1 #include <linux/module.h>
2 #include <linux/kernel.h>
3 #include <linux/slab.h>
5 #include <asm/cputype.h>
7 #include <asm/pgalloc.h>
8 #include <asm/pgtable.h>
9 #include <asm/sections.h>
10 #include <asm/system_info.h>
13 phys_addr_t (*arch_virt_to_idmap
) (unsigned long x
);
15 #ifdef CONFIG_ARM_LPAE
16 static void idmap_add_pmd(pud_t
*pud
, unsigned long addr
, unsigned long end
,
22 if (pud_none_or_clear_bad(pud
) || (pud_val(*pud
) & L_PGD_SWAPPER
)) {
23 pmd
= pmd_alloc_one(&init_mm
, addr
);
25 pr_warning("Failed to allocate identity pmd.\n");
28 pud_populate(&init_mm
, pud
, pmd
);
29 pmd
+= pmd_index(addr
);
31 pmd
= pmd_offset(pud
, addr
);
34 next
= pmd_addr_end(addr
, end
);
35 *pmd
= __pmd((addr
& PMD_MASK
) | prot
);
37 } while (pmd
++, addr
= next
, addr
!= end
);
39 #else /* !CONFIG_ARM_LPAE */
40 static void idmap_add_pmd(pud_t
*pud
, unsigned long addr
, unsigned long end
,
43 pmd_t
*pmd
= pmd_offset(pud
, addr
);
45 addr
= (addr
& PMD_MASK
) | prot
;
51 #endif /* CONFIG_ARM_LPAE */
53 static void idmap_add_pud(pgd_t
*pgd
, unsigned long addr
, unsigned long end
,
56 pud_t
*pud
= pud_offset(pgd
, addr
);
60 next
= pud_addr_end(addr
, end
);
61 idmap_add_pmd(pud
, addr
, next
, prot
);
62 } while (pud
++, addr
= next
, addr
!= end
);
65 static void identity_mapping_add(pgd_t
*pgd
, const char *text_start
,
66 const char *text_end
, unsigned long prot
)
68 unsigned long addr
, end
;
71 addr
= virt_to_idmap(text_start
);
72 end
= virt_to_idmap(text_end
);
73 pr_info("Setting up static identity map for 0x%lx - 0x%lx\n", addr
, end
);
75 prot
|= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
| PMD_SECT_AF
;
77 if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ
&& !cpu_is_xscale())
80 pgd
+= pgd_index(addr
);
82 next
= pgd_addr_end(addr
, end
);
83 idmap_add_pud(pgd
, addr
, next
, prot
);
84 } while (pgd
++, addr
= next
, addr
!= end
);
87 extern char __idmap_text_start
[], __idmap_text_end
[];
89 static int __init
init_static_idmap(void)
91 idmap_pgd
= pgd_alloc(&init_mm
);
95 identity_mapping_add(idmap_pgd
, __idmap_text_start
,
98 /* Flush L1 for the hardware to see this page table content */
103 early_initcall(init_static_idmap
);
106 * In order to soft-boot, we need to switch to a 1:1 mapping for the
107 * cpu_reset functions. This will then ensure that we have predictable
108 * results when turning off the mmu.
110 void setup_mm_for_reboot(void)
112 /* Switch to the identity mapping. */
113 cpu_switch_mm(idmap_pgd
, &init_mm
);
114 local_flush_bp_all();
116 #ifdef CONFIG_CPU_HAS_ASID
118 * We don't have a clean ASID for the identity mapping, which
119 * may clash with virtual addresses of the previous page tables
120 * and therefore potentially in the TLB.
122 local_flush_tlb_all();