linux-kernel - [PATCH v2 04/10] kvm: arm64: Remove hyp_adr/ldr_this

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Message-Id: <20200903091712.46456-5-dbrazdil@google.com>
Date:   Thu,  3 Sep 2020 11:17:06 +0200
From:   David Brazdil <dbrazdil@...gle.com>
To:     Marc Zyngier <maz@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Dennis Zhou <dennis@...nel.org>,
        Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...ux.com>,
        Arnd Bergmann <arnd@...db.de>
Cc:     James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kvmarm@...ts.cs.columbia.edu, linux-arch@...r.kernel.org,
        kernel-team@...roid.com, David Brazdil <dbrazdil@...gle.com>
Subject: [PATCH v2 04/10] kvm: arm64: Remove hyp_adr/ldr_this_cpu

The hyp_adr/ldr_this_cpu helpers were introduced for use in hyp code
because they always needed to use TPIDR_EL2 for base, while
adr/ldr_this_cpu from kernel proper would select between TPIDR_EL2 and
_EL1 based on VHE/nVHE.

Simplify this now that the nVHE hyp mode case can be handled using the
__KVM_NVHE_HYPERVISOR__ macro. VHE selects _EL2 with alternatives.

Signed-off-by: David Brazdil <dbrazdil@...gle.com>
---
 arch/arm64/include/asm/assembler.h | 27 +++++++++++++++++----------
 arch/arm64/include/asm/kvm_asm.h   | 14 +-------------
 arch/arm64/kvm/hyp/hyp-entry.S     |  2 +-
 3 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 54d181177656..b392a977efb6 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -218,6 +218,21 @@ lr	.req	x30		// link register
 	str	\src, [\tmp, :lo12:\sym]
 	.endm
 
+	/*
+	 * @dst: destination register (32 or 64 bit wide)
+	 */
+	.macro	this_cpu_offset, dst
+#ifdef __KVM_NVHE_HYPERVISOR__
+	mrs	\dst, tpidr_el2
+#else
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
+	mrs	\dst, tpidr_el1
+alternative_else
+	mrs	\dst, tpidr_el2
+alternative_endif
+#endif
+	.endm
+
 	/*
 	 * @dst: Result of per_cpu(sym, smp_processor_id()) (can be SP)
 	 * @sym: The name of the per-cpu variable
@@ -226,11 +241,7 @@ lr	.req	x30		// link register
 	.macro adr_this_cpu, dst, sym, tmp
 	adrp	\tmp, \sym
 	add	\dst, \tmp, #:lo12:\sym
-alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
-	mrs	\tmp, tpidr_el1
-alternative_else
-	mrs	\tmp, tpidr_el2
-alternative_endif
+	this_cpu_offset \tmp
 	add	\dst, \dst, \tmp
 	.endm
 
@@ -241,11 +252,7 @@ alternative_endif
 	 */
 	.macro ldr_this_cpu dst, sym, tmp
 	adr_l	\dst, \sym
-alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
-	mrs	\tmp, tpidr_el1
-alternative_else
-	mrs	\tmp, tpidr_el2
-alternative_endif
+	this_cpu_offset \tmp
 	ldr	\dst, [\dst, \tmp]
 	.endm
 
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 9149079f0269..469c0662f7f3 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -179,20 +179,8 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
 
 #else /* __ASSEMBLY__ */
 
-.macro hyp_adr_this_cpu reg, sym, tmp
-	adr_l	\reg, \sym
-	mrs	\tmp, tpidr_el2
-	add	\reg, \reg, \tmp
-.endm
-
-.macro hyp_ldr_this_cpu reg, sym, tmp
-	adr_l	\reg, \sym
-	mrs	\tmp, tpidr_el2
-	ldr	\reg,  [\reg, \tmp]
-.endm
-
 .macro get_host_ctxt reg, tmp
-	hyp_adr_this_cpu \reg, kvm_host_data, \tmp
+	adr_this_cpu \reg, kvm_host_data, \tmp
 	add	\reg, \reg, #HOST_DATA_CONTEXT
 .endm
 
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 46b4dab933d0..fba91c2ab410 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -132,7 +132,7 @@ alternative_cb_end
 	str	x0, [x2, #VCPU_WORKAROUND_FLAGS]
 
 	/* Check that we actually need to perform the call */
-	hyp_ldr_this_cpu x0, arm64_ssbd_callback_required, x2
+	ldr_this_cpu x0, arm64_ssbd_callback_required, x2
 	cbz	x0, wa2_end
 
 	mov	w0, #ARM_SMCCC_ARCH_WORKAROUND_2
-- 
2.28.0.402.g5ffc5be6b7-goog