init.c

  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/setup.h>
 16#include <asm/vm_mmu.h>
 17
 18/*
 19 * Define a startpg just past the end of the kernel image and a lastpg
 20 * that corresponds to the end of real or simulated platform memory.
 21 */
 22#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
 23
 24unsigned long bootmem_lastpg;	/*  Should be set by platform code  */
 25unsigned long __phys_offset;	/*  physical kernel offset >> 12  */
 26
 27/*  Set as variable to limit PMD copies  */
 28int max_kernel_seg = 0x303;
 29
 30/*  indicate pfn's of high memory  */
 31unsigned long highstart_pfn, highend_pfn;
 32
 33/* Default cache attribute for newly created page tables */
 34unsigned long _dflt_cache_att = CACHEDEF;
 35
 36/*
 37 * The current "generation" of kernel map, which should not roll
 38 * over until Hell freezes over.  Actual bound in years needs to be
 39 * calculated to confirm.
 40 */
 41DEFINE_SPINLOCK(kmap_gen_lock);
 42
 43/*  checkpatch says don't init this to 0.  */
 44unsigned long long kmap_generation;
 45
 46void sync_icache_dcache(pte_t pte)
 47{
 48	unsigned long addr;
 49	struct page *page;
 50
 51	page = pte_page(pte);
 52	addr = (unsigned long) page_address(page);
 53
 54	__vmcache_idsync(addr, PAGE_SIZE);
 55}
 56
 57/*
 58 * In order to set up page allocator "nodes",
 59 * somebody has to call free_area_init() for UMA.
 60 *
 61 * In this mode, we only have one pg_data_t
 62 * structure: contig_mem_data.
 63 */
 64static void __init paging_init(void)
 65{
 66	unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
 67
 68	/*
 69	 *  This is not particularly well documented anywhere, but
 70	 *  give ZONE_NORMAL all the memory, including the big holes
 71	 *  left by the kernel+bootmem_map which are already left as reserved
 72	 *  in the bootmem_map; free_area_init should see those bits and
 73	 *  adjust accordingly.
 74	 */
 75
 76	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
 77
 78	free_area_init(max_zone_pfn);  /*  sets up the zonelists and mem_map  */
 79
 80	/*
 81	 * Set the init_mm descriptors "context" value to point to the
 82	 * initial kernel segment table's physical address.
 83	 */
 84	init_mm.context.ptbase = __pa(init_mm.pgd);
 85}
 86
 87#ifndef DMA_RESERVE
 88#define DMA_RESERVE		(4)
 89#endif
 90
 91#define DMA_CHUNKSIZE		(1<<22)
 92#define DMA_RESERVED_BYTES	(DMA_RESERVE * DMA_CHUNKSIZE)
 93
 94/*
 95 * Pick out the memory size.  We look for mem=size,
 96 * where size is "size[KkMm]"
 97 */
 98static int __init early_mem(char *p)
 99{
100	unsigned long size;
101	char *endp;
102
103	size = memparse(p, &endp);
104
105	bootmem_lastpg = PFN_DOWN(size);
106
107	return 0;
108}
109early_param("mem", early_mem);
110
111size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22);
112
113void __init setup_arch_memory(void)
114{
115	/*  XXX Todo: this probably should be cleaned up  */
116	u32 *segtable = (u32 *) &swapper_pg_dir[0];
117	u32 *segtable_end;
118
119	/*
120	 * Set up boot memory allocator
121	 *
122	 * The Gorman book also talks about these functions.
123	 * This needs to change for highmem setups.
124	 */
125
126	/*  Prior to this, bootmem_lastpg is actually mem size  */
127	bootmem_lastpg += ARCH_PFN_OFFSET;
128
129	/* Memory size needs to be a multiple of 16M */
130	bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
131		~((BIG_KERNEL_PAGE_SIZE) - 1));
132
133	memblock_add(PHYS_OFFSET,
134		     (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
135
136	/* Reserve kernel text/data/bss */
137	memblock_reserve(PHYS_OFFSET,
138			 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
139	/*
140	 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
141	 * memory allocation
142	 */
143	max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
144	min_low_pfn = ARCH_PFN_OFFSET;
145	memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES);
146
147	printk(KERN_INFO "bootmem_startpg:  0x%08lx\n", bootmem_startpg);
148	printk(KERN_INFO "bootmem_lastpg:  0x%08lx\n", bootmem_lastpg);
149	printk(KERN_INFO "min_low_pfn:  0x%08lx\n", min_low_pfn);
150	printk(KERN_INFO "max_low_pfn:  0x%08lx\n", max_low_pfn);
151
152	/*
153	 * The default VM page tables (will be) populated with
154	 * VA=PA+PAGE_OFFSET mapping.  We go in and invalidate entries
155	 * higher than what we have memory for.
