mmap: move doc to README

kernel_module/README.adoc

@@ -18,8 +18,6 @@
 .. Module dependencies
 ... link:dep.c[]
 ... link:dep2.c[]
-. Pseudo filesystems
-.. link:mmap.c[]
 . Asynchronous
 .. link:irq.c[]
 .. link:schedule.c[]

kernel_module/mmap.c

@@ -1,18 +1,4 @@
-/*
-Remember: mmap, like most fops, does not work with debugfs as of 4.9! https://patchwork.kernel.org/patch/9252557/
-
-Adapted from:
-https://coherentmusings.wordpress.com/2014/06/10/implementing-mmap-for-transferring-data-from-user-space-to-kernel-space/
-
-Related:
-
-- https://stackoverflow.com/questions/10760479/mmap-kernel-buffer-to-user-space/10770582#10770582
-- https://stackoverflow.com/questions/1623008/allocating-memory-for-user-space-from-kernel-thread
-- https://stackoverflow.com/questions/6967933/mmap-mapping-in-user-space-a-kernel-buffer-allocated-with-kmalloc
-- https://github.com/jeremytrimble/ezdma
-- https://github.com/simonjhall/dma
-- https://github.com/ikwzm/udmabuf
-*/
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#kthreads */
 
 #include <linux/fs.h>
 #include <linux/init.h>