From 5b1c9a0d7f3bcac591767fa1aad1323564673b26 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 12 Mar 2021 12:50:23 +0000 Subject: powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx 8xx requires to tag the DAR with a magic value in order to fixup DAR on faults generated by 'dcbX', as the 8xx forgets to update the DAR for those faults. Do the tagging as early as possible, that is before enabling MMU. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/853a2e28ca7c5fc85617037030f99fe6070c9536.1615552867.git.christophe.leroy@csgroup.eu --- arch/powerpc/kernel/head_32.h | 6 ++++++ arch/powerpc/kernel/head_8xx.S | 18 ++++++------------ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 1b707755c68e..910f86642eec 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -57,6 +57,12 @@ .endm .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0 +#ifdef CONFIG_PPC_8xx + .if \handle_dar_dsisr + li r11, RPN_PATTERN + mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */ + .endif +#endif LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */ mtmsr r11 isync diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 792e2fd86479..cdbfa9d41353 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -30,6 +30,12 @@ #include #include +/* + * Value for the bits that have fixed value in RPN entries. + * Also used for tagging DAR for DTLBerror. + */ +#define RPN_PATTERN 0x00f0 + #include "head_32.h" .macro compare_to_kernel_boundary scratch, addr @@ -42,12 +48,6 @@ #endif .endm -/* - * Value for the bits that have fixed value in RPN entries. - * Also used for tagging DAR for DTLBerror. - */ -#define RPN_PATTERN 0x00f0 - #define PAGE_SHIFT_512K 19 #define PAGE_SHIFT_8M 23 @@ -124,8 +124,6 @@ instruction_counter: . = 0x200 MachineCheck: EXCEPTION_PROLOG handle_dar_dsisr=1 - li r6, RPN_PATTERN - mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */ addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_STD(0x200, machine_check_exception) @@ -136,8 +134,6 @@ MachineCheck: . = 0x600 Alignment: EXCEPTION_PROLOG handle_dar_dsisr=1 - li r6, RPN_PATTERN - mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */ addi r3,r1,STACK_FRAME_OVERHEAD b .Lalignment_exception_ool @@ -331,8 +327,6 @@ DataTLBError: cmpwi cr1, r11, RPN_PATTERN beq- cr1, FixupDAR /* must be a buggy dcbX, icbi insn. */ DARFixed:/* Return from dcbx instruction bug workaround */ - li r11, RPN_PATTERN - mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */ EXCEPTION_PROLOG_1 EXCEPTION_PROLOG_2 handle_dar_dsisr=1 lwz r4, _DAR(r11) -- cgit v1.2.3-59-g8ed1b