[PATCH v3 4/9] nvme: add nvme opcodes, structures and helper functions

[Ankit Kumar <ankit.kumar@samsung.com>]

Add NVMe specification opcodes, data structures and helper
functions to get identify namespace and form nvme uring command.

This will help the follow up patches to get nvme-ns generic
character device size, lba size.

Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>
Co-authored-by: Anuj Gupta <anuj20.g@samsung.com>
---
 Makefile       |   4 +-
 engines/nvme.c | 103 +++++++++++++++++++++++++++++++++++++
 engines/nvme.h | 136 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 241 insertions(+), 2 deletions(-)
 create mode 100644 engines/nvme.c
 create mode 100644 engines/nvme.h

diff --git a/Makefile b/Makefile
index ed66305a..188a74d7 100644
--- a/Makefile
+++ b/Makefile
@@ -231,7 +231,7 @@ ifdef CONFIG_LIBXNVME
 endif
 ifeq ($(CONFIG_TARGET_OS), Linux)
   SOURCE += diskutil.c fifo.c blktrace.c cgroup.c trim.c engines/sg.c \
-		oslib/linux-dev-lookup.c engines/io_uring.c
+		oslib/linux-dev-lookup.c engines/io_uring.c engines/nvme.c
   cmdprio_SRCS = engines/cmdprio.c
 ifdef CONFIG_HAS_BLKZONED
   SOURCE += oslib/linux-blkzoned.c
@@ -241,7 +241,7 @@ endif
 endif
 ifeq ($(CONFIG_TARGET_OS), Android)
   SOURCE += diskutil.c fifo.c blktrace.c cgroup.c trim.c profiles/tiobench.c \
-		oslib/linux-dev-lookup.c engines/io_uring.c
+		oslib/linux-dev-lookup.c engines/io_uring.c engines/nvme.c
   cmdprio_SRCS = engines/cmdprio.c
 ifdef CONFIG_HAS_BLKZONED
   SOURCE += oslib/linux-blkzoned.c
diff --git a/engines/nvme.c b/engines/nvme.c
new file mode 100644
index 00000000..6fecf0ba
--- /dev/null
+++ b/engines/nvme.c
@@ -0,0 +1,103 @@
+/*
+ * nvme structure declarations and helper functions for the
+ * io_uring_cmd engine.
+ */
+
+#include "nvme.h"
+
+int fio_nvme_uring_cmd_prep(struct nvme_uring_cmd *cmd, struct io_u *io_u,
+			    struct iovec *iov)
+{
+	struct nvme_data *data = FILE_ENG_DATA(io_u->file);
+	__u64 slba;
+	__u32 nlb;
+
+	memset(cmd, 0, sizeof(struct nvme_uring_cmd));
+
+	if (io_u->ddir == DDIR_READ)
+		cmd->opcode = nvme_cmd_read;
+	else if (io_u->ddir == DDIR_WRITE)
+		cmd->opcode = nvme_cmd_write;
+	else
+		return -ENOTSUP;
+
+	slba = io_u->offset >> data->lba_shift;
+	nlb = (io_u->xfer_buflen >> data->lba_shift) - 1;
+
+	/* cdw10 and cdw11 represent starting lba */
+	cmd->cdw10 = slba & 0xffffffff;
+	cmd->cdw11 = slba >> 32;
+	/* cdw12 represent number of lba's for read/write */
+	cmd->cdw12 = nlb;
+	if (iov) {
+		iov->iov_base = io_u->xfer_buf;
+		iov->iov_len = io_u->xfer_buflen;
+		cmd->addr = (__u64)(uintptr_t)iov;
+		cmd->data_len = 1;
+	} else {
+		cmd->addr = (__u64)(uintptr_t)io_u->xfer_buf;
+		cmd->data_len = io_u->xfer_buflen;
+	}
+	cmd->nsid = data->nsid;
+	return 0;
+}
+
+static int nvme_identify(int fd, __u32 nsid, enum nvme_identify_cns cns,
+			 enum nvme_csi csi, void *data)
+{
+	struct nvme_passthru_cmd cmd = {
+		.opcode         = nvme_admin_identify,
+		.nsid           = nsid,
+		.addr           = (__u64)(uintptr_t)data,
+		.data_len       = NVME_IDENTIFY_DATA_SIZE,
+		.cdw10          = cns,
+		.cdw11          = csi << NVME_IDENTIFY_CSI_SHIFT,
+		.timeout_ms     = NVME_DEFAULT_IOCTL_TIMEOUT,
+	};
+
+	return ioctl(fd, NVME_IOCTL_ADMIN_CMD, &cmd);
+}
+
+int fio_nvme_get_info(struct fio_file *f, __u32 *nsid, __u32 *lba_sz,
+		      __u64 *nlba)
+{
+	struct nvme_id_ns ns;
+	unsigned int namespace_id;
+	int fd, err;
+
