arch/arm/kernel/tcm.c - maze/linux - Git at Google

 /*
  * Copyright (C) 2008-2009 ST-Ericsson AB
  * License terms: GNU General Public License (GPL) version 2
  * TCM memory handling for ARM systems
  *
  * Author: Linus Walleij <linus.walleij@stericsson.com>
  * Author: Rickard Andersson <rickard.andersson@stericsson.com>
  */
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/stddef.h>
 #include <linux/ioport.h>
 #include <linux/genalloc.h>
 #include <linux/string.h> /* memcpy */
 #include <asm/cputype.h>
 #include <asm/mach/map.h>
 #include <asm/memory.h>
 #include <asm/system_info.h>
 #include "tcm.h"

 static struct gen_pool *tcm_pool;
 static bool dtcm_present;
 static bool itcm_present;

 /* TCM section definitions from the linker */
 extern char __itcm_start, __sitcm_text, __eitcm_text;
 extern char __dtcm_start, __sdtcm_data, __edtcm_data;

 /* These will be increased as we run */
 u32 dtcm_end = DTCM_OFFSET;
 u32 itcm_end = ITCM_OFFSET;

 /*
  * TCM memory resources
  */
 static struct resource dtcm_res = {
 	.name = "DTCM RAM",
 	.start = DTCM_OFFSET,
 	.end = DTCM_OFFSET,
 	.flags = IORESOURCE_MEM
 };

 static struct resource itcm_res = {
 	.name = "ITCM RAM",
 	.start = ITCM_OFFSET,
 	.end = ITCM_OFFSET,
 	.flags = IORESOURCE_MEM
 };

 static struct map_desc dtcm_iomap[] __initdata = {
 	{
 		.virtual	= DTCM_OFFSET,
 		.pfn		= __phys_to_pfn(DTCM_OFFSET),
 		.length		= 0,
 		.type		= MT_MEMORY_DTCM
 	}
 };

 static struct map_desc itcm_iomap[] __initdata = {
 	{
 		.virtual	= ITCM_OFFSET,
 		.pfn		= __phys_to_pfn(ITCM_OFFSET),
 		.length		= 0,
 		.type		= MT_MEMORY_ITCM
 	}
 };

 /*
  * Allocate a chunk of TCM memory
  */
 void *tcm_alloc(size_t len)
 {
 	unsigned long vaddr;

 	if (!tcm_pool)
 		return NULL;

 	vaddr = gen_pool_alloc(tcm_pool, len);
 	if (!vaddr)
 		return NULL;

 	return (void *) vaddr;
 }
 EXPORT_SYMBOL(tcm_alloc);

 /*
  * Free a chunk of TCM memory
  */
 void tcm_free(void *addr, size_t len)
 {
 	gen_pool_free(tcm_pool, (unsigned long) addr, len);
 }
 EXPORT_SYMBOL(tcm_free);

 bool tcm_dtcm_present(void)
 {
 	return dtcm_present;
 }
 EXPORT_SYMBOL(tcm_dtcm_present);

 bool tcm_itcm_present(void)
 {
 	return itcm_present;
 }
 EXPORT_SYMBOL(tcm_itcm_present);

 static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
 				  u32 *offset)
 {
 	const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
 				    256, 512, 1024, -1, -1, -1, -1 };
 	u32 tcm_region;
 	int tcm_size;

 	/*
 	 * If there are more than one TCM bank of this type,
 	 * select the TCM bank to operate on in the TCM selection
 	 * register.
 	 */
 	if (banks > 1)
 		asm("mcr	p15, 0, %0, c9, c2, 0"
 		    : /* No output operands */
 		    : "r" (bank));

 	/* Read the special TCM region register c9, 0 */
 	if (!type)
 		asm("mrc	p15, 0, %0, c9, c1, 0"
 		    : "=r" (tcm_region));
 	else
 		asm("mrc	p15, 0, %0, c9, c1, 1"
 		    : "=r" (tcm_region));

 	tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
 	if (tcm_size < 0) {
 		pr_err("CPU: %sTCM%d of unknown size\n",
 		       type ? "I" : "D", bank);
 		return -EINVAL;
 	} else if (tcm_size > 32) {
 		pr_err("CPU: %sTCM%d larger than 32k found\n",
 		       type ? "I" : "D", bank);
 		return -EINVAL;
 	} else {
 		pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
 			type ? "I" : "D",
 			bank,
 			tcm_size,
 			(tcm_region & 0xfffff000U),
 			(tcm_region & 1) ? "" : "not ");
 	}

