From d421a25891ba098ef5b6c67a0ef099351e20ff0a Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 14 Oct 2025 21:38:36 -0400
Subject: kern: dms: Add DMS QUERY opcode for devinfo

Add a new QUERY operation code that is used to fetch information about a
specific disk.

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/dms/dms_engine.c  | 10 ++++++++++
 src/sys/include/dms/dms.h |  7 +------
 src/sys/include/sys/dms.h | 20 ++++++++++++++++++++
 3 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/sys/dms/dms_engine.c b/src/sys/dms/dms_engine.c
index 35388cc..d2506a3 100644
--- a/src/sys/dms/dms_engine.c
+++ b/src/sys/dms/dms_engine.c
@@ -34,11 +34,13 @@
 #include <os/systm.h>
 #include <os/kalloc.h>
 #include <dms/dms.h>
+#include <string.h>
 
 static ssize_t
 dms_io(struct dms_frame *dfp)
 {
     struct dms_disk *dp;
+    struct dms_diskinfo info;
     size_t len;
     ssize_t retval = -ENXIO;
     int error;
@@ -81,6 +83,14 @@ dms_io(struct dms_frame *dfp)
 
         retval = dms_write(dp, kbuf, dfp->offset, dfp->len);
         break;
+    case DMS_OPC_QUERY:
+        memcpy(info.name, dp->name, sizeof(info.name));
+        info.bsize = dp->bsize;
+        info.id = dp->id;
+        if (dfp->len > sizeof(info))
+            dfp->len = sizeof(info);
+        retval = copyout(&info, dfp->buf, dfp->len);
+        break;
     }
 
     kfree(kbuf);
diff --git a/src/sys/include/dms/dms.h b/src/sys/include/dms/dms.h
index 8453723..835f667 100644
--- a/src/sys/include/dms/dms.h
+++ b/src/sys/include/dms/dms.h
@@ -34,6 +34,7 @@
 #include <sys/queue.h>
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <sys/dms.h>
 
 /*
  * Maximum attached disks, from kconf
@@ -49,12 +50,6 @@ __static_assert(
     "maxiumum disks cannot be zro!"
 );
 
-/* Parameters */
-#define DISKNAME_MAX 128    /* Disk name maxlen */
-
-/* ID of the disk */
-typedef uint16_t disk_id_t;
-
 /* Forward declarations */
 struct dms_disk;
 
diff --git a/src/sys/include/sys/dms.h b/src/sys/include/sys/dms.h
index b4d291d..fdc290a 100644
--- a/src/sys/include/sys/dms.h
+++ b/src/sys/include/sys/dms.h
@@ -36,8 +36,28 @@
 #include <stddef.h>
 #endif  /* !_KERNEL */
 
+#define DISKNAME_MAX 128    /* Disk name maxlen */
+
 #define DMS_OPC_READ    0x00    /* Read from drive */
 #define DMS_OPC_WRITE   0x01    /* Write to drive */
+#define DMS_OPC_QUERY   0x02    /* Query a drive */
+
+/* ID of the disk */
+typedef uint16_t disk_id_t;
+
+/*
+ * Represents disk information that can be requested
+ * from a device with a query
+ *
+ * @name: Name of disk
+ * @bsize: Block size
+ * @id: ID of disk
+ */
+struct dms_diskinfo {
+    char name[DISKNAME_MAX];
+    uint16_t bsize;
+    disk_id_t id;
+};
 
 /*
  * Represents data that can be sent between the
-- 
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