[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / plat-omap / sram.c

/*
 * linux/arch/arm/plat-omap/sram.c
 *
 * OMAP SRAM detection and management
 *
 * Copyright (C) 2005 Nokia Corporation
 * Written by Tony Lindgren <tony@atomide.com>
 *
 * Copyright (C) 2009-2012 Texas Instruments
 * Added OMAP4/5 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>

#include <asm/fncpy.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>

#include <asm/mach/map.h>

#include <plat/sram.h>

#define ROUND_DOWN(value,boundary)	((value) & (~((boundary)-1)))

static void __iomem *omap_sram_base;
static unsigned long omap_sram_skip;
static unsigned long omap_sram_size;
static void __iomem *omap_sram_ceil;

/*
 * Memory allocator for SRAM: calculates the new ceiling address
 * for pushing a function using the fncpy API.
 *
 * Note that fncpy requires the returned address to be aligned
 * to an 8-byte boundary.
 */
void *omap_sram_push_address(unsigned long size)
{
	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;

	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);

	if (size > available) {
		pr_err("Not enough space in SRAM\n");
		return NULL;
	}

	new_ceil -= size;
	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
	omap_sram_ceil = IOMEM(new_ceil);

	return (void *)omap_sram_ceil;
}

/*
 * The SRAM context is lost during off-idle and stack
 * needs to be reset.
 */
void omap_sram_reset(void)
{
	omap_sram_ceil = omap_sram_base + omap_sram_size;
}

/*
 * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
 */
void __init omap_map_sram(unsigned long start, unsigned long size,
				 unsigned long skip, int cached)
{
	if (size == 0)
		return;

	start = ROUND_DOWN(start, PAGE_SIZE);
	omap_sram_size = size;
	omap_sram_skip = skip;
	omap_sram_base = __arm_ioremap_exec(start, size, cached);
	if (!omap_sram_base) {
		pr_err("SRAM: Could not map\n");
		return;
	}

	omap_sram_reset();

	/*
	 * Looks like we need to preserve some bootloader code at the
	 * beginning of SRAM for jumping to flash for reboot to work...
	 */
	memset_io(omap_sram_base + omap_sram_skip, 0,
		  omap_sram_size - omap_sram_skip);
}
Commit	Line	Data
92105bb7 TL	1	/*
	2	* linux/arch/arm/plat-omap/sram.c
	3	*
	4	* OMAP SRAM detection and management
	5	*
	6	* Copyright (C) 2005 Nokia Corporation
	7	* Written by Tony Lindgren <tony@atomide.com>
	8	*
05e152c7 S	9	* Copyright (C) 2009-2012 Texas Instruments
05e152c7 S	10	* Added OMAP4/5 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
44169075	11	*
92105bb7 TL	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
c2d43e39	16	#undef DEBUG
92105bb7	17
92105bb7 TL	18	#include <linux/module.h>
	19	#include <linux/kernel.h>
	20	#include <linux/init.h>
fced80c7	21	#include <linux/io.h>
92105bb7	22
bf027ca1	23	#include <asm/fncpy.h>
53d9cc73	24	#include <asm/tlb.h>
92105bb7 TL	25	#include <asm/cacheflush.h>
92105bb7 TL	26
670c104a TL	27	#include <asm/mach/map.h>
670c104a TL	28
9fbe7c24 PW	29	#include <plat/sram.h>
9fbe7c24 PW	30
670c104a	31	#define ROUND_DOWN(value,boundary) ((value) & (~((boundary)-1)))
92105bb7	32
a66cb345	33	static void __iomem *omap_sram_base;
b2856734	34	static unsigned long omap_sram_skip;
92105bb7	35	static unsigned long omap_sram_size;
a66cb345	36	static void __iomem *omap_sram_ceil;
92105bb7	37
b6338bdc JP	38	/*
	39	* Memory allocator for SRAM: calculates the new ceiling address
	40	* for pushing a function using the fncpy API.
	41	*
	42	* Note that fncpy requires the returned address to be aligned
	43	* to an 8-byte boundary.
	44	*/
	45	void *omap_sram_push_address(unsigned long size)
92105bb7	46	{
a66cb345 TL	47	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
a66cb345 TL	48
b2856734	49	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
a66cb345 TL	50
a66cb345 TL	51	if (size > available) {
26a510ba	52	pr_err("Not enough space in SRAM\n");
92105bb7 TL	53	return NULL;
92105bb7 TL	54	}
670c104a	55
a66cb345 TL	56	new_ceil -= size;
	57	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
	58	omap_sram_ceil = IOMEM(new_ceil);
92105bb7 TL	59
	60	return (void *)omap_sram_ceil;
	61	}
	62
d8cfd6c8 TL	63	/*
	64	* The SRAM context is lost during off-idle and stack
	65	* needs to be reset.
	66	*/
	67	void omap_sram_reset(void)
	68	{
	69	omap_sram_ceil = omap_sram_base + omap_sram_size;
	70	}
	71
	72	/*
	73	* Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
	74	*/
	75	void __init omap_map_sram(unsigned long start, unsigned long size,
	76	unsigned long skip, int cached)
	77	{
	78	if (size == 0)
	79	return;
	80
	81	start = ROUND_DOWN(start, PAGE_SIZE);
	82	omap_sram_size = size;
	83	omap_sram_skip = skip;
	84	omap_sram_base = __arm_ioremap_exec(start, size, cached);
	85	if (!omap_sram_base) {
	86	pr_err("SRAM: Could not map\n");
	87	return;
	88	}
	89
	90	omap_sram_reset();
	91
	92	/*
	93	* Looks like we need to preserve some bootloader code at the
	94	* beginning of SRAM for jumping to flash for reboot to work...
	95	*/
	96	memset_io(omap_sram_base + omap_sram_skip, 0,
	97	omap_sram_size - omap_sram_skip);
	98	}