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Diffstat (limited to 'arch/hexagon/mm/init.c')
| -rw-r--r-- | arch/hexagon/mm/init.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c new file mode 100644 index 000000000..88977e42a --- /dev/null +++ b/arch/hexagon/mm/init.c @@ -0,0 +1,283 @@ +/* + * Memory subsystem initialization for Hexagon + * + * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/bootmem.h> +#include <asm/atomic.h> +#include <linux/highmem.h> +#include <asm/tlb.h> +#include <asm/sections.h> +#include <asm/vm_mmu.h> + +/* + * Define a startpg just past the end of the kernel image and a lastpg + * that corresponds to the end of real or simulated platform memory. + */ +#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET)) + +unsigned long bootmem_lastpg; /* Should be set by platform code */ +unsigned long __phys_offset; /* physical kernel offset >> 12 */ + +/* Set as variable to limit PMD copies */ +int max_kernel_seg = 0x303; + +/* think this should be (page_size-1) the way it's used...*/ +unsigned long zero_page_mask; + +/* indicate pfn's of high memory */ +unsigned long highstart_pfn, highend_pfn; + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); + +/* Default cache attribute for newly created page tables */ +unsigned long _dflt_cache_att = CACHEDEF; + +/* + * The current "generation" of kernel map, which should not roll + * over until Hell freezes over. Actual bound in years needs to be + * calculated to confirm. + */ +DEFINE_SPINLOCK(kmap_gen_lock); + +/* checkpatch says don't init this to 0. */ +unsigned long long kmap_generation; + +/* + * mem_init - initializes memory + * + * Frees up bootmem + * Fixes up more stuff for HIGHMEM + * Calculates and displays memory available/used + */ +void __init mem_init(void) +{ + /* No idea where this is actually declared. Seems to evade LXR. */ + free_all_bootmem(); + mem_init_print_info(NULL); + + /* + * To-Do: someone somewhere should wipe out the bootmem map + * after we're done? + */ + + /* + * This can be moved to some more virtual-memory-specific + * initialization hook at some point. Set the init_mm + * descriptors "context" value to point to the initial + * kernel segment table's physical address. + */ + init_mm.context.ptbase = __pa(init_mm.pgd); +} + +/* + * free_initmem - frees memory used by stuff declared with __init + * + * Todo: free pages between __init_begin and __init_end; possibly + * some devtree related stuff as well. + */ +void __init_refok free_initmem(void) +{ +} + +/* + * free_initrd_mem - frees... initrd memory. + * @start - start of init memory + * @end - end of init memory + * + * Apparently has to be passed the address of the initrd memory. + * + * Wrapped by #ifdef CONFIG_BLKDEV_INITRD + */ +void free_initrd_mem(unsigned long start, unsigned long end) +{ +} + +void sync_icache_dcache(pte_t pte) +{ + unsigned long addr; + struct page *page; + + page = pte_page(pte); + addr = (unsigned long) page_address(page); + + __vmcache_idsync(addr, PAGE_SIZE); +} + +/* + * In order to set up page allocator "nodes", + * somebody has to call free_area_init() for UMA. + * + * In this mode, we only have one pg_data_t + * structure: contig_mem_data. + */ +void __init paging_init(void) +{ + unsigned long zones_sizes[MAX_NR_ZONES] = {0, }; + + /* + * This is not particularly well documented anywhere, but + * give ZONE_NORMAL all the memory, including the big holes + * left by the kernel+bootmem_map which are already left as reserved + * in the bootmem_map; free_area_init should see those bits and + * adjust accordingly. + */ + + zones_sizes[ZONE_NORMAL] = max_low_pfn; + + free_area_init(zones_sizes); /* sets up the zonelists and mem_map */ + + /* + * Start of high memory area. Will probably need something more + * fancy if we... get more fancy. + */ + high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT); +} + +#ifndef DMA_RESERVE +#define DMA_RESERVE (4) +#endif + +#define DMA_CHUNKSIZE (1<<22) +#define DMA_RESERVED_BYTES (DMA_RESERVE * DMA_CHUNKSIZE) + +/* + * Pick out the memory size. We look for mem=size, + * where size is "size[KkMm]" + */ +static int __init early_mem(char *p) +{ + unsigned long size; + char *endp; + + size = memparse(p, &endp); + + bootmem_lastpg = PFN_DOWN(size); + + return 0; +} +early_param("mem", early_mem); + +size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22); + +void __init setup_arch_memory(void) +{ + int bootmap_size; + /* XXX Todo: this probably should be cleaned up */ + u32 *segtable = (u32 *) &swapper_pg_dir[0]; + u32 *segtable_end; + + /* + * Set up boot memory allocator + * + * The Gorman book also talks about these functions. + * This needs to change for highmem setups. + */ + + /* Prior to this, bootmem_lastpg is actually mem size */ + bootmem_lastpg += ARCH_PFN_OFFSET; + + /* Memory size needs to be a multiple of 16M */ + bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) & + ~((BIG_KERNEL_PAGE_SIZE) - 1)); + + /* + * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached) + * memory allocation + */ + + max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES); + min_low_pfn = ARCH_PFN_OFFSET; + bootmap_size = init_bootmem_node(NODE_DATA(0), bootmem_startpg, min_low_pfn, max_low_pfn); + + printk(KERN_INFO "bootmem_startpg: 0x%08lx\n", bootmem_startpg); + printk(KERN_INFO "bootmem_lastpg: 0x%08lx\n", bootmem_lastpg); + printk(KERN_INFO "bootmap_size: %d\n", bootmap_size); + printk(KERN_INFO "min_low_pfn: 0x%08lx\n", min_low_pfn); + printk(KERN_INFO "max_low_pfn: 0x%08lx\n", max_low_pfn); + + /* + * The default VM page tables (will be) populated with + * VA=PA+PAGE_OFFSET mapping. We go in and invalidate entries + * higher than what we have memory for. + */ + + /* this is pointer arithmetic; each entry covers 4MB */ + segtable = segtable + (PAGE_OFFSET >> 22); + + /* this actually only goes to the end of the first gig */ + segtable_end = segtable + (1<<(30-22)); + + /* + * Move forward to the start of empty pages; take into account + * phys_offset shift. + */ + + segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT); + { + int i; + + for (i = 1 ; i <= DMA_RESERVE ; i++) + segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB) + | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X + | __HEXAGON_C_UNC << 6 + | __HVM_PDE_S_4MB); + } + + printk(KERN_INFO "clearing segtable from %p to %p\n", segtable, + segtable_end); + while (segtable < (segtable_end-8)) + *(segtable++) = __HVM_PDE_S_INVALID; + /* stop the pointer at the device I/O 4MB page */ + + printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n", + segtable); + +#if 0 + /* Other half of the early device table from vm_init_segtable. */ + printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n", + (unsigned long) _K_init_devicetable-PAGE_OFFSET); + *segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) | + __HVM_PDE_S_4KB; + printk(KERN_INFO "*segtable = 0x%08x\n", *segtable); +#endif + + /* + * Free all the memory that wasn't taken up by the bootmap, the DMA + * reserve, or kernel itself. + */ + free_bootmem(PFN_PHYS(bootmem_startpg) + bootmap_size, + PFN_PHYS(bootmem_lastpg - bootmem_startpg) - bootmap_size - + DMA_RESERVED_BYTES); + + /* + * The bootmem allocator seemingly just lives to feed memory + * to the paging system + */ + printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE); + paging_init(); /* See Gorman Book, 2.3 */ + + /* + * At this point, the page allocator is kind of initialized, but + * apparently no pages are available (just like with the bootmem + * allocator), and need to be freed themselves via mem_init(), + * which is called by start_kernel() later on in the process + */ +} |