[PATCH AUTOSEL 4.19 222/671] ARM: 8849/1: NOMMU: Fix encodings for PMSAv8's PRBAR4/PRLAR4

Sasha Levin sashal at kernel.org
Thu Jan 16 08:52:11 PST 2020


From: Vladimir Murzin <vladimir.murzin at arm.com>

[ Upstream commit d410a8a49e3e00e07d43037e90f776d522b25a6a ]

To access PRBARn, where n is referenced as a binary number:

MRC p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0] ; Read PRBARn into Rt
MCR p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0] ; Write Rt into PRBARn

To access PRLARn, where n is referenced as a binary number:

MRC p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0]+1 ; Read PRLARn into Rt
MCR p15, 0, <Rt>, c6, c8+n[3:1], 4*n[0]+1 ; Write Rt into PRLARn

For PR{B,L}AR4, n is 4, n[0] is 0, n[3:1] is 2, while current encoding
done with n[0] set to 1 which is wrong. Use proper encoding instead.

Fixes: 046835b4aa22b9ab6aa0bb274e3b71047c4b887d ("ARM: 8757/1: NOMMU: Support PMSAv8 MPU")
Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 arch/arm/kernel/head-nommu.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 326a97aa3ea0..22efcf48604c 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -441,8 +441,8 @@ M_CLASS(str	r6, [r12, #PMSAv8_RLAR_A(3)])
 	str	r5, [r12, #PMSAv8_RBAR_A(0)]
 	str	r6, [r12, #PMSAv8_RLAR_A(0)]
 #else
-	mcr	p15, 0, r5, c6, c10, 1			@ PRBAR4
-	mcr	p15, 0, r6, c6, c10, 2			@ PRLAR4
+	mcr	p15, 0, r5, c6, c10, 0			@ PRBAR4
+	mcr	p15, 0, r6, c6, c10, 1			@ PRLAR4
 #endif
 #endif
 	ret	lr
-- 
2.20.1




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