---

yaml
---
r: 166357
b: refs/heads/master
c: d8f654e
h: refs/heads/master
i:
  166355: e09a907
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 99c4a6344f6574c97019ac16e8d54bfe5ad21f2d
+refs/heads/master: d8f654ef6a55495e548427b997a388e0d5a1ffb4

trunk/Documentation/arm/tcm.txt

@@ -0,0 +1,145 @@
+ARM TCM (Tightly-Coupled Memory) handling in Linux
+----
+Written by Linus Walleij <linus.walleij@stericsson.com>
+
+Some ARM SoC:s have a so-called TCM (Tightly-Coupled Memory).
+This is usually just a few (4-64) KiB of RAM inside the ARM
+processor.
+
+Due to being embedded inside the CPU The TCM has a
+Harvard-architecture, so there is an ITCM (instruction TCM)
+and a DTCM (data TCM). The DTCM can not contain any
+instructions, but the ITCM can actually contain data.
+The size of DTCM or ITCM is minimum 4KiB so the typical
+minimum configuration is 4KiB ITCM and 4KiB DTCM.
+
+ARM CPU:s have special registers to read out status, physical
+location and size of TCM memories. arch/arm/include/asm/cputype.h
+defines a CPUID_TCM register that you can read out from the
+system control coprocessor. Documentation from ARM can be found
+at http://infocenter.arm.com, search for "TCM Status Register"
+to see documents for all CPUs. Reading this register you can
+determine if ITCM (bit 0) and/or DTCM (bit 16) is present in the
+machine.
+
+There is further a TCM region register (search for "TCM Region
+Registers" at the ARM site) that can report and modify the location
+size of TCM memories at runtime. This is used to read out and modify
+TCM location and size. Notice that this is not a MMU table: you
+actually move the physical location of the TCM around. At the
+place you put it, it will mask any underlying RAM from the
+CPU so it is usually wise not to overlap any physical RAM with
+the TCM. The TCM memory exists totally outside the MMU and will
+override any MMU mappings.
+
+Code executing inside the ITCM does not "see" any MMU mappings
+and e.g. register accesses must be made to physical addresses.
+
+TCM is used for a few things:
+
+- FIQ and other interrupt handlers that need deterministic
+  timing and cannot wait for cache misses.
+
+- Idle loops where all external RAM is set to self-refresh
+  retention mode, so only on-chip RAM is accessible by
+  the CPU and then we hang inside ITCM waiting for an
+  interrupt.
+
+- Other operations which implies shutting off or reconfiguring
+  the external RAM controller.
+
+There is an interface for using TCM on the ARM architecture
+in <asm/tcm.h>. Using this interface it is possible to:
+
+- Define the physical address and size of ITCM and DTCM.
+
+- Tag functions to be compiled into ITCM.
+
+- Tag data and constants to be allocated to DTCM and ITCM.
+
+- Have the remaining TCM RAM added to a special
+  allocation pool with gen_pool_create() and gen_pool_add()
+  and provice tcm_alloc() and tcm_free() for this
+  memory. Such a heap is great for things like saving
+  device state when shutting off device power domains.
+
+A machine that has TCM memory shall select HAVE_TCM in
+arch/arm/Kconfig for itself, and then the
+rest of the functionality will depend on the physical
+location and size of ITCM and DTCM to be defined in
+mach/memory.h for the machine. Code that needs to use
+TCM shall #include <asm/tcm.h> If the TCM is not located
+at the place given in memory.h it will be moved using
+the TCM Region registers.
+
+Functions to go into itcm can be tagged like this:
+int __tcmfunc foo(int bar);
+
+Variables to go into dtcm can be tagged like this:
+int __tcmdata foo;
+
+Constants can be tagged like this:
+int __tcmconst foo;
+
+To put assembler into TCM just use
+.section ".tcm.text" or .section ".tcm.data"
+respectively.
+
+Example code:
+
+#include <asm/tcm.h>
+
+/* Uninitialized data */
+static u32 __tcmdata tcmvar;
+/* Initialized data */
+static u32 __tcmdata tcmassigned = 0x2BADBABEU;
+/* Constant */
+static const u32 __tcmconst tcmconst = 0xCAFEBABEU;
+
+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 void __init test_tcm(void)
+{
+	u32 *tcmem;
+	int i;
+
+	hello_tcm();
+	printk("Hello TCM executed from ITCM RAM\n");
+
+	printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar);
+	tcmvar = 0xDEADBEEFU;
+	printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar);
+
+	printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned);
+
+	printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst);
+
+	/* Allocate some TCM memory from the pool */
+	tcmem = tcm_alloc(20);
+	if (tcmem) {
+		printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem);
+		tcmem[0] = 0xDEADBEEFU;
+		tcmem[1] = 0x2BADBABEU;
+		tcmem[2] = 0xCAFEBABEU;
+		tcmem[3] = 0xDEADBEEFU;
+		tcmem[4] = 0x2BADBABEU;
+		for (i = 0; i < 5; i++)
+			printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]);
+		tcm_free(tcmem, 20);
+	}
+}

trunk/MAINTAINERS

@@ -683,7 +683,7 @@ S:	Maintained
 ARM/INTEL IXP4XX ARM ARCHITECTURE
 M:	Imre Kaloz <kaloz@openwrt.org>
 M:	Krzysztof Halasa <khc@pm.waw.pl>
-L:	linux-arm-kernel@lists.infradead.org
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-ixp4xx/
 
@@ -740,18 +740,22 @@ M:	Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
 M:	Dirk Opfer <dirk@opfer-online.de>
 S:	Maintained
 
