diff options
author | Jens Axboe <axboe@kernel.dk> | 2025-01-13 07:12:15 -0700 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2025-01-13 07:12:15 -0700 |
commit | 9752b55035b161e40220b9ec8fae6e363a601996 (patch) | |
tree | 6143154de8fd423044fa01d1ca6f2651876a6f24 /drivers/nvme/target/pci-epf.c | |
parent | afd69d5c4a1049230fa91c9b54fdd8132f755503 (diff) | |
parent | 4a324970fabad503260973cd588609f3a26baab9 (diff) |
Merge tag 'nvme-6.14-2025-01-12' of git://git.infradead.org/nvme into for-6.14/block
Pull NVMe updates from Keith:
"nvme updates for Linux 6.14
- Target support for PCI-Endpoint transport (Damien)
- TCP IO queue spreading fixes (Sagi, Chaitanya)
- Target handling for "limited retry" flags (Guixen)
- Poll type fix (Yongsoo)
- Xarray storage error handling (Keisuke)
- Host memory buffer free size fix on error (Francis)"
* tag 'nvme-6.14-2025-01-12' of git://git.infradead.org/nvme: (25 commits)
nvme-pci: use correct size to free the hmb buffer
nvme: Add error path for xa_store in nvme_init_effects
nvme-pci: fix comment typo
Documentation: Document the NVMe PCI endpoint target driver
nvmet: New NVMe PCI endpoint function target driver
nvmet: Implement arbitration feature support
nvmet: Implement interrupt config feature support
nvmet: Implement interrupt coalescing feature support
nvmet: Implement host identifier set feature support
nvmet: Introduce get/set_feature controller operations
nvmet: Do not require SGL for PCI target controller commands
nvmet: Add support for I/O queue management admin commands
nvmet: Introduce nvmet_sq_create() and nvmet_cq_create()
nvmet: Introduce nvmet_req_transfer_len()
nvmet: Improve nvmet_alloc_ctrl() interface and implementation
nvme: Add PCI transport type
nvmet: Add drvdata field to struct nvmet_ctrl
nvmet: Introduce nvmet_get_cmd_effects_admin()
nvmet: Export nvmet_update_cc() and nvmet_cc_xxx() helpers
nvmet: Add vendor_id and subsys_vendor_id subsystem attributes
...
Diffstat (limited to 'drivers/nvme/target/pci-epf.c')
-rw-r--r-- | drivers/nvme/target/pci-epf.c | 2591 |
1 files changed, 2591 insertions, 0 deletions
diff --git a/drivers/nvme/target/pci-epf.c b/drivers/nvme/target/pci-epf.c new file mode 100644 index 000000000000..ac30b42cc622 --- /dev/null +++ b/drivers/nvme/target/pci-epf.c @@ -0,0 +1,2591 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NVMe PCI Endpoint Function target driver. + * + * Copyright (c) 2024, Western Digital Corporation or its affiliates. + * Copyright (c) 2024, Rick Wertenbroek <rick.wertenbroek@gmail.com> + * REDS Institute, HEIG-VD, HES-SO, Switzerland + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/io.h> +#include <linux/mempool.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/nvme.h> +#include <linux/pci_ids.h> +#include <linux/pci-epc.h> +#include <linux/pci-epf.h> +#include <linux/pci_regs.h> +#include <linux/slab.h> + +#include "nvmet.h" + +static LIST_HEAD(nvmet_pci_epf_ports); +static DEFINE_MUTEX(nvmet_pci_epf_ports_mutex); + +/* + * Default and maximum allowed data transfer size. For the default, + * allow up to 128 page-sized segments. For the maximum allowed, + * use 4 times the default (which is completely arbitrary). + */ +#define NVMET_PCI_EPF_MAX_SEGS 128 +#define NVMET_PCI_EPF_MDTS_KB \ + (NVMET_PCI_EPF_MAX_SEGS << (PAGE_SHIFT - 10)) +#define NVMET_PCI_EPF_MAX_MDTS_KB (NVMET_PCI_EPF_MDTS_KB * 4) + +/* + * IRQ vector coalescing threshold: by default, post 8 CQEs before raising an + * interrupt vector to the host. This default 8 is completely arbitrary and can + * be changed by the host with a nvme_set_features command. + */ +#define NVMET_PCI_EPF_IV_THRESHOLD 8 + +/* + * BAR CC register and SQ polling intervals. + */ +#define NVMET_PCI_EPF_CC_POLL_INTERVAL msecs_to_jiffies(5) +#define NVMET_PCI_EPF_SQ_POLL_INTERVAL msecs_to_jiffies(5) +#define NVMET_PCI_EPF_SQ_POLL_IDLE msecs_to_jiffies(5000) + +/* + * SQ arbitration burst default: fetch at most 8 commands at a time from an SQ. + */ +#define NVMET_PCI_EPF_SQ_AB 8 + +/* + * Handling of CQs is normally immediate, unless we fail to map a CQ or the CQ + * is full, in which case we retry the CQ processing after this interval. + */ +#define NVMET_PCI_EPF_CQ_RETRY_INTERVAL msecs_to_jiffies(1) + +enum nvmet_pci_epf_queue_flags { + NVMET_PCI_EPF_Q_IS_SQ = 0, /* The queue is a submission queue */ + NVMET_PCI_EPF_Q_LIVE, /* The queue is live */ + NVMET_PCI_EPF_Q_IRQ_ENABLED, /* IRQ is enabled for this queue */ +}; + +/* + * IRQ vector descriptor. + */ +struct nvmet_pci_epf_irq_vector { + unsigned int vector; + unsigned int ref; + bool cd; + int nr_irqs; +}; + +struct nvmet_pci_epf_queue { + union { + struct nvmet_sq nvme_sq; + struct nvmet_cq nvme_cq; + }; + struct nvmet_pci_epf_ctrl *ctrl; + unsigned long flags; + + u64 pci_addr; + size_t pci_size; + struct pci_epc_map pci_map; + + u16 qid; + u16 depth; + u16 vector; + u16 head; + u16 tail; + u16 phase; + u32 db; + + size_t qes; + + struct nvmet_pci_epf_irq_vector *iv; + struct workqueue_struct *iod_wq; + struct delayed_work work; + spinlock_t lock; + struct list_head list; +}; + +/* + * PCI Root Complex (RC) address data segment for mapping an admin or + * I/O command buffer @buf of @length bytes to the PCI address @pci_addr. + */ +struct nvmet_pci_epf_segment { + void *buf; + u64 pci_addr; + u32 length; +}; + +/* + * Command descriptors. + */ +struct nvmet_pci_epf_iod { + struct list_head link; + + struct nvmet_req req; + struct nvme_command cmd; + struct nvme_completion cqe; + unsigned int status; + + struct nvmet_pci_epf_ctrl *ctrl; + + struct nvmet_pci_epf_queue *sq; + struct nvmet_pci_epf_queue *cq; + + /* Data transfer size and direction for the command. */ + size_t data_len; + enum dma_data_direction dma_dir; + + /* + * PCI Root Complex (RC) address data segments: if nr_data_segs is 1, we + * use only @data_seg. Otherwise, the array of segments @data_segs is + * allocated to manage multiple PCI address data segments. @data_sgl and + * @data_sgt are used to setup the command request for execution by the + * target core. + */ + unsigned int nr_data_segs; + struct nvmet_pci_epf_segment data_seg; + struct nvmet_pci_epf_segment *data_segs; + struct scatterlist data_sgl; + struct sg_table data_sgt; + + struct work_struct work; + struct completion done; +}; + +/* + * PCI target controller private data. + */ +struct nvmet_pci_epf_ctrl { + struct nvmet_pci_epf *nvme_epf; + struct nvmet_port *port; + struct nvmet_ctrl *tctrl; + struct device *dev; + + unsigned int nr_queues; + struct nvmet_pci_epf_queue *sq; + struct nvmet_pci_epf_queue *cq; + unsigned int sq_ab; + + mempool_t iod_pool; + void *bar; + u64 cap; + u32 cc; + u32 csts; + + size_t io_sqes; + size_t io_cqes; + + size_t mps_shift; + size_t mps; + size_t mps_mask; + + unsigned int mdts; + + struct delayed_work poll_cc; + struct delayed_work poll_sqs; + + struct mutex irq_lock; + struct nvmet_pci_epf_irq_vector *irq_vectors; + unsigned int irq_vector_threshold; + + bool link_up; + bool enabled; +}; + +/* + * PCI EPF driver private data. + */ +struct nvmet_pci_epf { + struct pci_epf *epf; + + const struct pci_epc_features *epc_features; + + void *reg_bar; + size_t msix_table_offset; + + unsigned int irq_type; + unsigned int nr_vectors; + + struct nvmet_pci_epf_ctrl ctrl; + + bool dma_enabled; + struct dma_chan *dma_tx_chan; + struct mutex dma_tx_lock; + struct dma_chan *dma_rx_chan; + struct mutex dma_rx_lock; + + struct mutex mmio_lock; + + /* PCI endpoint function configfs attributes. */ + struct config_group group; + __le16 portid; + char subsysnqn[NVMF_NQN_SIZE]; + unsigned int mdts_kb; +}; + +static inline u32 nvmet_pci_epf_bar_read32(struct nvmet_pci_epf_ctrl *ctrl, + u32 off) +{ + __le32 *bar_reg = ctrl->bar + off; + + return le32_to_cpu(READ_ONCE(*bar_reg)); +} + +static inline void nvmet_pci_epf_bar_write32(struct nvmet_pci_epf_ctrl *ctrl, + u32 off, u32 val) +{ + __le32 *bar_reg = ctrl->bar + off; + + WRITE_ONCE(*bar_reg, cpu_to_le32(val)); +} + +static inline u64 nvmet_pci_epf_bar_read64(struct nvmet_pci_epf_ctrl *ctrl, + u32 off) +{ + return (u64)nvmet_pci_epf_bar_read32(ctrl, off) | + ((u64)nvmet_pci_epf_bar_read32(ctrl, off + 4) << 32); +} + +static inline void nvmet_pci_epf_bar_write64(struct nvmet_pci_epf_ctrl *ctrl, + u32 off, u64 val) +{ + nvmet_pci_epf_bar_write32(ctrl, off, val & 0xFFFFFFFF); + nvmet_pci_epf_bar_write32(ctrl, off + 4, (val >> 32) & 0xFFFFFFFF); +} + +static inline int nvmet_pci_epf_mem_map(struct