lightnvm: add ioctls for vector I/Os

Enable user-space to issue vector I/O commands through ioctls. To issue
a vector I/O, the ppa list with addresses is also required and must be
mapped for the controller to access.

For each ioctl, the result and status bits are returned as well, such
that user-space can retrieve the open-channel SSD completion bits.

The implementation covers the traditional use-cases of bad block
management, and vectored read/write/erase.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Metadata implementation, test, and fixes.
Signed-off-by: Simon A.F. Lund <slund@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 220 insertions, 0 deletions

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 733992a25d6a..3b6cd9bdba7e 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -26,6 +26,8 @@
 #include <linux/bitops.h>
 #include <linux/lightnvm.h>
 #include <linux/vmalloc.h>
+#include <linux/sched/sysctl.h>
+#include <uapi/linux/lightnvm.h>
 
 enum nvme_nvm_admin_opcode {
 	nvme_nvm_admin_identity		= 0xe2,
@@ -583,6 +585,224 @@ static struct nvm_dev_ops nvme_nvm_dev_ops = {
 	.max_phys_sect		= 64,
 };
 
+static void nvme_nvm_end_user_vio(struct request *rq, int error)
+{
+	struct completion *waiting = rq->end_io_data;
+
+	complete(waiting);
+}
+
+static int nvme_nvm_submit_user_cmd(struct request_queue *q,
+				struct nvme_ns *ns,
+				struct nvme_nvm_command *vcmd,
+				void __user *ubuf, unsigned int bufflen,
+				void __user *meta_buf, unsigned int meta_len,
+				void __user *ppa_buf, unsigned int ppa_len,
+				u32 *result, u64 *status, unsigned int timeout)
+{
+	bool write = nvme_is_write((struct nvme_command *)vcmd);
+	struct nvm_dev *dev = ns->ndev;
+	struct gendisk *disk = ns->disk;
+	struct request *rq;
+	struct bio *bio = NULL;
+	__le64 *ppa_list = NULL;
+	dma_addr_t ppa_dma;
+	__le64 *metadata = NULL;
+	dma_addr_t metadata_dma;
+	DECLARE_COMPLETION_ONSTACK(wait);
+	int ret;
+
+	rq = nvme_alloc_request(q, (struct nvme_command *)vcmd, 0,
+			NVME_QID_ANY);
+	if (IS_ERR(rq)) {
+		ret = -ENOMEM;
+		goto err_cmd;
+	}
+
+	rq->timeout = timeout ? timeout : ADMIN_TIMEOUT;
+
+	rq->cmd_flags &= ~REQ_FAILFAST_DRIVER;
+	rq->end_io_data = &wait;
+
+	if (ppa_buf && ppa_len) {
+		ppa_list = dma_pool_alloc(dev->dma_pool, GFP_KERNEL, &ppa_dma);
+		if (!ppa_list) {
+			ret = -ENOMEM;
+			goto err_rq;
+		}
+		if (copy_from_user(ppa_list, (void __user *)ppa_buf,
+						sizeof(u64) * (ppa_len + 1))) {
+			ret = -EFAULT;
+			goto err_ppa;
+		}
+		vcmd->ph_rw.spba = cpu_to_le64(ppa_dma);
+	} else {
+		vcmd->ph_rw.spba = cpu_to_le64((uintptr_t)ppa_buf);
+	}
+
+	if (ubuf && bufflen) {
+		ret = blk_rq_map_user(q, rq, NULL, ubuf, bufflen, GFP_KERNEL);
+		if (ret)
+			goto err_ppa;
+		bio = rq->bio;
+
+		if (meta_buf && meta_len) {
+			metadata = dma_pool_alloc(dev->dma_pool, GFP_KERNEL,
+								&metadata_dma);
+			if (!metadata) {
+				ret = -ENOMEM;
+				goto err_map;
+			}
+
+			if (write) {
+				if (copy_from_user(metadata,
+						(void __user *)meta_buf,
+						meta_len)) {
+					ret = -EFAULT;
+					goto err_meta;
+				}
+			}
+			vcmd->ph_rw.metadata = cpu_to_le64(metadata_dma);
+		}
+
+		if (!disk)
+			goto submit;
+
+		bio->bi_bdev = bdget_disk(disk, 0);
+		if (!bio->bi_bdev) {
+			ret = -ENODEV;
+			goto err_meta;
+		}
+	}
+
+submit:
+	blk_execute_rq_nowait(q, NULL, rq, 0, nvme_nvm_end_user_vio);
+
