[PATCH v6 1/6] arm64: head: Move all finalise_el2 calls to after __enable_mmu

[Ard Biesheuvel]

In the primary boot path, finalise_el2() is called much later than on
the secondary boot or resume-from-suspend paths, and this does not
appear to be intentional.

Since we aim to do as little as possible before enabling the MMU and
caches, align secondary and resume with primary boot, and defer the call
to after the MMU is turned on. This also removes the need to clean
finalise_el2() to the PoC once we enable support for booting with the
MMU on.

Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
 arch/arm64/kernel/head.S  | 5 ++++-
 arch/arm64/kernel/sleep.S | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 952e17bd1c0b4f91..c4e12d466a5f35f0 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -587,7 +587,6 @@ SYM_FUNC_START_LOCAL(secondary_startup)
 	 * Common entry point for secondary CPUs.
 	 */
 	mov	x20, x0				// preserve boot mode
-	bl	finalise_el2
 	bl	__cpu_secondary_check52bitva
 #if VA_BITS > 48
 	ldr_l	x0, vabits_actual
@@ -603,6 +602,10 @@ SYM_FUNC_END(secondary_startup)
 SYM_FUNC_START_LOCAL(__secondary_switched)
 	mov	x0, x20
 	bl	set_cpu_boot_mode_flag
+
+	mov	x0, x20
+	bl	finalise_el2
+
 	str_l	xzr, __early_cpu_boot_status, x3
 	adr_l	x5, vectors
 	msr	vbar_el1, x5
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index 97c9de57725dfddb..7b7c56e048346e97 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -100,7 +100,7 @@ SYM_FUNC_END(__cpu_suspend_enter)
 	.pushsection ".idmap.text", "awx"
 SYM_CODE_START(cpu_resume)
 	bl	init_kernel_el
-	bl	finalise_el2
+	mov	x19, x0			// preserve boot mode
 #if VA_BITS > 48
 	ldr_l	x0, vabits_actual
 #endif
@@ -116,6 +116,9 @@ SYM_CODE_END(cpu_resume)
 	.popsection
 
 SYM_FUNC_START(_cpu_resume)
+	mov	x0, x19
+	bl	finalise_el2
+
 	mrs	x1, mpidr_el1
 	adr_l	x8, mpidr_hash		// x8 = struct mpidr_hash virt address
 
-- 
2.35.1