nvmet_pci_epf *nvme_epf, + u64 pci_addr, size_t size, struct pci_epc_map *map) +{ + struct pci_epf *epf = nvme_epf->epf; + + return pci_epc_mem_map(epf->epc, epf->func_no, epf->vfunc_no, + pci_addr, size, map); +} + +static inline void nvmet_pci_epf_mem_unmap(struct nvmet_pci_epf *nvme_epf, + struct pci_epc_map *map) +{ + struct pci_epf *epf = nvme_epf->epf; + + pci_epc_mem_unmap(epf->epc, epf->func_no, epf->vfunc_no, map); +} + +struct nvmet_pci_epf_dma_filter { + struct device *dev; + u32 dma_mask; +}; + +static bool nvmet_pci_epf_dma_filter(struct dma_chan *chan, void *arg) +{ + struct nvmet_pci_epf_dma_filter *filter = arg; + struct dma_slave_caps caps; + + memset(&caps, 0, sizeof(caps)); + dma_get_slave_caps(chan, &caps); + + return chan->device->dev == filter->dev && + (filter->dma_mask & caps.directions); +} + +static void nvmet_pci_epf_init_dma(struct nvmet_pci_epf *nvme_epf) +{ + struct pci_epf *epf = nvme_epf->epf; + struct device *dev = &epf->dev; + struct nvmet_pci_epf_dma_filter filter; + struct dma_chan *chan; + dma_cap_mask_t mask; + + mutex_init(&nvme_epf->dma_rx_lock); + mutex_init(&nvme_epf->dma_tx_lock); + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + filter.dev = epf->epc->dev.parent; + filter.dma_mask = BIT(DMA_DEV_TO_MEM); + + chan = dma_request_channel(mask, nvmet_pci_epf_dma_filter, &filter); + if (!chan) + goto out_dma_no_rx; + + nvme_epf->dma_rx_chan = chan; + + filter.dma_mask = BIT(DMA_MEM_TO_DEV); + chan = dma_request_channel(mask, nvmet_pci_epf_dma_filter, &filter); + if (!chan) + goto out_dma_no_tx; + + nvme_epf->dma_tx_chan = chan; + + nvme_epf->dma_enabled = true; + + dev_dbg(dev, "Using DMA RX channel %s, maximum segment size %u B\n", + dma_chan_name(chan), + dma_get_max_seg_size(dmaengine_get_dma_device(chan))); + + dev_dbg(dev, "Using DMA TX channel %s, maximum segment size %u B\n", + dma_chan_name(chan), + dma_get_max_seg_size(dmaengine_get_dma_device(chan))); + + return; + +out_dma_no_tx: + dma_release_channel(nvme_epf->dma_rx_chan); + nvme_epf->dma_rx_chan = NULL; + +out_dma_no_rx: + mutex_destroy(&nvme_epf->dma_rx_lock); + mutex_destroy(&nvme_epf->dma_tx_lock); + nvme_epf->dma_enabled = false; + + dev_info(&epf->dev, "DMA not supported, falling back to MMIO\n"); +} + +static void nvmet_pci_epf_deinit_dma(struct nvmet_pci_epf *nvme_epf) +{ + if (!nvme_epf->dma_enabled) + return; + + dma_release_channel(nvme_epf->dma_tx_chan); + nvme_epf->dma_tx_chan = NULL; + dma_release_channel(nvme_epf->dma_rx_chan); + nvme_epf->dma_rx_chan = NULL; + mutex_destroy(&nvme_epf->dma_rx_lock); + mutex_destroy(&nvme_epf->dma_tx_lock); + nvme_epf->dma_enabled = false; +} + +static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf, + struct nvmet_pci_epf_segment *seg, enum dma_data_direction dir) +{ + struct pci_epf *epf = nvme_epf->epf; + struct dma_async_tx_descriptor *desc; + struct dma_slave_config sconf = {}; + struct device *dev = &epf->dev; + struct device *dma_dev; + struct dma_chan *chan; + dma_cookie_t cookie; + dma_addr_t dma_addr; + struct mutex *lock; + int ret; + + switch (dir) { + case DMA_FROM_DEVICE: + lock = &nvme_epf->dma_rx_lock; + chan = nvme_epf->dma_rx_chan; + sconf.direction = DMA_DEV_TO_MEM; + sconf.src_addr = seg->pci_addr; + break; + case DMA_TO_DEVICE: + lock = &nvme_epf->dma_tx_lock; + chan = nvme_epf->dma_tx_chan; + sconf.direction = DMA_MEM_TO_DEV; + sconf.dst_addr = seg->pci_addr; + break; + default: + return -EINVAL; + } + + mutex_lock(lock); + + dma_dev = dmaengine_get_dma_device(chan); + dma_addr = dma_map_single(dma_dev, seg->buf, seg->length, dir); + ret = dma_mapping_error(dma_dev, dma_addr); + if (ret) + goto unlock; + + ret = dmaengine_slave_config(chan, &sconf); + if (ret) { + dev_err(dev, "Failed to configure DMA channel\n"); + goto unmap; + } + + desc = dmaengine_prep_slave_single(chan, dma_addr, seg->length, + sconf.direction, DMA_CTRL_ACK); + if (!desc) { + dev_err(dev, "Failed to prepare DMA\n"); + ret = -EIO; + goto unmap; + } + + cookie = dmaengine_submit(desc); + ret = dma_submit_error(cookie); + if (ret) { + dev_err(dev, "Failed to do DMA submit (err=%d)\n", ret); + goto unmap; + } + + if (dma_sync_wait(chan, cookie) != DMA_COMPLETE) { + dev_err(dev, "DMA transfer failed\n"); + ret = -EIO; + } + + dmaengine_terminate_sync(chan); + +unmap: + dma_unmap_single(dma_dev, dma_addr, seg->length, dir); + +unlock: + mutex_unlock(lock); + + return ret; +} + +static int nvmet_pci_epf_mmio_transfer(struct nvmet_pci_epf *nvme_epf, + struct nvmet_pci_epf_segment *seg, enum dma_data_direction dir) +{ + u64 pci_addr = seg->pci_addr; + u32 length = seg->length; + void *buf = seg->buf; + struct pci_epc_map map; + int ret = -EINVAL; + + /* + * Note: MMIO transfers do not need serialization but this is a + * simple way to avoid using too many mapping windows. + */ + mutex_lock(&nvme_epf->mmio_lock); + + while (length) { + ret = nvmet_pci_epf_mem_map(nvme_epf, pci_addr, length, &map); + if (ret) + break; + + switch (dir) { + case DMA_FROM_DEVICE: + memcpy_fromio(buf, map.virt_addr, map.pci_size); + break; + case DMA_TO_DEVICE: + memcpy_toio(map.virt_addr, buf, map.pci_size); + break; + default: + ret = -EINVAL; + goto unlock; + } + + pci_addr += map.pci_size; + buf += map.pci_size; + length -= map.pci_size; + + nvmet_pci_epf_mem_unmap(nvme_epf, &map); + } + +unlock: + mutex_unlock(&nvme_epf->mmio_lock); + + return ret; +} + +static inline int nvmet_pci_epf_transfer_seg(struct nvmet_pci_epf *nvme_epf, + struct nvmet_pci_epf_segment *seg, enum dma_data_direction dir) +{ + if (nvme_epf->dma_enabled) + return nvmet_pci_epf_dma_transfer(nvme_epf, seg, dir); + + return nvmet_pci_epf_mmio_transfer(nvme_epf, seg, dir); +} + +static inline int nvmet_pci_epf_transfer(struct nvmet_pci_epf_ctrl *ctrl, + void *buf, u64 pci_addr, u32 length, + enum dma_data_direction dir) +{ + struct nvmet_pci_epf_segment seg = { + .buf = buf, + .pci_addr = pci_addr, + .length = length, + }; + + return nvmet_pci_epf_transfer_seg(ctrl->nvme_epf, &seg, dir); +} + +static int nvmet_pci_epf_alloc_irq_vectors(struct nvmet_pci_epf_ctrl *ctrl) +{ + ctrl->irq_vectors = kcalloc(ctrl->nr_queues, + sizeof(struct nvmet_pci_epf_irq_vector), + GFP_KERNEL); + if (!ctrl->irq_vectors) + return -ENOMEM; + + mutex_init(&ctrl->irq_lock); + + return 0; +} + +static void nvmet_pci_epf_free_irq_vectors(struct nvmet_pci_epf_ctrl *ctrl) +{ + if (ctrl->irq_vectors) { + mutex_destroy(&ctrl->irq_lock); + kfree(ctrl->irq_vectors); + ctrl->irq_vectors = NULL; + } +} + +static struct nvmet_pci_epf_irq_vector * +nvmet_pci_epf_find_irq_vector(struct nvmet_pci_epf_ctrl *ctrl, u16 vector) +{ + struct nvmet_pci_epf_irq_vector *iv; + int i; + + lockdep_assert_held(&ctrl->irq_lock); + + for (i = 0; i < ctrl->nr_queues; i++) { + iv = &ctrl->irq_vectors[i]; + if (iv->ref && iv->vector == vector) + return iv; + } + + return NULL; +} + +static struct nvmet_pci_epf_irq_vector * +nvmet_pci_epf_add_irq_vector(struct nvmet_pci_epf_ctrl *ctrl, u16 vector) +{ + struct nvmet_pci_epf_irq_vector *iv; + int i; + + mutex_lock(&ctrl->irq_lock); + + iv = nvmet_pci_epf_find_irq_vector(ctrl, vector); + if (iv) { + iv->ref++; + goto unlock; + } + + for (i = 0; i < ctrl->nr_queues; i++) { + iv = &ctrl->irq_vectors[i]; + if (!iv->ref) + break; + } + + if (WARN_ON_ONCE(!iv)) + goto unlock; + + iv->ref = 1; + iv->vector = vector; + iv->nr_irqs = 0; + +unlock: + mutex_unlock(&ctrl->irq_lock); + + return iv; +} + +static void nvmet_pci_epf_remove_irq_vector(struct nvmet_pci_epf_ctrl *ctrl, + u16 vector) +{ + struct nvmet_pci_epf_irq_vector *iv; + + mutex_lock(&ctrl->irq_lock); + + iv = nvmet_pci_epf_find_irq_vector(ctrl, vector); + if (iv) { + iv->ref--; + if (!iv->ref) { + iv->vector = 0; + iv->nr_irqs = 0; + } + } + + mutex_unlock(&ctrl->irq_lock); +} + +static bool nvmet_pci_epf_should_raise_irq(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_queue *cq, bool force) +{ + struct nvmet_pci_epf_irq_vector *iv = cq->iv; + bool ret; + + if (!test_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags)) + return false; + + /* IRQ coalescing for the admin queue is not allowed. */ + if (!cq->qid) + return true; + + if (iv->cd) + return true; + + if (force) { + ret = iv->nr_irqs > 0; + } else { + iv->nr_irqs++; + ret = iv->nr_irqs >= ctrl->irq_vector_threshold; + } + if (ret) + iv->nr_irqs = 0; + + return ret; +} + +static void nvmet_pci_epf_raise_irq(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_queue *cq, bool force) +{ + struct nvmet_pci_epf *nvme_epf = ctrl->nvme_epf; + struct pci_epf *epf = nvme_epf->epf; + int ret = 0; + + if (!test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags)) + return; + + mutex_lock(&ctrl->irq_lock); + + if (!nvmet_pci_epf_should_raise_irq(ctrl, cq, force)) + goto unlock; + + switch (nvme_epf->irq_type) { + case PCI_IRQ_MSIX: + case PCI_IRQ_MSI: + ret = pci_epc_raise_irq(epf->epc, epf->func_no, epf->vfunc_no, + nvme_epf->irq_type, cq->vector + 1); + if (!ret) + break; + /* + * If we got an error, it is likely because the host is using + * legacy IRQs (e.g. BIOS, grub). + */ + fallthrough; + case PCI_IRQ_INTX: + ret = pci_epc_raise_irq(epf->epc, epf->func_no, epf->vfunc_no, + PCI_IRQ_INTX, 0); + break; + default: + WARN_ON_ONCE(1); + ret = -EINVAL; + break; + } + + if (ret) + dev_err(ctrl->dev, "Failed to raise IRQ (err=%d)\n", ret); + +unlock: + mutex_unlock(&ctrl->irq_lock); +} + +static inline const char *nvmet_pci_epf_iod_name(struct nvmet_pci_epf_iod *iod) +{ + return nvme_opcode_str(iod->sq->qid, iod->cmd.common.opcode); +} + +static void nvmet_pci_epf_exec_iod_work(struct work_struct *work); + +static struct nvmet_pci_epf_iod * +nvmet_pci_epf_alloc_iod(struct nvmet_pci_epf_queue *sq) +{ + struct nvmet_pci_epf_ctrl *ctrl = sq->ctrl; + struct nvmet_pci_epf_iod *iod; + + iod = mempool_alloc(&ctrl->iod_pool, GFP_KERNEL); + if (unlikely(!iod)) + return NULL; + + memset(iod, 0, sizeof(*iod)); + iod->req.cmd = &iod->cmd; + iod->req.cqe = &iod->cqe; + iod->req.port = ctrl->port; + iod->ctrl = ctrl; + iod->sq = sq; + iod->cq = &ctrl->cq[sq->qid]; + INIT_LIST_HEAD(&iod->link); + iod->dma_dir = DMA_NONE; + INIT_WORK(&iod->work, nvmet_pci_epf_exec_iod_work); + init_completion(&iod->done); + + return iod; +} + +/* + * Allocate or grow a command table of PCI segments. + */ +static int nvmet_pci_epf_alloc_iod_data_segs(struct nvmet_pci_epf_iod *iod, + int nsegs) +{ + struct nvmet_pci_epf_segment *segs; + int nr_segs = iod->nr_data_segs + nsegs; + + segs = krealloc(iod->data_segs, + nr_segs * sizeof(struct nvmet_pci_epf_segment), + GFP_KERNEL | __GFP_ZERO); + if (!segs) + return -ENOMEM; + + iod->nr_data_segs = nr_segs; + iod->data_segs = segs; + + return 0; +} + +static void nvmet_pci_epf_free_iod(struct nvmet_pci_epf_iod *iod) +{ + int i; + + if (iod->data_segs) { + for (i = 0; i < iod->nr_data_segs; i++) + kfree(iod->data_segs[i].buf); + if (iod->data_segs != &iod->data_seg) + kfree(iod->data_segs); + } + if (iod->data_sgt.nents > 1) + sg_free_table(&iod->data_sgt); + mempool_free(iod, &iod->ctrl->iod_pool); +} + +static int nvmet_pci_epf_transfer_iod_data(struct nvmet_pci_epf_iod *iod) +{ + struct nvmet_pci_epf *nvme_epf = iod->ctrl->nvme_epf; + struct nvmet_pci_epf_segment *seg = &iod->data_segs[0]; + int i, ret; + + /* Split the data transfer according to the PCI segments. */ + for (i = 0; i < iod->nr_data_segs; i++, seg++) { + ret = nvmet_pci_epf_transfer_seg(nvme_epf, seg, iod->dma_dir); + if (ret) { + iod->status = NVME_SC_DATA_XFER_ERROR | NVME_STATUS_DNR; + return ret; + } + } + + return 0; +} + +static inline u32 nvmet_pci_epf_prp_ofst(struct nvmet_pci_epf_ctrl *ctrl, + u64 prp) +{ + return prp & ctrl->mps_mask; +} + +static inline size_t nvmet_pci_epf_prp_size(struct nvmet_pci_epf_ctrl *ctrl, + u64 prp) +{ + return ctrl->mps - nvmet_pci_epf_prp_ofst(ctrl, prp); +} + +/* + * Transfer a PRP list from the host and return the number of prps. + */ +static int nvmet_pci_epf_get_prp_list(struct nvmet_pci_epf_ctrl *ctrl, u64 prp, + size_t xfer_len, __le64 *prps) +{ + size_t nr_prps = (xfer_len + ctrl->mps_mask) >> ctrl->mps_shift; + u32 length; + int ret; + + /* + * Compute the number of PRPs required for the number of bytes to + * transfer (xfer_len). If this number overflows the memory page size + * with the PRP list pointer specified, only return the space available + * in the memory page, the last PRP in there will be a PRP list pointer + * to the remaining PRPs. + */ + length = min(nvmet_pci_epf_prp_size(ctrl, prp), nr_prps << 3); + ret = nvmet_pci_epf_transfer(ctrl, prps, prp, length, DMA_FROM_DEVICE); + if (ret) + return ret; + + return length >> 3; +} + +static int nvmet_pci_epf_iod_parse_prp_list(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_iod *iod) +{ + struct nvme_command *cmd = &iod->cmd; + struct nvmet_pci_epf_segment *seg; + size_t size = 0, ofst, prp_size, xfer_len; + size_t transfer_len = iod->data_len; + int nr_segs, nr_prps = 0; + u64 pci_addr, prp; + int i = 0, ret; + __le64 *prps; + + prps = kzalloc(ctrl->mps, GFP_KERNEL); + if (!prps) + goto err_internal; + + /* + * Allocate PCI segments for the command: this considers the worst case + * scenario where all prps are discontiguous, so get as many segments + * as we can have prps. In practice, most of the time, we will have + * far less PCI segments than prps. + */ + prp = le64_to_cpu(cmd->common.dptr.prp1); + if (!prp) + goto err_invalid_field; + + ofst = nvmet_pci_epf_prp_ofst(ctrl, prp); + nr_segs = (transfer_len + ofst + ctrl->mps - 1) >> ctrl->mps_shift; + + ret = nvmet_pci_epf_alloc_iod_data_segs(iod, nr_segs); + if (ret) + goto err_internal; + + /* Set the first segment using prp1. */ + seg = &iod->data_segs[0]; + seg->pci_addr = prp; + seg->length = nvmet_pci_epf_prp_size(ctrl, prp); + + size = seg->length; + pci_addr = prp + size; + nr_segs = 1; + + /* + * Now build the PCI address segments using the PRP lists, starting + * from prp2. + */ + prp = le64_to_cpu(cmd->common.dptr.prp2); + if (!prp) + goto err_invalid_field; + + while (size < transfer_len) { + xfer_len = transfer_len - size; + + if (!nr_prps) { + nr_prps = nvmet_pci_epf_get_prp_list(ctrl, prp, + xfer_len, prps); + if (nr_prps < 0) + goto err_internal; + + i = 0; + ofst = 0; + } + + /* Current entry */ + prp = le64_to_cpu(prps[i]); + if (!prp) + goto err_invalid_field; + + /* Did we reach the last PRP entry of the list? */ + if (xfer_len > ctrl->mps && i == nr_prps - 1) { + /* We need more PRPs: PRP is a list pointer. */ + nr_prps = 0; + continue; + } + + /* Only the first PRP is allowed to have an offset. */ + if (nvmet_pci_epf_prp_ofst(ctrl, prp)) + goto err_invalid_offset; + + if (prp != pci_addr) { + /* Discontiguous prp: new segment. */ + nr_segs++; + if (WARN_ON_ONCE(nr_segs > iod->nr_data_segs)) + goto err_internal; + + seg++; + seg->pci_addr = prp; + seg->length = 0; + pci_addr = prp; + } + + prp_size = min_t(size_t, ctrl->mps, xfer_len); + seg->length += prp_size; + pci_addr += prp_size; + size += prp_size; + + i++; + } + + iod->nr_data_segs = nr_segs; + ret = 0; + + if (size != transfer_len) { + dev_err(ctrl->dev, + "PRPs transfer length mismatch: got %zu B, need %zu B\n", + size, transfer_len); + goto err_internal; + } + + kfree(prps); + + return 0; + +err_invalid_offset: + dev_err(ctrl->dev, "PRPs list invalid offset\n"); + iod->status = NVME_SC_PRP_INVALID_OFFSET | NVME_STATUS_DNR; + goto err; + +err_invalid_field: + dev_err(ctrl->dev, "PRPs list invalid field\n"); + iod->status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + goto err; + +err_internal: + dev_err(ctrl->dev, "PRPs list internal error\n"); + iod->status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + +err: + kfree(prps); + return -EINVAL; +} + +static int nvmet_pci_epf_iod_parse_prp_simple(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_iod *iod) +{ + struct nvme_command *cmd = &iod->cmd; + size_t transfer_len = iod->data_len; + int ret, nr_segs = 1; + u64 prp1, prp2 = 0; + size_t prp1_size; + + prp1 = le64_to_cpu(cmd->common.dptr.prp1); + prp1_size = nvmet_pci_epf_prp_size(ctrl, prp1); + + /* For commands crossing a page boundary, we should have prp2. */ + if (transfer_len > prp1_size) { + prp2 = le64_to_cpu(cmd->common.dptr.prp2); + if (!prp2) { + iod->status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + return -EINVAL; + } + if (nvmet_pci_epf_prp_ofst(ctrl, prp2)) { + iod->status = + NVME_SC_PRP_INVALID_OFFSET | NVME_STATUS_DNR; + return -EINVAL; + } + if (prp2 != prp1 + prp1_size) + nr_segs = 2; + } + + if (nr_segs == 1) { + iod->nr_data_segs = 1; + iod->data_segs = &iod->data_seg; + iod->data_segs[0].pci_addr = prp1; + iod->data_segs[0].length = transfer_len; + return 0; + } + + ret = nvmet_pci_epf_alloc_iod_data_segs(iod, nr_segs); + if (ret) { + iod->status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + return ret; + } + + iod->data_segs[0].pci_addr = prp1; + iod->data_segs[0].length = prp1_size; + iod->data_segs[1].pci_addr = prp2; + iod->data_segs[1].length = transfer_len - prp1_size; + + return 0; +} + +static int nvmet_pci_epf_iod_parse_prps(struct nvmet_pci_epf_iod *iod) +{ + struct nvmet_pci_epf_ctrl *ctrl = iod->ctrl; + u64 prp1 = le64_to_cpu(iod->cmd.common.dptr.prp1); + size_t ofst; + + /* Get the PCI address segments for the command using its PRPs. */ + ofst = nvmet_pci_epf_prp_ofst(ctrl, prp1); + if (ofst & 0x3) { + iod->status = NVME_SC_PRP_INVALID_OFFSET | NVME_STATUS_DNR; + return -EINVAL; + } + + if (iod->data_len + ofst <= ctrl->mps * 2) + return nvmet_pci_epf_iod_parse_prp_simple(ctrl, iod); + + return nvmet_pci_epf_iod_parse_prp_list(ctrl, iod); +} + +/* + * Transfer an SGL segment from the host and return the number of data + * descriptors and the next segment descriptor, if any. + */ +static struct nvme_sgl_desc * +nvmet_pci_epf_get_sgl_segment(struct nvmet_pci_epf_ctrl *ctrl, + struct nvme_sgl_desc *desc, unsigned int *nr_sgls) +{ + struct nvme_sgl_desc *sgls; + u32 length = le32_to_cpu(desc->length); + int nr_descs, ret; + void *buf; + + buf = kmalloc(length, GFP_KERNEL); + if (!buf) + return NULL; + + ret = nvmet_pci_epf_transfer(ctrl, buf, le64_to_cpu(desc->addr), length, + DMA_FROM_DEVICE); + if (ret) { + kfree(buf); + return NULL; + } + + sgls = buf; + nr_descs = length / sizeof(struct nvme_sgl_desc); + if (sgls[nr_descs - 1].type == (NVME_SGL_FMT_SEG_DESC << 4) || + sgls[nr_descs - 1].type == (NVME_SGL_FMT_LAST_SEG_DESC << 4)) { + /* + * We have another SGL segment following this one: do not count + * it as a regular data SGL descriptor and return it to the + * caller. + */ + *desc = sgls[nr_descs - 1]; + nr_descs--; + } else { + /* We do not have another SGL segment after this one. */ + desc->length = 0; + } + + *nr_sgls = nr_descs; + + return sgls; +} + +static int nvmet_pci_epf_iod_parse_sgl_segments(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_iod *iod) +{ + struct nvme_command *cmd = &iod->cmd; + struct nvme_sgl_desc seg = cmd->common.dptr.sgl; + struct nvme_sgl_desc *sgls = NULL; + int n = 0, i, nr_sgls; + int ret; + + /* + * We do not support inline data nor keyed SGLs, so we should be seeing + * only segment descriptors. + */ + if (seg.type != (NVME_SGL_FMT_SEG_DESC << 4) && + seg.type != (NVME_SGL_FMT_LAST_SEG_DESC << 4)) { + iod->status = NVME_SC_SGL_INVALID_TYPE | NVME_STATUS_DNR; + return -EIO; + } + + while (seg.length) { + sgls = nvmet_pci_epf_get_sgl_segment(ctrl, &seg, &nr_sgls); + if (!sgls) { + iod->status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + return -EIO; + } + + /* Grow the PCI segment table as needed. */ + ret = nvmet_pci_epf_alloc_iod_data_segs(iod, nr_sgls); + if (ret) { + iod->status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + goto out; + } + + /* + * Parse the SGL descriptors to build the PCI segment table, + * checking the descriptor type as we go. + */ + for (i = 0; i < nr_sgls; i++) { + if (sgls[i].type != (NVME_SGL_FMT_DATA_DESC << 4)) { + iod->status = NVME_SC_SGL_INVALID_TYPE | + NVME_STATUS_DNR; + goto out; + } + iod->data_segs[n].pci_addr = le64_to_cpu(sgls[i].addr); + iod->data_segs[n].length = le32_to_cpu(sgls[i].length); + n++; + } + + kfree(sgls); + } + + out: + if (iod->status != NVME_SC_SUCCESS) { + kfree(sgls); + return -EIO; + } + + return 0; +} + +static int nvmet_pci_epf_iod_parse_sgls(struct nvmet_pci_epf_iod *iod) +{ + struct nvmet_pci_epf_ctrl *ctrl = iod->ctrl; + struct nvme_sgl_desc *sgl = &iod->cmd.common.dptr.sgl; + + if (sgl->type == (NVME_SGL_FMT_DATA_DESC << 4)) { + /* Single data descriptor case. */ + iod->nr_data_segs = 1; + iod->data_segs = &iod->data_seg; + iod->data_seg.pci_addr = le64_to_cpu(sgl->addr); + iod->data_seg.length = le32_to_cpu(sgl->length); + return 0; + } + + return nvmet_pci_epf_iod_parse_sgl_segments(ctrl, iod); +} + +static int nvmet_pci_epf_alloc_iod_data_buf(struct nvmet_pci_epf_iod *iod) +{ + struct nvmet_pci_epf_ctrl *ctrl = iod->ctrl; + struct nvmet_req *req = &iod->req; + struct nvmet_pci_epf_segment *seg; + struct scatterlist *sg; + int ret, i; + + if (iod->data_len > ctrl->mdts) { + iod->status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + return -EINVAL; + } + + /* + * Get the PCI address segments for the command data buffer using either + * its SGLs or PRPs. + */ + if (iod->cmd.common.flags & NVME_CMD_SGL_ALL) + ret = nvmet_pci_epf_iod_parse_sgls(iod); + else + ret = nvmet_pci_epf_iod_parse_prps(iod); + if (ret) + return ret; + + /* Get a command buffer using SGLs matching the PCI segments. */ + if (iod->nr_data_segs == 1) { + sg_init_table(&iod->data_sgl, 1); + iod->data_sgt.sgl = &iod->data_sgl; + iod->data_sgt.nents = 1; + iod->data_sgt.orig_nents = 1; + } else { + ret = sg_alloc_table(&iod->data_sgt, iod->nr_data_segs, + GFP_KERNEL); + if (ret) + goto err_nomem; + } + + for_each_sgtable_sg(&iod->data_sgt, sg, i) { + seg = &iod->data_segs[i]; + seg->buf = kmalloc(seg->length, GFP_KERNEL); + if (!seg->buf) + goto err_nomem; + sg_set_buf(sg, seg->buf, seg->length); + } + + req->transfer_len = iod->data_len; + req->sg = iod->data_sgt.sgl; + req->sg_cnt = iod->data_sgt.nents; + + return 0; + +err_nomem: + iod->status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + return -ENOMEM; +} + +static void nvmet_pci_epf_complete_iod(struct nvmet_pci_epf_iod *iod) +{ + struct nvmet_pci_epf_queue *cq = iod->cq; + unsigned long flags; + + /* Print an error message for failed commands, except AENs. */ + iod->status = le16_to_cpu(iod->cqe.status) >> 1; + if (iod->status && iod->cmd.common.opcode != nvme_admin_async_event) + dev_err(iod->ctrl->dev, + "CQ[%d]: Command %s (0x%x) status 0x%0x\n", + iod->sq->qid, nvmet_pci_epf_iod_name(iod), + iod->cmd.common.opcode, iod->status); + + /* + * Add the command to the list of completed commands and schedule the + * CQ work. + */ + spin_lock_irqsave(&cq->lock, flags); + list_add_tail(&iod->link, &cq->list); + queue_delayed_work(system_highpri_wq, &cq->work, 0); + spin_unlock_irqrestore(&cq->lock, flags); +} + +static void nvmet_pci_epf_drain_queue(struct nvmet_pci_epf_queue *queue) +{ + struct nvmet_pci_epf_iod *iod; + unsigned long flags; + + spin_lock_irqsave(&queue->lock, flags); + while (!list_empty(&queue->list)) { + iod = list_first_entry(&queue->list, struct nvmet_pci_epf_iod, + link); + list_del_init(&iod->link); + nvmet_pci_epf_free_iod(iod); + } + spin_unlock_irqrestore(&queue->lock, flags); +} + +static int nvmet_pci_epf_add_port(struct nvmet_port *port) +{ + mutex_lock(&nvmet_pci_epf_ports_mutex); + list_add_tail(&port->entry, &nvmet_pci_epf_ports); + mutex_unlock(&nvmet_pci_epf_ports_mutex); + return 0; +} + +static void nvmet_pci_epf_remove_port(struct nvmet_port *port) +{ + mutex_lock(&nvmet_pci_epf_ports_mutex); + list_del_init(&port->entry); + mutex_unlock(&nvmet_pci_epf_ports_mutex); +} + +static struct nvmet_port * +nvmet_pci_epf_find_port(struct nvmet_pci_epf_ctrl *ctrl, __le16 portid) +{ + struct nvmet_port *p, *port = NULL; + + mutex_lock(&nvmet_pci_epf_ports_mutex); + list_for_each_entry(p, &nvmet_pci_epf_ports, entry) { + if (p->disc_addr.portid == portid) { + port = p; + break; + } + } + mutex_unlock(&nvmet_pci_epf_ports_mutex); + + return port; +} + +static void nvmet_pci_epf_queue_response(struct nvmet_req *req) +{ + struct nvmet_pci_epf_iod *iod = + container_of(req, struct nvmet_pci_epf_iod, req); + + iod->status = le16_to_cpu(req->cqe->status) >> 1; + + /* If we have no data to transfer, directly complete the command. */ + if (!iod->data_len || iod->dma_dir != DMA_TO_DEVICE) { + nvmet_pci_epf_complete_iod(iod); + return; + } + + complete(&iod->done); +} + +static u8 nvmet_pci_epf_get_mdts(const struct nvmet_ctrl *tctrl) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + int page_shift = NVME_CAP_MPSMIN(tctrl->cap) + 12; + + return ilog2(ctrl->mdts) - page_shift; +} + +static u16 nvmet_pci_epf_create_cq(struct nvmet_ctrl *tctrl, + u16 cqid, u16 flags, u16 qsize, u64 pci_addr, u16 vector) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_pci_epf_queue *cq = &ctrl->cq[cqid]; + u16 status; + + if (test_and_set_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags)) + return NVME_SC_QID_INVALID | NVME_STATUS_DNR; + + if (!