diff mbox series

[v5,06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe()

Message ID 20210125105019.2946057-7-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series arm64: Early CPU feature override, and applications to VHE, BTI and PAuth | expand

Commit Message

Marc Zyngier Jan. 25, 2021, 10:50 a.m. UTC 
There isn't much that a VHE kernel needs on top of whatever has
been done for nVHE, so let's move the little we need to the
VHE stub (the SPE setup), and drop the init_el2_state macro.

No expected functional change.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kernel/hyp-stub.S | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

Comments

Catalin Marinas Jan. 25, 2021, 12:14 p.m. UTC | #1 
On Mon, Jan 25, 2021 at 10:50:04AM +0000, Marc Zyngier wrote:
> There isn't much that a VHE kernel needs on top of whatever has
> been done for nVHE, so let's move the little we need to the
> VHE stub (the SPE setup), and drop the init_el2_state macro.
> 
> No expected functional change.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Acked-by: David Brazdil <dbrazdil@google.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 373ed2213e1d..6b5c73cf9d52 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -92,9 +92,6 @@  SYM_CODE_START_LOCAL(mutate_to_vhe)
 	msr	hcr_el2, x0
 	isb
 
-	// Doesn't do much on VHE, but still, worth a shot
-	init_el2_state vhe
-
 	// Use the EL1 allocated stack, per-cpu offset
 	mrs	x0, sp_el1
 	mov	sp, x0
@@ -107,6 +104,31 @@  SYM_CODE_START_LOCAL(mutate_to_vhe)
 	mrs_s	x0, SYS_VBAR_EL12
 	msr	vbar_el1, x0
 
+	// Fixup SPE configuration, if supported...
+	mrs	x1, id_aa64dfr0_el1
+	ubfx	x1, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
+	mov	x2, xzr
+	cbz	x1, skip_spe
+
+	// ... and not owned by EL3
+	mrs_s	x0, SYS_PMBIDR_EL1
+	and	x0, x0, #(1 << SYS_PMBIDR_EL1_P_SHIFT)
+	cbnz	x0, skip_spe
+
+	// Let the SPE driver in control of the sampling
+	mrs_s	x0, SYS_PMSCR_EL1
+	bic	x0, x0, #(1 << SYS_PMSCR_EL2_PCT_SHIFT)
+	bic	x0, x0, #(1 << SYS_PMSCR_EL2_PA_SHIFT)
+	msr_s	SYS_PMSCR_EL1, x0
+	mov	x2, #MDCR_EL2_TPMS
+
+skip_spe:
+	// For VHE, use EL2 translation and disable access from EL1
+	mrs	x0, mdcr_el2
+	bic	x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
+	orr	x0, x0, x2
+	msr	mdcr_el2, x0
+
 	// Transfer the MM state from EL1 to EL2
 	mrs_s	x0, SYS_TCR_EL12
 	msr	tcr_el1, x0