From 25d0dc19d53694d891612953bd386826bb8a887a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Josef=20S=C3=B6ntgen?= <jws@sysret.de>
Date: Sun, 13 Nov 2022 20:11:16 +0000
Subject: [PATCH] nvme_drv: provide get/set feature command

These admin commands are used to configure features of the NVMe device.

Issue #4715.
---
 repos/os/src/drivers/nvme/main.cc | 39 +++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/repos/os/src/drivers/nvme/main.cc b/repos/os/src/drivers/nvme/main.cc
index eeaf138dad..ec2fc4817d 100644
--- a/repos/os/src/drivers/nvme/main.cc
+++ b/repos/os/src/drivers/nvme/main.cc
@@ -66,6 +66,8 @@ namespace Nvme {
 	struct Sqe_create_cq;
 	struct Sqe_create_sq;
 	struct Sqe_identify;
+	struct Sqe_get_feature;
+	struct Sqe_set_feature;
 	struct Sqe_io;
 
 	struct Queue;
@@ -133,6 +135,13 @@ namespace Nvme {
 		WRITE_ZEROS  = 0x08,
 	};
 
+	enum Feature_sel {
+		CURRENT   = 0b000,
+		DEFAULT   = 0b001,
+		SAVED     = 0b010,
+		SUPPORTED = 0b011,
+	};
+
 	struct Block_session_component;
 	struct Driver;
 	struct Main;
@@ -332,6 +341,36 @@ struct Nvme::Sqe_identify : Nvme::Sqe
 };
 
 
+/*
+ * Get feature command
+ */
+struct Nvme::Sqe_get_feature : Nvme::Sqe
+{
+	struct Cdw10 : Register<0x28, 32>
+	{
+		struct Fid : Bitfield< 0, 8> { }; /* feature identifier */
+		struct Sel : Bitfield< 8, 2> { }; /* select which value is returned */
+	};
+
+	Sqe_get_feature(addr_t const base) : Sqe(base) { }
+};
+
+
+/*
+ * Set feature command
+ */
+struct Nvme::Sqe_set_feature : Nvme::Sqe
+{
+	struct Cdw10 : Register<0x28, 32>
+	{
+		struct Fid : Bitfield< 0, 8> { }; /* feature identifier */
+		struct Sv  : Bitfield<31, 1> { }; /* save */
+	};
+
+	Sqe_set_feature(addr_t const base) : Sqe(base) { }
+};
+
+
 /*
  *  Create completion queue command
  */