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
13static inline unsigned long
14rdfpcr(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
43static inline void
44wrfpcr(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
72static inline unsigned long
73swcr_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
84extern unsigned long alpha_read_fp_reg (unsigned long reg);
85extern void alpha_write_fp_reg (unsigned long reg, unsigned long val);
86extern unsigned long alpha_read_fp_reg_s (unsigned long reg);
87extern void alpha_write_fp_reg_s (unsigned long reg, unsigned long val);
88
89#endif /* __ASM_ALPHA_FPU_H */
90