1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
new file mode 100644
index 000000000000..391b1465ebfd
--- /dev/null
+++ b/drivers/nvme/host/pr.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015 Intel Corporation
+ *	Keith Busch <kbusch@kernel.org>
+ */
+#include <linux/blkdev.h>
+#include <linux/pr.h>
+#include <asm/unaligned.h>
+
+#include "nvme.h"
+
+static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
+{
+	switch (type) {
+	case PR_WRITE_EXCLUSIVE:
+		return NVME_PR_WRITE_EXCLUSIVE;
+	case PR_EXCLUSIVE_ACCESS:
+		return NVME_PR_EXCLUSIVE_ACCESS;
+	case PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return NVME_PR_WRITE_EXCLUSIVE_REG_ONLY;
+	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY;
+	case PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return NVME_PR_WRITE_EXCLUSIVE_ALL_REGS;
+	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS;
+	}
+
+	return 0;
+}
+
+static enum pr_type block_pr_type_from_nvme(enum nvme_pr_type type)
+{
+	switch (type) {
+	case NVME_PR_WRITE_EXCLUSIVE:
+		return PR_WRITE_EXCLUSIVE;
+	case NVME_PR_EXCLUSIVE_ACCESS:
+		return PR_EXCLUSIVE_ACCESS;
+	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return PR_WRITE_EXCLUSIVE_REG_ONLY;
+	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
+	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return PR_WRITE_EXCLUSIVE_ALL_REGS;
+	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
+	}
+
+	return 0;
+}
+
+static int nvme_send_ns_head_pr_command(struct block_device *bdev,
+		struct nvme_command *c, void *data, unsigned int data_len)
+{
+	struct nvme_ns_head *head = bdev->bd_disk->private_data;
+	int srcu_idx = srcu_read_lock(&head->srcu);
+	struct nvme_ns *ns = nvme_find_path(head);
+	int ret = -EWOULDBLOCK;
+
+	if (ns) {
+		c->common.nsid = cpu_to_le32(ns->head->ns_id);
+		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
+	}
+	srcu_read_unlock(&head->srcu, srcu_idx);
+	return ret;
+}
+
+static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
+		void *data, unsigned int data_len)
+{
+	c->common.nsid = cpu_to_le32(ns->head->ns_id);
+	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
+}
+
+static int nvme_sc_to_pr_err(int nvme_sc)
+{
+	if (nvme_is_path_error(nvme_sc))
+		return PR_STS_PATH_FAILED;
+
+	switch (nvme_sc) {
+	case NVME_SC_SUCCESS:
+		return PR_STS_SUCCESS;
+	case NVME_SC_RESERVATION_CONFLICT:
+		return PR_STS_RESERVATION_CONFLICT;
+	case NVME_SC_ONCS_NOT_SUPPORTED:
+		return -EOPNOTSUPP;
+	case NVME_SC_BAD_ATTRIBUTES:
+	case NVME_SC_INVALID_OPCODE:
+	case NVME_SC_INVALID_FIELD:
+	case NVME_SC_INVALID_NS:
+		return -EINVAL;
+	default:
+		return PR_STS_IOERR;
+	}
+}
+
+static int nvme_send_pr_command(struct block_device *bdev,
+		struct nvme_command *c, void *data, unsigned int data_len)
+{
+	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
+	    bdev->bd_disk->fops == &nvme_ns_head_ops)
+		return nvme_send_ns_head_pr_command(bdev, c, data, data_len);
+
+	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, c, data,
+				       data_len);
+}
+
+static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
+				u64 key, u64 sa_key, u8 op)
+{
+	struct nvme_command c = { };
+	u8 data[16] = { 0, };
+	int ret;
+
+	put_unaligned_le64(key, &data[0]);
+	put_unaligned_le64(sa_key, &data[8]);
+
+	c.common.opcode = op;
+	c.common.cdw10 = cpu_to_le32(cdw10);
+
+	ret = nvme_send_pr_command(bdev, &c, data, sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	return nvme_sc_to_pr_err(ret);
+}
+
+static int nvme_pr_register(struct block_device *bdev, u64 old,
+		u64 new, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = old ? 2 : 0;
+	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
+	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
+}
+
+static int nvme_pr_reserve(struct block_device *bdev, u64 key,
+		enum pr_type type, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = nvme_pr_type_from_blk(type) << 8;
+	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
+		enum pr_type type, bool abort)
+{
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (abort ? 2 : 1);
+
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_clear(struct block_device *bdev, u64 key)
+{
+	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
+{
+	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+static int nvme_pr_resv_report(struct block_device *bdev, void *data,
+		u32 data_len, bool *eds)
+{
+	struct nvme_command c = { };
+	int ret;
+
+	c.common.opcode = nvme_cmd_resv_report;
+	c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
+	c.common.cdw11 = cpu_to_le32(NVME_EXTENDED_DATA_STRUCT);
+	*eds = true;
+
+retry:
+	ret = nvme_send_pr_command(bdev, &c, data, data_len);
+	if (ret == NVME_SC_HOST_ID_INCONSIST &&
+	    c.common.cdw11 == cpu_to_le32(NVME_EXTENDED_DATA_STRUCT)) {
+		c.common.cdw11 = 0;
+		*eds = false;
+		goto retry;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return nvme_sc_to_pr_err(ret);
+}
+
+static int nvme_pr_read_keys(struct block_device *bdev,
+		struct pr_keys *keys_info)
+{
+	u32 rse_len, num_keys = keys_info->num_keys;
+	struct nvme_reservation_status_ext *rse;
+	int ret, i;
+	bool eds;
+
+	/*
+	 * Assume we are using 128-bit host IDs and allocate a buffer large
+	 * enough to get enough keys to fill the return keys buffer.
