From a04565741284f695db4cfe5a3e61940d2259cb8f Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 21 Aug 2019 20:00:34 +0000 Subject: [PATCH] powerpc/8xx: drop unused self-modifying code alternative to FixupDAR. The code which fixups the DAR on TLB errors for dbcX instructions has a self-modifying code alternative that has never been used. Drop it. Signed-off-by: Christophe Leroy Reviewed-by: Joakim Tjernlund Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b095e12c82fcba1ac4c09fc3b85d969f36614746.1566417610.git.christophe.leroy@c-s.fr --- arch/powerpc/kernel/head_8xx.S | 24 ------------------------ 1 file changed, 24 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 5ab9178c2347..5db461db63cc 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -574,8 +574,6 @@ InstructionBreakpoint: * by decoding the registers used by the dcbx instruction and adding them. * DAR is set to the calculated address. */ - /* define if you don't want to use self modifying code */ -#define NO_SELF_MODIFYING_CODE FixupDAR:/* Entry point for dcbx workaround. */ mtspr SPRN_M_TW, r10 /* fetch instruction from memory. */ @@ -639,27 +637,6 @@ FixupDAR:/* Entry point for dcbx workaround. */ rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */ mtspr SPRN_DSISR, r10 142: /* continue, it was a dcbx, dcbi instruction. */ -#ifndef NO_SELF_MODIFYING_CODE - andis. r10,r11,0x1f /* test if reg RA is r0 */ - li r10,modified_instr@l - dcbtst r0,r10 /* touch for store */ - rlwinm r11,r11,0,0,20 /* Zero lower 10 bits */ - oris r11,r11,640 /* Transform instr. to a "add r10,RA,RB" */ - ori r11,r11,532 - stw r11,0(r10) /* store add/and instruction */ - dcbf 0,r10 /* flush new instr. to memory. */ - icbi 0,r10 /* invalidate instr. cache line */ - mfspr r11, SPRN_SPRG_SCRATCH1 /* restore r11 */ - mfspr r10, SPRN_SPRG_SCRATCH0 /* restore r10 */ - isync /* Wait until new instr is loaded from memory */ -modified_instr: - .space 4 /* this is where the add instr. is stored */ - bne+ 143f - subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */ -143: mtdar r10 /* store faulting EA in DAR */ - mfspr r10,SPRN_M_TW - b DARFixed /* Go back to normal TLB handling */ -#else mfctr r10 mtdar r10 /* save ctr reg in DAR */ rlwinm r10, r11, 24, 24, 28 /* offset into jump table for reg RB */ @@ -723,7 +700,6 @@ modified_instr: add r10, r10, r11 /* add it */ mfctr r11 /* restore r11 */ b 151b -#endif /* * This is where the main kernel code starts.