Blame view

kernel/linux-imx6_3.14.28/arch/xtensa/mm/mmu.c 1.82 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
  /*
   * xtensa mmu stuff
   *
   * Extracted from init.c
   */
  #include <linux/percpu.h>
  #include <linux/init.h>
  #include <linux/string.h>
  #include <linux/slab.h>
  #include <linux/cache.h>
  
  #include <asm/tlb.h>
  #include <asm/tlbflush.h>
  #include <asm/mmu_context.h>
  #include <asm/page.h>
  #include <asm/initialize_mmu.h>
  #include <asm/io.h>
  
  void __init paging_init(void)
  {
  	memset(swapper_pg_dir, 0, PAGE_SIZE);
  }
  
  /*
   * Flush the mmu and reset associated register to default values.
   */
  void init_mmu(void)
  {
  #if !(XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY)
  	/*
  	 * Writing zeros to the instruction and data TLBCFG special
  	 * registers ensure that valid values exist in the register.
  	 *
  	 * For existing PGSZID<w> fields, zero selects the first element
  	 * of the page-size array.  For nonexistent PGSZID<w> fields,
  	 * zero is the best value to write.  Also, when changing PGSZID<w>
  	 * fields, the corresponding TLB must be flushed.
  	 */
  	set_itlbcfg_register(0);
  	set_dtlbcfg_register(0);
  #endif
  #if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY && defined(CONFIG_OF)
  	/*
  	 * Update the IO area mapping in case xtensa_kio_paddr has changed
  	 */
  	write_dtlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
  			XCHAL_KIO_CACHED_VADDR + 6);
  	write_itlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
  			XCHAL_KIO_CACHED_VADDR + 6);
  	write_dtlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
  			XCHAL_KIO_BYPASS_VADDR + 6);
  	write_itlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
  			XCHAL_KIO_BYPASS_VADDR + 6);
  #endif
  
  	local_flush_tlb_all();
  
  	/* Set rasid register to a known value. */
  
  	set_rasid_register(ASID_INSERT(ASID_USER_FIRST));
  
  	/* Set PTEVADDR special register to the start of the page
  	 * table, which is in kernel mappable space (ie. not
  	 * statically mapped).  This register's value is undefined on
  	 * reset.
  	 */
  	set_ptevaddr_register(PGTABLE_START);
  }