1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_ALPHA_FPU_H
3 #define __ASM_ALPHA_FPU_H
4
5 #include <asm/special_insns.h>
6 #include <uapi/asm/fpu.h>
7
8 /* The following two functions don't need trapb/excb instructions
9 around the mf_fpcr/mt_fpcr instructions because (a) the kernel
10 never generates arithmetic faults and (b) call_pal instructions
11 are implied trap barriers. */
12
13 static inline unsigned long
14 rdfpcr(void)
15 {
16 unsigned long tmp, ret;
17
18 preempt_disable();
19 if (current_thread_info()->status & TS_SAVED_FP) {
20 ret = current_thread_info()->fp[31];
21 } else {
22 #if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
23 __asm__ __volatile__ (
24 "ftoit $f0,%0\n\t"
25 "mf_fpcr $f0\n\t"
26 "ftoit $f0,%1\n\t"
27 "itoft %0,$f0"
28 : "=r"(tmp), "=r"(ret));
29 #else
30 __asm__ __volatile__ (
31 "stt $f0,%0\n\t"
32 "mf_fpcr $f0\n\t"
33 "stt $f0,%1\n\t"
34 "ldt $f0,%0"
35 : "=m"(tmp), "=m"(ret));
36 #endif
37 }
38 preempt_enable();
39
40 return ret;
41 }
42
43 static inline void
44 wrfpcr(unsigned long val)
45 {
46 unsigned long tmp;
47
48 preempt_disable();
49 if (current_thread_info()->status & TS_SAVED_FP) {
50 current_thread_info()->status |= TS_RESTORE_FP;
51 current_thread_info()->fp[31] = val;
52 } else {
53 #if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67)
54 __asm__ __volatile__ (
55 "ftoit $f0,%0\n\t"
56 "itoft %1,$f0\n\t"
57 "mt_fpcr $f0\n\t"
58 "itoft %0,$f0"
59 : "=&r"(tmp) : "r"(val));
60 #else
61 __asm__ __volatile__ (
62 "stt $f0,%0\n\t"
63 "ldt $f0,%1\n\t"
64 "mt_fpcr $f0\n\t"
65 "ldt $f0,%0"
66 : "=m"(tmp) : "m"(val));
67 #endif
68 }
69 preempt_enable();
70 }
71
72 static inline unsigned long
73 swcr_update_status(unsigned long swcr, unsigned long fpcr)
74 {
75 /* EV6 implements most of the bits in hardware. Collect
76 the acrued exception bits from the real fpcr. */
77 if (implver() == IMPLVER_EV6) {
78 swcr &= ~IEEE_STATUS_MASK;
79 swcr |= (fpcr >> 35) & IEEE_STATUS_MASK;
80 }
81 return swcr;
82 }
83
84 extern unsigned long alpha_read_fp_reg (unsigned long reg);
85 extern void alpha_write_fp_reg (unsigned long reg, unsigned long val);
86 extern unsigned long alpha_read_fp_reg_s (unsigned long reg);
87 extern void alpha_write_fp_reg_s (unsigned long reg, unsigned long val);
88
89 #endif /* __ASM_ALPHA_FPU_H */
90
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