cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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init.c (6530B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Memory subsystem initialization for Hexagon
      4 *
      5 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
      6 */
      7
      8#include <linux/init.h>
      9#include <linux/mm.h>
     10#include <linux/memblock.h>
     11#include <asm/atomic.h>
     12#include <linux/highmem.h>
     13#include <asm/tlb.h>
     14#include <asm/sections.h>
     15#include <asm/vm_mmu.h>
     16
     17/*
     18 * Define a startpg just past the end of the kernel image and a lastpg
     19 * that corresponds to the end of real or simulated platform memory.
     20 */
     21#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
     22
     23unsigned long bootmem_lastpg;	/*  Should be set by platform code  */
     24unsigned long __phys_offset;	/*  physical kernel offset >> 12  */
     25
     26/*  Set as variable to limit PMD copies  */
     27int max_kernel_seg = 0x303;
     28
     29/*  indicate pfn's of high memory  */
     30unsigned long highstart_pfn, highend_pfn;
     31
     32/* Default cache attribute for newly created page tables */
     33unsigned long _dflt_cache_att = CACHEDEF;
     34
     35/*
     36 * The current "generation" of kernel map, which should not roll
     37 * over until Hell freezes over.  Actual bound in years needs to be
     38 * calculated to confirm.
     39 */
     40DEFINE_SPINLOCK(kmap_gen_lock);
     41
     42/*  checkpatch says don't init this to 0.  */
     43unsigned long long kmap_generation;
     44
     45/*
     46 * mem_init - initializes memory
     47 *
     48 * Frees up bootmem
     49 * Fixes up more stuff for HIGHMEM
     50 * Calculates and displays memory available/used
     51 */
     52void __init mem_init(void)
     53{
     54	/*  No idea where this is actually declared.  Seems to evade LXR.  */
     55	memblock_free_all();
     56
     57	/*
     58	 *  To-Do:  someone somewhere should wipe out the bootmem map
     59	 *  after we're done?
     60	 */
     61
     62	/*
     63	 * This can be moved to some more virtual-memory-specific
     64	 * initialization hook at some point.  Set the init_mm
     65	 * descriptors "context" value to point to the initial
     66	 * kernel segment table's physical address.
     67	 */
     68	init_mm.context.ptbase = __pa(init_mm.pgd);
     69}
     70
     71void sync_icache_dcache(pte_t pte)
     72{
     73	unsigned long addr;
     74	struct page *page;
     75
     76	page = pte_page(pte);
     77	addr = (unsigned long) page_address(page);
     78
     79	__vmcache_idsync(addr, PAGE_SIZE);
     80}
     81
     82/*
     83 * In order to set up page allocator "nodes",
     84 * somebody has to call free_area_init() for UMA.
     85 *
     86 * In this mode, we only have one pg_data_t
     87 * structure: contig_mem_data.
     88 */
     89void __init paging_init(void)
     90{
     91	unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
     92
     93	/*
     94	 *  This is not particularly well documented anywhere, but
     95	 *  give ZONE_NORMAL all the memory, including the big holes
     96	 *  left by the kernel+bootmem_map which are already left as reserved
     97	 *  in the bootmem_map; free_area_init should see those bits and
     98	 *  adjust accordingly.
     99	 */
    100
    101	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
    102
    103	free_area_init(max_zone_pfn);  /*  sets up the zonelists and mem_map  */
    104
    105	/*
    106	 * Start of high memory area.  Will probably need something more
    107	 * fancy if we...  get more fancy.