 	/* Not much fun you can do with a size 0 bank */
 	if (tcm_size == 0)
 		return 0;

 	/* Force move the TCM bank to where we want it, enable */
 	tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;

 	if (!type)
 		asm("mcr	p15, 0, %0, c9, c1, 0"
 		    : /* No output operands */
 		    : "r" (tcm_region));
 	else
 		asm("mcr	p15, 0, %0, c9, c1, 1"
 		    : /* No output operands */
 		    : "r" (tcm_region));

 	/* Increase offset */
 	*offset += (tcm_size << 10);

 	pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
 		type ? "I" : "D",
 		bank,
 		tcm_size,
 		(tcm_region & 0xfffff000U));
 	return 0;
 }

 /*
  * This initializes the TCM memory
  */
 void __init tcm_init(void)
 {
 	u32 tcm_status;
 	u8 dtcm_banks;
 	u8 itcm_banks;
 	size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
 	size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
 	char *start;
 	char *end;
 	char *ram;
 	int ret;
 	int i;

 	/*
 	 * Prior to ARMv5 there is no TCM, and trying to read the status
 	 * register will hang the processor.
 	 */
 	if (cpu_architecture() < CPU_ARCH_ARMv5) {
 		if (dtcm_code_sz || itcm_code_sz)
 			pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
 				"ITCM code compiled in, but no TCM present "
 				"in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz);
 		return;
 	}

 	tcm_status = read_cpuid_tcmstatus();
 	dtcm_banks = (tcm_status >> 16) & 0x03;
 	itcm_banks = (tcm_status & 0x03);

 	/* Values greater than 2 for D/ITCM banks are "reserved" */
 	if (dtcm_banks > 2)
 		dtcm_banks = 0;
 	if (itcm_banks > 2)
 		itcm_banks = 0;

 	/* Setup DTCM if present */
 	if (dtcm_banks > 0) {
 		for (i = 0; i < dtcm_banks; i++) {
 			ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
 			if (ret)
 				return;
 		}
 		/* This means you compiled more code than fits into DTCM */
 		if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
 			pr_info("CPU DTCM: %u bytes of code compiled to "
 				"DTCM but only %lu bytes of DTCM present\n",
 				dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
 			goto no_dtcm;
 		}
 		dtcm_res.end = dtcm_end - 1;
 		request_resource(&iomem_resource, &dtcm_res);
 		dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
 		iotable_init(dtcm_iomap, 1);
 		/* Copy data from RAM to DTCM */
 		start = &__sdtcm_data;
 		end   = &__edtcm_data;
 		ram   = &__dtcm_start;
 		memcpy(start, ram, dtcm_code_sz);
 		pr_debug("CPU DTCM: copied data from %p - %p\n",
 			 start, end);
 		dtcm_present = true;
 	} else if (dtcm_code_sz) {
 		pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
 			"DTCM banks present in CPU\n", dtcm_code_sz);
 	}

 no_dtcm:
 	/* Setup ITCM if present */
 	if (itcm_banks > 0) {
 		for (i = 0; i < itcm_banks; i++) {
 			ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
 			if (ret)
 				return;
 		}
 		/* This means you compiled more code than fits into ITCM */
 		if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
 			pr_info("CPU ITCM: %u bytes of code compiled to "
 				"ITCM but only %lu bytes of ITCM present\n",
 				itcm_code_sz, (itcm_end - ITCM_OFFSET));
 			return;
 		}
 		itcm_res.end = itcm_end - 1;
 		request_resource(&iomem_resource, &itcm_res);
 		itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
 		iotable_init(itcm_iomap, 1);
 		/* Copy code from RAM to ITCM */
 		start = &__sitcm_text;
 		end   = &__eitcm_text;
 		ram   = &__itcm_start;
 		memcpy(start, ram, itcm_code_sz);
 		pr_debug("CPU ITCM: copied code from %p - %p\n",
 			 start, end);
 		itcm_present = true;
 	} else if (itcm_code_sz) {
 		pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
 			"ITCM banks present in CPU\n", itcm_code_sz);
 	}
 }

