// SPDX-License-Identifier: GPL-2.0-only /* * Memory subsystem initialization for Hexagon * * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. */ #include <linux/init.h> #include <linux/mm.h> #include <linux/memblock.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; /* 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. */ memblock_free_all(); 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); } 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) { /* 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)); memblock_add(PHYS_OFFSET, (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); /* Reserve kernel text/data/bss */ memblock_reserve(PHYS_OFFSET, (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); /* * 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; memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES); printk(KERN_INFO "bootmem_startpg: 0x%08lx\n", bootmem_startpg); printk(KERN_INFO "bootmem_lastpg: 0x%08lx\n", bootmem_lastpg); 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 /* * 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 */ }