projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| d9bc1579 G |
1 | /* |
| 2 | * linux/arch/unicore32/kernel/fpu-ucf64.c | |
| 3 | * | |
| 4 | * Code specific to PKUnity SoC and UniCore ISA | |
| 5 | * | |
| 6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | #include <linux/module.h> | |
| 13 | #include <linux/types.h> | |
| 14 | #include <linux/kernel.h> | |
| 15 | #include <linux/signal.h> | |
| 16 | #include <linux/sched.h> | |
| 17 | #include <linux/init.h> | |
| 18 | ||
| 19 | #include <asm/fpu-ucf64.h> | |
| 20 | ||
| 21 | /* | |
| 22 | * A special flag to tell the normalisation code not to normalise. | |
| 23 | */ | |
| 24 | #define F64_NAN_FLAG 0x100 | |
| 25 | ||
| 26 | /* | |
| 27 | * A bit pattern used to indicate the initial (unset) value of the | |
| 28 | * exception mask, in case nothing handles an instruction. This | |
| 29 | * doesn't include the NAN flag, which get masked out before | |
| 30 | * we check for an error. | |
| 31 | */ | |
| 32 | #define F64_EXCEPTION_ERROR ((u32)-1 & ~F64_NAN_FLAG) | |
| 33 | ||
| 34 | /* | |
| 35 | * Since we aren't building with -mfpu=f64, we need to code | |
| 36 | * these instructions using their MRC/MCR equivalents. | |
| 37 | */ | |
| 38 | #define f64reg(_f64_) #_f64_ | |
| 39 | ||
| 40 | #define cff(_f64_) ({ \ | |
| 41 | u32 __v; \ | |
| 42 | asm("cff %0, " f64reg(_f64_) "@ fmrx %0, " #_f64_ \ | |
| 43 | : "=r" (__v) : : "cc"); \ | |
| 44 | __v; \ | |
| 45 | }) | |
| 46 | ||
| 47 | #define ctf(_f64_, _var_) \ | |
| 48 | asm("ctf %0, " f64reg(_f64_) "@ fmxr " #_f64_ ", %0" \ | |
| 49 | : : "r" (_var_) : "cc") | |
| 50 | ||
| 51 | /* | |
| 52 | * Raise a SIGFPE for the current process. | |
| 53 | * sicode describes the signal being raised. | |
| 54 | */ | |
| 55 | void ucf64_raise_sigfpe(unsigned int sicode, struct pt_regs *regs) | |
| 56 | { | |
| 57 | siginfo_t info; | |
| 58 | ||
| 59 | memset(&info, 0, sizeof(info)); | |
| 60 | ||
| 61 | info.si_signo = SIGFPE; | |
| 62 | info.si_code = sicode; | |
| 63 | info.si_addr = (void __user *)(instruction_pointer(regs) - 4); | |
| 64 | ||
| 65 | /* | |
| 66 | * This is the same as NWFPE, because it's not clear what | |
| 67 | * this is used for | |
| 68 | */ | |
| 69 | current->thread.error_code = 0; | |
| 70 | current->thread.trap_no = 6; | |
| 71 | ||
| 72 | send_sig_info(SIGFPE, &info, current); | |
| 73 | } | |
| 74 | ||
| 75 | /* | |
| 76 | * Handle exceptions of UniCore-F64. | |
| 77 | */ | |
| 78 | void ucf64_exchandler(u32 inst, u32 fpexc, struct pt_regs *regs) | |
| 79 | { | |
| 80 | u32 tmp = fpexc; | |
| 81 | u32 exc = F64_EXCEPTION_ERROR & fpexc; | |
| 82 | ||
| 83 | pr_debug("UniCore-F64: instruction %08x fpscr %08x\n", | |
| 84 | inst, fpexc); | |
| 85 | ||
| 86 | if (exc & FPSCR_CMPINSTR_BIT) { | |
| 87 | if (exc & FPSCR_CON) | |
| 88 | tmp |= FPSCR_CON; | |
| 89 | else | |
| 90 | tmp &= ~(FPSCR_CON); | |
| 91 | exc &= ~(FPSCR_CMPINSTR_BIT | FPSCR_CON); | |
| 92 | } else { | |
| 9b597fd3 MI |
93 | pr_debug("UniCore-F64 Error: unhandled exceptions\n"); |
| 94 | pr_debug("UniCore-F64 FPSCR 0x%08x INST 0x%08x\n", | |
| d9bc1579 G |
95 | cff(FPSCR), inst); |
| 96 | ||
| 97 | ucf64_raise_sigfpe(0, regs); | |
| 98 | return; | |
| 99 | } | |
| 100 | ||
| 101 | /* | |
| 102 | * Update the FPSCR with the additional exception flags. | |
| 103 | * Comparison instructions always return at least one of | |
| 104 | * these flags set. | |
| 105 | */ | |
| 106 | tmp &= ~(FPSCR_TRAP | FPSCR_IOS | FPSCR_OFS | FPSCR_UFS | | |
| 107 | FPSCR_IXS | FPSCR_HIS | FPSCR_IOC | FPSCR_OFC | | |
| 108 | FPSCR_UFC | FPSCR_IXC | FPSCR_HIC); | |
| 109 | ||
| 110 | tmp |= exc; | |
| 111 | ctf(FPSCR, tmp); | |
| 112 | } | |
| 113 | ||
| 114 | /* | |
| 115 | * F64 support code initialisation. | |
| 116 | */ | |
| 117 | static int __init ucf64_init(void) | |
| 118 | { | |
| 119 | ctf(FPSCR, 0x0); /* FPSCR_UFE | FPSCR_NDE perhaps better */ | |
| 120 | ||
| 121 | printk(KERN_INFO "Enable UniCore-F64 support.\n"); | |
| 122 | ||
| 123 | return 0; | |
| 124 | } | |
| 125 | ||
| 126 | late_initcall(ucf64_init); |