From 14aa7e8bf6d84c9a42c48e7f93472d830f694b1e Mon Sep 17 00:00:00 2001 From: Aurelien Jacquiot Date: Tue, 4 Oct 2011 12:17:19 -0400 Subject: C6X: memory management and DMA support Original port to early 2.6 kernel using TI COFF toolchain. Brought up to date by Mark Salter The C6X architecture currently lacks an MMU so memory management is relatively simple. There is no bus snooping between L2 and main memory but coherent DMA memory is supported by making regions of main memory uncached. If such a region is desired, it can be specified on the commandline with a "memdma=" argument. Signed-off-by: Aurelien Jacquiot Signed-off-by: Mark Salter Acked-by: Arnd Bergmann --- arch/c6x/mm/init.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 arch/c6x/mm/init.c (limited to 'arch/c6x/mm/init.c') diff --git a/arch/c6x/mm/init.c b/arch/c6x/mm/init.c new file mode 100644 index 000000000000..89395f09648a --- /dev/null +++ b/arch/c6x/mm/init.c @@ -0,0 +1,113 @@ +/* + * Port on Texas Instruments TMS320C6x architecture + * + * Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated + * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.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. + */ +#include +#include +#include +#include +#ifdef CONFIG_BLK_DEV_RAM +#include +#endif +#include + +#include + +/* + * ZERO_PAGE is a special page that is used for zero-initialized + * data and COW. + */ +unsigned long empty_zero_page; +EXPORT_SYMBOL(empty_zero_page); + +/* + * paging_init() continues the virtual memory environment setup which + * was begun by the code in arch/head.S. + * The parameters are pointers to where to stick the starting and ending + * addresses of available kernel virtual memory. + */ +void __init paging_init(void) +{ + struct pglist_data *pgdat = NODE_DATA(0); + unsigned long zones_size[MAX_NR_ZONES] = {0, }; + + empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); + memset((void *)empty_zero_page, 0, PAGE_SIZE); + + /* + * Set up user data space + */ + set_fs(KERNEL_DS); + + /* + * Define zones + */ + zones_size[ZONE_NORMAL] = (memory_end - PAGE_OFFSET) >> PAGE_SHIFT; + pgdat->node_zones[ZONE_NORMAL].zone_start_pfn = + __pa(PAGE_OFFSET) >> PAGE_SHIFT; + + free_area_init(zones_size); +} + +void __init mem_init(void) +{ + int codek, datak; + unsigned long tmp; + unsigned long len = memory_end - memory_start; + + high_memory = (void *)(memory_end & PAGE_MASK); + + /* this will put all memory onto the freelists */ + totalram_pages = free_all_bootmem(); + + codek = (_etext - _stext) >> 10; + datak = (_end - _sdata) >> 10; + + tmp = nr_free_pages() << PAGE_SHIFT; + printk(KERN_INFO "Memory: %luk/%luk RAM (%dk kernel code, %dk data)\n", + tmp >> 10, len >> 10, codek, datak); +} + +#ifdef CONFIG_BLK_DEV_INITRD +void __init free_initrd_mem(unsigned long start, unsigned long end) +{ + int pages = 0; + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + init_page_count(virt_to_page(start)); + free_page(start); + totalram_pages++; + pages++; + } + printk(KERN_INFO "Freeing initrd memory: %luk freed\n", + (pages * PAGE_SIZE) >> 10); +} +#endif + +void __init free_initmem(void) +{ + unsigned long addr; + + /* + * The following code should be cool even if these sections + * are not page aligned. + */ + addr = PAGE_ALIGN((unsigned long)(__init_begin)); + + /* next to check that the page we free is not a partial page */ + for (; addr + PAGE_SIZE < (unsigned long)(__init_end); + addr += PAGE_SIZE) { + ClearPageReserved(virt_to_page(addr)); + init_page_count(virt_to_page(addr)); + free_page(addr); + totalram_pages++; + } + printk(KERN_INFO "Freeing unused kernel memory: %dK freed\n", + (int) ((addr - PAGE_ALIGN((long) &__init_begin)) >> 10)); +} -- cgit