diff options
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 252 |
1 files changed, 10 insertions, 242 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index c39303e5c234..682e92664b07 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -446,258 +446,26 @@ ENDPROC(__irq_usr) __und_usr: usr_entry uaccess=0 - mov r2, r4 - mov r3, r5 - - @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the - @ faulting instruction depending on Thumb mode. - @ r3 = regs->ARM_cpsr - @ - @ The emulation code returns using r9 if it has emulated the - @ instruction, or the more conventional lr if we are to treat - @ this as a real undefined instruction - @ - badr r9, ret_from_exception - @ IRQs must be enabled before attempting to read the instruction from @ user space since that could cause a page/translation fault if the @ page table was modified by another CPU. enable_irq - tst r3, #PSR_T_BIT @ Thumb mode? - bne __und_usr_thumb - sub r4, r2, #4 @ ARM instr at LR - 4 -1: ldrt r0, [r4] - ARM_BE8(rev r0, r0) @ little endian instruction - - uaccess_disable ip - - @ r0 = 32-bit ARM instruction which caused the exception - @ r2 = PC value for the following instruction (:= regs->ARM_pc) - @ r4 = PC value for the faulting instruction - @ lr = 32-bit undefined instruction function - badr lr, __und_usr_fault_32 - b call_fpe - -__und_usr_thumb: - @ Thumb instruction - sub r4, r2, #2 @ First half of thumb instr at LR - 2 -#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7 -/* - * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms - * can never be supported in a single kernel, this code is not applicable at - * all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be - * made about .arch directives. - */ -#if __LINUX_ARM_ARCH__ < 7 -/* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */ - ldr_va r5, cpu_architecture - cmp r5, #CPU_ARCH_ARMv7 - blo __und_usr_fault_16 @ 16bit undefined instruction -/* - * The following code won't get run unless the running CPU really is v7, so - * coding round the lack of ldrht on older arches is pointless. Temporarily - * override the assembler target arch with the minimum required instead: - */ - .arch armv6t2 + tst r5, #PSR_T_BIT @ Thumb mode? + mov r1, #2 @ set insn size to 2 for Thumb + bne 0f @ handle as Thumb undef exception +#ifdef CONFIG_FPE_NWFPE + adr r9, ret_from_exception + bl call_fpe @ returns via R9 on success #endif -2: ldrht r5, [r4] -ARM_BE8(rev16 r5, r5) @ little endian instruction - cmp r5, #0xe800 @ 32bit instruction if xx != 0 - blo __und_usr_fault_16_pan @ 16bit undefined instruction -3: ldrht r0, [r2] -ARM_BE8(rev16 r0, r0) @ little endian instruction + mov r1, #4 @ set insn size to 4 for ARM +0: mov r0, sp uaccess_disable ip - add r2, r2, #2 @ r2 is PC + 2, make it PC + 4 - str r2, [sp, #S_PC] @ it's a 2x16bit instr, update - orr r0, r0, r5, lsl #16 - badr lr, __und_usr_fault_32 - @ r0 = the two 16-bit Thumb instructions which caused the exception - @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc) - @ r4 = PC value for the first 16-bit Thumb instruction - @ lr = 32bit undefined instruction function - -#if __LINUX_ARM_ARCH__ < 7 -/* If the target arch was overridden, change it back: */ -#ifdef CONFIG_CPU_32v6K - .arch armv6k -#else - .arch armv6 -#endif -#endif /* __LINUX_ARM_ARCH__ < 7 */ -#else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */ - b __und_usr_fault_16 -#endif + bl __und_fault + b ret_from_exception UNWIND(.fnend) ENDPROC(__und_usr) -/* - * The out of line fixup for the ldrt instructions above. - */ - .pushsection .text.fixup, "ax" - .align 2 -4: str r4, [sp, #S_PC] @ retry current instruction - ret r9 - .popsection - .pushsection __ex_table,"a" - .long 1b, 4b -#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7 - .long 2b, 4b - .long 3b, 4b -#endif - .popsection - -/* - * Check whether the instruction is a co-processor instruction. - * If yes, we