156	 */
157
158	/*  this is pointer arithmetic; each entry covers 4MB  */
159	segtable = segtable + (PAGE_OFFSET >> 22);
160
161	/*  this actually only goes to the end of the first gig  */
162	segtable_end = segtable + (1<<(30-22));
163
164	/*
165	 * Move forward to the start of empty pages; take into account
166	 * phys_offset shift.
167	 */
168
169	segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
170	{
171		int i;
172
173		for (i = 1 ; i <= DMA_RESERVE ; i++)
174			segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
175				| __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
176				| __HEXAGON_C_UNC << 6
177				| __HVM_PDE_S_4MB);
178	}
179
180	printk(KERN_INFO "clearing segtable from %p to %p\n", segtable,
181		segtable_end);
182	while (segtable < (segtable_end-8))
183		*(segtable++) = __HVM_PDE_S_INVALID;
184	/* stop the pointer at the device I/O 4MB page  */
185
186	printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n",
187		segtable);
188
189#if 0
190	/*  Other half of the early device table from vm_init_segtable. */
191	printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n",
192		(unsigned long) _K_init_devicetable-PAGE_OFFSET);
193	*segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) |
194		__HVM_PDE_S_4KB;
195	printk(KERN_INFO "*segtable = 0x%08x\n", *segtable);
196#endif
197
198	/*
199	 *  The bootmem allocator seemingly just lives to feed memory
200	 *  to the paging system
201	 */
202	printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE);
203	paging_init();  /*  See Gorman Book, 2.3  */
204
205	/*
206	 *  At this point, the page allocator is kind of initialized, but
207	 *  apparently no pages are available (just like with the bootmem
208	 *  allocator), and need to be freed themselves via mem_init(),
209	 *  which is called by start_kernel() later on in the process
210	 */
211}
212
213static const pgprot_t protection_map[16] = {
214	[VM_NONE]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
215								   CACHEDEF),
216	[VM_READ]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
217								   _PAGE_READ | CACHEDEF),
218	[VM_WRITE]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
219								   CACHEDEF),
220	[VM_WRITE | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
221								   _PAGE_READ | CACHEDEF),
222	[VM_EXEC]					= __pgprot(_PAGE_PRESENT | _PAGE_USER |
223								   _PAGE_EXECUTE | CACHEDEF),
224	[VM_EXEC | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
225								   _PAGE_EXECUTE | _PAGE_READ |
226								   CACHEDEF),
227	[VM_EXEC | VM_WRITE]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
228								   _PAGE_EXECUTE | CACHEDEF),
229	[VM_EXEC | VM_WRITE | VM_READ]			= __pgprot(_PAGE_PRESENT | _PAGE_USER |
230								   _PAGE_EXECUTE | _PAGE_READ |
231								   CACHEDEF),
232	[VM_SHARED]                                     = __pgprot(_PAGE_PRESENT | _PAGE_USER |
233								   CACHEDEF),
234	[VM_SHARED | VM_READ]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
235								   _PAGE_READ | CACHEDEF),
236	[VM_SHARED | VM_WRITE]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
237								   _PAGE_WRITE | CACHEDEF),
238	[VM_SHARED | VM_WRITE | VM_READ]		= __pgprot(_PAGE_PRESENT | _PAGE_USER |
239								   _PAGE_READ | _PAGE_WRITE |
240								   CACHEDEF),
241	[VM_SHARED | VM_EXEC]				= __pgprot(_PAGE_PRESENT | _PAGE_USER |
242								   _PAGE_EXECUTE | CACHEDEF),
243	[VM_SHARED | VM_EXEC | VM_READ]			= __pgprot(_PAGE_PRESENT | _PAGE_USER |
244								   _PAGE_EXECUTE | _PAGE_READ |
245								   CACHEDEF),
246	[VM_SHARED | VM_EXEC | VM_WRITE]		= __pgprot(_PAGE_PRESENT | _PAGE_USER |
247								   _PAGE_EXECUTE | _PAGE_WRITE |
248								   CACHEDEF),
249	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= __pgprot(_PAGE_PRESENT | _PAGE_USER |
250								   _PAGE_READ | _PAGE_EXECUTE |
251								   _PAGE_WRITE | CACHEDEF)
252};
253DECLARE_VM_GET_PAGE_PROT