {
+                       printk("nvme_debug_admin_rq: %x\n", 
ndr->cmd.common.opcode);
+                       break;
+               }
+       }
+       blk_mq_end_request(req, BLK_STS_NOTSUPP);
+}
+
+static void nvme_debug_rw(struct nvme_debug_namespace *ns, struct request *req)
+{
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       __u64 lba = cpu_to_le64(ndr->cmd.rw.slba);
+       __u64 len = (__u64)cpu_to_le16(ndr->cmd.rw.length) + 1;
+       void *addr;
+       if (unlikely(lba + len < lba) || unlikely(lba + len > ns->n_sectors)) {
+               blk_mq_end_request(req, BLK_STS_NOTSUPP);
+               return;
+       }
+       addr = ns->space + (lba << ns->sector_size_bits);
+       copy_data_request(req, addr, len << ns->sector_size_bits, 
ndr->cmd.rw.opcode == nvme_cmd_read);
+       blk_mq_end_request(req, BLK_STS_OK);
+}
+
+static void nvme_debug_copy(struct nvme_debug_namespace *ns, struct request 
*req)
+{
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       __u64 dlba = cpu_to_le64(ndr->cmd.copy.sdlba);
+       unsigned n_descs = ndr->cmd.copy.length + 1;
+       struct nvme_copy_desc *descs;
+       unsigned i, ret;
+
+       descs = kmalloc(sizeof(struct nvme_copy_desc) * n_descs, GFP_NOIO | 
__GFP_NORETRY | __GFP_NOWARN);
+       if (!descs) {
+               blk_mq_end_request(req, BLK_STS_RESOURCE);
+               return;
+       }
+
+       copy_data_request(req, descs, sizeof(struct nvme_copy_desc) * n_descs, 
false);
+
+       for (i = 0; i < n_descs; i++) {
+               struct nvme_copy_desc *desc = &descs[i];
+               __u64 slba = cpu_to_le64(desc->slba);
+               __u64 len = (__u64)cpu_to_le16(desc->length) + 1;
+               void *saddr, *daddr;
+
+               if (unlikely(slba + len < slba) || unlikely(slba + len > 
ns->n_sectors) ||
+                   unlikely(dlba + len < dlba) || unlikely(dlba + len > 
ns->n_sectors)) {
+                       ret = BLK_STS_NOTSUPP;
+                       goto free_ret;
+               }
+
+               saddr = ns->space + (slba << ns->sector_size_bits);
+               daddr = ns->space + (dlba << ns->sector_size_bits);
+
+               memcpy(daddr, saddr, len << ns->sector_size_bits);
+
+               dlba += len;
+       }
+
+       ret = BLK_STS_OK;
+
+free_ret:
+       kfree(descs);
+
+       blk_mq_end_request(req, ret);
+}
+
+static void nvme_debug_io_rq(struct work_struct *w)
+{
+       struct nvme_debug_request *ndr = container_of(w, struct 
nvme_debug_request, work);
+       struct request *req = (struct request *)ndr - 1;
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(ndr->req.ctrl);
+       __u32 nsid = le32_to_cpu(ndr->cmd.common.nsid);
+       struct nvme_debug_namespace *ns;
+
+       percpu_down_read(&nvme_debug_sem);
+       ns = nvme_debug_find_namespace(ctrl, nsid);
+       if (unlikely(!ns))
+               goto ret_notsupp;
+
+       switch (ndr->cmd.common.opcode) {
+               case nvme_cmd_flush: {
+                       blk_mq_end_request(req, BLK_STS_OK);
+                       goto ret;
+               }
+               case nvme_cmd_read:
+               case nvme_cmd_write: {
+                       nvme_debug_rw(ns, req);
+                       goto ret;
+               }
+               case nvme_cmd_copy: {
+                       nvme_debug_copy(ns, req);
+                       goto ret;
+               }
+               default: {
+                       printk("nvme_debug_io_rq: %x\n", 
ndr->cmd.common.opcode);
+                       break;
+               }
+       }
+ret_notsupp:
+       blk_mq_end_request(req, BLK_STS_NOTSUPP);
+ret:
+       percpu_up_read(&nvme_debug_sem);
+}
+
+static blk_status_t nvme_debug_queue_rq(struct blk_mq_hw_ctx *hctx, const 
