From e07bf16bfda84f7bac83b6e8c6f4a5805249e6f5 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 21 Feb 2023 23:03:25 +0200
Subject: [PATCH 1/3] devicemodel: Remove duplicate owner assignment

platform_driver_register() macro already does the correct assignment for
the owner of the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 examples/devicemodel.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/examples/devicemodel.c b/examples/devicemodel.c
index f2d97dc..6fe923e 100644
--- a/examples/devicemodel.c
+++ b/examples/devicemodel.c
@@ -63,7 +63,6 @@ static struct platform_driver devicemodel_driver = {
     .driver =
         {
             .name = "devicemodel_example",
-            .owner = THIS_MODULE,
             .pm = &devicemodel_pm_ops,
         },
     .probe = devicemodel_probe,

From e62dff0df4baddcae6a07f229a644dd8700abe3c Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Wed, 22 Feb 2023 17:43:27 +0200
Subject: [PATCH 2/3] treewide: Clean up the headers

The rule of thumb is to include the headers we are the direct user of.
In particular, if we need an atomic API, we include <linux/atomic.h>.

On the other hand we should not use headers for no reason. In particular,
if we are not doing any IRQ job, why is the <linux/irq.h> included?

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 examples/chardev.c          | 10 +++++++---
 examples/chardev2.c         |  8 +++++---
 examples/completions.c      |  1 +
 examples/example_atomic.c   |  3 ++-
 examples/example_mutex.c    |  1 -
 examples/example_rwlock.c   |  2 +-
 examples/example_spinlock.c |  1 -
 examples/sleep.c            | 10 ++++++++--
 8 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/examples/chardev.c b/examples/chardev.c
index a337d19..7972304 100644
--- a/examples/chardev.c
+++ b/examples/chardev.c
@@ -3,15 +3,19 @@
  * you have read from the dev file
  */
 
+#include <linux/atomic.h>
 #include <linux/cdev.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/init.h>
-#include <linux/irq.h>
-#include <linux/kernel.h>
+#include <linux/kernel.h> /* for sprintf() */
 #include <linux/module.h>
-#include <linux/poll.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <linux/uaccess.h> /* for get_user and put_user */
+
+#include <asm/errno.h>
 
 /*  Prototypes - this would normally go in a .h file */
 static int device_open(struct inode *, struct file *);
diff --git a/examples/chardev2.c b/examples/chardev2.c
index 58ed57b..4c8b930 100644
--- a/examples/chardev2.c
+++ b/examples/chardev2.c
@@ -2,15 +2,17 @@
  * chardev2.c - Create an input/output character device
  */
 
+#include <linux/atomic.h>
 #include <linux/cdev.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/init.h>
-#include <linux/irq.h>
-#include <linux/kernel.h> /* We are doing kernel work */
 #include <linux/module.h> /* Specifically, a module */
-#include <linux/poll.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+
+#include <asm/errno.h>
 
 #include "chardev.h"
 #define SUCCESS 0
diff --git a/examples/completions.c b/examples/completions.c
index dddf5d7..197dea9 100644
--- a/examples/completions.c
+++ b/examples/completions.c
@@ -2,6 +2,7 @@
  * completions.c
  */
 #include <linux/completion.h>
+#include <linux/err.h> /* for IS_ERR() */
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
diff --git a/examples/example_atomic.c b/examples/example_atomic.c
index 02d770f..4cd4897 100644
--- a/examples/example_atomic.c
+++ b/examples/example_atomic.c
@@ -1,7 +1,8 @@
 /*
  * example_atomic.c
  */
-#include <linux/interrupt.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 
diff --git a/examples/example_mutex.c b/examples/example_mutex.c
index 4eaf823..3149c23 100644
--- a/examples/example_mutex.c
+++ b/examples/example_mutex.c
@@ -1,7 +1,6 @@
 /*
  * example_mutex.c
  */
-#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
diff --git a/examples/example_rwlock.c b/examples/example_rwlock.c
index 74a903f..9668e75 100644
--- a/examples/example_rwlock.c
+++ b/examples/example_rwlock.c
@@ -1,9 +1,9 @@
 /*
  * example_rwlock.c
  */
-#include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/rwlock.h>
 
 static DEFINE_RWLOCK(myrwlock);
 
diff --git a/examples/example_spinlock.c b/examples/example_spinlock.c
index 5b69df1..862291b 100644
--- a/examples/example_spinlock.c
+++ b/examples/example_spinlock.c
@@ -2,7 +2,6 @@
  * example_spinlock.c
  */
 #include <linux/init.h>
-#include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
diff --git a/examples/sleep.c b/examples/sleep.c
index 931ff5d..dff612a 100644
--- a/examples/sleep.c
+++ b/examples/sleep.c
@@ -3,13 +3,19 @@
  * at the same time, put all but one to sleep.
  */
 
