[PATCH liburing 3/5] nvme: add nvme opcodes, structures and helper functions

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

Add bare minimum structures and helper functions required for
io_uring passthrough commands. This will enable the follow up
patch to add tests for nvme-ns generic character device.

Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>
---
 test/nvme.h | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 168 insertions(+)
 create mode 100644 test/nvme.h

diff --git a/test/nvme.h b/test/nvme.h
new file mode 100644
index 0000000..866a7e6
--- /dev/null
+++ b/test/nvme.h
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Description: Helpers for NVMe uring passthrough commands
+ */
+#ifndef LIBURING_NVME_H
+#define LIBURING_NVME_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/ioctl.h>
+#include <linux/nvme_ioctl.h>
+
+/*
+ * If the uapi headers installed on the system lacks nvme uring command
+ * support, use the local version to prevent compilation issues.
+ */
+#ifndef CONFIG_HAVE_NVME_URING
+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_HAVE_NVME_URING */
+
+#define NVME_DEFAULT_IOCTL_TIMEOUT 0
+#define NVME_IDENTIFY_DATA_SIZE 4096
+#define NVME_IDENTIFY_CSI_SHIFT 24
+#define NVME_IDENTIFY_CNS_NS 0
+#define NVME_CSI_NVM 0
+
+enum nvme_admin_opcode {
+	nvme_admin_identify		= 0x06,
+};
+
+enum nvme_io_opcode {
+	nvme_cmd_write			= 0x01,
+	nvme_cmd_read			= 0x02,
+};
+
+int 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(const char *file)
+{
+	struct nvme_id_ns ns;
+	int fd, err;
+	__u32 lba_size;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+
+	nsid = ioctl(fd, NVME_IOCTL_ID);
+	if (nsid < 0) {
+		fprintf(stderr, "failed to fetch namespace-id\n");
+		close(fd);
+		return -errno;
+	}
+
+	struct nvme_passthru_cmd cmd = {
+		.opcode         = nvme_admin_identify,
+		.nsid           = nsid,
+		.addr           = (__u64)(uintptr_t)&ns,
+		.data_len       = NVME_IDENTIFY_DATA_SIZE,
+		.cdw10          = NVME_IDENTIFY_CNS_NS,
+		.cdw11          = NVME_CSI_NVM << NVME_IDENTIFY_CSI_SHIFT,
+		.timeout_ms     = NVME_DEFAULT_IOCTL_TIMEOUT,
+	};
+
+	err = ioctl(fd, NVME_IOCTL_ADMIN_CMD, &cmd);
+	if (err) {
+		fprintf(stderr, "failed to fetch identify namespace\n");
+		close(fd);
+		return err;
+	}
+
+	lba_size = 1 << ns.lbaf[(ns.flbas & 0x0f)].ds;
+	lba_shift = ilog2(lba_size);
+
+	close(fd);
+	return 0;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
-- 
2.17.1