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From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	broonie@kernel.org, danielmentz@google.com, saravanak@google.com,
	kernel-team@android.com
Subject: [PATCH v2 6/9] arm64: Expose a __check_override primitive for oddball features
Date: Thu, 30 Jun 2022 17:04:57 +0100	[thread overview]
Message-ID: <20220630160500.1536744-7-maz@kernel.org> (raw)
In-Reply-To: <20220630160500.1536744-1-maz@kernel.org>

In order to feal with early override of features that are not
classically encoded in a standard ID register with a 4 bit wide
field, add a primitive that takes a sysreg value as an input
(instead of the usual sysreg name) as well as a bit field
width (usually 4).

No functional change.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kernel/hyp-stub.S | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 43c94e7a2c1d..de1ab9843c31 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -17,17 +17,17 @@
 #include <asm/virt.h>
 
 // Warning, hardcoded register allocation
-// This will clobber x1 and x2.
-.macro check_override idreg, fld, pass, fail
-	mrs	x1, \idreg\()_el1
-	ubfx	x1, x1, #\fld, #4
+// This will clobber x1 and x2, and expect x1 to contain
+// the id register value as read from the HW
+.macro __check_override idreg, fld, width, pass, fail
+	ubfx	x1, x1, #\fld, #\width
 	cbz	x1, \fail
 
 	adr_l	x1, \idreg\()_override
 	ldr	x2, [x1, FTR_OVR_VAL_OFFSET]
 	ldr	x1, [x1, FTR_OVR_MASK_OFFSET]
-	ubfx	x2, x2, #\fld, #4
-	ubfx	x1, x1, #\fld, #4
+	ubfx	x2, x2, #\fld, #\width
+	ubfx	x1, x1, #\fld, #\width
 	cmp	x1, xzr
 	and	x2, x2, x1
 	csinv	x2, x2, xzr, ne
@@ -35,6 +35,11 @@
 	b	\fail
 .endm
 
+.macro check_override idreg, fld, pass, fail
+	mrs	x1, \idreg\()_el1
+	__check_override \idreg \fld 4 \pass \fail
+.endm
+
 	.text
 	.pushsection	.hyp.text, "ax"
 
-- 
2.34.1


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  parent reply	other threads:[~2022-06-30 16:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-30 16:04 [PATCH v2 0/9] arm64: Disabling SVE/SME from the command-line Marc Zyngier
2022-06-30 16:04 ` [PATCH v2 1/9] arm64: Rename the VHE switch to "finalise_el2" Marc Zyngier
2022-06-30 16:04 ` [PATCH v2 2/9] arm64: Save state of HCR_EL2.E2H before switch to EL1 Marc Zyngier
2022-06-30 16:04 ` [PATCH v2 3/9] arm64: Allow sticky E2H when entering EL1 Marc Zyngier
2022-06-30 16:04 ` [PATCH v2 4/9] arm64: Factor out checking of a feature against the override into a macro Marc Zyngier
2022-06-30 16:04 ` [PATCH v2 5/9] arm64: Allow the idreg override to deal with variable field width Marc Zyngier
2022-07-01 14:00   ` Mark Brown
2022-06-30 16:04 ` Marc Zyngier [this message]
2022-07-01 14:03   ` [PATCH v2 6/9] arm64: Expose a __check_override primitive for oddball features Mark Brown
2022-06-30 16:04 ` [PATCH v2 7/9] arm64: Add the arm64.nosme command line option Marc Zyngier
2022-07-01 13:44   ` Mark Brown
2022-06-30 16:04 ` [PATCH v2 8/9] arm64: Add the arm64.nosve " Marc Zyngier
2022-07-01 13:45   ` Mark Brown
2022-06-30 16:05 ` [PATCH v2 9/9] arm64: Add an override for ID_AA64SMFR0_EL1.FA64 Marc Zyngier
2022-07-01 13:52   ` Mark Brown
2022-07-01 15:41 ` [PATCH v2 0/9] arm64: Disabling SVE/SME from the command-line Will Deacon

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