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129 lines
2.8 KiB
129 lines
2.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/arch/arm/plat-omap/sram.c |
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* |
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* OMAP SRAM detection and management |
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* |
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* Copyright (C) 2005 Nokia Corporation |
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* Written by Tony Lindgren <[email protected]> |
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* |
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* Copyright (C) 2009-2012 Texas Instruments |
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* Added OMAP4/5 support - Santosh Shilimkar <[email protected]> |
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*/ |
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#undef DEBUG |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <asm/fncpy.h> |
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#include <asm/tlb.h> |
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#include <asm/cacheflush.h> |
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#include <asm/set_memory.h> |
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#include <asm/mach/map.h> |
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#include <plat/sram.h> |
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#define ROUND_DOWN(value,boundary) ((value) & (~((boundary)-1))) |
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static void __iomem *omap_sram_base; |
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static unsigned long omap_sram_skip; |
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static unsigned long omap_sram_size; |
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static void __iomem *omap_sram_ceil; |
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/* |
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* Memory allocator for SRAM: calculates the new ceiling address |
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* for pushing a function using the fncpy API. |
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* |
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* Note that fncpy requires the returned address to be aligned |
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* to an 8-byte boundary. |
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*/ |
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static void *omap_sram_push_address(unsigned long size) |
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{ |
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unsigned long available, new_ceil = (unsigned long)omap_sram_ceil; |
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available = omap_sram_ceil - (omap_sram_base + omap_sram_skip); |
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if (size > available) { |
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pr_err("Not enough space in SRAM\n"); |
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return NULL; |
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} |
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new_ceil -= size; |
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new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN); |
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omap_sram_ceil = IOMEM(new_ceil); |
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return (void *)omap_sram_ceil; |
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} |
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void *omap_sram_push(void *funcp, unsigned long size) |
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{ |
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void *sram; |
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unsigned long base; |
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int pages; |
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void *dst = NULL; |
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sram = omap_sram_push_address(size); |
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if (!sram) |
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return NULL; |
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base = (unsigned long)sram & PAGE_MASK; |
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pages = PAGE_ALIGN(size) / PAGE_SIZE; |
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set_memory_rw(base, pages); |
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dst = fncpy(sram, funcp, size); |
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set_memory_ro(base, pages); |
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set_memory_x(base, pages); |
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return dst; |
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} |
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/* |
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* The SRAM context is lost during off-idle and stack |
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* needs to be reset. |
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*/ |
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void omap_sram_reset(void) |
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{ |
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omap_sram_ceil = omap_sram_base + omap_sram_size; |
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} |
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/* |
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* Note that we cannot use ioremap for SRAM, as clock init needs SRAM early. |
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*/ |
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void __init omap_map_sram(unsigned long start, unsigned long size, |
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unsigned long skip, int cached) |
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{ |
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unsigned long base; |
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int pages; |
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if (size == 0) |
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return; |
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start = ROUND_DOWN(start, PAGE_SIZE); |
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omap_sram_size = size; |
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omap_sram_skip = skip; |
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omap_sram_base = __arm_ioremap_exec(start, size, cached); |
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if (!omap_sram_base) { |
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pr_err("SRAM: Could not map\n"); |
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return; |
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} |
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omap_sram_reset(); |
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/* |
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* Looks like we need to preserve some bootloader code at the |
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* beginning of SRAM for jumping to flash for reboot to work... |
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*/ |
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memset_io(omap_sram_base + omap_sram_skip, 0, |
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omap_sram_size - omap_sram_skip); |
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base = (unsigned long)omap_sram_base; |
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pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE; |
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set_memory_ro(base, pages); |
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set_memory_x(base, pages); |
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}
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