+#include <linux/atomic.h>
+#include <linux/fs.h>
 #include <linux/kernel.h> /* We're doing kernel work */
 #include <linux/module.h> /* Specifically, a module */
 #include <linux/proc_fs.h> /* Necessary because we use proc fs */
-#include <linux/sched.h> /* For putting processes to sleep and
-                                   waking them up */
+#include <linux/types.h>
 #include <linux/uaccess.h> /* for get_user and put_user */
 #include <linux/version.h>
+#include <linux/wait.h> /* For putting processes to sleep and
+                                   waking them up */
+
+#include <asm/current.h>
+#include <asm/errno.h>
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
 #define HAVE_PROC_OPS

From b8bbcd8a07a6fd124408804d7ea9a85a8d66d64f Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Thu, 23 Feb 2023 12:41:23 +0200
Subject: [PATCH 3/3] treewide: Replace kernel.h by printk.h

The kernel.h should be discouraged for use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 examples/bottomhalf.c       | 2 +-
 examples/completions.c      | 2 +-
 examples/example_atomic.c   | 2 +-
 examples/example_mutex.c    | 2 +-
 examples/example_rwlock.c   | 2 +-
 examples/example_spinlock.c | 2 +-
 examples/example_tasklet.c  | 2 +-
 examples/hello-1.c          | 2 +-
 examples/hello-2.c          | 2 +-
 examples/hello-3.c          | 2 +-
 examples/hello-4.c          | 2 +-
 examples/hello-5.c          | 3 ++-
 examples/intrpt.c           | 3 ++-
 examples/sleep.c            | 3 ++-
 lkmpg.tex                   | 2 +-
 15 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/examples/bottomhalf.c b/examples/bottomhalf.c
index 91be30e..a4cbf5e 100644
--- a/examples/bottomhalf.c
+++ b/examples/bottomhalf.c
@@ -11,8 +11,8 @@
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
-#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 
 /* Macro DECLARE_TASKLET_OLD exists for compatibiity.
  * See https://lwn.net/Articles/830964/
diff --git a/examples/completions.c b/examples/completions.c
index 197dea9..e9a87c6 100644
--- a/examples/completions.c
+++ b/examples/completions.c
@@ -4,9 +4,9 @@
 #include <linux/completion.h>
 #include <linux/err.h> /* for IS_ERR() */
 #include <linux/init.h>
-#include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 
 static struct {
     struct completion crank_comp;
diff --git a/examples/example_atomic.c b/examples/example_atomic.c
index 4cd4897..7ae8fb8 100644
--- a/examples/example_atomic.c
+++ b/examples/example_atomic.c
@@ -3,8 +3,8 @@
  */
 #include <linux/atomic.h>
 #include <linux/bitops.h>
-#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 
 #define BYTE_TO_BINARY_PATTERN "%c%c%c%c%c%c%c%c"
 #define BYTE_TO_BINARY(byte)                                                   \
diff --git a/examples/example_mutex.c b/examples/example_mutex.c
index 3149c23..6baf61f 100644
--- a/examples/example_mutex.c
+++ b/examples/example_mutex.c
@@ -1,9 +1,9 @@
 /*
  * example_mutex.c
  */
-#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/printk.h>
 
 static DEFINE_MUTEX(mymutex);
 
diff --git a/examples/example_rwlock.c b/examples/example_rwlock.c
index 9668e75..3bdcb14 100644
--- a/examples/example_rwlock.c
+++ b/examples/example_rwlock.c
@@ -1,8 +1,8 @@
 /*
  * example_rwlock.c
  */
-#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 #include <linux/rwlock.h>
 
 static DEFINE_RWLOCK(myrwlock);
diff --git a/examples/example_spinlock.c b/examples/example_spinlock.c
index 862291b..483034f 100644
--- a/examples/example_spinlock.c
+++ b/examples/example_spinlock.c
@@ -2,8 +2,8 @@
  * example_spinlock.c
  */
 #include <linux/init.h>
-#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 #include <linux/spinlock.h>
 
 static DEFINE_SPINLOCK(sl_static);
diff --git a/examples/example_tasklet.c b/examples/example_tasklet.c
index 49c825e..bd894dc 100644
--- a/examples/example_tasklet.c
+++ b/examples/example_tasklet.c
@@ -3,8 +3,8 @@
  */
 #include <linux/delay.h>
 #include <linux/interrupt.h>
-#include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/printk.h>
 
