summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/process.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r--arch/mips/kernel/process.c226
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
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-16 16:47:13 +0000