diff options
Diffstat (limited to 'kernel/arch/arm/plat-omap/sram.c')
-rw-r--r-- | kernel/arch/arm/plat-omap/sram.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/kernel/arch/arm/plat-omap/sram.c b/kernel/arch/arm/plat-omap/sram.c new file mode 100644 index 000000000..a5bc92d7e --- /dev/null +++ b/kernel/arch/arm/plat-omap/sram.c @@ -0,0 +1,98 @@ +/* + * 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); +} |