xref: /openbmc/linux/arch/alpha/include/asm/fpu.h (revision 1dd24dae)
1 #ifndef __ASM_ALPHA_FPU_H
2 #define __ASM_ALPHA_FPU_H
3 
4 #include <asm/special_insns.h>
5 #include <uapi/asm/fpu.h>
6 
7 /* The following two functions don't need trapb/excb instructions
8    around the mf_fpcr/mt_fpcr instructions because (a) the kernel
9    never generates arithmetic faults and (b) call_pal instructions
10    are implied trap barriers.  */
11 
12 static inline unsigned long
13 rdfpcr(void)
14 {
15 	unsigned long tmp, ret;
16 
17 #if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
18 	__asm__ __volatile__ (
19 		"ftoit $f0,%0\n\t"
20 		"mf_fpcr $f0\n\t"
21 		"ftoit $f0,%1\n\t"
22 		"itoft %0,$f0"
23 		: "=r"(tmp), "=r"(ret));
24 #else
25 	__asm__ __volatile__ (
26 		"stt $f0,%0\n\t"
27 		"mf_fpcr $f0\n\t"
28 		"stt $f0,%1\n\t"
29 		"ldt $f0,%0"
30 		: "=m"(tmp), "=m"(ret));
31 #endif
32 
33 	return ret;
34 }
35 
36 static inline void
37 wrfpcr(unsigned long val)
38 {
39 	unsigned long tmp;
40 
41 #if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
42 	__asm__ __volatile__ (
43 		"ftoit $f0,%0\n\t"
44 		"itoft %1,$f0\n\t"
45 		"mt_fpcr $f0\n\t"
46 		"itoft %0,$f0"
47 		: "=&r"(tmp) : "r"(val));
48 #else
49 	__asm__ __volatile__ (
50 		"stt $f0,%0\n\t"
51 		"ldt $f0,%1\n\t"
52 		"mt_fpcr $f0\n\t"
53 		"ldt $f0,%0"
54 		: "=m"(tmp) : "m"(val));
55 #endif
56 }
57 
58 static inline unsigned long
59 swcr_update_status(unsigned long swcr, unsigned long fpcr)
60 {
61 	/* EV6 implements most of the bits in hardware.  Collect
62 	   the acrued exception bits from the real fpcr.  */
63 	if (implver() == IMPLVER_EV6) {
64 		swcr &= ~IEEE_STATUS_MASK;
65 		swcr |= (fpcr >> 35) & IEEE_STATUS_MASK;
66 	}
67 	return swcr;
68 }
69 
70 extern unsigned long alpha_read_fp_reg (unsigned long reg);
71 extern void alpha_write_fp_reg (unsigned long reg, unsigned long val);
72 extern unsigned long alpha_read_fp_reg_s (unsigned long reg);
73 extern void alpha_write_fp_reg_s (unsigned long reg, unsigned long val);
74 
75 #endif /* __ASM_ALPHA_FPU_H */
76