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git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/blob - arch/arm/mm/idmap.c
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>
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_phys(text_start
);
72 end
= virt_to_phys(text_end
);
74 prot
|= PMD_TYPE_SECT
| PMD_SECT_AP_WRITE
| PMD_SECT_AF
;
76 if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ
&& !cpu_is_xscale())
79 pgd
+= pgd_index(addr
);
81 next
= pgd_addr_end(addr
, end
);
82 idmap_add_pud(pgd
, addr
, next
, prot
);
83 } while (pgd
++, addr
= next
, addr
!= end
);
86 #if defined(CONFIG_ARM_VIRT_EXT) && defined(CONFIG_ARM_LPAE)
89 extern char __hyp_idmap_text_start
[], __hyp_idmap_text_end
[];
91 static int __init
init_static_idmap_hyp(void)
93 hyp_pgd
= kzalloc(PTRS_PER_PGD
* sizeof(pgd_t
), GFP_KERNEL
);
97 pr_info("Setting up static HYP identity map for 0x%p - 0x%p\n",
98 __hyp_idmap_text_start
, __hyp_idmap_text_end
);
99 identity_mapping_add(hyp_pgd
, __hyp_idmap_text_start
,
100 __hyp_idmap_text_end
, PMD_SECT_AP1
);
105 static int __init
init_static_idmap_hyp(void)
111 extern char __idmap_text_start
[], __idmap_text_end
[];
113 static int __init
init_static_idmap(void)
117 idmap_pgd
= pgd_alloc(&init_mm
);
121 pr_info("Setting up static identity map for 0x%p - 0x%p\n",
122 __idmap_text_start
, __idmap_text_end
);
123 identity_mapping_add(idmap_pgd
, __idmap_text_start
,
124 __idmap_text_end
, 0);
126 ret
= init_static_idmap_hyp();
128 /* Flush L1 for the hardware to see this page table content */
133 early_initcall(init_static_idmap
);
136 * In order to soft-boot, we need to switch to a 1:1 mapping for the
137 * cpu_reset functions. This will then ensure that we have predictable
138 * results when turning off the mmu.
140 void setup_mm_for_reboot(void)
142 /* Switch to the identity mapping. */
143 cpu_switch_mm(idmap_pgd
, &init_mm
);
145 #ifdef CONFIG_CPU_HAS_ASID
147 * We don't have a clean ASID for the identity mapping, which
148 * may clash with virtual addresses of the previous page tables
149 * and therefore potentially in the TLB.
151 local_flush_tlb_all();