git: 1b5cc3c48cb8 - stable/15 - nvme: add support for DIOCGIDENT

The branch stable/15 has been updated by asomers:

URL: https://cgit.FreeBSD.org/src/commit/?id=1b5cc3c48cb8ff80f0b6a75981d5f85e87cf7e8e

commit 1b5cc3c48cb8ff80f0b6a75981d5f85e87cf7e8e
Author:     Alan Somers <asomers@FreeBSD.org>
AuthorDate: 2025-10-16 22:00:14 +0000
Commit:     Alan Somers <asomers@FreeBSD.org>
CommitDate: 2025-11-22 17:54:42 +0000

    nvme: add support for DIOCGIDENT
    
    Add support for the DIOCGIDENT ioctl to both nvme controller device
    nodes and namespace device nodes.
    
    This information was already available via the nda(4) device node.
    However, mapping /dev/nvmeX to /dev/ndaY device nodes is not
    straightforward, so it's better to get it directly from the /dev/nvme
    device node.
    
    PR:             290259
    Sponsored by:   ConnectWise
    Submitted by:   imp (mostly)
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1875
    
    (cherry picked from commit 6d0001d44490becdd20d627ce663c72a30b9aac3)
---
 sys/dev/nvme/nvme_ctrlr.c   | 24 ++++++++++++++++++++++++
 sys/dev/nvme/nvme_ns.c      |  5 +++++
 sys/dev/nvme/nvme_private.h |  1 +
 3 files changed, 30 insertions(+)

diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c
index 63b8643d97d7..12b39ce3b3ac 100644
--- a/sys/dev/nvme/nvme_ctrlr.c
+++ b/sys/dev/nvme/nvme_ctrlr.c
@@ -33,6 +33,7 @@
 #include <sys/buf.h>
 #include <sys/bus.h>
 #include <sys/conf.h>
+#include <sys/disk.h>
 #include <sys/ioccom.h>
 #include <sys/proc.h>
 #include <sys/smp.h>
@@ -1263,6 +1264,24 @@ nvme_ctrlr_poll(struct nvme_controller *ctrlr)
 			nvme_qpair_process_completions(&ctrlr->ioq[i]);
 }
 
+/*
+ * Copy the NVME device's serial number to the provided buffer, which must be
+ * at least DISK_IDENT_SIZE bytes large.
+ */
+void
+nvme_ctrlr_get_ident(const struct nvme_controller *ctrlr, uint8_t *sn)
+{
+	_Static_assert(NVME_SERIAL_NUMBER_LENGTH < DISK_IDENT_SIZE,
+		"NVME serial number too big for disk ident");
+
+	memmove(sn, ctrlr->cdata.sn, NVME_SERIAL_NUMBER_LENGTH);
+	sn[NVME_SERIAL_NUMBER_LENGTH] = '\0';
+	for (int i = 0; sn[i] != '\0'; i++) {
+		if (sn[i] < 0x20 || sn[i] >= 0x80)
+			sn[i] = ' ';
+	}
+}
+
 /*
  * Poll the single-vector interrupt case: num_io_queues will be 1 and
  * there's only a single vector. While we're polling, we mask further
@@ -1513,6 +1532,11 @@ nvme_ctrlr_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
 	case NVME_GET_CONTROLLER_DATA:
 		memcpy(arg, &ctrlr->cdata, sizeof(ctrlr->cdata));
 		break;
+	case DIOCGIDENT: {
+		uint8_t *sn = arg;
+		nvme_ctrlr_get_ident(ctrlr, sn);
+		break;
+	}
 	/* Linux Compatible (see nvme_linux.h) */
 	case NVME_IOCTL_ID:
 		td->td_retval[0] = 0xfffffffful;
diff --git a/sys/dev/nvme/nvme_ns.c b/sys/dev/nvme/nvme_ns.c
index 21d7965bf7a6..17f6c205752b 100644
--- a/sys/dev/nvme/nvme_ns.c
+++ b/sys/dev/nvme/nvme_ns.c
@@ -88,6 +88,11 @@ nvme_ns_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
 		gnsid->nsid = ns->id;
 		break;
 	}
+	case DIOCGIDENT: {
+		uint8_t *sn = arg;
+		nvme_ctrlr_get_ident(ctrlr, sn);
+		break;
+	}
 	case DIOCGMEDIASIZE:
 		*(off_t *)arg = (off_t)nvme_ns_get_size(ns);
 		break;
diff --git a/sys/dev/nvme/nvme_private.h b/sys/dev/nvme/nvme_private.h
index a425a6a5ad62..dd45e1acd0aa 100644
--- a/sys/dev/nvme/nvme_private.h
+++ b/sys/dev/nvme/nvme_private.h
@@ -565,6 +565,7 @@ void	nvme_notify_new_controller(struct nvme_controller *ctrlr);
 void	nvme_notify_ns(struct nvme_controller *ctrlr, int nsid);
 
 void	nvme_ctrlr_shared_handler(void *arg);
+void	nvme_ctrlr_get_ident(const struct nvme_controller *ctrlr, uint8_t *sn);
 void	nvme_ctrlr_poll(struct nvme_controller *ctrlr);
 
 int	nvme_ctrlr_suspend(struct nvme_controller *ctrlr);