 /*
  * This creates the TCM memory pool and has to be done later,
  * during the core_initicalls, since the allocator is not yet
  * up and running when the first initialization runs.
  */
 static int __init setup_tcm_pool(void)
 {
 	u32 dtcm_pool_start = (u32) &__edtcm_data;
 	u32 itcm_pool_start = (u32) &__eitcm_text;
 	int ret;

 	/*
 	 * Set up malloc pool, 2^2 = 4 bytes granularity since
 	 * the TCM is sometimes just 4 KiB. NB: pages and cache
 	 * line alignments does not matter in TCM!
 	 */
 	tcm_pool = gen_pool_create(2, -1);

 	pr_debug("Setting up TCM memory pool\n");

 	/* Add the rest of DTCM to the TCM pool */
 	if (dtcm_present) {
 		if (dtcm_pool_start < dtcm_end) {
 			ret = gen_pool_add(tcm_pool, dtcm_pool_start,
 					   dtcm_end - dtcm_pool_start, -1);
 			if (ret) {
 				pr_err("CPU DTCM: could not add DTCM " \
 				       "remainder to pool!\n");
 				return ret;
 			}
 			pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
 				 "the TCM memory pool\n",
 				 dtcm_end - dtcm_pool_start,
 				 dtcm_pool_start);
 		}
 	}

 	/* Add the rest of ITCM to the TCM pool */
 	if (itcm_present) {
 		if (itcm_pool_start < itcm_end) {
 			ret = gen_pool_add(tcm_pool, itcm_pool_start,
 					   itcm_end - itcm_pool_start, -1);
 			if (ret) {
 				pr_err("CPU ITCM: could not add ITCM " \
 				       "remainder to pool!\n");
 				return ret;
 			}
 			pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
 				 "the TCM memory pool\n",
 				 itcm_end - itcm_pool_start,
 				 itcm_pool_start);
 		}
 	}
 	return 0;
 }

 core_initcall(setup_tcm_pool);
	/*
	* Copyright (C) 2008-2009 ST-Ericsson AB
	* License terms: GNU General Public License (GPL) version 2
	* TCM memory handling for ARM systems
	*
	* Author: Linus Walleij <linus.walleij@stericsson.com>
	* Author: Rickard Andersson <rickard.andersson@stericsson.com>
	*/
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/stddef.h>
	#include <linux/ioport.h>
	#include <linux/genalloc.h>
	#include <linux/string.h> /* memcpy */
	#include <asm/cputype.h>
	#include <asm/mach/map.h>
	#include <asm/memory.h>
	#include <asm/system_info.h>
	#include "tcm.h"

	static struct gen_pool *tcm_pool;
	static bool dtcm_present;
	static bool itcm_present;

	/* TCM section definitions from the linker */
	extern char __itcm_start, __sitcm_text, __eitcm_text;
	extern char __dtcm_start, __sdtcm_data, __edtcm_data;

	/* These will be increased as we run */
	u32 dtcm_end = DTCM_OFFSET;
	u32 itcm_end = ITCM_OFFSET;

	/*
	* TCM memory resources
	*/
	static struct resource dtcm_res = {
	.name = "DTCM RAM",
	.start = DTCM_OFFSET,
	.end = DTCM_OFFSET,
	.flags = IORESOURCE_MEM
	};

	static struct resource itcm_res = {
	.name = "ITCM RAM",
	.start = ITCM_OFFSET,
	.end = ITCM_OFFSET,
	.flags = IORESOURCE_MEM
	};

	static struct map_desc dtcm_iomap[] __initdata = {
	{
	.virtual = DTCM_OFFSET,
	.pfn = __phys_to_pfn(DTCM_OFFSET),
	.length = 0,
	.type = MT_MEMORY_DTCM
	}
	};

	static struct map_desc itcm_iomap[] __initdata = {
	{
	.virtual = ITCM_OFFSET,
	.pfn = __phys_to_pfn(ITCM_OFFSET),
	.length = 0,
	.type = MT_MEMORY_ITCM
	}
	};