(flags & NVME_QUEUE_PHYS_CONTIG)) + return NVME_SC_INVALID_QUEUE | NVME_STATUS_DNR; + + if (flags & NVME_CQ_IRQ_ENABLED) + set_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags); + + cq->pci_addr = pci_addr; + cq->qid = cqid; + cq->depth = qsize + 1; + cq->vector = vector; + cq->head = 0; + cq->tail = 0; + cq->phase = 1; + cq->db = NVME_REG_DBS + (((cqid * 2) + 1) * sizeof(u32)); + nvmet_pci_epf_bar_write32(ctrl, cq->db, 0); + + if (!cqid) + cq->qes = sizeof(struct nvme_completion); + else + cq->qes = ctrl->io_cqes; + cq->pci_size = cq->qes * cq->depth; + + cq->iv = nvmet_pci_epf_add_irq_vector(ctrl, vector); + if (!cq->iv) { + status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + goto err; + } + + status = nvmet_cq_create(tctrl, &cq->nvme_cq, cqid, cq->depth); + if (status != NVME_SC_SUCCESS) + goto err; + + dev_dbg(ctrl->dev, "CQ[%u]: %u entries of %zu B, IRQ vector %u\n", + cqid, qsize, cq->qes, cq->vector); + + return NVME_SC_SUCCESS; + +err: + clear_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags); + clear_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags); + return status; +} + +static u16 nvmet_pci_epf_delete_cq(struct nvmet_ctrl *tctrl, u16 cqid) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_pci_epf_queue *cq = &ctrl->cq[cqid]; + + if (!test_and_clear_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags)) + return NVME_SC_QID_INVALID | NVME_STATUS_DNR; + + cancel_delayed_work_sync(&cq->work); + nvmet_pci_epf_drain_queue(cq); + nvmet_pci_epf_remove_irq_vector(ctrl, cq->vector); + + return NVME_SC_SUCCESS; +} + +static u16 nvmet_pci_epf_create_sq(struct nvmet_ctrl *tctrl, + u16 sqid, u16 flags, u16 qsize, u64 pci_addr) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_pci_epf_queue *sq = &ctrl->sq[sqid]; + u16 status; + + if (test_and_set_bit(NVMET_PCI_EPF_Q_LIVE, &sq->flags)) + return NVME_SC_QID_INVALID | NVME_STATUS_DNR; + + if (!(flags & NVME_QUEUE_PHYS_CONTIG)) + return NVME_SC_INVALID_QUEUE | NVME_STATUS_DNR; + + sq->pci_addr = pci_addr; + sq->qid = sqid; + sq->depth = qsize + 1; + sq->head = 0; + sq->tail = 0; + sq->phase = 0; + sq->db = NVME_REG_DBS + (sqid * 2 * sizeof(u32)); + nvmet_pci_epf_bar_write32(ctrl, sq->db, 0); + if (!sqid) + sq->qes = 1UL << NVME_ADM_SQES; + else + sq->qes = ctrl->io_sqes; + sq->pci_size = sq->qes * sq->depth; + + status = nvmet_sq_create(tctrl, &sq->nvme_sq, sqid, sq->depth); + if (status != NVME_SC_SUCCESS) + goto out_clear_bit; + + sq->iod_wq = alloc_workqueue("sq%d_wq", WQ_UNBOUND, + min_t(int, sq->depth, WQ_MAX_ACTIVE), sqid); + if (!sq->iod_wq) { + dev_err(ctrl->dev, "Failed to create SQ %d work queue\n", sqid); + status = NVME_SC_INTERNAL | NVME_STATUS_DNR; + goto out_destroy_sq; + } + + dev_dbg(ctrl->dev, "SQ[%u]: %u entries of %zu B\n", + sqid, qsize, sq->qes); + + return NVME_SC_SUCCESS; + +out_destroy_sq: + nvmet_sq_destroy(&sq->nvme_sq); +out_clear_bit: + clear_bit(NVMET_PCI_EPF_Q_LIVE, &sq->flags); + return status; +} + +static u16 nvmet_pci_epf_delete_sq(struct nvmet_ctrl *tctrl, u16 sqid) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_pci_epf_queue *sq = &ctrl->sq[sqid]; + + if (!test_and_clear_bit(NVMET_PCI_EPF_Q_LIVE, &sq->flags)) + return NVME_SC_QID_INVALID | NVME_STATUS_DNR; + + flush_workqueue(sq->iod_wq); + destroy_workqueue(sq->iod_wq); + sq->iod_wq = NULL; + + nvmet_pci_epf_drain_queue(sq); + + if (sq->nvme_sq.ctrl) + nvmet_sq_destroy(&sq->nvme_sq); + + return NVME_SC_SUCCESS; +} + +static u16 nvmet_pci_epf_get_feat(const struct nvmet_ctrl *tctrl, + u8 feat, void *data) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_feat_arbitration *arb; + struct nvmet_feat_irq_coalesce *irqc; + struct nvmet_feat_irq_config *irqcfg; + struct nvmet_pci_epf_irq_vector *iv; + u16 status; + + switch (feat) { + case NVME_FEAT_ARBITRATION: + arb = data; + if (!ctrl->sq_ab) + arb->ab = 0x7; + else + arb->ab = ilog2(ctrl->sq_ab); + return NVME_SC_SUCCESS; + + case NVME_FEAT_IRQ_COALESCE: + irqc = data; + irqc->thr = ctrl->irq_vector_threshold; + irqc->time = 0; + return NVME_SC_SUCCESS; + + case NVME_FEAT_IRQ_CONFIG: + irqcfg = data; + mutex_lock(&ctrl->irq_lock); + iv = nvmet_pci_epf_find_irq_vector(ctrl, irqcfg->iv); + if (iv) { + irqcfg->cd = iv->cd; + status = NVME_SC_SUCCESS; + } else { + status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + } + mutex_unlock(&ctrl->irq_lock); + return status; + + default: + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + } +} + +static u16 nvmet_pci_epf_set_feat(const struct nvmet_ctrl *tctrl, + u8 feat, void *data) +{ + struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata; + struct nvmet_feat_arbitration *arb; + struct nvmet_feat_irq_coalesce *irqc; + struct nvmet_feat_irq_config *irqcfg; + struct nvmet_pci_epf_irq_vector *iv; + u16 status; + + switch (feat) { + case NVME_FEAT_ARBITRATION: + arb = data; + if (arb->ab == 0x7) + ctrl->sq_ab = 0; + else + ctrl->sq_ab = 1 << arb->ab; + return NVME_SC_SUCCESS; + + case NVME_FEAT_IRQ_COALESCE: + /* + * Since we do not implement precise IRQ coalescing timing, + * ignore the time field. + */ + irqc = data; + ctrl->irq_vector_threshold = irqc->thr + 1; + return NVME_SC_SUCCESS; + + case NVME_FEAT_IRQ_CONFIG: + irqcfg = data; + mutex_lock(&ctrl->irq_lock); + iv = nvmet_pci_epf_find_irq_vector(ctrl, irqcfg->iv); + if (iv) { + iv->cd = irqcfg->cd; + status = NVME_SC_SUCCESS; + } else { + status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + } + mutex_unlock(&ctrl->irq_lock); + return status; + + default: + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; + } +} + +static const struct nvmet_fabrics_ops nvmet_pci_epf_fabrics_ops = { + .owner = THIS_MODULE, + .type = NVMF_TRTYPE_PCI, + .add_port = nvmet_pci_epf_add_port, + .remove_port = nvmet_pci_epf_remove_port, + .queue_response = nvmet_pci_epf_queue_response, + .get_mdts = nvmet_pci_epf_get_mdts, + .create_cq = nvmet_pci_epf_create_cq, + .delete_cq = nvmet_pci_epf_delete_cq, + .create_sq = nvmet_pci_epf_create_sq, + .delete_sq = nvmet_pci_epf_delete_sq, + .get_feature = nvmet_pci_epf_get_feat, + .set_feature = nvmet_pci_epf_set_feat, +}; + +static void nvmet_pci_epf_cq_work(struct work_struct *work); + +static void nvmet_pci_epf_init_queue(struct nvmet_pci_epf_ctrl *ctrl, + unsigned int qid, bool sq) +{ + struct nvmet_pci_epf_queue *queue; + + if (sq) { + queue = &ctrl->sq[qid]; + set_bit(NVMET_PCI_EPF_Q_IS_SQ, &queue->flags); + } else { + queue = &ctrl->cq[qid]; + INIT_DELAYED_WORK(&queue->work, nvmet_pci_epf_cq_work); + } + queue->ctrl = ctrl; + queue->qid = qid; + spin_lock_init(&queue->lock); + INIT_LIST_HEAD(&queue->list); +} + +static int nvmet_pci_epf_alloc_queues(struct nvmet_pci_epf_ctrl *ctrl) +{ + unsigned int qid; + + ctrl->sq = kcalloc(ctrl->nr_queues, + sizeof(struct nvmet_pci_epf_queue), GFP_KERNEL); + if (!ctrl->sq) + return -ENOMEM; + + ctrl->cq = kcalloc(ctrl->nr_queues, + sizeof(struct nvmet_pci_epf_queue), GFP_KERNEL); + if (!ctrl->cq) { + kfree(ctrl->sq); + ctrl->sq = NULL; + return -ENOMEM; + } + + for (qid = 0; qid < ctrl->nr_queues; qid++) { + nvmet_pci_epf_init_queue(ctrl, qid, true); + nvmet_pci_epf_init_queue(ctrl, qid, false); + } + + return 0; +} + +static void nvmet_pci_epf_free_queues(struct nvmet_pci_epf_ctrl *ctrl) +{ + kfree(ctrl->sq); + ctrl->sq = NULL; + kfree(ctrl->cq); + ctrl->cq = NULL; +} + +static int nvmet_pci_epf_map_queue(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_queue *queue) +{ + struct nvmet_pci_epf *nvme_epf = ctrl->nvme_epf; + int ret; + + ret = nvmet_pci_epf_mem_map(nvme_epf, queue->pci_addr, + queue->pci_size, &queue->pci_map); + if (ret) { + dev_err(ctrl->dev, "Failed to map queue %u (err=%d)\n", + queue->qid, ret); + return ret; + } + + if (queue->pci_map.pci_size < queue->pci_size) { + dev_err(ctrl->dev, "Invalid partial mapping of queue %u\n", + queue->qid); + nvmet_pci_epf_mem_unmap(nvme_epf, &queue->pci_map); + return -ENOMEM; + } + + return 0; +} + +static inline void nvmet_pci_epf_unmap_queue(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_queue *queue) +{ + nvmet_pci_epf_mem_unmap(ctrl->nvme_epf, &queue->pci_map); +} + +static void nvmet_pci_epf_exec_iod_work(struct work_struct *work) +{ + struct nvmet_pci_epf_iod *iod = + container_of(work, struct nvmet_pci_epf_iod, work); + struct nvmet_req *req = &iod->req; + int ret; + + if (!iod->ctrl->link_up) { + nvmet_pci_epf_free_iod(iod); + return; + } + + if (!test_bit(NVMET_PCI_EPF_Q_LIVE, &iod->sq->flags)) { + iod->status = NVME_SC_QID_INVALID | NVME_STATUS_DNR; + goto complete; + } + + if (!nvmet_req_init(req, &iod->cq->nvme_cq, &iod->sq->nvme_sq, + &nvmet_pci_epf_fabrics_ops)) + goto complete; + + iod->data_len = nvmet_req_transfer_len(req); + if (iod->data_len) { + /* + * Get the data DMA transfer direction. Here "device" means the + * PCI root-complex host. + */ + if (nvme_is_write(&iod->cmd)) + iod->dma_dir = DMA_FROM_DEVICE; + else + iod->dma_dir = DMA_TO_DEVICE; + + /* + * Setup the command data buffer and get the command data from + * the host if needed. + */ + ret = nvmet_pci_epf_alloc_iod_data_buf(iod); + if (!ret && iod->dma_dir == DMA_FROM_DEVICE) + ret = nvmet_pci_epf_transfer_iod_data(iod); + if (ret) { + nvmet_req_uninit(req); + goto complete; + } + } + + req->execute(req); + + /* + * If we do not have data to transfer after the command execution + * finishes, nvmet_pci_epf_queue_response() will complete the command + * directly. No need to wait for the completion in this case. + */ + if (!iod->data_len || iod->dma_dir != DMA_TO_DEVICE) + return; + + wait_for_completion(&iod->done); + + if (iod->status == NVME_SC_SUCCESS) { + WARN_ON_ONCE(!iod->data_len || iod->dma_dir != DMA_TO_DEVICE); + nvmet_pci_epf_transfer_iod_data(iod); + } + +complete: + nvmet_pci_epf_complete_iod(iod); +} + +static int nvmet_pci_epf_process_sq(struct nvmet_pci_epf_ctrl *ctrl, + struct nvmet_pci_epf_queue *sq) +{ + struct nvmet_pci_epf_iod *iod; + int ret, n = 0; + + sq->tail = nvmet_pci_epf_bar_read32(ctrl, sq->db); + while (sq->head != sq->tail && (!ctrl->sq_ab || n < ctrl->sq_ab)) { + iod = nvmet_pci_epf_alloc_iod(sq); + if (!iod) + break; + + /* Get the NVMe command submitted by the host. */ + ret = nvmet_pci_epf_transfer(ctrl, &iod->cmd, + sq->pci_addr + sq->head * sq->qes, + sq->qes, DMA_FROM_DEVICE); + if (ret) { + /* Not much we can do... */ + nvmet_pci_epf_free_iod(iod); + break; + } + + dev_dbg(ctrl->dev, "SQ[%u]: head %u, tail %u, command %s\n", + sq->qid, sq->head, sq->tail, + nvmet_pci_epf_iod_name(iod)); + + sq->head++; + if (sq->head == sq->depth) + sq->head = 0; + n++; + + queue_work_on(WORK_CPU_UNBOUND, sq->iod_wq, &iod->work); + + sq->tail = nvmet_pci_epf_bar_read32(ctrl, sq->db); + } + + return n; +} + +static void nvmet_pci_epf_poll_sqs_work(struct work_struct *work) +{ + struct nvmet_pci_epf_ctrl *ctrl = + container_of(work, struct nvmet_pci_epf_ctrl, poll_sqs.work); + struct nvmet_pci_epf_queue *sq; + unsigned long last = 0; + int i, nr_sqs; + + while (ctrl->link_up && ctrl->enabled) { + nr_sqs = 0; + /* Do round-robin arbitration. */ + for (i = 0; i < ctrl->nr_queues; i++) { + sq = &ctrl->sq[i]; + if (!test_bit(NVMET_PCI_EPF_Q_LIVE, &sq->flags)) + continue; + if (nvmet_pci_epf_process_sq(ctrl, sq)) + nr_sqs++; + } + + if (nr_sqs) { + last = jiffies; + continue; + } + + /* + * If we have not received any command on any queue for more + * than NVMET_PCI_EPF_SQ_POLL_IDLE, assume we are idle and + * reschedule. This avoids "burning" a CPU when the controller + * is idle for a long time. + */ + if (time_is_before_jiffies(last + NVMET_PCI_EPF_SQ_POLL_IDLE)) + break; + + cpu_relax(); + } + + schedule_delayed_work(&ctrl->poll_sqs, NVMET_PCI_EPF_SQ_POLL_INTERVAL); +} + +static void nvmet_pci_epf_cq_work(struct work_struct *work) +{ + struct nvmet_pci_epf_queue *cq = + container_of(work, struct nvmet_pci_epf_queue, work.work); + struct nvmet_pci_epf_ctrl *ctrl = cq->ctrl; + struct nvme_completion *cqe; + struct nvmet_pci_epf_iod *iod; + unsigned long flags; + int ret, n = 0; + + ret = nvmet_pci_epf_map_queue(ctrl, cq); + if (ret) + goto again; + + while (test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags) && ctrl->link_up) { + + /* Check that the CQ is not full. */ + cq->head = nvmet_pci_epf_bar_read32(ctrl, cq->db); + if (cq->head == cq->tail + 1) { + ret = -EAGAIN; + break; + } + + spin_lock_irqsave(&cq->lock, flags); + iod = list_first_entry_or_null(&cq->list, + struct nvmet_pci_epf_iod, link); + if (iod) + list_del_init(&iod->link); + spin_unlock_irqrestore(&cq->lock, flags); + + if (!iod) + break; + + /* Post the IOD completion entry. */ + cqe = &iod->cqe; + cqe->status = cpu_to_le16((iod->status << 1) | cq->phase); + + dev_dbg(ctrl->dev, + "CQ[%u]: %s status 0x%x, result 0x%llx, head %u, tail %u, phase %u\n", + cq->qid, nvmet_pci_epf_iod_name(iod), iod->status, + le64_to_cpu(cqe->result.u64), cq->head, cq->tail, + cq->phase); + + memcpy_toio(cq->pci_map.virt_addr + cq->tail * cq->qes, + cqe, cq->qes); + + cq->tail++; + if (cq->tail >= cq->depth) { + cq->tail = 0; + cq->phase ^= 1; + } + + nvmet_pci_epf_free_iod(iod); + + /* Signal the host. */ + nvmet_pci_epf_raise_irq(ctrl, cq, false); + n++; + } + + nvmet_pci_epf_unmap_queue(ctrl, cq); + + /* + * We do not support precise IRQ coalescing time (100ns units as per + * NVMe specifications). So if we have posted completion entries without + * reaching the interrupt coalescing threshold, raise an interrupt. + */ + if (n) + nvmet_pci_epf_raise_irq(ctrl, cq, true); + +again: + if (ret < 0) + queue_delayed_work(system_highpri_wq, &cq->work, + NVMET_PCI_EPF_CQ_RETRY_INTERVAL); +} + +static int nvmet_pci_epf_enable_ctrl(struct nvmet_pci_epf_ctrl *ctrl) +{ + u64 pci_addr, asq, acq; + u32 aqa; + u16 status, qsize; + + if (ctrl->enabled) + return 0; + + dev_info(ctrl->dev, "Enabling controller\n"); + + ctrl->mps_shift = nvmet_cc_mps(ctrl->cc) + 12; + ctrl->mps = 1UL << ctrl->mps_shift; + ctrl->mps_mask = ctrl->mps - 1; + + ctrl->io_sqes = 1UL << nvmet_cc_iosqes(ctrl->cc); + if (ctrl->io_sqes < sizeof(struct nvme_command)) { + dev_err(ctrl->dev, "Unsupported I/O SQES %zu (need %zu)\n", + ctrl->io_sqes, sizeof(struct nvme_command)); + return -EINVAL; + } + + ctrl->io_cqes = 1UL << nvmet_cc_iocqes(ctrl->cc); + if (ctrl->io_cqes < sizeof(struct nvme_completion)) { + dev_err(ctrl->dev, "Unsupported I/O CQES %zu (need %zu)\n", + ctrl->io_sqes, sizeof(struct nvme_completion)); + return -EINVAL; + } + + /* Create the admin queue. */ + aqa = nvmet_pci_epf_bar_read32(ctrl, NVME_REG_AQA); + asq = nvmet_pci_epf_bar_read64(ctrl, NVME_REG_ASQ); + acq = nvmet_pci_epf_bar_read64(ctrl, NVME_REG_ACQ); + + qsize = (aqa & 0x0fff0000) >> 16; + pci_addr = acq & GENMASK_ULL(63, 12); + status = nvmet_pci_epf_create_cq(ctrl->tctrl, 0, + NVME_CQ_IRQ_ENABLED | NVME_QUEUE_PHYS_CONTIG, + qsize, pci_addr, 0); + if (status != NVME_SC_SUCCESS) { + dev_err(ctrl->dev, "Failed to create admin completion queue\n"); + return -EINVAL; + } + + qsize = aqa & 0x00000fff; + pci_addr = asq & GENMASK_ULL(63, 12); + status = nvmet_pci_epf_create_sq(ctrl->tctrl, 0, NVME_QUEUE_PHYS_CONTIG, + qsize, pci_addr); + if (status != NVME_SC_SUCCESS) { + dev_err(ctrl->dev, "Failed to create admin submission queue\n"); + nvmet_pci_epf_delete_cq(ctrl->tctrl, 0); + return -EINVAL; + } + + ctrl->sq_ab = NVMET_PCI_EPF_SQ_AB; + ctrl->irq_vector_threshold = NVMET_PCI_EPF_IV_THRESHOLD; + ctrl->enabled = true; + + /* Start polling the controller SQs. */ + schedule_delayed_work(&ctrl->poll_sqs, 0); + + return 0; +} + +static void nvmet_pci_epf_disable_ctrl(struct nvmet_pci_epf_ctrl *ctrl) +{ + int qid; + + if (!ctrl->enabled) + return; + + dev_info(ctrl->dev, "Disabling controller\n"); + + ctrl->enabled = false; + cancel_delayed_work_sync(&ctrl->poll_sqs); + + /* Delete all I/O queues first. */ + for (qid = 1; qid < ctrl->nr_queues; qid++) + nvmet_pci_epf_delete_sq(ctrl->tctrl, qid); + + for (qid = 1; qid < ctrl->nr_queues; qid++) + nvmet_pci_epf_delete_cq(ctrl->tctrl, qid); + + /* Delete the admin queue last. */ + nvmet_pci_epf_delete_sq(ctrl->tctrl, 0); + nvmet_pci_epf_delete_cq(ctrl->tctrl, 0); +} + +static void nvmet_pci_epf_poll_cc_work(struct work_struct *work) +{ + struct nvmet_pci_epf_ctrl *ctrl = + container_of(work, struct nvmet_pci_epf_ctrl, poll_cc.work); + u32 old_cc, new_cc; + int ret; + + if (!ctrl->tctrl) + return; + + old_cc = ctrl->cc; + new_cc = nvmet_pci_epf_bar_read32(ctrl, NVME_REG_CC); + ctrl->cc = new_cc; + + if (nvmet_cc_en(new_cc) && !nvmet_cc_en(old_cc)) { + ret = nvmet_pci_epf_enable_ctrl(ctrl); + if (ret) + return; + ctrl->csts |= NVME_CSTS_RDY; + } + + if (!nvmet_cc_en(new_cc) && nvmet_cc_en(old_cc)) { + nvmet_pci_epf_disable_ctrl(ctrl); + ctrl->csts &= ~NVME_CSTS_RDY; + } + + if (nvmet_cc_shn(new_cc) && !nvmet_cc_shn(old_cc)) { + nvmet_pci_epf_disable_ctrl(ctrl); + ctrl->csts |= NVME_CSTS_SHST_CMPLT; + } + + if (!nvmet_cc_shn(new_cc) && nvmet_cc_shn(old_cc)) + ctrl->csts &= ~NVME_CSTS_SHST_CMPLT; + + nvmet_update_cc(ctrl->tctrl, ctrl->cc); + nvmet_pci_epf_bar_write32(ctrl, NVME_REG_CSTS, ctrl->csts); + + schedule_delayed_work(&ctrl->poll_cc, NVMET_PCI_EPF_CC_POLL_INTERVAL); +} + +static