diff options
| -rw-r--r-- | arch/sh/kernel/cpu/sh2a/Makefile | 5 | ||||
| -rw-r--r-- | arch/sh/kernel/cpu/sh2a/opcode_helper.c | 55 | ||||
| -rw-r--r-- | arch/sh/kernel/kgdb_stub.c | 2 | ||||
| -rw-r--r-- | arch/sh/kernel/process.c | 5 | ||||
| -rw-r--r-- | arch/sh/kernel/signal.c | 8 | ||||
| -rw-r--r-- | include/asm-sh/system.h | 9 |
6 files changed, 74 insertions, 10 deletions
diff --git a/arch/sh/kernel/cpu/sh2a/Makefile b/arch/sh/kernel/cpu/sh2a/Makefile index 350972ae9410..965fa2572b23 100644 --- a/arch/sh/kernel/cpu/sh2a/Makefile +++ b/arch/sh/kernel/cpu/sh2a/Makefile @@ -2,9 +2,8 @@ # Makefile for the Linux/SuperH SH-2A backends. # -obj-y := common.o probe.o +obj-y := common.o probe.o opcode_helper.o -common-y += $(addprefix ../sh2/, ex.o) -common-y += $(addprefix ../sh2/, entry.o) +common-y += $(addprefix ../sh2/, ex.o entry.o) obj-$(CONFIG_CPU_SUBTYPE_SH7206) += setup-sh7206.o clock-sh7206.o diff --git a/arch/sh/kernel/cpu/sh2a/opcode_helper.c b/arch/sh/kernel/cpu/sh2a/opcode_helper.c new file mode 100644 index 000000000000..9704b7926d8b --- /dev/null +++ b/arch/sh/kernel/cpu/sh2a/opcode_helper.c @@ -0,0 +1,55 @@ +/* + * arch/sh/kernel/cpu/sh2a/opcode_helper.c + * + * Helper for the SH-2A 32-bit opcodes. + * + * Copyright (C) 2007 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/kernel.h> +#include <asm/system.h> + +/* + * Instructions on SH are generally fixed at 16-bits, however, SH-2A + * introduces some 32-bit instructions. Since there are no real + * constraints on their use (and they can be mixed and matched), we need + * to check the instruction encoding to work out if it's a true 32-bit + * instruction or not. + * + * Presently, 32-bit opcodes have only slight variations in what the + * actual encoding looks like in the first-half of the instruction, which + * makes it fairly straightforward to differentiate from the 16-bit ones. + * + * First 16-bits of encoding Used by + * + * 0011nnnnmmmm0001 mov.b, mov.w, mov.l, fmov.d, + * fmov.s, movu.b, movu.w + * + * 0011nnnn0iii1001 bclr.b, bld.b, bset.b, bst.b, band.b, + * bandnot.b, bldnot.b, bor.b, bornot.b, + * bxor.b + * + * 0000nnnniiii0000 movi20 + * 0000nnnniiii0001 movi20s + */ +unsigned int instruction_size(unsigned int insn) +{ + /* Look for the common cases */ + switch ((insn & 0xf00f)) { + case 0x0000: /* movi20 */ + case 0x0001: /* movi20s */ + case 0x3001: /* 32-bit mov/fmov/movu variants */ + return 4; + } + + /* And the special cases.. */ + switch ((insn & 0xf08f)) { + case 0x3009: /* 32-bit b*.b bit operations */ + return 4; + } + + return 2; +} diff --git a/arch/sh/kernel/kgdb_stub.c b/arch/sh/kernel/kgdb_stub.c index a5323364cbca..ffe3e3ee580d 100644 --- a/arch/sh/kernel/kgdb_stub.c +++ b/arch/sh/kernel/kgdb_stub.c @@ -867,7 +867,7 @@ static void kgdb_command_loop(const int excep_code, const int trapa_value) trap 0xff, since that indicates a compiled-in breakpoint which will not be replaced (and we would retake the trap forever) */ if ((excep_code == TRAP_VEC) && (trapa_value != (0x3c << 2))) - trap_registers.pc -= 2; + trap_registers.pc -= instruction_size(trap_registers.pc); /* Undo any stepping we may have done */ undo_single_step(); diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c index 4688b890aef8..209cc9b42186 100644 --- a/arch/sh/kernel/process.c +++ b/arch/sh/kernel/process.c @@ -19,6 +19,7 @@ #include <asm/uaccess.h> #include <asm/mmu_context.h> #include <asm/pgalloc.h> +#include <asm/system.h> #include <asm/ubc.h> static int hlt_counter; @@ -497,7 +498,7 @@ asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5, struct pt_regs *regs = RELOC_HIDE(&__regs, 0); /* Rewind */ - regs->pc -= 2; + regs->pc -= instruction_size(regs->pc); if (notify_die(DIE_TRAP, regs, regs->tra & 0xff, SIGTRAP) == NOTIFY_STOP) @@ -516,7 +517,7 @@ asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5, struct pt_regs *regs = RELOC_HIDE(&__regs, 0); /* Rewind */ - regs->pc -= 2; + regs->pc -= instruction_size(regs->pc); if (notify_die(DIE_TRAP, regs, TRAPA_BUG_OPCODE & 0xff, SIGTRAP) == NOTIFY_STOP) diff --git a/arch/sh/kernel/signal.c b/arch/sh/kernel/signal.c index eb0191c374b6..d7d98d691c64 100644 --- a/arch/sh/kernel/signal.c +++ b/arch/sh/kernel/signal.c @@ -23,7 +23,7 @@ #include <linux/personality.h> #include <linux/binfmts.h> #include <linux/freezer.h> - +#include <asm/system.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -500,7 +500,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, } /* fallthrough */ case -ERESTARTNOINTR: - regs->pc -= 2; + regs->pc -= instruction_size(regs->pc); } } else { /* gUSA handling */ @@ -600,9 +600,9 @@ static void do_signal(struct pt_regs *regs, unsigned int save_r0) regs->regs[0] == -ERESTARTSYS || regs->regs[0] == -ERESTARTNOINTR) { regs->regs[0] = save_r0; - regs->pc -= 2; + regs->pc -= instruction_size(regs->pc); } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) { - regs->pc -= 2; + regs->pc -= instruction_size(regs->pc); regs->regs[3] = __NR_restart_syscall; } } diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h index e7e96ee0c8a5..82f3e229e621 100644 --- a/include/asm-sh/system.h +++ b/include/asm-sh/system.h @@ -255,6 +255,15 @@ static inline void *set_exception_table_evt(unsigned int evt, void *handler) return set_exception_table_vec(evt >> 5, handler); } +/* + * SH-2A has both 16 and 32-bit opcodes, do lame encoding checks. + */ +#ifdef CONFIG_CPU_SH2A +extern unsigned int instruction_size(unsigned int insn); +#else +#define instruction_size(insn) (2) +#endif + /* XXX * disable hlt during certain critical i/o operations */ |