1 /* $Id: muldiv.c,v 1.5 1997/12/15 20:07:20 ecd Exp $
2 * muldiv.c: Hardware multiply/division illegal instruction trap
3 * for sun4c/sun4 (which do not have those instructions)
5 * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
12 #include <asm/ptrace.h>
13 #include <asm/processor.h>
14 #include <asm/system.h>
15 #include <asm/uaccess.h>
17 /* #define DEBUG_MULDIV */
19 static inline int has_imm13(int insn)
21 return (insn & 0x2000);
24 static inline int is_foocc(int insn)
26 return (insn & 0x800000);
29 static inline int sign_extend_imm13(int imm)
31 return imm << 19 >> 19;
34 static inline void advance(struct pt_regs *regs)
40 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
43 if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
45 __asm__ __volatile__("save %sp, -0x40, %sp\n\t"
46 "save %sp, -0x40, %sp\n\t"
47 "save %sp, -0x40, %sp\n\t"
48 "save %sp, -0x40, %sp\n\t"
49 "save %sp, -0x40, %sp\n\t"
50 "save %sp, -0x40, %sp\n\t"
51 "save %sp, -0x40, %sp\n\t"
52 "restore; restore; restore; restore;\n\t"
53 "restore; restore; restore;\n\t");
57 #define fetch_reg(reg, regs) ({ \
58 struct reg_window __user *win; \
59 register unsigned long ret; \
61 if (!(reg)) ret = 0; \
62 else if ((reg) < 16) { \
63 ret = regs->u_regs[(reg)]; \
65 /* Ho hum, the slightly complicated case. */ \
66 win = (struct reg_window __user *)regs->u_regs[UREG_FP];\
67 if (get_user (ret, &win->locals[(reg) - 16])) return -1;\
73 store_reg(unsigned int result, unsigned int reg, struct pt_regs *regs)
75 struct reg_window __user *win;
80 regs->u_regs[reg] = result;
83 /* need to use put_user() in this case: */
84 win = (struct reg_window __user *) regs->u_regs[UREG_FP];
85 return (put_user(result, &win->locals[reg - 16]));
89 extern void handle_hw_divzero (struct pt_regs *regs, unsigned long pc,
90 unsigned long npc, unsigned long psr);
92 /* Should return 0 if mul/div emulation succeeded and SIGILL should
95 int do_user_muldiv(struct pt_regs *regs, unsigned long pc)
99 unsigned int rs1, rs2, rdv;
102 return -1; /* This happens to often, I think */
103 if (get_user (insn, (unsigned int __user *)pc))
105 if ((insn & 0xc1400000) != 0x80400000)
107 inst = ((insn >> 19) & 0xf);
108 if ((inst & 0xe) != 10 && (inst & 0xe) != 14)
111 /* Now we know we have to do something with umul, smul, udiv or sdiv */
112 rs1 = (insn >> 14) & 0x1f;
114 rdv = (insn >> 25) & 0x1f;
115 if (has_imm13(insn)) {
116 maybe_flush_windows(rs1, 0, rdv);
117 rs2 = sign_extend_imm13(insn);
119 maybe_flush_windows(rs1, rs2, rdv);
120 rs2 = fetch_reg(rs2, regs);
122 rs1 = fetch_reg(rs1, regs);
126 printk ("unsigned muldiv: 0x%x * 0x%x = ", rs1, rs2);
128 __asm__ __volatile__ ("\n\t"
134 : "=r" (rs1), "=r" (rs2)
136 : "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc");
138 printk ("0x%x%08x\n", rs2, rs1);
140 if (store_reg(rs1, rdv, regs))
146 printk ("signed muldiv: 0x%x * 0x%x = ", rs1, rs2);
148 __asm__ __volatile__ ("\n\t"
154 : "=r" (rs1), "=r" (rs2)
156 : "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc");
158 printk ("0x%x%08x\n", rs2, rs1);
160 if (store_reg(rs1, rdv, regs))
166 printk ("unsigned muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2);
170 printk ("DIVISION BY ZERO\n");
172 handle_hw_divzero (regs, pc, regs->npc, regs->psr);
175 __asm__ __volatile__ ("\n\t"
183 : "=r" (rs1), "=r" (rs2)
185 : "o0", "o1", "o2", "o3", "o4", "o5", "o7",
186 "g1", "g2", "g3", "cc");
188 printk ("0x%x\n", rs1);
190 if (store_reg(rs1, rdv, regs))
195 printk ("signed muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2);
199 printk ("DIVISION BY ZERO\n");
201 handle_hw_divzero (regs, pc, regs->npc, regs->psr);
204 __asm__ __volatile__ ("\n\t"
212 : "=r" (rs1), "=r" (rs2)
214 : "o0", "o1", "o2", "o3", "o4", "o5", "o7",
215 "g1", "g2", "g3", "cc");
217 printk ("0x%x\n", rs1);
219 if (store_reg(rs1, rdv, regs))
223 if (is_foocc (insn)) {
224 regs->psr &= ~PSR_ICC;
225 if ((inst & 0xe) == 14) {
227 if (rs2) regs->psr |= PSR_V;
229 if (!rs1) regs->psr |= PSR_Z;
230 if (((int)rs1) < 0) regs->psr |= PSR_N;
232 printk ("psr muldiv: %08x\n", regs->psr);