[PATCH 21/21] nvme: Support atomic writes

John Garry
2023-09-29T10:33:10Z

From: Alan Adamson <alan.adamson@oracle.com>

Support reading atomic write registers to fill in request_queue
properties.

Use following method to calculate limits:
atomic_write_max_bytes = flp2(NAWUPF ?: AWUPF)
atomic_write_unit_min = logical_block_size
atomic_write_unit_max = flp2(NAWUPF ?: AWUPF)
atomic_write_boundary = NABSPF

Signed-off-by: Alan Adamson <alan.adamson@oracle.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
drivers/nvme/host/core.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 21783aa2ee8e..aa0daacf4d7c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1926,6 +1926,35 @@ static void nvme_update_disk_info(struct gendisk *disk,
blk_queue_io_min(disk->queue, phys_bs);
blk_queue_io_opt(disk->queue, io_opt);

+ atomic_bs = rounddown_pow_of_two(atomic_bs);
+ if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf) {
+ if (id->nabo) {
+ dev_err(ns->ctrl->device, "Support atomic NABO=%x\n",
+ id->nabo);
+ } else {
+ u32 boundary = 0;
+
+ if (le16_to_cpu(id->nabspf))
+ boundary = (le16_to_cpu(id->nabspf) + 1) * bs;
+
+ if (is_power_of_2(boundary) || !boundary) {
+ blk_queue_atomic_write_max_bytes(disk->queue, atomic_bs);
+ blk_queue_atomic_write_unit_min_sectors(disk->queue, 1);
+ blk_queue_atomic_write_unit_max_sectors(disk->queue,
+ atomic_bs / bs);
+ blk_queue_atomic_write_boundary_bytes(disk->queue, boundary);
+ } else {
+ dev_err(ns->ctrl->device, "Unsupported atomic boundary=0x%x\n",
+ boundary);
+ }
+ }
+ } else if (ns->ctrl->subsys->awupf) {
+ blk_queue_atomic_write_max_bytes(disk->queue, atomic_bs);
+ blk_queue_atomic_write_unit_min_sectors(disk->queue, 1);
+ blk_queue_atomic_write_unit_max_sectors(disk->queue, atomic_bs / bs);
+ blk_queue_atomic_write_boundary_bytes(disk->queue, 0);
+ }
+
/*
* Register a metadata profile for PI, or the plain non-integrity NVMe
* metadata masquerading as Type 0 if supported, otherwise reject block
--
2.31.1