	/*
	* Allocate a chunk of TCM memory
	*/
	void *tcm_alloc(size_t len)
	{
	unsigned long vaddr;

	if (!tcm_pool)
	return NULL;

	vaddr = gen_pool_alloc(tcm_pool, len);
	if (!vaddr)
	return NULL;

	return (void *) vaddr;
	}
	EXPORT_SYMBOL(tcm_alloc);

	/*
	* Free a chunk of TCM memory
	*/
	void tcm_free(void *addr, size_t len)
	{
	gen_pool_free(tcm_pool, (unsigned long) addr, len);
	}
	EXPORT_SYMBOL(tcm_free);

	bool tcm_dtcm_present(void)
	{
	return dtcm_present;
	}
	EXPORT_SYMBOL(tcm_dtcm_present);

	bool tcm_itcm_present(void)
	{
	return itcm_present;
	}
	EXPORT_SYMBOL(tcm_itcm_present);

	static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
	u32 *offset)
	{
	const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
	256, 512, 1024, -1, -1, -1, -1 };
	u32 tcm_region;
	int tcm_size;

	/*
	* If there are more than one TCM bank of this type,
	* select the TCM bank to operate on in the TCM selection
	* register.
	*/
	if (banks > 1)
	asm("mcr p15, 0, %0, c9, c2, 0"
	: /* No output operands */
	: "r" (bank));

	/* Read the special TCM region register c9, 0 */
	if (!type)
	asm("mrc p15, 0, %0, c9, c1, 0"
	: "=r" (tcm_region));
	else
	asm("mrc p15, 0, %0, c9, c1, 1"
	: "=r" (tcm_region));

	tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
	if (tcm_size < 0) {
	pr_err("CPU: %sTCM%d of unknown size\n",
	type ? "I" : "D", bank);
	return -EINVAL;
	} else if (tcm_size > 32) {
	pr_err("CPU: %sTCM%d larger than 32k found\n",
	type ? "I" : "D", bank);
	return -EINVAL;
	} else {
	pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
	type ? "I" : "D",
	bank,
	tcm_size,
	(tcm_region & 0xfffff000U),
	(tcm_region & 1) ? "" : "not ");
	}

	/* Not much fun you can do with a size 0 bank */
	if (tcm_size == 0)
	return 0;

	/* Force move the TCM bank to where we want it, enable */
	tcm_region = *offset \| (tcm_region & 0x00000ffeU) \| 1;

	if (!type)
	asm("mcr p15, 0, %0, c9, c1, 0"
	: /* No output operands */
	: "r" (tcm_region));
	else
	asm("mcr p15, 0, %0, c9, c1, 1"
	: /* No output operands */
	: "r" (tcm_region));

	/* Increase offset */
	*offset += (tcm_size << 10);

	pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
	type ? "I" : "D",
	bank,
	tcm_size,
	(tcm_region & 0xfffff000U));
	return 0;
	}

	/*
	* This initializes the TCM memory
	*/
	void __init tcm_init(void)
	{
	u32 tcm_status;
	u8 dtcm_banks;
	u8 itcm_banks;
	size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
	size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
	char *start;
	char *end;
	char *ram;
	int ret;
	int i;

	/*
	* Prior to ARMv5 there is no TCM, and trying to read the status
	* register will hang the processor.
	*/
	if (cpu_architecture() < CPU_ARCH_ARMv5) {
	if (dtcm_code_sz \|\| itcm_code_sz)
	pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
	"ITCM code compiled in, but no TCM present "
	"in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz);
	return;
	}

	tcm_status = read_cpuid_tcmstatus();
	dtcm_banks = (tcm_status >> 16) & 0x03;
	itcm_banks = (tcm_status & 0x03);