struct blk_mq_queue_data *bd)
+{
+       struct request *req = bd->rq;
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       struct nvme_debug_ctrl *ctrl = to_debug_ctrl(ndr->req.ctrl);
+       struct nvme_ns *ns = hctx->queue->queuedata;
+       blk_status_t r;
+
+       r = nvme_setup_cmd(ns, req);
+       if (unlikely(r))
+               return r;
+
+       if (!ns) {
+               INIT_WORK(&ndr->work, nvme_debug_admin_rq);
+               queue_work(ctrl->admin_wq, &ndr->work);
+               return BLK_STS_OK;
+       } else if (unlikely((req->cmd_flags & REQ_OP_MASK) == 
REQ_OP_COPY_READ_TOKEN)) {
+               blk_mq_end_request(req, BLK_STS_OK);
+               return BLK_STS_OK;
+       } else {
+               INIT_WORK(&ndr->work, nvme_debug_io_rq);
+               queue_work(ctrl->io_wq, &ndr->work);
+               return BLK_STS_OK;
+       }
+}
+
+static int nvme_debug_init_request(struct blk_mq_tag_set *set, struct request 
*req, unsigned hctx_idx, unsigned numa_node)
+{
+       struct nvme_debug_ctrl *ctrl = set->driver_data;
+       struct nvme_debug_request *ndr = blk_mq_rq_to_pdu(req);
+       nvme_req(req)->ctrl = &ctrl->ctrl;
+       nvme_req(req)->cmd = &ndr->cmd;
+       return 0;
+}
+
+static int nvme_debug_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, 
unsigned hctx_idx)
+{
+       struct nvme_debug_ctrl *ctrl = data;
+       hctx->driver_data = ctrl;
+       return 0;
+}
+
+static const struct blk_mq_ops nvme_debug_mq_ops = {
+       .queue_rq = nvme_debug_queue_rq,
+       .init_request = nvme_debug_init_request,
+       .init_hctx = nvme_debug_init_hctx,
+};
+
+static int nvme_debug_configure_admin_queue(struct nvme_debug_ctrl *ctrl)
+{
+       int r;
+
+       memset(&ctrl->admin_tag_set, 0, sizeof(ctrl->admin_tag_set));
+       ctrl->admin_tag_set.ops = &nvme_debug_mq_ops;
+       ctrl->admin_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
+       ctrl->admin_tag_set.reserved_tags = NVMF_RESERVED_TAGS;
+       ctrl->admin_tag_set.numa_node = ctrl->ctrl.numa_node;
+       ctrl->admin_tag_set.cmd_size = sizeof(struct nvme_debug_request);
+       ctrl->admin_tag_set.driver_data = ctrl;
+       ctrl->admin_tag_set.nr_hw_queues = 1;
+       ctrl->admin_tag_set.timeout = NVME_ADMIN_TIMEOUT;
+       ctrl->admin_tag_set.flags = BLK_MQ_F_NO_SCHED;
+
+       r = blk_mq_alloc_tag_set(&ctrl->admin_tag_set);
+       if (r)
+               goto ret0;
+       ctrl->ctrl.admin_tagset = &ctrl->admin_tag_set;
+
+       ctrl->ctrl.admin_q = blk_mq_init_queue(&ctrl->admin_tag_set);
+       if (IS_ERR(ctrl->ctrl.admin_q)) {
+               r = PTR_ERR(ctrl->ctrl.admin_q);
+               goto ret1;
+       }
+
+       r = nvme_enable_ctrl(&ctrl->ctrl);
+       if (r)
+               goto ret2;
+
+       nvme_start_admin_queue(&ctrl->ctrl);
+
+       r = nvme_init_ctrl_finish(&ctrl->ctrl);
+       if (r)
+               goto ret3;
+
+       return 0;
+
+ret3:
+       nvme_stop_admin_queue(&ctrl->ctrl);
+       blk_sync_queue(ctrl->ctrl.admin_q);
+ret2:
+       blk_cleanup_queue(ctrl->ctrl.admin_q);
+ret1:
+       blk_mq_free_tag_set(&ctrl->admin_tag_set);
+ret0:
+       return r;
+}
+
+static int nvme_debug_configure_io_queue(struct nvme_debug_ctrl *ctrl)
+{
+       int r;
+
+       memset(&ctrl->io_tag_set, 0, sizeof(ctrl->io_tag_set));
+       ctrl->io_tag_set.ops = &nvme_debug_mq_ops;
+       ctrl->io_tag_set.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
+       ctrl->io_tag_set.reserved_tags = NVMF_RESERVED_TAGS;
+       ctrl->io_tag_set.numa_node = ctrl->ctrl.numa_node;
+       ctrl->io_tag_set.cmd_size = sizeof(struct nvme_debug_request);
+       ctrl->io_tag_set.driver_data = ctrl;
+       ctrl->io_tag_set.nr_hw_queues = 1;
+       ctrl->io_tag_set.timeout = NVME_ADMIN_TIMEOUT;