+	wait_for_completion_io(&wait);
+
+	ret = nvme_error_status(rq->errors);
+	if (result)
+		*result = rq->errors & 0x7ff;
+	if (status)
+		*status = le64_to_cpu(nvme_req(rq)->result.u64);
+
+	if (metadata && !ret && !write) {
+		if (copy_to_user(meta_buf, (void *)metadata, meta_len))
+			ret = -EFAULT;
+	}
+err_meta:
+	if (meta_buf && meta_len)
+		dma_pool_free(dev->dma_pool, metadata, metadata_dma);
+err_map:
+	if (bio) {
+		if (disk && bio->bi_bdev)
+			bdput(bio->bi_bdev);
+		blk_rq_unmap_user(bio);
+	}
+err_ppa:
+	if (ppa_buf && ppa_len)
+		dma_pool_free(dev->dma_pool, ppa_list, ppa_dma);
+err_rq:
+	blk_mq_free_request(rq);
+err_cmd:
+	return ret;
+}
+
+static int nvme_nvm_submit_vio(struct nvme_ns *ns,
+					struct nvm_user_vio __user *uvio)
+{
+	struct nvm_user_vio vio;
+	struct nvme_nvm_command c;
+	unsigned int length;
+	int ret;
+
+	if (copy_from_user(&vio, uvio, sizeof(vio)))
+		return -EFAULT;
+	if (vio.flags)
+		return -EINVAL;
+
+	memset(&c, 0, sizeof(c));
+	c.ph_rw.opcode = vio.opcode;
+	c.ph_rw.nsid = cpu_to_le32(ns->ns_id);
+	c.ph_rw.control = cpu_to_le16(vio.control);
+	c.ph_rw.length = cpu_to_le16(vio.nppas);
+
+	length = (vio.nppas + 1) << ns->lba_shift;
+
+	ret = nvme_nvm_submit_user_cmd(ns->queue, ns, &c,
+			(void __user *)(uintptr_t)vio.addr, length,
+			(void __user *)(uintptr_t)vio.metadata,
+							vio.metadata_len,
+			(void __user *)(uintptr_t)vio.ppa_list, vio.nppas,
+			&vio.result, &vio.status, 0);
+
+	if (ret && copy_to_user(uvio, &vio, sizeof(vio)))
+		return -EFAULT;
+
+	return ret;
+}
+
+static int nvme_nvm_user_vcmd(struct nvme_ns *ns, int admin,
+					struct nvm_passthru_vio __user *uvcmd)
+{
+	struct nvm_passthru_vio vcmd;
+	struct nvme_nvm_command c;
+	struct request_queue *q;
+	unsigned int timeout = 0;
+	int ret;
+
+	if (copy_from_user(&vcmd, uvcmd, sizeof(vcmd)))
+		return -EFAULT;
+	if ((vcmd.opcode != 0xF2) && (!capable(CAP_SYS_ADMIN)))
+		return -EACCES;
+	if (vcmd.flags)
+		return -EINVAL;
+
+	memset(&c, 0, sizeof(c));
+	c.common.opcode = vcmd.opcode;
+	c.common.nsid = cpu_to_le32(ns->ns_id);
+	c.common.cdw2[0] = cpu_to_le32(vcmd.cdw2);
+	c.common.cdw2[1] = cpu_to_le32(vcmd.cdw3);
+	/* cdw11-12 */
+	c.ph_rw.length = cpu_to_le16(vcmd.nppas);
+	c.ph_rw.control  = cpu_to_le32(vcmd.control);
+	c.common.cdw10[3] = cpu_to_le32(vcmd.cdw13);
+	c.common.cdw10[4] = cpu_to_le32(vcmd.cdw14);
+	c.common.cdw10[5] = cpu_to_le32(vcmd.cdw15);
+
+	if (vcmd.timeout_ms)
+		timeout = msecs_to_jiffies(vcmd.timeout_ms);
+
+	q = admin ? ns->ctrl->admin_q : ns->queue;
+
+	ret = nvme_nvm_submit_user_cmd(q, ns,
+			(struct nvme_nvm_command *)&c,
+			(void __user *)(uintptr_t)vcmd.addr, vcmd.data_len,
+			(void __user *)(uintptr_t)vcmd.metadata,
+							vcmd.metadata_len,
+			(void __user *)(uintptr_t)vcmd.ppa_list, vcmd.nppas,
+			&vcmd.result, &vcmd.status, timeout);
+
+	if (ret && copy_to_user(uvcmd, &vcmd, sizeof(vcmd)))
+		return -EFAULT;
+
+	return ret;
+}
+
+int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case NVME_NVM_IOCTL_ADMIN_VIO:
+		return nvme_nvm_user_vcmd(ns, 1, (void __user *)arg);
+	case NVME_NVM_IOCTL_IO_VIO:
+		return nvme_nvm_user_vcmd(ns, 0, (void __user *)arg);
+	case NVME_NVM_IOCTL_SUBMIT_VIO:
+		return nvme_nvm_submit_vio(ns, (void __user *)arg);
+	default:
+		return -ENOTTY;
+	}
+}
+
 int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node)
 {
 	struct request_queue *q = ns->queue;