diff options
Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r-- | arch/mips/kernel/process.c | 226 |
1 files changed, 151 insertions, 75 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 9514e5f2209f..c558bce989cd 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -33,6 +33,7 @@ #include <asm/dsemul.h> #include <asm/dsp.h> #include <asm/fpu.h> +#include <asm/irq.h> #include <asm/msa.h> #include <asm/pgtable.h> #include <asm/mipsregs.h> @@ -49,9 +50,7 @@ #ifdef CONFIG_HOTPLUG_CPU void arch_cpu_idle_dead(void) { - /* What the heck is this check doing ? */ - if (!cpumask_test_cpu(smp_processor_id(), &cpu_callin_map)) - play_dead(); + play_dead(); } #endif @@ -195,11 +194,9 @@ struct mips_frame_info { #define J_TARGET(pc,target) \ (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) -static inline int is_ra_save_ins(union mips_instruction *ip) +static inline int is_ra_save_ins(union mips_instruction *ip, int *poff) { #ifdef CONFIG_CPU_MICROMIPS - union mips_instruction mmi; - /* * swsp ra,offset * swm16 reglist,offset(sp) @@ -209,29 +206,71 @@ static inline int is_ra_save_ins(union mips_instruction *ip) * * microMIPS is way more fun... */ - if (mm_insn_16bit(ip->halfword[0])) { - mmi.word = (ip->halfword[0] << 16); - return (mmi.mm16_r5_format.opcode == mm_swsp16_op && - mmi.mm16_r5_format.rt == 31) || - (mmi.mm16_m_format.opcode == mm_pool16c_op && - mmi.mm16_m_format.func == mm_swm16_op); + if (mm_insn_16bit(ip->halfword[1])) { + switch (ip->mm16_r5_format.opcode) { + case mm_swsp16_op: + if (ip->mm16_r5_format.rt != 31) + return 0; + + *poff = ip->mm16_r5_format.simmediate; + *poff = (*poff << 2) / sizeof(ulong); + return 1; + + case mm_pool16c_op: + switch (ip->mm16_m_format.func) { + case mm_swm16_op: + *poff = ip->mm16_m_format.imm; + *poff += 1 + ip->mm16_m_format.rlist; + *poff = (*poff << 2) / sizeof(ulong); + return 1; + + default: + return 0; + } + + default: + return 0; + } } - else { - mmi.halfword[0] = ip->halfword[1]; - mmi.halfword[1] = ip->halfword[0]; - return (mmi.mm_m_format.opcode == mm_pool32b_op && - mmi.mm_m_format.rd > 9 && - mmi.mm_m_format.base == 29 && - mmi.mm_m_format.func == mm_swm32_func) || - (mmi.i_format.opcode == mm_sw32_op && - mmi.i_format.rs == 29 && - mmi.i_format.rt == 31); + + switch (ip->i_format.opcode) { + case mm_sw32_op: + if (ip->i_format.rs != 29) + return 0; + if (ip->i_format.rt != 31) + return 0; + + *poff = ip->i_format.simmediate / sizeof(ulong); + return 1; + + case mm_pool32b_op: + switch (ip->mm_m_format.func) { + case mm_swm32_func: + if (ip->mm_m_format.rd < 0x10) + return 0; + if (ip->mm_m_format.base != 29) + return 0; + + *poff = ip->mm_m_format.simmediate; + *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32); + *poff /= sizeof(ulong); + return 1; + default: + return 0; + } + + default: + return 0; } #else /* sw / sd $ra, offset($sp) */ - return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && - ip->i_format.rs == 29 && - ip->i_format.rt == 31; + if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && + ip->i_format.rs == 29 && ip->i_format.rt == 31) { + *poff = ip->i_format.simmediate / sizeof(ulong); + return 1; + } + + return 0; #endif } @@ -246,13 +285,16 @@ static inline int is_jump_ins(union mips_instruction *ip) * * microMIPS is kind of more fun... */ - union mips_instruction mmi; - - mmi.word = (ip->halfword[0] << 16); + if (mm_insn_16bit(ip->halfword[1])) { + if ((ip->mm16_r5_format.opcode == mm_pool16c_op && + (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op)) + return 1; + return 0; + } - if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && - (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || - ip->j_format.opcode == mm_jal32_op) + if (ip->j_format.opcode == mm_j32_op) + return 1; + if (ip->j_format.opcode == mm_jal32_op) return 1; if (ip->r_format.opcode != mm_pool32a_op || ip->r_format.func != mm_pool32axf_op) @@ -280,15 +322,13 @@ static inline int is_sp_move_ins(union mips_instruction *ip) * * microMIPS is not more fun... */ - if (mm_insn_16bit(ip->halfword[0])) { - union mips_instruction mmi; - - mmi.word = (ip->halfword[0] << 16); - return (mmi.mm16_r3_format.opcode == mm_pool16d_op && - mmi.mm16_r3_format.simmediate && mm_addiusp_func) || - (mmi.mm16_r5_format.opcode == mm_pool16d_op && - mmi.mm16_r5_format.rt == 29); + if (mm_insn_16bit(ip->halfword[1])) { + return (ip->mm16_r3_format.opcode == mm_pool16d_op && + ip->mm16_r3_format.simmediate && mm_addiusp_func) || + (ip->mm16_r5_format.opcode == mm_pool16d_op && + ip->mm16_r5_format.rt == 29); } + return ip->mm_i_format.opcode == mm_addiu32_op && ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29; #else @@ -303,30 +343,36 @@ static inline int is_sp_move_ins(union mips_instruction *ip) static int get_frame_info(struct mips_frame_info *info) { -#ifdef CONFIG_CPU_MICROMIPS - union mips_instruction *ip = (void *) (((char *) info->func) - 1); -#else - union mips_instruction *ip = info->func; -#endif - unsigned max_insns = info->func_size / sizeof(union mips_instruction); - unsigned i; + bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS); + union mips_instruction insn, *ip, *ip_end; + const unsigned int max_insns = 128; + unsigned int i; info->pc_offset = -1; info->frame_size = 0; + ip = (void *)msk_isa16_mode((ulong)info->func); if (!ip) goto err; - if (max_insns == 0) - max_insns = 128U; /* unknown function size */ - max_insns = min(128U, max_insns); + ip_end = (void *)ip + info->func_size; - for (i = 0; i < max_insns; i++, ip++) { + for (i = 0; i < max_insns && ip < ip_end; i++, ip++) { + if (is_mmips && mm_insn_16bit(ip->halfword[0])) { + insn.halfword[0] = 0; + insn.halfword[1] = ip->halfword[0]; + } else if (is_mmips) { + insn.halfword[0] = ip->halfword[1]; + insn.halfword[1] = ip->halfword[0]; + } else { + insn.word = ip->word; + } - if (is_jump_ins(ip)) + if (is_jump_ins(&insn)) break; + if (!info->frame_size) { - if (is_sp_move_ins(ip)) + if (is_sp_move_ins(&insn)) { #ifdef CONFIG_CPU_MICROMIPS if (mm_insn_16bit(ip->halfword[0])) @@ -349,11 +395,9 @@ static int get_frame_info(struct mips_frame_info *info) } continue; } - if (info->pc_offset == -1 && is_ra_save_ins(ip)) { - info->pc_offset = - ip->i_format.simmediate / sizeof(long); + if (info->pc_offset == -1 && + is_ra_save_ins(&insn, &info->pc_offset)) break; - } } if (info->frame_size && info->pc_offset >= 0) /* nested */ return 0; @@ -441,31 +485,52 @@ unsigned long notrace unwind_stack_by_address(unsigned long stack_page, unsigned long pc, unsigned long *ra) { + unsigned long low, high, irq_stack_high; struct mips_frame_info info; unsigned long size, ofs; + struct pt_regs *regs; int leaf; - extern void ret_from_irq(void); - extern void ret_from_exception(void); if (!stack_page) return 0; /* - * If we reached the bottom of interrupt context, - * return saved pc in pt_regs. + * IRQ stacks start at IRQ_STACK_START + * task stacks at THREAD_SIZE - 32 */ - if (pc == (unsigned long)ret_from_irq || - pc == (unsigned long)ret_from_exception) { - struct pt_regs *regs; - if (*sp >= stack_page && - *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { - regs = (struct pt_regs *)*sp; - pc = regs->cp0_epc; - if (!user_mode(regs) && __kernel_text_address(pc)) { - *sp = regs->regs[29]; - *ra = regs->regs[31]; - return pc; - } + low = stack_page; + if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) { + high = stack_page + IRQ_STACK_START; + irq_stack_high = high; + } else { + high = stack_page + THREAD_SIZE - 32; + irq_stack_high = 0; + } + + /* + * If we reached the top of the interrupt stack, start unwinding + * the interrupted task stack. + */ + if (unlikely(*sp == irq_stack_high)) { + unsigned long task_sp = *(unsigned long *)*sp; + + /* + * Check that the pointer saved in the IRQ stack head points to + * something within the stack of the current task + */ + if (!object_is_on_stack((void *)task_sp)) + return 0; + + /* + * Follow pointer to tasks kernel stack frame where interrupted + * state was saved. + */ + regs = (struct pt_regs *)task_sp; + pc = regs->cp0_epc; + if (!user_mode(regs) && __kernel_text_address(pc)) { + *sp = regs->regs[29]; + *ra = regs->regs[31]; + return pc; } return 0; } @@ -486,8 +551,7 @@ unsigned long notrace unwind_stack_by_address(unsigned long stack_page, if (leaf < 0) return 0; - if (*sp < stack_page || - *sp + info.frame_size > stack_page + THREAD_SIZE - 32) + if (*sp < low || *sp + info.frame_size > high) return 0; if (leaf) @@ -511,7 +575,19 @@ EXPORT_SYMBOL(unwind_stack_by_address); unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, unsigned long pc, unsigned long *ra) { - unsigned long stack_page = (unsigned long)task_stack_page(task); + unsigned long stack_page = 0; + int cpu; + + for_each_possible_cpu(cpu) { + if (on_irq_stack(cpu, *sp)) { + stack_page = (unsigned long)irq_stack[cpu]; + break; + } + } + + if (!stack_page) + stack_page = (unsigned long)task_stack_page(task); + return unwind_stack_by_address(stack_page, sp, pc, ra); } #endif |