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Diffstat (limited to 'arch/arm64/kernel/head.S')
-rw-r--r--arch/arm64/kernel/head.S31
1 files changed, 27 insertions, 4 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index d75f41920645..dc56e1d8f36e 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -70,7 +70,7 @@
__EFI_PE_HEADER
- __INIT
+ .section ".idmap.text","awx"
/*
* The following callee saved general purpose registers are used on the
@@ -90,6 +90,17 @@ SYM_CODE_START(primary_entry)
bl record_mmu_state
bl preserve_boot_args
bl create_idmap
+
+ /*
+ * If we entered with the MMU and caches on, clean the ID mapped part
+ * of the primary boot code to the PoC so we can safely execute it with
+ * the MMU off.
+ */
+ cbz x19, 0f
+ adrp x0, __idmap_text_start
+ adr_l x1, __idmap_text_end
+ bl dcache_clean_poc
+0: mov x0, x19
bl init_kernel_el // w0=cpu_boot_mode
mov x20, x0
@@ -111,6 +122,7 @@ SYM_CODE_START(primary_entry)
b __primary_switch
SYM_CODE_END(primary_entry)
+ __INIT
SYM_CODE_START_LOCAL(record_mmu_state)
mrs x19, CurrentEL
cmp x19, #CurrentEL_EL2
@@ -507,10 +519,12 @@ SYM_FUNC_END(__primary_switched)
* Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in x0 if
* booted in EL1 or EL2 respectively, with the top 32 bits containing
* potential context flags. These flags are *not* stored in __boot_cpu_mode.
+ *
+ * x0: whether we are being called from the primary boot path with the MMU on
*/
SYM_FUNC_START(init_kernel_el)
- mrs x0, CurrentEL
- cmp x0, #CurrentEL_EL2
+ mrs x1, CurrentEL
+ cmp x1, #CurrentEL_EL2
b.eq init_el2
SYM_INNER_LABEL(init_el1, SYM_L_LOCAL)
@@ -525,6 +539,14 @@ SYM_INNER_LABEL(init_el1, SYM_L_LOCAL)
eret
SYM_INNER_LABEL(init_el2, SYM_L_LOCAL)
+ msr elr_el2, lr
+
+ // clean all HYP code to the PoC if we booted at EL2 with the MMU on
+ cbz x0, 0f
+ adrp x0, __hyp_idmap_text_start
+ adr_l x1, __hyp_text_end
+ bl dcache_clean_poc
+0:
mov_q x0, HCR_HOST_NVHE_FLAGS
msr hcr_el2, x0
isb
@@ -558,7 +580,6 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL)
msr sctlr_el1, x1
mov x2, xzr
2:
- msr elr_el2, lr
mov w0, #BOOT_CPU_MODE_EL2
orr x0, x0, x2
eret
@@ -569,6 +590,7 @@ SYM_FUNC_END(init_kernel_el)
* cores are held until we're ready for them to initialise.
*/
SYM_FUNC_START(secondary_holding_pen)
+ mov x0, xzr
bl init_kernel_el // w0=cpu_boot_mode
mrs x2, mpidr_el1
mov_q x1, MPIDR_HWID_BITMASK
@@ -586,6 +608,7 @@ SYM_FUNC_END(secondary_holding_pen)
* be used where CPUs are brought online dynamically by the kernel.
*/
SYM_FUNC_START(secondary_entry)
+ mov x0, xzr
bl init_kernel_el // w0=cpu_boot_mode
b secondary_startup
SYM_FUNC_END(secondary_entry)