From c032524f0ddea5fcc3a2cece0d4a61f37e5ca9cd Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Fri, 28 Oct 2005 22:48:08 +1000 Subject: powerpc: Make single-stepping emulation (mostly) usable on 32-bit The sc instruction emulation can't be done the same way on 32-bit as 64-bit yet, but this should work OK. Signed-off-by: Paul Mackerras diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index e79123d..666c2aa 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -10,13 +10,18 @@ */ #include #include +#include #include #include extern char system_call_common[]; +#ifdef CONFIG_PPC64 /* Bits in SRR1 that are copied from MSR */ #define MSR_MASK 0xffffffff87c0ffff +#else +#define MSR_MASK 0x87c0ffff +#endif /* * Determine whether a conditional branch instruction would branch. @@ -66,6 +71,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr) if (branch_taken(instr, regs)) regs->nip = imm; return 1; +#ifdef CONFIG_PPC64 case 17: /* sc */ /* * N.B. this uses knowledge about how the syscall @@ -79,6 +85,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr) regs->nip = (unsigned long) &system_call_common; regs->msr = MSR_KERNEL; return 1; +#endif case 18: /* b */ imm = instr & 0x03fffffc; if (imm & 0x02000000) @@ -121,6 +128,15 @@ int emulate_step(struct pt_regs *regs, unsigned int instr) if ((regs->msr & MSR_SF) == 0) regs->nip &= 0xffffffffUL; return 1; + case 0x124: /* mtmsr */ + imm = regs->gpr[rd]; + if ((imm & MSR_RI) == 0) + /* can't step mtmsr that would clear MSR_RI */ + return -1; + regs->msr = imm; + regs->nip += 4; + return 1; +#ifdef CONFIG_PPC64 case 0x164: /* mtmsrd */ /* only MSR_EE and MSR_RI get changed if bit 15 set */ /* mtmsrd doesn't change MSR_HV and MSR_ME */ @@ -135,6 +151,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr) if ((imm & MSR_SF) == 0) regs->nip &= 0xffffffffUL; return 1; +#endif } } return 0; diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h index 68058d7..bfb45a4 100644 --- a/include/asm-powerpc/reg.h +++ b/include/asm-powerpc/reg.h @@ -51,9 +51,17 @@ #define __MASK(X) (1UL<<(X)) #endif +#ifdef CONFIG_PPC64 #define MSR_SF __MASK(MSR_SF_LG) /* Enable 64 bit mode */ #define MSR_ISF __MASK(MSR_ISF_LG) /* Interrupt 64b mode valid on 630 */ #define MSR_HV __MASK(MSR_HV_LG) /* Hypervisor state */ +#else +/* so tests for these bits fail on 32-bit */ +#define MSR_SF 0 +#define MSR_ISF 0 +#define MSR_HV 0 +#endif + #define MSR_VEC __MASK(MSR_VEC_LG) /* Enable AltiVec */ #define MSR_POW __MASK(MSR_POW_LG) /* Enable Power Management */ #define MSR_WE __MASK(MSR_WE_LG) /* Wait State Enable */ diff --git a/include/asm-powerpc/sstep.h b/include/asm-powerpc/sstep.h new file mode 100644 index 0000000..630a988 --- /dev/null +++ b/include/asm-powerpc/sstep.h @@ -0,0 +1,26 @@ +/* + * Copyright (C) 2004 Paul Mackerras , IBM + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +struct pt_regs; + +/* + * We don't allow single-stepping an mtmsrd that would clear + * MSR_RI, since that would make the exception unrecoverable. + * Since we need to single-step to proceed from a breakpoint, + * we don't allow putting a breakpoint on an mtmsrd instruction. + * Similarly we don't allow breakpoints on rfid instructions. + * These macros tell us if an instruction is a mtmsrd or rfid. + * Note that IS_MTMSRD returns true for both an mtmsr (32-bit) + * and an mtmsrd (64-bit). + */ +#define IS_MTMSRD(instr) (((instr) & 0xfc0007be) == 0x7c000124) +#define IS_RFID(instr) (((instr) & 0xfc0007fe) == 0x4c000024) + +/* Emulate instructions that cause a transfer of control. */ +extern int emulate_step(struct pt_regs *regs, unsigned int instr); diff --git a/include/asm-ppc64/sstep.h b/include/asm-ppc64/sstep.h deleted file mode 100644 index 4a68db5..0000000 --- a/include/asm-ppc64/sstep.h +++ /dev/null @@ -1,24 +0,0 @@ -/* - * Copyright (C) 2004 Paul Mackerras , IBM - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -struct pt_regs; - -/* - * We don't allow single-stepping an mtmsrd that would clear - * MSR_RI, since that would make the exception unrecoverable. - * Since we need to single-step to proceed from a breakpoint, - * we don't allow putting a breakpoint on an mtmsrd instruction. - * Similarly we don't allow breakpoints on rfid instructions. - * These macros tell us if an instruction is a mtmsrd or rfid. - */ -#define IS_MTMSRD(instr) (((instr) & 0xfc0007fe) == 0x7c000164) -#define IS_RFID(instr) (((instr) & 0xfc0007fe) == 0x4c000024) - -/* Emulate instructions that cause a transfer of control. */ -extern int emulate_step(struct pt_regs *regs, unsigned int instr); -- cgit v0.10.2