void nvmet_pci_epf_init_bar(struct nvmet_pci_epf_ctrl *ctrl) +{ + struct nvmet_ctrl *tctrl = ctrl->tctrl; + + ctrl->bar = ctrl->nvme_epf->reg_bar; + + /* Copy the target controller capabilities as a base. */ + ctrl->cap = tctrl->cap; + + /* Contiguous Queues Required (CQR). */ + ctrl->cap |= 0x1ULL << 16; + + /* Set Doorbell stride to 4B (DSTRB). */ + ctrl->cap &= ~GENMASK_ULL(35, 32); + + /* Clear NVM Subsystem Reset Supported (NSSRS). */ + ctrl->cap &= ~(0x1ULL << 36); + + /* Clear Boot Partition Support (BPS). */ + ctrl->cap &= ~(0x1ULL << 45); + + /* Clear Persistent Memory Region Supported (PMRS). */ + ctrl->cap &= ~(0x1ULL << 56); + + /* Clear Controller Memory Buffer Supported (CMBS). */ + ctrl->cap &= ~(0x1ULL << 57); + + /* Controller configuration. */ + ctrl->cc = tctrl->cc & (~NVME_CC_ENABLE); + + /* Controller status. */ + ctrl->csts = ctrl->tctrl->csts; + + nvmet_pci_epf_bar_write64(ctrl, NVME_REG_CAP, ctrl->cap); + nvmet_pci_epf_bar_write32(ctrl, NVME_REG_VS, tctrl->subsys->ver); + nvmet_pci_epf_bar_write32(ctrl, NVME_REG_CSTS, ctrl->csts); + nvmet_pci_epf_bar_write32(ctrl, NVME_REG_CC, ctrl->cc); +} + +static int nvmet_pci_epf_create_ctrl(struct nvmet_pci_epf *nvme_epf, + unsigned int max_nr_queues) +{ + struct nvmet_pci_epf_ctrl *ctrl = &nvme_epf->ctrl; + struct nvmet_alloc_ctrl_args args = {}; + char hostnqn[NVMF_NQN_SIZE]; + uuid_t id; + int ret; + + memset(ctrl, 0, sizeof(*ctrl)); + ctrl->dev = &nvme_epf->epf->dev; + mutex_init(&ctrl->irq_lock); + ctrl->nvme_epf = nvme_epf; + ctrl->mdts = nvme_epf->mdts_kb * SZ_1K; + INIT_DELAYED_WORK(&ctrl->poll_cc, nvmet_pci_epf_poll_cc_work); + INIT_DELAYED_WORK(&ctrl->poll_sqs, nvmet_pci_epf_poll_sqs_work); + + ret = mempool_init_kmalloc_pool(&ctrl->iod_pool, + max_nr_queues * NVMET_MAX_QUEUE_SIZE, + sizeof(struct nvmet_pci_epf_iod)); + if (ret) { + dev_err(ctrl->dev, "Failed to initialize IOD mempool\n"); + return ret; + } + + ctrl->port = nvmet_pci_epf_find_port(ctrl, nvme_epf->portid); + if (!ctrl->port) { + dev_err(ctrl->dev, "Port not found\n"); + ret = -EINVAL; + goto out_mempool_exit; + } + + /* Create the target controller. */ + uuid_gen(&id); + snprintf(hostnqn, NVMF_NQN_SIZE, + "nqn.2014-08.org.nvmexpress:uuid:%pUb", &id); + args.port = ctrl->port; + args.subsysnqn = nvme_epf->subsysnqn; + memset(&id, 0, sizeof(uuid_t)); + args.hostid = &id; + args.hostnqn = hostnqn; + args.ops = &nvmet_pci_epf_fabrics_ops; + + ctrl->tctrl = nvmet_alloc_ctrl(&args); + if (!ctrl->tctrl) { + dev_err(ctrl->dev, "Failed to create target controller\n"); + ret = -ENOMEM; + goto out_mempool_exit; + } + ctrl->tctrl->drvdata = ctrl; + + /* We do not support protection information for now. */ + if (ctrl->tctrl->pi_support) { + dev_err(ctrl->dev, + "Protection information (PI) is not supported\n"); + ret = -ENOTSUPP; + goto out_put_ctrl; + } + + /* Allocate our queues, up to the maximum number. */ + ctrl->nr_queues = min(ctrl->tctrl->subsys->max_qid + 1, max_nr_queues); + ret = nvmet_pci_epf_alloc_queues(ctrl); + if (ret) + goto out_put_ctrl; + + /* + * Allocate the IRQ vectors descriptors. We cannot have more than the + * maximum number of queues. + */ + ret = nvmet_pci_epf_alloc_irq_vectors(ctrl); + if (ret) + goto out_free_queues; + + dev_info(ctrl->dev, + "New PCI ctrl \"%s\", %u I/O queues, mdts %u B\n", + ctrl->tctrl->subsys->subsysnqn, ctrl->nr_queues - 1, + ctrl->mdts); + + /* Initialize BAR 0 using the target controller CAP. */ + nvmet_pci_epf_init_bar(ctrl); + + return 0; + +out_free_queues: + nvmet_pci_epf_free_queues(ctrl); +out_put_ctrl: + nvmet_ctrl_put(ctrl->tctrl); + ctrl->tctrl = NULL; +out_mempool_exit: + mempool_exit(&ctrl->iod_pool); + return ret; +} + +static void nvmet_pci_epf_start_ctrl(struct nvmet_pci_epf_ctrl *ctrl) +{ + schedule_delayed_work(&ctrl->poll_cc, NVMET_PCI_EPF_CC_POLL_INTERVAL); +} + +static void nvmet_pci_epf_stop_ctrl(struct nvmet_pci_epf_ctrl *ctrl) +{ + cancel_delayed_work_sync(&ctrl->poll_cc); + + nvmet_pci_epf_disable_ctrl(ctrl); +} + +static void nvmet_pci_epf_destroy_ctrl(struct nvmet_pci_epf_ctrl *ctrl) +{ + if (!ctrl->tctrl) + return; + + dev_info(ctrl->dev, "Destroying PCI ctrl \"%s\"\n", + ctrl->tctrl->subsys->subsysnqn); + + nvmet_pci_epf_stop_ctrl(ctrl); + + nvmet_pci_epf_free_queues(ctrl); + nvmet_pci_epf_free_irq_vectors(ctrl); + + nvmet_ctrl_put(ctrl->tctrl); + ctrl->tctrl = NULL; + + mempool_exit(&ctrl->iod_pool); +} + +static int nvmet_pci_epf_configure_bar(struct nvmet_pci_epf *nvme_epf) +{ + struct pci_epf *epf = nvme_epf->epf; + const struct pci_epc_features *epc_features = nvme_epf->epc_features; + size_t reg_size, reg_bar_size; + size_t msix_table_size = 0; + + /* + * The first free BAR will be our register BAR and per NVMe + * specifications, it must be BAR 0. + */ + if (pci_epc_get_first_free_bar(epc_features) != BAR_0) { + dev_err(&epf->dev, "BAR 0 is not free\n"); + return -ENODEV; + } + + if (epc_features->bar[BAR_0].only_64bit) + epf->bar[BAR_0].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; + + /* + * Calculate the size of the register bar: NVMe registers first with + * enough space for the doorbells, followed by the MSI-X table + * if supported. + */ + reg_size = NVME_REG_DBS + (NVMET_NR_QUEUES * 2 * sizeof(u32)); + reg_size = ALIGN(reg_size, 8); + + if (epc_features->msix_capable) { + size_t pba_size; + + msix_table_size = PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts; + nvme_epf->msix_table_offset = reg_size; + pba_size = ALIGN(DIV_ROUND_UP(epf->msix_interrupts, 8), 8); + + reg_size += msix_table_size + pba_size; + } + + if (epc_features->bar[BAR_0].type == BAR_FIXED) { + if (reg_size > epc_features->bar[BAR_0].fixed_size) { + dev_err(&epf->dev, + "BAR 0 size %llu B too small, need %zu B\n", + epc_features->bar[BAR_0].fixed_size, + reg_size); + return -ENOMEM; + } + reg_bar_size = epc_features->bar[BAR_0].fixed_size; + } else { + reg_bar_size = ALIGN(reg_size, max(epc_features->align, 4096)); + } + + nvme_epf->reg_bar = pci_epf_alloc_space(epf, reg_bar_size, BAR_0, + epc_features, PRIMARY_INTERFACE); + if (!nvme_epf->reg_bar) { + dev_err(&epf->dev, "Failed to allocate BAR 0\n"); + return -ENOMEM; + } + memset(nvme_epf->reg_bar, 0, reg_bar_size); + + return 0; +} + +static void nvmet_pci_epf_free_bar(struct nvmet_pci_epf *nvme_epf) +{ + struct pci_epf *epf = nvme_epf->epf; + + if (!nvme_epf->reg_bar) + return; + + pci_epf_free_space(epf, nvme_epf->reg_bar, BAR_0, PRIMARY_INTERFACE); + nvme_epf->reg_bar = NULL; +} + +static void nvmet_pci_epf_clear_bar(struct nvmet_pci_epf *nvme_epf) +{ + struct pci_epf *epf = nvme_epf->epf; + + pci_epc_clear_bar(epf->epc, epf->func_no, epf->vfunc_no, + &epf->bar[BAR_0]); +} + +static int nvmet_pci_epf_init_irq(struct nvmet_pci_epf *nvme_epf) +{ + const struct pci_epc_features *epc_features = nvme_epf->epc_features; + struct pci_epf *epf = nvme_epf->epf; + int ret; + + /* Enable MSI-X if supported, otherwise, use MSI. */ + if (epc_features->msix_capable && epf->msix_interrupts) { + ret = pci_epc_set_msix(epf->epc, epf->func_no, epf->vfunc_no, + epf->msix_interrupts, BAR_0, + nvme_epf->msix_table_offset); + if (ret) { + dev_err(&epf->dev, "Failed to configure MSI-X\n"); + return ret; + } + + nvme_epf->nr_vectors = epf->msix_interrupts; + nvme_epf->irq_type = PCI_IRQ_MSIX; + + return 0; + } + + if (epc_features->msi_capable && epf->msi_interrupts) { + ret = pci_epc_set_msi(epf->epc, epf->func_no, epf->vfunc_no, + epf->msi_interrupts); + if (ret) { + dev_err(&epf->dev, "Failed to configure MSI\n"); + return ret; + } + + nvme_epf->nr_vectors = epf->msi_interrupts; + nvme_epf->irq_type = PCI_IRQ_MSI; + + return 0; + } + + /* MSI and MSI-X are not supported: fall back to INTx. */ + nvme_epf->nr_vectors = 1; + nvme_epf->irq_type = PCI_IRQ_INTX; + + return 0; +} + +static int nvmet_pci_epf_epc_init(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + const struct pci_epc_features *epc_features = nvme_epf->epc_features; + struct nvmet_pci_epf_ctrl *ctrl = &nvme_epf->ctrl; + unsigned int max_nr_queues = NVMET_NR_QUEUES; + int ret; + + /* For now, do not support virtual functions. */ + if (epf->vfunc_no > 0) { + dev_err(&epf->dev, "Virtual functions are not supported\n"); + return -EINVAL; + } + + /* + * Cap the maximum number of queues we can support on the controller + * with the number of IRQs we can use. + */ + if (epc_features->msix_capable && epf->msix_interrupts) { + dev_info(&epf->dev, + "PCI endpoint