    108	 */
    109	high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT);
    110}
    111
    112#ifndef DMA_RESERVE
    113#define DMA_RESERVE		(4)
    114#endif
    115
    116#define DMA_CHUNKSIZE		(1<<22)
    117#define DMA_RESERVED_BYTES	(DMA_RESERVE * DMA_CHUNKSIZE)
    118
    119/*
    120 * Pick out the memory size.  We look for mem=size,
    121 * where size is "size[KkMm]"
    122 */
    123static int __init early_mem(char *p)
    124{
    125	unsigned long size;
    126	char *endp;
    127
    128	size = memparse(p, &endp);
    129
    130	bootmem_lastpg = PFN_DOWN(size);
    131
    132	return 0;
    133}
    134early_param("mem", early_mem);
    135
    136size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22);
    137
    138void __init setup_arch_memory(void)
    139{
    140	/*  XXX Todo: this probably should be cleaned up  */
    141	u32 *segtable = (u32 *) &swapper_pg_dir[0];
    142	u32 *segtable_end;
    143
    144	/*
    145	 * Set up boot memory allocator
    146	 *
    147	 * The Gorman book also talks about these functions.
    148	 * This needs to change for highmem setups.
    149	 */
    150
    151	/*  Prior to this, bootmem_lastpg is actually mem size  */
    152	bootmem_lastpg += ARCH_PFN_OFFSET;
    153
    154	/* Memory size needs to be a multiple of 16M */
    155	bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
    156		~((BIG_KERNEL_PAGE_SIZE) - 1));
    157
    158	memblock_add(PHYS_OFFSET,
    159		     (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
    160
    161	/* Reserve kernel text/data/bss */
    162	memblock_reserve(PHYS_OFFSET,
    163			 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
    164	/*
    165	 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
    166	 * memory allocation
    167	 */
    168	max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
    169	min_low_pfn = ARCH_PFN_OFFSET;
    170	memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES);
    171
    172	printk(KERN_INFO "bootmem_startpg:  0x%08lx\n", bootmem_startpg);
    173	printk(KERN_INFO "bootmem_lastpg:  0x%08lx\n", bootmem_lastpg);
    174	printk(KERN_INFO "min_low_pfn:  0x%08lx\n", min_low_pfn);
    175	printk(KERN_INFO "max_low_pfn:  0x%08lx\n", max_low_pfn);
    176
    177	/*
    178	 * The default VM page tables (will be) populated with
    179	 * VA=PA+PAGE_OFFSET mapping.  We go in and invalidate entries
    180	 * higher than what we have memory for.
    181	 */
    182
    183	/*  this is pointer arithmetic; each entry covers 4MB  */
    184	segtable = segtable + (PAGE_OFFSET >> 22);
    185
    186	/*  this actually only goes to the end of the first gig  */
    187	segtable_end = segtable + (1<<(30-22));
    188
    189	/*
    190	 * Move forward to the start of empty pages; take into account
    191	 * phys_offset shift.
    192	 */
    193
    194	segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
    195	{
    196		int i;
    197
    198		for (i = 1 ; i <= DMA_RESERVE ; i++)
    199			segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
    200				| __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
    201				| __HEXAGON_C_UNC << 6
    202				| __HVM_PDE_S_4MB);
    203	}
    204
    205	printk(KERN_INFO "clearing segtable from %p to %p\n", segtable,
    206		segtable_end);
    207	while (segtable < (segtable_end-8))
    208		*(segtable++) = __HVM_PDE_S_INVALID;
    209	/* stop the pointer at the device I/O 4MB page  */
    210
    211	printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n",
    212		segtable);
    213
    214#if 0
    215	/*  Other half of the early device table from vm_init_segtable. */
    216	printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n",
    217		(unsigned long) _K_init_devicetable-PAGE_OFFSET);
    218	*segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) |
    219		__HVM_PDE_S_4KB;
    220	printk(KERN_INFO "*segtable = 0x%08x\n", *segtable);
    221#endif
    222
    223	/*
    224	 *  The bootmem allocator seemingly just lives to feed memory
    225	 *  to the paging system
    226	 */
    227	printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE);
    228	paging_init();  /*  See Gorman Book, 2.3  */
    229
    230	/*
    231	 *  At this point, the page allocator is kind of initialized, but
    232	 *  apparently no pages are available (just like with the bootmem
    233	 *  allocator), and need to be freed themselves via mem_init(),
    234	 *  which is called by start_kernel() later on in the process
    235	 */
    236}