ARM TCM sample codetcm

This is a simple sample snippet of ARM TCM code use, we create
arm/test to host the code.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

6 files changed, 123 insertions, 0 deletions

diff --git a/Documentation/arm/tcm.rst b/Documentation/arm/tcm.rst
index b256f9783883..535d4de0a2f4 100644
--- a/Documentation/arm/tcm.rst
+++ b/Documentation/arm/tcm.rst
@@ -159,3 +159,6 @@ Example code::
 		tcm_free(tcmem, 20);
 	}
   }
+
+Example code can be found in the samples/arm_tcm directory of the kernel
+tree, and can be compiled in using menuconfig.
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index f46e18a77645..ded4bb190046 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1935,3 +1935,4 @@ config PID_IN_CONTEXTIDR
 	  are planning to use hardware trace tools with this kernel.
 
 source "drivers/hwtracing/coresight/Kconfig"
+source "arch/arm/test/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 7d5cd0f85461..46355d840ba3 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -292,6 +292,8 @@ core-y				+= $(machdirs) $(platdirs)
 core-				+= $(patsubst %,arch/arm/mach-%/, $(machine-))
 core-				+= $(patsubst %,arch/arm/plat-%/, $(plat-))
 
+core-$(CONFIG_ARM_TEST)		+= arch/arm/test/
+
 drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
 
 libs-y				:= arch/arm/lib/ $(libs-y)
diff --git a/arch/arm/test/Kconfig b/arch/arm/test/Kconfig
new file mode 100644
index 000000000000..13c38e11ab6d
--- /dev/null
+++ b/arch/arm/test/Kconfig
@@ -0,0 +1,20 @@
+config ARM_TEST
+       bool "Enable ARM kernel tests"
+
+if ARM_TEST
+
+menu "ARM Kernel tests"
+
+comment "test code to exercise the ARM kernel"
+
+config ARM_TCM_TEST
+	bool "ARM TCM test"
+	depends on HAVE_TCM
+	help
+		Enables some test code snippets to exercise the TCM memory
+		on platforms that have it. The code will not be executed
+		if no TCM memory is found.
+
+endmenu
+
+endif
diff --git a/arch/arm/test/Makefile b/arch/arm/test/Makefile
new file mode 100644
index 000000000000..9161440d5345
--- /dev/null
+++ b/arch/arm/test/Makefile
@@ -0,0 +1,2 @@
+obj-y :=
+obj-$(CONFIG_ARM_TCM_TEST) += tcm-example.o
diff --git a/arch/arm/test/tcm-example.c b/arch/arm/test/tcm-example.c
new file mode 100644
index 000000000000..b90273869a3c
--- /dev/null
+++ b/arch/arm/test/tcm-example.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2010 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * TCM memory test
+ *
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/bug.h>
+#include <asm/tcm.h>
+
+#define CANARY1 0xDEADBEEFU
+#define CANARY2 0x2BADBABEU
+#define CANARY3 0xCAFEBABEU
+
+/* Uninitialized data */
+static u32 __tcmdata tcmvar;
+/* Initialized data */
+static u32 __tcmdata tcmassigned = CANARY2;
+/* Constant */
+static const u32 __tcmconst tcmconst = CANARY3;
+
+static void __tcmlocalfunc tcm_to_tcm(void)
+{
+	int i;
+	for (i = 0; i < 100; i++)
+		tcmvar ++;
+}
+
+static void __tcmfunc hello_tcm(void)
+{
+	/* Some abstract code that runs in ITCM */
+	int i;
+	for (i = 0; i < 100; i++) {
+		tcmvar ++;
+	}
+	tcm_to_tcm();
+}
+
+static int __init test_tcm(void)
+{
+	u32 *tcmem;
+	int i;
+
+	if (!tcm_dtcm_present() && !tcm_itcm_present()) {
+		pr_info("CPU: no TCMs present, skipping tests\n");
+		return 0;
+	}
+
+	if (!tcm_itcm_present())
+		goto skip_itcm_tests;
+
+	hello_tcm();
+	pr_info("CPU: hello TCM executed from ITCM RAM\n");
+
+	pr_info("CPU: TCM variable from testrun: %u @ %p\n",
+		tcmvar, &tcmvar);
+	BUG_ON(tcmvar != 200);
+
+skip_itcm_tests:
+	tcmvar = CANARY1;
+	pr_info("CPU: TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar);
+	BUG_ON(tcmvar != CANARY1);
+
+	pr_info("CPU: TCM assigned variable: 0x%x @ %p\n",
+		tcmassigned, &tcmassigned);
+	BUG_ON(tcmassigned != CANARY2);
+
+	pr_info("CPU: TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst);
+	BUG_ON(tcmconst != CANARY3);
+
+	/* Allocate some TCM memory from the pool */
+	tcmem = tcm_alloc(20);
+	if (tcmem) {
+		pr_info("CPU: TCM Allocated 20 bytes of TCM @ %p\n", tcmem);
+		tcmem[0] = CANARY1;
+		tcmem[1] = CANARY2;
+		tcmem[2] = CANARY3;
+		tcmem[3] = CANARY1;
+		tcmem[4] = CANARY2;
+		for (i = 0; i < 5; i++)
+			pr_info("CPU: TCM tcmem[%d] = %08x\n", i, tcmem[i]);
+		BUG_ON(tcmem[0] != CANARY1);
+		BUG_ON(tcmem[1] != CANARY2);
+		BUG_ON(tcmem[2] != CANARY3);
+		BUG_ON(tcmem[3] != CANARY1);
+		BUG_ON(tcmem[4] != CANARY2);
+		tcm_free(tcmem, 20);
+	}
+	return 0;
+}
+
+late_initcall(test_tcm);