From a29f40e073a0308bd74f0f9803a4660aa233c3ab Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Sat, 12 Mar 2022 16:39:39 -0800
Subject: "Dynamic" Mutex Allocation

---
 include/globals.h    |  3 +++
 include/util/lock.h  |  2 --
 include/util/mutex.h |  5 +++++
 linker.ld            |  4 ++++
 src/globals.c        |  3 +++
 src/util/lock.c      |  1 +
 src/util/mutex.c     | 26 ++++++++++++++++++++++++++
 7 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/include/globals.h b/include/globals.h
index 7bda83c..249ffe7 100644
--- a/include/globals.h
+++ b/include/globals.h
@@ -1,6 +1,7 @@
 #ifndef GLOBALS_H
 #define GLOBALS_H
 #include <sys/schedule.h>
+#include <util/mutex.h>
 
 #ifndef GLOBALS_C
 extern unsigned long irqlr;
@@ -16,6 +17,8 @@ extern struct Thread usrloopthread;
 extern unsigned int gwidth, gheight, gpitch, gisrgb;
 extern unsigned char thread_table[MAX_THREADS];
 extern struct Thread threads[MAX_THREADS];
+extern unsigned long mutex_table[MAX_MUTEXS];
+extern struct Mutex mutexs[MAX_MUTEXS];
 #endif
 
 #endif
diff --git a/include/util/lock.h b/include/util/lock.h
index c5b2f7e..da18f81 100644
--- a/include/util/lock.h
+++ b/include/util/lock.h
@@ -1,8 +1,6 @@
 #ifndef UTIL_LOCK_H
 #define UTIL_LOCK_H
 
-#include <util/mutex.h>
-
 struct Lock {
 	unsigned long pid;
 } __attribute__((packed, aligned(4)));
diff --git a/include/util/mutex.h b/include/util/mutex.h
index ab318b4..c0dd17b 100644
--- a/include/util/mutex.h
+++ b/include/util/mutex.h
@@ -8,6 +8,8 @@
 #define CORE3_PID 4
 #define FIRST_AVAIL_PID CORE3_PID+1
 
+#define MAX_MUTEXS 0x100
+
 // PID field is first so that it can be treated
 //  as a lock
 struct Mutex {
@@ -15,4 +17,7 @@ struct Mutex {
 	void* addr;
 } __attribute__((packed, aligned(4)));
 
+struct Mutex* create_mutex(void* addr);
+unsigned char delete_mutex(struct Mutex* m);
+
 #endif
diff --git a/linker.ld b/linker.ld
index dcb5a9b..e12ab5c 100644
--- a/linker.ld
+++ b/linker.ld
@@ -38,6 +38,10 @@ SECTIONS
 	. = ALIGN(4096);
 	KEEP(*(.bss.threads"))
 	. = ALIGN(4096);
+	KEEP(*(.bss.mutexl"))
+	. = ALIGN(4096);
+	KEEP(*(.bss.mutexs"))
+	. = ALIGN(4096);
         *(.bss)
         *(.bss.*)
 	KEEP(*(.bss.mmheap))
diff --git a/src/globals.c b/src/globals.c
index 29760b6..c704cb4 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -1,5 +1,6 @@
 #define GLOBALS_C
 #include <sys/schedule.h>
+#include <util/mutex.h>
 char* os_name = "Jobbed";
 #ifndef VERSION
 char* os_info_v = "?";
@@ -16,6 +17,8 @@ __attribute__((section(".bss"))) unsigned int gwidth;
 __attribute__((section(".bss"))) unsigned int gheight;
 __attribute__((section(".bss"))) unsigned int gpitch;
 __attribute__((section(".bss"))) unsigned int gisrgb;
+__attribute__((section(".bss.mutexl"))) unsigned long mutex_table[MAX_MUTEXS];
+__attribute__((section(".bss.mutexs"))) struct Mutex mutexs[MAX_MUTEXS];
 // 0 - Free
 // 1 - Ready
 // 2 - Waiting for Mutex
diff --git a/src/util/lock.c b/src/util/lock.c
index 95f93af..eaeb5a8 100644
--- a/src/util/lock.c
+++ b/src/util/lock.c
@@ -1,5 +1,6 @@
 #include <cpu.h>
 #include <cpu/atomic/swap.h>
+#include <util/mutex.h>
 #include <util/lock.h>
 
 // TODO: Improve locking for system
diff --git a/src/util/mutex.c b/src/util/mutex.c
index e69de29..3171501 100644
--- a/src/util/mutex.c
+++ b/src/util/mutex.c
@@ -0,0 +1,26 @@
+#include <util/mutex.h>
+#include <globals.h>
+
+struct Mutex* create_mutex(void* addr)
+{
+	for (unsigned long m = 0; m < MAX_MUTEXS; m++) {
+		if (mutex_table[m] == 0) {
+			mutex_table[m] = (unsigned long)addr;
+			mutexs[m].pid = 0;
+			mutexs[m].addr = addr;
+			return &mutexs[m];
+		}
+	}
+	return 0;
+}
+
+unsigned char delete_mutex(struct Mutex* m)
+{
+	for (unsigned long i = 0; i < MAX_MUTEXS; i++) {
+		if (mutex_table[i] == (unsigned long)m->addr) {
+			mutex_table[i] = 0;
+			return 0;
+		}
+	}
+	return 1;
+}
-- 
cgit v1.2.1