	/* Values greater than 2 for D/ITCM banks are "reserved" */
	if (dtcm_banks > 2)
	dtcm_banks = 0;
	if (itcm_banks > 2)
	itcm_banks = 0;

	/* Setup DTCM if present */
	if (dtcm_banks > 0) {
	for (i = 0; i < dtcm_banks; i++) {
	ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
	if (ret)
	return;
	}
	/* This means you compiled more code than fits into DTCM */
	if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
	pr_info("CPU DTCM: %u bytes of code compiled to "
	"DTCM but only %lu bytes of DTCM present\n",
	dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
	goto no_dtcm;
	}
	dtcm_res.end = dtcm_end - 1;
	request_resource(&iomem_resource, &dtcm_res);
	dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
	iotable_init(dtcm_iomap, 1);
	/* Copy data from RAM to DTCM */
	start = &__sdtcm_data;
	end = &__edtcm_data;
	ram = &__dtcm_start;
	memcpy(start, ram, dtcm_code_sz);
	pr_debug("CPU DTCM: copied data from %p - %p\n",
	start, end);
	dtcm_present = true;
	} else if (dtcm_code_sz) {
	pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
	"DTCM banks present in CPU\n", dtcm_code_sz);
	}

	no_dtcm:
	/* Setup ITCM if present */
	if (itcm_banks > 0) {
	for (i = 0; i < itcm_banks; i++) {
	ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
	if (ret)
	return;
	}
	/* This means you compiled more code than fits into ITCM */
	if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
	pr_info("CPU ITCM: %u bytes of code compiled to "
	"ITCM but only %lu bytes of ITCM present\n",
	itcm_code_sz, (itcm_end - ITCM_OFFSET));
	return;
	}
	itcm_res.end = itcm_end - 1;
	request_resource(&iomem_resource, &itcm_res);
	itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
	iotable_init(itcm_iomap, 1);
	/* Copy code from RAM to ITCM */
	start = &__sitcm_text;
	end = &__eitcm_text;
	ram = &__itcm_start;
	memcpy(start, ram, itcm_code_sz);
	pr_debug("CPU ITCM: copied code from %p - %p\n",
	start, end);
	itcm_present = true;
	} else if (itcm_code_sz) {
	pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
	"ITCM banks present in CPU\n", itcm_code_sz);
	}
	}

	/*
	* This creates the TCM memory pool and has to be done later,
	* during the core_initicalls, since the allocator is not yet
	* up and running when the first initialization runs.
	*/
	static int __init setup_tcm_pool(void)
	{
	u32 dtcm_pool_start = (u32) &__edtcm_data;
	u32 itcm_pool_start = (u32) &__eitcm_text;
	int ret;

	/*
	* Set up malloc pool, 2^2 = 4 bytes granularity since
	* the TCM is sometimes just 4 KiB. NB: pages and cache
	* line alignments does not matter in TCM!
	*/
	tcm_pool = gen_pool_create(2, -1);

	pr_debug("Setting up TCM memory pool\n");

	/* Add the rest of DTCM to the TCM pool */
	if (dtcm_present) {
	if (dtcm_pool_start < dtcm_end) {
	ret = gen_pool_add(tcm_pool, dtcm_pool_start,
	dtcm_end - dtcm_pool_start, -1);
	if (ret) {
	pr_err("CPU DTCM: could not add DTCM " \
	"remainder to pool!\n");
	return ret;
	}
	pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
	"the TCM memory pool\n",
	dtcm_end - dtcm_pool_start,
	dtcm_pool_start);
	}
	}

	/* Add the rest of ITCM to the TCM pool */
	if (itcm_present) {
	if (itcm_pool_start < itcm_end) {
	ret = gen_pool_add(tcm_pool, itcm_pool_start,
	itcm_end - itcm_pool_start, -1);
	if (ret) {
	pr_err("CPU ITCM: could not add ITCM " \
	"remainder to pool!\n");
	return ret;
	}
	pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
	"the TCM memory pool\n",
	itcm_end - itcm_pool_start,
	itcm_pool_start);
	}
	}
	return 0;
	}

	core_initcall(setup_tcm_pool);