[PATCH v6 05/18] arm64: create macro to park cpu in an infinite loop

From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>,
	Kees Cook <keescook@chromium.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Kristina Martsenko <kristina.martsenko@arm.com>,
	Dave Martin <Dave.Martin@arm.com>,
	Mark Brown <broonie@kernel.org>,
	James Morse <james.morse@arm.com>,
	Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>,
	Amit Daniel Kachhap <amit.kachhap@arm.com>,
	Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH v6 05/18] arm64: create macro to park cpu in an infinite loop
Date: Fri,  6 Mar 2020 12:05:12 +0530	[thread overview]
Message-ID: <1583476525-13505-6-git-send-email-amit.kachhap@arm.com> (raw)
In-Reply-To: <1583476525-13505-1-git-send-email-amit.kachhap@arm.com>

A macro early_park_cpu is added to park the faulted cpu in an infinite
loop. Currently, this macro is substituted in two instances and may be
reused in future.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 arch/arm64/kernel/head.S | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 989b194..3d18163 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -761,6 +761,17 @@ ENDPROC(__secondary_too_slow)
 	.endm
 
 /*
+ * Macro to park the cpu in an infinite loop.
+ */
+	.macro	early_park_cpu status
+	update_early_cpu_boot_status \status | CPU_STUCK_IN_KERNEL, x1, x2
+.Lepc_\@:
+	wfe
+	wfi
+	b	.Lepc_\@
+	.endm
+
+/*
  * Enable the MMU.
  *
  *  x0  = SCTLR_EL1 value for turning on the MMU.
@@ -808,24 +819,14 @@ ENTRY(__cpu_secondary_check52bitva)
 	and	x0, x0, #(0xf << ID_AA64MMFR2_LVA_SHIFT)
 	cbnz	x0, 2f
 
-	update_early_cpu_boot_status \
-		CPU_STUCK_IN_KERNEL | CPU_STUCK_REASON_52_BIT_VA, x0, x1
-1:	wfe
-	wfi
-	b	1b
-
+	early_park_cpu CPU_STUCK_REASON_52_BIT_VA
 #endif
 2:	ret
 ENDPROC(__cpu_secondary_check52bitva)
 
 __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 | CPU_STUCK_REASON_NO_GRAN, x1, x2
-1:
-	wfe
-	wfi
-	b	1b
+	early_park_cpu CPU_STUCK_REASON_NO_GRAN
 ENDPROC(__no_granule_support)
 
 #ifdef CONFIG_RELOCATABLE
-- 
2.7.4


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