controller supports MSI-X, %u vectors\n", + epf->msix_interrupts); + max_nr_queues = min(max_nr_queues, epf->msix_interrupts); + } else if (epc_features->msi_capable && epf->msi_interrupts) { + dev_info(&epf->dev, + "PCI endpoint controller supports MSI, %u vectors\n", + epf->msi_interrupts); + max_nr_queues = min(max_nr_queues, epf->msi_interrupts); + } + + if (max_nr_queues < 2) { + dev_err(&epf->dev, "Invalid maximum number of queues %u\n", + max_nr_queues); + return -EINVAL; + } + + /* Create the target controller. */ + ret = nvmet_pci_epf_create_ctrl(nvme_epf, max_nr_queues); + if (ret) { + dev_err(&epf->dev, + "Failed to create NVMe PCI target controller (err=%d)\n", + ret); + return ret; + } + + /* Set device ID, class, etc. */ + epf->header->vendorid = ctrl->tctrl->subsys->vendor_id; + epf->header->subsys_vendor_id = ctrl->tctrl->subsys->subsys_vendor_id; + ret = pci_epc_write_header(epf->epc, epf->func_no, epf->vfunc_no, + epf->header); + if (ret) { + dev_err(&epf->dev, + "Failed to write configuration header (err=%d)\n", ret); + goto out_destroy_ctrl; + } + + ret = pci_epc_set_bar(epf->epc, epf->func_no, epf->vfunc_no, + &epf->bar[BAR_0]); + if (ret) { + dev_err(&epf->dev, "Failed to set BAR 0 (err=%d)\n", ret); + goto out_destroy_ctrl; + } + + /* + * Enable interrupts and start polling the controller BAR if we do not + * have a link up notifier. + */ + ret = nvmet_pci_epf_init_irq(nvme_epf); + if (ret) + goto out_clear_bar; + + if (!epc_features->linkup_notifier) { + ctrl->link_up = true; + nvmet_pci_epf_start_ctrl(&nvme_epf->ctrl); + } + + return 0; + +out_clear_bar: + nvmet_pci_epf_clear_bar(nvme_epf); +out_destroy_ctrl: + nvmet_pci_epf_destroy_ctrl(&nvme_epf->ctrl); + return ret; +} + +static void nvmet_pci_epf_epc_deinit(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + struct nvmet_pci_epf_ctrl *ctrl = &nvme_epf->ctrl; + + ctrl->link_up = false; + nvmet_pci_epf_destroy_ctrl(ctrl); + + nvmet_pci_epf_deinit_dma(nvme_epf); + nvmet_pci_epf_clear_bar(nvme_epf); +} + +static int nvmet_pci_epf_link_up(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + struct nvmet_pci_epf_ctrl *ctrl = &nvme_epf->ctrl; + + ctrl->link_up = true; + nvmet_pci_epf_start_ctrl(ctrl); + + return 0; +} + +static int nvmet_pci_epf_link_down(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + struct nvmet_pci_epf_ctrl *ctrl = &nvme_epf->ctrl; + + ctrl->link_up = false; + nvmet_pci_epf_stop_ctrl(ctrl); + + return 0; +} + +static const struct pci_epc_event_ops nvmet_pci_epf_event_ops = { + .epc_init = nvmet_pci_epf_epc_init, + .epc_deinit = nvmet_pci_epf_epc_deinit, + .link_up = nvmet_pci_epf_link_up, + .link_down = nvmet_pci_epf_link_down, +}; + +static int nvmet_pci_epf_bind(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + const struct pci_epc_features *epc_features; + struct pci_epc *epc = epf->epc; + int ret; + + if (WARN_ON_ONCE(!epc)) + return -EINVAL; + + epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no); + if (!epc_features) { + dev_err(&epf->dev, "epc_features not implemented\n"); + return -EOPNOTSUPP; + } + nvme_epf->epc_features = epc_features; + + ret = nvmet_pci_epf_configure_bar(nvme_epf); + if (ret) + return ret; + + nvmet_pci_epf_init_dma(nvme_epf); + + return 0; +} + +static void nvmet_pci_epf_unbind(struct pci_epf *epf) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + struct pci_epc *epc = epf->epc; + + nvmet_pci_epf_destroy_ctrl(&nvme_epf->ctrl); + + if (epc->init_complete) { + nvmet_pci_epf_deinit_dma(nvme_epf); + nvmet_pci_epf_clear_bar(nvme_epf); + } + + nvmet_pci_epf_free_bar(nvme_epf); +} + +static struct pci_epf_header nvme_epf_pci_header = { + .vendorid = PCI_ANY_ID, + .deviceid = PCI_ANY_ID, + .progif_code = 0x02, /* NVM Express */ + .baseclass_code = PCI_BASE_CLASS_STORAGE, + .subclass_code = 0x08, /* Non-Volatile Memory controller */ + .interrupt_pin = PCI_INTERRUPT_INTA, +}; + +static int nvmet_pci_epf_probe(struct pci_epf *epf, + const struct pci_epf_device_id *id) +{ + struct nvmet_pci_epf *nvme_epf; + int ret; + + nvme_epf = devm_kzalloc(&epf->dev, sizeof(*nvme_epf), GFP_KERNEL); + if (!nvme_epf) + return -ENOMEM; + + ret = devm_mutex_init(&epf->dev, &nvme_epf->mmio_lock); + if (ret) + return ret; + + nvme_epf->epf = epf; + nvme_epf->mdts_kb = NVMET_PCI_EPF_MDTS_KB; + + epf->event_ops = &nvmet_pci_epf_event_ops; + epf->header = &nvme_epf_pci_header; + epf_set_drvdata(epf, nvme_epf); + + return 0; +} + +#define to_nvme_epf(epf_group) \ + container_of(epf_group, struct nvmet_pci_epf, group) + +static ssize_t nvmet_pci_epf_portid_show(struct config_item *item, char *page) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + + return sysfs_emit(page, "%u\n", le16_to_cpu(nvme_epf->portid)); +} + +static ssize_t nvmet_pci_epf_portid_store(struct config_item *item, + const char *page, size_t len) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + u16 portid; + + /* Do not allow setting this when the function is already started. */ + if (nvme_epf->ctrl.tctrl) + return -EBUSY; + + if (!len) + return -EINVAL; + + if (kstrtou16(page, 0, &portid)) + return -EINVAL; + + nvme_epf->portid = cpu_to_le16(portid); + + return len; +} + +CONFIGFS_ATTR(nvmet_pci_epf_, portid); + +static ssize_t nvmet_pci_epf_subsysnqn_show(struct config_item *item, + char *page) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + + return sysfs_emit(page, "%s\n", nvme_epf->subsysnqn); +} + +static ssize_t nvmet_pci_epf_subsysnqn_store(struct config_item *item, + const char *page, size_t len) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + + /* Do not allow setting this when the function is already started. */ + if (nvme_epf->ctrl.tctrl) + return -EBUSY; + + if (!len) + return -EINVAL; + + strscpy(nvme_epf->subsysnqn, page, len); + + return len; +} + +CONFIGFS_ATTR(nvmet_pci_epf_, subsysnqn); + +static ssize_t nvmet_pci_epf_mdts_kb_show(struct config_item *item, char *page) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + + return sysfs_emit(page, "%u\n", nvme_epf->mdts_kb); +} + +static ssize_t nvmet_pci_epf_mdts_kb_store(struct config_item *item, + const char *page, size_t len) +{ + struct config_group *group = to_config_group(item); + struct nvmet_pci_epf *nvme_epf = to_nvme_epf(group); + unsigned long mdts_kb; + int ret; + + if (nvme_epf->ctrl.tctrl) + return -EBUSY; + + ret = kstrtoul(page, 0, &mdts_kb); + if (ret) + return ret; + if (!mdts_kb) + mdts_kb = NVMET_PCI_EPF_MDTS_KB; + else if (mdts_kb > NVMET_PCI_EPF_MAX_MDTS_KB) + mdts_kb = NVMET_PCI_EPF_MAX_MDTS_KB; + + if (!is_power_of_2(mdts_kb)) + return -EINVAL; + + nvme_epf->mdts_kb = mdts_kb; + + return len; +} + +CONFIGFS_ATTR(nvmet_pci_epf_, mdts_kb); + +static struct configfs_attribute *nvmet_pci_epf_attrs[] = { + &nvmet_pci_epf_attr_portid, + &nvmet_pci_epf_attr_subsysnqn, + &nvmet_pci_epf_attr_mdts_kb, + NULL, +}; + +static const struct config_item_type nvmet_pci_epf_group_type = { + .ct_attrs = nvmet_pci_epf_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct config_group *nvmet_pci_epf_add_cfs(struct pci_epf *epf, + struct config_group *group) +{ + struct nvmet_pci_epf *nvme_epf = epf_get_drvdata(epf); + + config_group_init_type_name(&nvme_epf->group, "nvme", + &nvmet_pci_epf_group_type); + + return &nvme_epf->group; +} + +static const struct pci_epf_device_id nvmet_pci_epf_ids[] = { + { .name = "nvmet_pci_epf" }, + {}, +}; + +static struct pci_epf_ops nvmet_pci_epf_ops = { + .bind = nvmet_pci_epf_bind, + .unbind = nvmet_pci_epf_unbind, + .add_cfs = nvmet_pci_epf_add_cfs, +}; + +static struct pci_epf_driver nvmet_pci_epf_driver = { + .driver.name = "nvmet_pci_epf", + .probe = nvmet_pci_epf_probe, + .id_table = nvmet_pci_epf_ids, + .ops = &nvmet_pci_epf_ops, + .owner = THIS_MODULE, +}; + +static int __init nvmet_pci_epf_init_module(void) +{ + int ret; + + ret = pci_epf_register_driver(&nvmet_pci_epf_driver); + if (ret) + return ret; + + ret = nvmet_register_transport(&nvmet_pci_epf_fabrics_ops); + if (ret) { + pci_epf_unregister_driver(&nvmet_pci_epf_driver); + return ret; + } + + return 0; +} + +static void __exit nvmet_pci_epf_cleanup_module(void) +{ + nvmet_unregister_transport(&nvmet_pci_epf_fabrics_ops); + pci_epf_unregister_driver(&nvmet_pci_epf_driver); +} + +module_init(nvmet_pci_epf_init_module); +module_exit(nvmet_pci_epf_cleanup_module); + +MODULE_DESCRIPTION("NVMe PCI Endpoint Function target driver"); +MODULE_AUTHOR("Damien Le Moal <dlemoal@kernel.org>"); +MODULE_LICENSE("GPL"); |