+	if (f->filetype != FIO_TYPE_CHAR) {
+		log_err("ioengine io_uring_cmd only works with nvme ns "
+			"generic char devices (/dev/ngXnY)\n");
+		return 1;
+	}
+
+	fd = open(f->file_name, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+
+	namespace_id = ioctl(fd, NVME_IOCTL_ID);
+	if (namespace_id < 0) {
+		log_err("failed to fetch namespace-id");
+		close(fd);
+		return -errno;
+	}
+
+	/*
+	 * Identify namespace to get namespace-id, namespace size in LBA's
+	 * and LBA data size.
+	 */
+	err = nvme_identify(fd, namespace_id, NVME_IDENTIFY_CNS_NS,
+				NVME_CSI_NVM, &ns);
+	if (err) {
+		log_err("failed to fetch identify namespace\n");
+		close(fd);
+		return err;
+	}
+
+	*nsid = namespace_id;
+	*lba_sz = 1 << ns.lbaf[(ns.flbas & 0x0f)].ds;
+	*nlba = ns.nsze;
+
+	close(fd);
+	return 0;
+}
diff --git a/engines/nvme.h b/engines/nvme.h
new file mode 100644
index 00000000..8e626bb2
--- /dev/null
+++ b/engines/nvme.h
@@ -0,0 +1,136 @@
+/*
+ * nvme structure declarations and helper functions for the
+ * io_uring_cmd engine.
+ */
+
+#ifndef FIO_NVME_H
+#define FIO_NVME_H
+
+#include <linux/nvme_ioctl.h>
+#include "../fio.h"
+
+/*
+ * If the uapi headers installed on the system lacks nvme uring command
+ * support, use the local version to prevent compilation issues.
+ */
+#ifndef CONFIG_NVME_URING_CMD
+struct nvme_uring_cmd {
+	__u8	opcode;
+	__u8	flags;
+	__u16	rsvd1;
+	__u32	nsid;
+	__u32	cdw2;
+	__u32	cdw3;
+	__u64	metadata;
+	__u64	addr;
+	__u32	metadata_len;
+	__u32	data_len;
+	__u32	cdw10;
+	__u32	cdw11;
+	__u32	cdw12;
+	__u32	cdw13;
+	__u32	cdw14;
+	__u32	cdw15;
+	__u32	timeout_ms;
+	__u32   rsvd2;
+};
+
+#define NVME_URING_CMD_IO	_IOWR('N', 0x80, struct nvme_uring_cmd)
+#define NVME_URING_CMD_IO_VEC	_IOWR('N', 0x81, struct nvme_uring_cmd)
+#endif /* CONFIG_NVME_URING_CMD */
+
+#define NVME_DEFAULT_IOCTL_TIMEOUT 0
+#define NVME_IDENTIFY_DATA_SIZE 4096
+#define NVME_IDENTIFY_CSI_SHIFT 24
+
+enum nvme_identify_cns {
+	NVME_IDENTIFY_CNS_NS = 0x00,
+};
+
+enum nvme_csi {
+	NVME_CSI_NVM			= 0,
+	NVME_CSI_KV			= 1,
+	NVME_CSI_ZNS			= 2,
+};
+
+enum nvme_admin_opcode {
+	nvme_admin_identify		= 0x06,
+};
+
+enum nvme_io_opcode {
+	nvme_cmd_write			= 0x01,
+	nvme_cmd_read			= 0x02,
+};
+
+struct nvme_data {
+	__u32 nsid;
+	__u32 lba_shift;
+};
+
+struct nvme_lbaf {
+	__le16			ms;
+	__u8			ds;
+	__u8			rp;
+};
+
+struct nvme_id_ns {
+	__le64			nsze;
+	__le64			ncap;
+	__le64			nuse;
+	__u8			nsfeat;
+	__u8			nlbaf;
+	__u8			flbas;
+	__u8			mc;
+	__u8			dpc;
+	__u8			dps;
+	__u8			nmic;
+	__u8			rescap;
+	__u8			fpi;
+	__u8			dlfeat;
+	__le16			nawun;
+	__le16			nawupf;
+	__le16			nacwu;
+	__le16			nabsn;
+	__le16			nabo;
+	__le16			nabspf;
+	__le16			noiob;
+	__u8			nvmcap[16];
+	__le16			npwg;
+	__le16			npwa;
+	__le16			npdg;
+	__le16			npda;
+	__le16			nows;
+	__le16			mssrl;
+	__le32			mcl;
+	__u8			msrc;
+	__u8			rsvd81[11];
+	__le32			anagrpid;
+	__u8			rsvd96[3];
+	__u8			nsattr;
+	__le16			nvmsetid;
+	__le16			endgid;
+	__u8			nguid[16];
+	__u8			eui64[8];
+	struct nvme_lbaf	lbaf[16];
+	__u8			rsvd192[192];
+	__u8			vs[3712];
+};
+
+static inline int ilog2(uint32_t i)
+{
+	int log = -1;
+
+	while (i) {
+		i >>= 1;
+		log++;
+	}
+	return log;
+}
+
+int fio_nvme_get_info(struct fio_file *f, __u32 *nsid, __u32 *lba_sz,
+		      __u64 *nlba);
+
+int fio_nvme_uring_cmd_prep(struct nvme_uring_cmd *cmd, struct io_u *io_u,
+			    struct iovec *iov);
+
+#endif
-- 
2.17.1