need to call the relevant co-processor handler. - * - * Note that we don't do a full check here for the co-processor - * instructions; all instructions with bit 27 set are well - * defined. The only instructions that should fault are the - * co-processor instructions. However, we have to watch out - * for the ARM6/ARM7 SWI bug. - * - * NEON is a special case that has to be handled here. Not all - * NEON instructions are co-processor instructions, so we have - * to make a special case of checking for them. Plus, there's - * five groups of them, so we have a table of mask/opcode pairs - * to check against, and if any match then we branch off into the - * NEON handler code. - * - * Emulators may wish to make use of the following registers: - * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb) - * r2 = PC value to resume execution after successful emulation - * r9 = normal "successful" return address - * r10 = this threads thread_info structure - * lr = unrecognised instruction return address - * IRQs enabled, FIQs enabled. - */ - @ - @ Fall-through from Thumb-2 __und_usr - @ -#ifdef CONFIG_NEON - get_thread_info r10 @ get current thread - adr r6, .LCneon_thumb_opcodes - b 2f -#endif -call_fpe: - get_thread_info r10 @ get current thread -#ifdef CONFIG_NEON - adr r6, .LCneon_arm_opcodes -2: ldr r5, [r6], #4 @ mask value - ldr r7, [r6], #4 @ opcode bits matching in mask - cmp r5, #0 @ end mask? - beq 1f - and r8, r0, r5 - cmp r8, r7 @ NEON instruction? - bne 2b - mov r7, #1 - strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used - strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used - b do_vfp @ let VFP handler handle this -1: -#endif - tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 - tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2 - reteq lr - and r8, r0, #0x00000f00 @ mask out CP number - mov r7, #1 - add r6, r10, r8, lsr #8 @ add used_cp[] array offset first - strb r7, [r6, #TI_USED_CP] @ set appropriate used_cp[] -#ifdef CONFIG_IWMMXT - @ Test if we need to give access to iWMMXt coprocessors - ldr r5, [r10, #TI_FLAGS] - rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only - movscs r7, r5, lsr #(TIF_USING_IWMMXT + 1) - bcs iwmmxt_task_enable -#endif - ARM( add pc, pc, r8, lsr #6 ) - THUMB( lsr r8, r8, #6 ) - THUMB( add pc, r8 ) - nop - - ret.w lr @ CP#0 - W(b) do_fpe @ CP#1 (FPE) - W(b) do_fpe @ CP#2 (FPE) - ret.w lr @ CP#3 - ret.w lr @ CP#4 - ret.w lr @ CP#5 - ret.w lr @ CP#6 - ret.w lr @ CP#7 - ret.w lr @ CP#8 - ret.w lr @ CP#9 -#ifdef CONFIG_VFP - W(b) do_vfp @ CP#10 (VFP) - W(b) do_vfp @ CP#11 (VFP) -#else - ret.w lr @ CP#10 (VFP) - ret.w lr @ CP#11 (VFP) -#endif - ret.w lr @ CP#12 - ret.w lr @ CP#13 - ret.w lr @ CP#14 (Debug) - ret.w lr @ CP#15 (Control) - -#ifdef CONFIG_NEON - .align 6 - -.LCneon_arm_opcodes: - .word 0xfe000000 @ mask - .word 0xf2000000 @ opcode - - .word 0xff100000 @ mask - .word 0xf4000000 @ opcode - - .word 0x00000000 @ mask - .word 0x00000000 @ opcode - -.LCneon_thumb_opcodes: - .word 0xef000000 @ mask - .word 0xef000000 @ opcode - - .word 0xff100000 @ mask - .word 0xf9000000 @ opcode - - .word 0x00000000 @ mask - .word 0x00000000 @ opcode -#endif - -do_fpe: - add r10, r10, #TI_FPSTATE @ r10 = workspace - ldr_va pc, fp_enter, tmp=r4 @ Call FP module USR entry point - -/* - * The FP module is called with these registers set: - * r0 = instruction - * r2 = PC+4 - * r9 = normal "successful" return address - * r10 = FP workspace - * lr = unrecognised FP instruction return address - */ - - .pushsection .data - .align 2 -ENTRY(fp_enter) - .word no_fp - .popsection - -ENTRY(no_fp) - ret lr -ENDPROC(no_fp) - -__und_usr_fault_32: - mov r1, #4 - b 1f -__und_usr_fault_16_pan: - uaccess_disable ip -__und_usr_fault_16: - mov r1, #2 -1: mov r0, sp - badr lr, ret_from_exception - b __und_fault -ENDPROC(__und_usr_fault_32) -ENDPROC(__und_usr_fault_16) - .align 5 __pabt_usr: usr_entry |