Expand control argument

[MaisenbacherD]

Let's expand the control argument that is currently describing the upper 16 bits of cdw12.
This will be an improvement for the library user as the cdw12 doesn't have to be partially build by the caller anymore.
We can then use the SHIFT/MASK paradigm for the individual fields.

Affected ioctl functions:

• nvme_read
• nvme_write
• nvme_compare
• nvme_write_zeros
• nvme_write_uncorrectable
• nvme_verify
• nvme_zns_append

[igaw]

that means we should also retire this enum here:

/**
 * enum nvme_io_control_flags - I/O control flags
 * @NVME_IO_DTYPE_STREAMS:	Directive Type Streams
 * @NVME_IO_NSZ:		Namespace Zeroes
 * @NVME_IO_STC:		Storage Tag Check
 * @NVME_IO_DEAC:		Deallocate
 * @NVME_IO_ZNS_APPEND_PIREMAP:	Protection Information Remap
 * @NVME_IO_PRINFO_PRCHK_REF:	Protection Information Check Reference Tag
 * @NVME_IO_PRINFO_PRCHK_APP:	Protection Information Check Application Tag
 * @NVME_IO_PRINFO_PRCHK_GUARD: Protection Information Check Guard field
 * @NVME_IO_PRINFO_PRACT:	Protection Information Action
 * @NVME_IO_FUA:		Force Unit Access
 * @NVME_IO_LR:			Limited Retry
 */
enum nvme_io_control_flags {
	NVME_IO_DTYPE_STREAMS		= 1 << 4,
	NVME_IO_NSZ			= 1 << 7,
	NVME_IO_STC			= 1 << 8,
	NVME_IO_DEAC			= 1 << 9,
	NVME_IO_ZNS_APPEND_PIREMAP	= 1 << 9,
	NVME_IO_PRINFO_PRCHK_REF	= 1 << 10,
	NVME_IO_PRINFO_PRCHK_APP	= 1 << 11,
	NVME_IO_PRINFO_PRCHK_GUARD	= 1 << 12,
	NVME_IO_PRINFO_PRACT		= 1 << 13,
	NVME_IO_FUA			= 1 << 14,
	NVME_IO_LR			= 1 << 15,
};

[igaw]

What about introducing a new helper which constructs the cdw12. similiar to

static inline void
nvme_init_get_log_lpo(struct nvme_passthru_cmd *cmd, __u64 lpo)
{
	cmd->cdw12 = lpo & 0xffffffff;
	cmd->cdw13 = lpo >> 32;
}

I don't think we want to extend all the existing nvme_init_* with even more arguments. Though we would need a nvme_init_{read|write|compare|...}_control because the are not completely identical. Thoughts?

[MaisenbacherD]

Sounds like a good tradeoff :)