-ARM/PALMTX,PALMT5,PALMLD,PALMTE2 SUPPORT
-M:	Marek Vasut <marek.vasut@gmail.com>
+ARM/PALMTX,PALMT5,PALMLD,PALMTE2,PALMTC SUPPORT
+P:	Marek Vasut
+M:	marek.vasut@gmail.com
+L:	linux-arm-kernel@lists.infradead.org
 W:	http://hackndev.com
 S:	Maintained
 
 ARM/PALM TREO 680 SUPPORT
 M:	Tomas Cech <sleep_walker@suse.cz>
+L:	linux-arm-kernel@lists.infradead.org
 W:	http://hackndev.com
 S:	Maintained
 
 ARM/PALMZ72 SUPPORT
 M:	Sergey Lapin <slapin@ossfans.org>
+L:	linux-arm-kernel@lists.infradead.org
 W:	http://hackndev.com
 S:	Maintained
 

trunk/arch/alpha/kernel/init_task.c

@@ -13,6 +13,5 @@ static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
 struct task_struct init_task = INIT_TASK(init_task);
 EXPORT_SYMBOL(init_task);
 
-union thread_union init_thread_union
-	__attribute__((section(".data.init_thread")))
-	= { INIT_THREAD_INFO(init_task) };
+union thread_union init_thread_union __init_task_data =
+	{ INIT_THREAD_INFO(init_task) };

trunk/arch/alpha/kernel/vmlinux.lds.S

@@ -1,5 +1,6 @@
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/page.h>
+#include <asm/thread_info.h>
 
 OUTPUT_FORMAT("elf64-alpha")
 OUTPUT_ARCH(alpha)
@@ -31,88 +32,21 @@ SECTIONS
 	} :kernel
 
 	RODATA
-
-	/* Exception table */
-	. = ALIGN(16);
-	__ex_table : {
-		__start___ex_table = .;
-		*(__ex_table)
-		__stop___ex_table = .;
-	}
+	EXCEPTION_TABLE(16)
 
 	/* Will be freed after init */
-	. = ALIGN(PAGE_SIZE);
-	/* Init code and data */
-	__init_begin = .;
-	.init.text : {
-		_sinittext = .;
-		INIT_TEXT
-		_einittext = .;
-	}
-	.init.data : {
-		INIT_DATA
-	}
-
-	. = ALIGN(16);
-	.init.setup : {
-		__setup_start = .;
-		*(.init.setup)
-		__setup_end = .;
-	}
-
-	. = ALIGN(8);
-	.initcall.init : {
-		__initcall_start = .;
-		INITCALLS
-		__initcall_end = .;
-	}
-
-#ifdef CONFIG_BLK_DEV_INITRD
-	. = ALIGN(PAGE_SIZE);
-	.init.ramfs : {
-		__initramfs_start = .;
-		*(.init.ramfs)
-		__initramfs_end = .;
-	}
-#endif
-
-	. = ALIGN(8);
-	.con_initcall.init : {
-		__con_initcall_start = .;
-		*(.con_initcall.init)
-		__con_initcall_end = .;
-	}
-
-	. = ALIGN(8);
-	SECURITY_INIT
-
+	__init_begin = ALIGN(PAGE_SIZE);
+	INIT_TEXT_SECTION(PAGE_SIZE)
+	INIT_DATA_SECTION(16)
 	PERCPU(PAGE_SIZE)
-
-	. = ALIGN(2 * PAGE_SIZE);
+	/* Align to THREAD_SIZE rather than PAGE_SIZE here so any padding page
+	   needed for the THREAD_SIZE aligned init_task gets freed after init */
+	. = ALIGN(THREAD_SIZE);
 	__init_end = .;
 	/* Freed after init ends here */
 
-	/* Note 2 page alignment above.  */
-	.data.init_thread : {
-		*(.data.init_thread)
-	}
-
-	. = ALIGN(PAGE_SIZE);
-	.data.page_aligned : {
-		*(.data.page_aligned)
-	}
-
-	. = ALIGN(64);
-	.data.cacheline_aligned : {
-		*(.data.cacheline_aligned)
-	}
-
 	_data = .;
-	/* Data */
-	.data : {
-		DATA_DATA
-		CONSTRUCTORS
-	}
+	RW_DATA_SECTION(64, PAGE_SIZE, THREAD_SIZE)
 
 	.got : {
 		*(.got)
@@ -122,16 +56,7 @@ SECTIONS
 	}
 	_edata = .;	/* End of data section */
 
-	__bss_start = .;
-	.sbss : {
-		*(.sbss)
-		*(.scommon)
-	}
-	.bss : {
-		*(.bss)
-		*(COMMON)
-	}
-	__bss_stop = .;
+	BSS_SECTION(0, 0, 0)
 	_end = .;
 
 	.mdebug 0 : {

trunk/arch/arm/Kconfig

@@ -46,6 +46,10 @@ config GENERIC_CLOCKEVENTS_BROADCAST
 	depends on GENERIC_CLOCKEVENTS
 	default y if SMP && !LOCAL_TIMERS
 
+config HAVE_TCM
+	bool
+	select GENERIC_ALLOCATOR
+
 config NO_IOPORT
 	bool
 
@@ -649,6 +653,7 @@ config ARCH_U300
 	bool "ST-Ericsson U300 Series"
 	depends on MMU
 	select CPU_ARM926T
+	select HAVE_TCM
 	select ARM_AMBA
 	select ARM_VIC
 	select GENERIC_TIME