[RESEND PATCH v4 2/6] arm64/mm: Pass ttbr1 as a parameter to __enable_mmu().

From: Jun Yao
Date: Wed Aug 22 2018 - 05:54:51 EST


The kernel sets up the initial page table in the init_pg_dir.
However, it will create the final page table in the swapper_pg_dir
during the initialization process. We need to let __enable_mmu()
know which page table to use.

Signed-off-by: Jun Yao <yaojun8558363@xxxxxxxxx>
---
arch/arm64/kernel/head.S | 21 ++++++++++++---------
arch/arm64/kernel/sleep.S | 1 +
2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 2c83a8c47e3f..c3e4b1886cde 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -714,6 +714,7 @@ secondary_startup:
* Common entry point for secondary CPUs.
*/
bl __cpu_setup // initialise processor
+ adrp x1, swapper_pg_dir
bl __enable_mmu
ldr x8, =__secondary_switched
br x8
@@ -756,6 +757,7 @@ ENDPROC(__secondary_switched)
* Enable the MMU.
*
* x0 = SCTLR_EL1 value for turning on the MMU.
+ * x1 = TTBR1_EL1 value for turning on the MMU.
*
* Returns to the caller via x30/lr. This requires the caller to be covered
* by the .idmap.text section.
@@ -764,15 +766,15 @@ ENDPROC(__secondary_switched)
* If it isn't, park the CPU
*/
ENTRY(__enable_mmu)
- mrs x1, ID_AA64MMFR0_EL1
- ubfx x2, x1, #ID_AA64MMFR0_TGRAN_SHIFT, 4
- cmp x2, #ID_AA64MMFR0_TGRAN_SUPPORTED
+ mrs x5, ID_AA64MMFR0_EL1
+ ubfx x6, x5, #ID_AA64MMFR0_TGRAN_SHIFT, 4
+ cmp x6, #ID_AA64MMFR0_TGRAN_SUPPORTED
b.ne __no_granule_support
- update_early_cpu_boot_status 0, x1, x2
- adrp x1, idmap_pg_dir
- adrp x2, swapper_pg_dir
- phys_to_ttbr x3, x1
- phys_to_ttbr x4, x2
+ update_early_cpu_boot_status 0, x5, x6
+ adrp x5, idmap_pg_dir
+ mov x6, x1
+ phys_to_ttbr x3, x5
+ phys_to_ttbr x4, x6
msr ttbr0_el1, x3 // load TTBR0
msr ttbr1_el1, x4 // load TTBR1
isb
@@ -791,7 +793,7 @@ ENDPROC(__enable_mmu)

__no_granule_support:
/* Indicate that this CPU can't boot and is stuck in the kernel */
- update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x1, x2
+ update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x5, x6
1:
wfe
wfi
@@ -831,6 +833,7 @@ __primary_switch:
mrs x20, sctlr_el1 // preserve old SCTLR_EL1 value
#endif

+ adrp x1, swapper_pg_dir
bl __enable_mmu
#ifdef CONFIG_RELOCATABLE
bl __relocate_kernel
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index bebec8ef9372..3e53ffa07994 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -101,6 +101,7 @@ ENTRY(cpu_resume)
bl el2_setup // if in EL2 drop to EL1 cleanly
bl __cpu_setup
/* enable the MMU early - so we can access sleep_save_stash by va */
+ adrp x1, swapper_pg_dir
bl __enable_mmu
ldr x8, =_cpu_resume
br x8
--
2.17.1