 /* Macro DECLARE_TASKLET_OLD exists for compatibility.
  * See https://lwn.net/Articles/830964/
diff --git a/examples/hello-1.c b/examples/hello-1.c
index 0abcf64..12f1a5d 100644
--- a/examples/hello-1.c
+++ b/examples/hello-1.c
@@ -1,8 +1,8 @@
 /*
  * hello-1.c - The simplest kernel module.
  */
-#include <linux/kernel.h> /* Needed for pr_info() */
 #include <linux/module.h> /* Needed by all modules */
+#include <linux/printk.h> /* Needed for pr_info() */
 
 int init_module(void)
 {
diff --git a/examples/hello-2.c b/examples/hello-2.c
index b5c360d..d76e716 100644
--- a/examples/hello-2.c
+++ b/examples/hello-2.c
@@ -3,8 +3,8 @@
  * This is preferred over using init_module() and cleanup_module().
  */
 #include <linux/init.h> /* Needed for the macros */
-#include <linux/kernel.h> /* Needed for pr_info() */
 #include <linux/module.h> /* Needed by all modules */
+#include <linux/printk.h> /* Needed for pr_info() */
 
 static int __init hello_2_init(void)
 {
diff --git a/examples/hello-3.c b/examples/hello-3.c
index a82c385..84ea2c1 100644
--- a/examples/hello-3.c
+++ b/examples/hello-3.c
@@ -2,8 +2,8 @@
  * hello-3.c - Illustrating the __init, __initdata and __exit macros.
  */
 #include <linux/init.h> /* Needed for the macros */
-#include <linux/kernel.h> /* Needed for pr_info() */
 #include <linux/module.h> /* Needed by all modules */
+#include <linux/printk.h> /* Needed for pr_info() */
 
 static int hello3_data __initdata = 3;
 
diff --git a/examples/hello-4.c b/examples/hello-4.c
index 8e2937d..c029761 100644
--- a/examples/hello-4.c
+++ b/examples/hello-4.c
@@ -2,8 +2,8 @@
  * hello-4.c - Demonstrates module documentation.
  */
 #include <linux/init.h> /* Needed for the macros */
-#include <linux/kernel.h> /* Needed for pr_info() */
 #include <linux/module.h> /* Needed by all modules */
+#include <linux/printk.h> /* Needed for pr_info() */
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("LKMPG");
diff --git a/examples/hello-5.c b/examples/hello-5.c
index 5978e71..3447855 100644
--- a/examples/hello-5.c
+++ b/examples/hello-5.c
@@ -2,9 +2,10 @@
  * hello-5.c - Demonstrates command line argument passing to a module.
  */
 #include <linux/init.h>
-#include <linux/kernel.h>
+#include <linux/kernel.h> /* for ARRAY_SIZE() */
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/printk.h>
 #include <linux/stat.h>
 
 MODULE_LICENSE("GPL");
diff --git a/examples/intrpt.c b/examples/intrpt.c
index 0a6b252..beeddd6 100644
--- a/examples/intrpt.c
+++ b/examples/intrpt.c
@@ -10,8 +10,9 @@
 
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
-#include <linux/kernel.h>
+#include <linux/kernel.h> /* for ARRAY_SIZE() */
 #include <linux/module.h>
+#include <linux/printk.h>
 
 static int button_irqs[] = { -1, -1 };
 
diff --git a/examples/sleep.c b/examples/sleep.c
index dff612a..ad8c1dd 100644
--- a/examples/sleep.c
+++ b/examples/sleep.c
@@ -5,8 +5,9 @@
 
 #include <linux/atomic.h>
 #include <linux/fs.h>
-#include <linux/kernel.h> /* We're doing kernel work */
+#include <linux/kernel.h> /* for sprintf() */
 #include <linux/module.h> /* Specifically, a module */
+#include <linux/printk.h>
 #include <linux/proc_fs.h> /* Necessary because we use proc fs */
 #include <linux/types.h>
 #include <linux/uaccess.h> /* for get_user and put_user */
diff --git a/lkmpg.tex b/lkmpg.tex
index d2fa59d..1976fee 100644
--- a/lkmpg.tex
+++ b/lkmpg.tex
@@ -401,7 +401,7 @@ The \cpp|cleanup_module()| function is supposed to undo whatever \cpp|init_modul
 
 Lastly, every kernel module needs to include \verb|<linux/module.h>|.
 % TODO: adjust the section anchor
-We needed to include \verb|<linux/kernel.h>| only for the macro expansion for the \cpp|pr_alert()| log level, which you'll learn about in Section \ref{sec:printk}.
+We needed to include \verb|<linux/printk.h>| only for the macro expansion for the \cpp|pr_alert()| log level, which you'll learn about in Section \ref{sec:printk}.
 
 \begin{enumerate}
   \item A point about coding style.