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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2016-08-31 12:05:13 +0100
committerWill Deacon <will.deacon@arm.com>2016-09-02 11:30:13 +0100
commit3c5e9f238bc475b0712419eaebc643c07c73cb94 (patch)
tree0cebd8fa5a29715f3a0948d63010ddf2dc6040f6 /arch/arm64/kernel/head.S
parent23c8a500c24d02dd2de1bff968d4467b441717bb (diff)
arm64: head.S: move KASLR processing out of __enable_mmu()
The KASLR processing is only used by the primary boot path, and complements the processing that takes place in __primary_switch(). Move the two parts together, to make the code easier to understand. Also, fix up a minor whitespace issue. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: fixed conflict with -rc3 due to lack of fd363bd417dd] Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/head.S')
-rw-r--r--arch/arm64/kernel/head.S69
1 files changed, 42 insertions, 27 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index be02c5593ba6..5543068da3ae 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -222,9 +222,7 @@ ENTRY(stext)
* the TCR will have been set.
*/
bl __cpu_setup // initialise processor
- adr_l x27, __primary_switch // address to jump to after
- // MMU has been enabled
- b __enable_mmu
+ b __primary_switch
ENDPROC(stext)
/*
@@ -453,7 +451,7 @@ __primary_switched:
cbz x0, 0f // KASLR disabled? just proceed
orr x23, x23, x0 // record KASLR offset
ret x28 // we must enable KASLR, return
- // to __enable_mmu()
+ // to __primary_switch()
0:
#endif
b start_kernel
@@ -726,7 +724,6 @@ ENDPROC(__secondary_switched)
* If it isn't, park the CPU
*/
ENTRY(__enable_mmu)
- mrs x22, sctlr_el1 // preserve old SCTLR_EL1 value
mrs x1, ID_AA64MMFR0_EL1
ubfx x2, x1, #ID_AA64MMFR0_TGRAN_SHIFT, 4
cmp x2, #ID_AA64MMFR0_TGRAN_SUPPORTED
@@ -747,25 +744,6 @@ ENTRY(__enable_mmu)
ic iallu
dsb nsh
isb
-#ifdef CONFIG_RANDOMIZE_BASE
- mov x19, x0 // preserve new SCTLR_EL1 value
- blr x27
-
- /*
- * If we return here, we have a KASLR displacement in x23 which we need
- * to take into account by discarding the current kernel mapping and
- * creating a new one.
- */
- msr sctlr_el1, x22 // disable the MMU
- isb
- bl __create_page_tables // recreate kernel mapping
-
- msr sctlr_el1, x19 // re-enable the MMU
- isb
- ic iallu // flush instructions fetched
- dsb nsh // via old mapping
- isb
-#endif
br x27
ENDPROC(__enable_mmu)
@@ -775,11 +753,11 @@ __no_granule_support:
1:
wfe
wfi
- b 1b
+ b 1b
ENDPROC(__no_granule_support)
-__primary_switch:
#ifdef CONFIG_RELOCATABLE
+__relocate_kernel:
/*
* Iterate over each entry in the relocation table, and apply the
* relocations in place.
@@ -801,8 +779,45 @@ __primary_switch:
add x13, x13, x23 // relocate
str x13, [x11, x23]
b 0b
+1: ret
+ENDPROC(__relocate_kernel)
+#endif
-1:
+__primary_switch:
+#ifdef CONFIG_RANDOMIZE_BASE
+ mov x19, x0 // preserve new SCTLR_EL1 value
+ mrs x20, sctlr_el1 // preserve old SCTLR_EL1 value
+#endif
+
+ adr x27, 0f
+ b __enable_mmu
+0:
+#ifdef CONFIG_RELOCATABLE
+ bl __relocate_kernel
+#ifdef CONFIG_RANDOMIZE_BASE
+ ldr x8, =__primary_switched
+ blr x8
+
+ /*
+ * If we return here, we have a KASLR displacement in x23 which we need
+ * to take into account by discarding the current kernel mapping and
+ * creating a new one.
+ */
+ msr sctlr_el1, x20 // disable the MMU
+ isb
+ bl __create_page_tables // recreate kernel mapping
+
+ tlbi vmalle1 // Remove any stale TLB entries
+ dsb nsh
+
+ msr sctlr_el1, x19 // re-enable the MMU
+ isb
+ ic iallu // flush instructions fetched
+ dsb nsh // via old mapping
+ isb
+
+ bl __relocate_kernel
+#endif
#endif
ldr x8, =__primary_switched
br x8