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    Subject[PATCH 4.19 238/639] ARM: 8849/1: NOMMU: Fix encodings for PMSAv8s PRBAR4/PRLAR4
    Date
    From: Vladimir Murzin <vladimir.murzin@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@arm.com>
    Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
    Signed-off-by: Sasha Levin <sashal@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 326a97aa3ea0c..22efcf48604cd 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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