+       ctrl->io_tag_set.flags = BLK_MQ_F_NO_SCHED;
+
+       r = blk_mq_alloc_tag_set(&ctrl->io_tag_set);
+       if (r)
+               goto ret0;
+       ctrl->ctrl.tagset = &ctrl->io_tag_set;
+       return 0;
+
+ret0:
+       return r;
+}
+
+static const struct nvme_ctrl_ops nvme_debug_ctrl_ops = {
+       .name = "debug",
+       .module = THIS_MODULE,
+       .flags = NVME_F_FABRICS,
+       .reg_read32 = nvme_debug_reg_read32,
+       .reg_read64 = nvme_debug_reg_read64,
+       .reg_write32 = nvme_debug_reg_write32,
+       .free_ctrl = nvme_debug_free_ctrl,
+       .submit_async_event = nvme_debug_submit_async_event,
+       .delete_ctrl = nvme_debug_delete_ctrl,
+       .get_address = nvme_debug_get_address,
+};
+
+static struct nvme_ctrl *nvme_debug_create_ctrl(struct device *dev,
+               struct nvmf_ctrl_options *opts)
+{
+       int r;
+       struct nvme_debug_ctrl *ctrl;
+
+       ctrl = kzalloc(sizeof(struct nvme_debug_ctrl), GFP_KERNEL);
+       if (!ctrl) {
+               r = -ENOMEM;
+               goto ret0;
+       }
+
+       INIT_LIST_HEAD(&ctrl->list);
+       INIT_LIST_HEAD(&ctrl->namespaces);
+       ctrl->ctrl.opts = opts;
+       ctrl->ctrl.queue_count = 2;
+       INIT_WORK(&ctrl->ctrl.reset_work, nvme_debug_reset_ctrl_work);
+
+       ctrl->admin_wq = alloc_workqueue("nvme-debug-admin", WQ_MEM_RECLAIM | 
WQ_UNBOUND, 1);
+       if (!ctrl->admin_wq)
+               goto ret1;
+
+       ctrl->io_wq = alloc_workqueue("nvme-debug-io", WQ_MEM_RECLAIM, 0);
+       if (!ctrl->io_wq)
+               goto ret1;
+
+       if (!nvme_debug_alloc_namespace(ctrl)) {
+               r = -ENOMEM;
+               goto ret1;
+       }
+
+       r = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_debug_ctrl_ops, 0);
+       if (r)
+               goto ret1;
+
+        if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
+               goto ret2;
+
+       r = nvme_debug_configure_admin_queue(ctrl);
+       if (r)
+               goto ret2;
+
+       r = nvme_debug_configure_io_queue(ctrl);
+       if (r)
+               goto ret2;
+
+        if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE))
+               goto ret2;
+
+       nvme_start_ctrl(&ctrl->ctrl);
+
+       mutex_lock(&nvme_debug_ctrl_mutex);
+       list_add_tail(&ctrl->list, &nvme_debug_ctrl_list);
+       mutex_unlock(&nvme_debug_ctrl_mutex);
+
+       return &ctrl->ctrl;
+
+ret2:
+       nvme_uninit_ctrl(&ctrl->ctrl);
+       nvme_put_ctrl(&ctrl->ctrl);
+       return ERR_PTR(r);
+ret1:
+       nvme_debug_free_namespaces(ctrl);
+       if (ctrl->admin_wq)
+               destroy_workqueue(ctrl->admin_wq);
+       if (ctrl->io_wq)
+               destroy_workqueue(ctrl->io_wq);
+       kfree(ctrl);
+ret0:
+       return ERR_PTR(r);
+}
+
+static struct nvmf_transport_ops nvme_debug_transport = {
+       .name           = "debug",
+       .module         = THIS_MODULE,
+       .required_opts  = NVMF_OPT_TRADDR,
+       .allowed_opts   = NVMF_OPT_CTRL_LOSS_TMO,
+       .create_ctrl    = nvme_debug_create_ctrl,
+};
+
+static int __init nvme_debug_init_module(void)
+{
+       nvmf_register_transport(&nvme_debug_transport);
+       return 0;
+}
+
+static void __exit nvme_debug_cleanup_module(void)
+{
+       struct nvme_debug_ctrl *ctrl;
+
+       nvmf_unregister_transport(&nvme_debug_transport);
+
+       mutex_lock(&nvme_debug_ctrl_mutex);
+       list_for_each_entry(ctrl, &nvme_debug_ctrl_list, list) {
+               nvme_delete_ctrl(&ctrl->ctrl);
+       }
+       mutex_unlock(&nvme_debug_ctrl_mutex);
+       flush_workqueue(nvme_delete_wq);
+}
+
+module_init(nvme_debug_init_module);
+module_exit(nvme_debug_cleanup_module);
+
+MODULE_LICENSE("GPL v2");

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