diff options
Diffstat (limited to 'arch/openrisc/kernel/traps.c')
| -rw-r--r-- | arch/openrisc/kernel/traps.c | 185 |
1 files changed, 184 insertions, 1 deletions
diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index a4574cb4b0fb..7e81ad258bca 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -23,7 +23,7 @@ #include <linux/init.h> #include <linux/sched.h> #include <linux/kernel.h> -#include <linux/module.h> +#include <linux/extable.h> #include <linux/kmod.h> #include <linux/string.h> #include <linux/errno.h> @@ -40,6 +40,8 @@ extern char _etext, _stext; int kstack_depth_to_print = 0x180; +int lwa_flag; +unsigned long __user *lwa_addr; static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) { @@ -334,10 +336,191 @@ asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) } } +static inline int in_delay_slot(struct pt_regs *regs) +{ +#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX + /* No delay slot flag, do the old way */ + unsigned int op, insn; + + insn = *((unsigned int *)regs->pc); + op = insn >> 26; + switch (op) { + case 0x00: /* l.j */ + case 0x01: /* l.jal */ + case 0x03: /* l.bnf */ + case 0x04: /* l.bf */ + case 0x11: /* l.jr */ + case 0x12: /* l.jalr */ + return 1; + default: + return 0; + } +#else + return regs->sr & SPR_SR_DSX; +#endif +} + +static inline void adjust_pc(struct pt_regs *regs, unsigned long address) +{ + int displacement; + unsigned int rb, op, jmp; + + if (unlikely(in_delay_slot(regs))) { + /* In delay slot, instruction at pc is a branch, simulate it */ + jmp = *((unsigned int *)regs->pc); + + displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); + rb = (jmp & 0x0000ffff) >> 11; + op = jmp >> 26; + + switch (op) { + case 0x00: /* l.j */ + regs->pc += displacement; + return; + case 0x01: /* l.jal */ + regs->pc += displacement; + regs->gpr[9] = regs->pc + 8; + return; + case 0x03: /* l.bnf */ + if (regs->sr & SPR_SR_F) + regs->pc += 8; + else + regs->pc += displacement; + return; + case 0x04: /* l.bf */ + if (regs->sr & SPR_SR_F) + regs->pc += displacement; + else + regs->pc += 8; + return; + case 0x11: /* l.jr */ + regs->pc = regs->gpr[rb]; + return; + case 0x12: /* l.jalr */ + regs->pc = regs->gpr[rb]; + regs->gpr[9] = regs->pc + 8; + return; + default: + break; + } + } else { + regs->pc += 4; + } +} + +static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, + unsigned int insn) +{ + unsigned int ra, rd; + unsigned long value; + unsigned long orig_pc; + long imm; + + const struct exception_table_entry *entry; + + orig_pc = regs->pc; + adjust_pc(regs, address); + + ra = (insn >> 16) & 0x1f; + rd = (insn >> 21) & 0x1f; + imm = (short)insn; + lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); + + if ((unsigned long)lwa_addr & 0x3) { + do_unaligned_access(regs, address); + return; + } + + if (get_user(value, lwa_addr)) { + if (user_mode(regs)) { + force_sig(SIGSEGV, current); + return; + } + + if ((entry = search_exception_tables(orig_pc))) { + regs->pc = entry->fixup; + return; + } + + /* kernel access in kernel space, load it directly */ + value = *((unsigned long *)lwa_addr); + } + + lwa_flag = 1; + regs->gpr[rd] = value; +} + +static inline void simulate_swa(struct pt_regs *regs, unsigned long address, + unsigned int insn) +{ + unsigned long __user *vaddr; + unsigned long orig_pc; + unsigned int ra, rb; + long imm; + + const struct exception_table_entry *entry; + + orig_pc = regs->pc; + adjust_pc(regs, address); + + ra = (insn >> 16) & 0x1f; + rb = (insn >> 11) & 0x1f; + imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); + vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); + + if (!lwa_flag || vaddr != lwa_addr) { + regs->sr &= ~SPR_SR_F; + return; + } + + if ((unsigned long)vaddr & 0x3) { + do_unaligned_access(regs, address); + return; + } + + if (put_user(regs->gpr[rb], vaddr)) { + if (user_mode(regs)) { + force_sig(SIGSEGV, current); + return; + } + + if ((entry = search_exception_tables(orig_pc))) { + regs->pc = entry->fixup; + return; + } + + /* kernel access in kernel space, store it directly */ + *((unsigned long *)vaddr) = regs->gpr[rb]; + } + + lwa_flag = 0; + regs->sr |= SPR_SR_F; +} + +#define INSN_LWA 0x1b +#define INSN_SWA 0x33 + asmlinkage void do_illegal_instruction(struct pt_regs *regs, unsigned long address) { siginfo_t info; + unsigned int op; + unsigned int insn = *((unsigned int *)address); + + op = insn >> 26; + + switch (op) { + case INSN_LWA: + simulate_lwa(regs, address, insn); + return; + + case INSN_SWA: + simulate_swa(regs, address, insn); + return; + + default: + break; + } if (user_mode(regs)) { /* Send a SIGILL */ |