diff options
Diffstat (limited to 'arch/alpha/kernel/traps.c')
| -rw-r--r-- | arch/alpha/kernel/traps.c | 99 |
1 files changed, 18 insertions, 81 deletions
diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c index 8a66fe544c69..7004397937cf 100644 --- a/arch/alpha/kernel/traps.c +++ b/arch/alpha/kernel/traps.c @@ -9,6 +9,7 @@ * This file initializes the trap entry points */ +#include <linux/cpu.h> #include <linux/jiffies.h> #include <linux/mm.h> #include <linux/sched/signal.h> @@ -21,7 +22,7 @@ #include <asm/gentrap.h> #include <linux/uaccess.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> #include <asm/sysinfo.h> #include <asm/hwrpb.h> #include <asm/mmu_context.h> @@ -29,39 +30,6 @@ #include "proto.h" -/* Work-around for some SRMs which mishandle opDEC faults. */ - -static int opDEC_fix; - -static void -opDEC_check(void) -{ - __asm__ __volatile__ ( - /* Load the address of... */ - " br $16, 1f\n" - /* A stub instruction fault handler. Just add 4 to the - pc and continue. */ - " ldq $16, 8($sp)\n" - " addq $16, 4, $16\n" - " stq $16, 8($sp)\n" - " call_pal %[rti]\n" - /* Install the instruction fault handler. */ - "1: lda $17, 3\n" - " call_pal %[wrent]\n" - /* With that in place, the fault from the round-to-minf fp - insn will arrive either at the "lda 4" insn (bad) or one - past that (good). This places the correct fixup in %0. */ - " lda %[fix], 0\n" - " cvttq/svm $f31,$f31\n" - " lda %[fix], 4" - : [fix] "=r" (opDEC_fix) - : [rti] "n" (PAL_rti), [wrent] "n" (PAL_wrent) - : "$0", "$1", "$16", "$17", "$22", "$23", "$24", "$25"); - - if (opDEC_fix) - printk("opDEC fixup enabled.\n"); -} - void dik_show_regs(struct pt_regs *regs, unsigned long *r9_15) { @@ -233,7 +201,21 @@ do_entIF(unsigned long type, struct pt_regs *regs) { int signo, code; - if ((regs->ps & ~IPL_MAX) == 0) { + if (type == 3) { /* FEN fault */ + /* Irritating users can call PAL_clrfen to disable the + FPU for the process. The kernel will then trap in + do_switch_stack and undo_switch_stack when we try + to save and restore the FP registers. + + Given that GCC by default generates code that uses the + FP registers, PAL_clrfen is not useful except for DoS + attacks. So turn the bleeding FPU back on and be done + with it. */ + current_thread_info()->pcb.flags |= 1; + __reload_thread(¤t_thread_info()->pcb); + return; + } + if (!user_mode(regs)) { if (type == 1) { const unsigned int *data = (const unsigned int *) regs->pc; @@ -338,48 +320,8 @@ do_entIF(unsigned long type, struct pt_regs *regs) return; case 4: /* opDEC */ - if (implver() == IMPLVER_EV4) { - long si_code; - - /* The some versions of SRM do not handle - the opDEC properly - they return the PC of the - opDEC fault, not the instruction after as the - Alpha architecture requires. Here we fix it up. - We do this by intentionally causing an opDEC - fault during the boot sequence and testing if - we get the correct PC. If not, we set a flag - to correct it every time through. */ - regs->pc += opDEC_fix; - - /* EV4 does not implement anything except normal - rounding. Everything else will come here as - an illegal instruction. Emulate them. */ - si_code = alpha_fp_emul(regs->pc - 4); - if (si_code == 0) - return; - if (si_code > 0) { - send_sig_fault_trapno(SIGFPE, si_code, - (void __user *) regs->pc, - 0, current); - return; - } - } break; - case 3: /* FEN fault */ - /* Irritating users can call PAL_clrfen to disable the - FPU for the process. The kernel will then trap in - do_switch_stack and undo_switch_stack when we try - to save and restore the FP registers. - - Given that GCC by default generates code that uses the - FP registers, PAL_clrfen is not useful except for DoS - attacks. So turn the bleeding FPU back on and be done - with it. */ - current_thread_info()->pcb.flags |= 1; - __reload_thread(¤t_thread_info()->pcb); - return; - case 5: /* illoc */ default: /* unexpected instruction-fault type */ ; @@ -707,7 +649,7 @@ s_reg_to_mem (unsigned long s_reg) static int unauser_reg_offsets[32] = { R(r0), R(r1), R(r2), R(r3), R(r4), R(r5), R(r6), R(r7), R(r8), /* r9 ... r15 are stored in front of regs. */ - -56, -48, -40, -32, -24, -16, -8, + -64, -56, -48, -40, -32, -24, -16, /* padding at -8 */ R(r16), R(r17), R(r18), R(r19), R(r20), R(r21), R(r22), R(r23), R(r24), R(r25), R(r26), R(r27), R(r28), R(gp), @@ -978,11 +920,6 @@ trap_init(void) register unsigned long gptr __asm__("$29"); wrkgp(gptr); - /* Hack for Multia (UDB) and JENSEN: some of their SRMs have - a bug in the handling of the opDEC fault. Fix it up if so. */ - if (implver() == IMPLVER_EV4) - opDEC_check(); - wrent(entArith, 1); wrent(entMM, 2); wrent(entIF, 3); |