+	 */
+	rse_len = struct_size(rse, regctl_eds, num_keys);
+	rse = kzalloc(rse_len, GFP_KERNEL);
+	if (!rse)
+		return -ENOMEM;
+
+	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
+	if (ret)
+		goto free_rse;
+
+	keys_info->generation = le32_to_cpu(rse->gen);
+	keys_info->num_keys = get_unaligned_le16(&rse->regctl);
+
+	num_keys = min(num_keys, keys_info->num_keys);
+	for (i = 0; i < num_keys; i++) {
+		if (eds) {
+			keys_info->keys[i] =
+					le64_to_cpu(rse->regctl_eds[i].rkey);
+		} else {
+			struct nvme_reservation_status *rs;
+
+			rs = (struct nvme_reservation_status *)rse;
+			keys_info->keys[i] = le64_to_cpu(rs->regctl_ds[i].rkey);
+		}
+	}
+
+free_rse:
+	kfree(rse);
+	return ret;
+}
+
+static int nvme_pr_read_reservation(struct block_device *bdev,
+		struct pr_held_reservation *resv)
+{
+	struct nvme_reservation_status_ext tmp_rse, *rse;
+	int ret, i, num_regs;
+	u32 rse_len;
+	bool eds;
+
+get_num_regs:
+	/*
+	 * Get the number of registrations so we know how big to allocate
+	 * the response buffer.
+	 */
+	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);
+	if (ret)
+		return ret;
+
+	num_regs = get_unaligned_le16(&tmp_rse.regctl);
+	if (!num_regs) {
+		resv->generation = le32_to_cpu(tmp_rse.gen);
+		return 0;
+	}
+
+	rse_len = struct_size(rse, regctl_eds, num_regs);
+	rse = kzalloc(rse_len, GFP_KERNEL);
+	if (!rse)
+		return -ENOMEM;
+
+	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
+	if (ret)
+		goto free_rse;
+
+	if (num_regs != get_unaligned_le16(&rse->regctl)) {
+		kfree(rse);
+		goto get_num_regs;
+	}
+
+	resv->generation = le32_to_cpu(rse->gen);
+	resv->type = block_pr_type_from_nvme(rse->rtype);
+
+	for (i = 0; i < num_regs; i++) {
+		if (eds) {
+			if (rse->regctl_eds[i].rcsts) {
+				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);
+				break;
+			}
+		} else {
+			struct nvme_reservation_status *rs;
+
+			rs = (struct nvme_reservation_status *)rse;
+			if (rs->regctl_ds[i].rcsts) {
+				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);
+				break;
+			}
+		}
+	}
+
+free_rse:
+	kfree(rse);
+	return ret;
+}
+
+const struct pr_ops nvme_pr_ops = {
+	.pr_register	= nvme_pr_register,
+	.pr_reserve	= nvme_pr_reserve,
+	.pr_release	= nvme_pr_release,
+	.pr_preempt	= nvme_pr_preempt,
+	.pr_clear	= nvme_pr_clear,
+	.pr_read_keys	= nvme_pr_read_keys,
+	.pr_read_reservation = nvme_pr_read_reservation,
+};