Linux 4.13.16
[linux/fpc-iii.git] / arch / sparc / kernel / windows.c
blob435a467b0595f10f305a2fc150f1c8134be4e3aa
1 /* windows.c: Routines to deal with register window management
2 * at the C-code level.
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 */
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/string.h>
10 #include <linux/mm.h>
11 #include <linux/smp.h>
13 #include <asm/cacheflush.h>
14 #include <linux/uaccess.h>
16 #include "kernel.h"
18 /* Do save's until all user register windows are out of the cpu. */
19 void flush_user_windows(void)
21 register int ctr asm("g5");
23 ctr = 0;
24 __asm__ __volatile__(
25 "\n1:\n\t"
26 "ld [%%g6 + %2], %%g4\n\t"
27 "orcc %%g0, %%g4, %%g0\n\t"
28 "add %0, 1, %0\n\t"
29 "bne 1b\n\t"
30 " save %%sp, -64, %%sp\n"
31 "2:\n\t"
32 "subcc %0, 1, %0\n\t"
33 "bne 2b\n\t"
34 " restore %%g0, %%g0, %%g0\n"
35 : "=&r" (ctr)
36 : "0" (ctr),
37 "i" ((const unsigned long)TI_UWINMASK)
38 : "g4", "cc");
41 static inline void shift_window_buffer(int first_win, int last_win, struct thread_info *tp)
43 int i;
45 for(i = first_win; i < last_win; i++) {
46 tp->rwbuf_stkptrs[i] = tp->rwbuf_stkptrs[i+1];
47 memcpy(&tp->reg_window[i], &tp->reg_window[i+1], sizeof(struct reg_window32));
51 /* Place as many of the user's current register windows
52 * on the stack that we can. Even if the %sp is unaligned
53 * we still copy the window there, the only case that we don't
54 * succeed is if the %sp points to a bum mapping altogether.
55 * setup_frame() and do_sigreturn() use this before shifting
56 * the user stack around. Future instruction and hardware
57 * bug workaround routines will need this functionality as
58 * well.
60 void synchronize_user_stack(void)
62 struct thread_info *tp = current_thread_info();
63 int window;
65 flush_user_windows();
66 if(!tp->w_saved)
67 return;
69 /* Ok, there is some dirty work to do. */
70 for(window = tp->w_saved - 1; window >= 0; window--) {
71 unsigned long sp = tp->rwbuf_stkptrs[window];
73 /* Ok, let it rip. */
74 if (copy_to_user((char __user *) sp, &tp->reg_window[window],
75 sizeof(struct reg_window32)))
76 continue;
78 shift_window_buffer(window, tp->w_saved - 1, tp);
79 tp->w_saved--;
83 #if 0
84 /* An optimization. */
85 static inline void copy_aligned_window(void *dest, const void *src)
87 __asm__ __volatile__("ldd [%1], %%g2\n\t"
88 "ldd [%1 + 0x8], %%g4\n\t"
89 "std %%g2, [%0]\n\t"
90 "std %%g4, [%0 + 0x8]\n\t"
91 "ldd [%1 + 0x10], %%g2\n\t"
92 "ldd [%1 + 0x18], %%g4\n\t"
93 "std %%g2, [%0 + 0x10]\n\t"
94 "std %%g4, [%0 + 0x18]\n\t"
95 "ldd [%1 + 0x20], %%g2\n\t"
96 "ldd [%1 + 0x28], %%g4\n\t"
97 "std %%g2, [%0 + 0x20]\n\t"
98 "std %%g4, [%0 + 0x28]\n\t"
99 "ldd [%1 + 0x30], %%g2\n\t"
100 "ldd [%1 + 0x38], %%g4\n\t"
101 "std %%g2, [%0 + 0x30]\n\t"
102 "std %%g4, [%0 + 0x38]\n\t" : :
103 "r" (dest), "r" (src) :
104 "g2", "g3", "g4", "g5");
106 #endif
108 /* Try to push the windows in a threads window buffer to the
109 * user stack. Unaligned %sp's are not allowed here.
112 void try_to_clear_window_buffer(struct pt_regs *regs, int who)
114 struct thread_info *tp = current_thread_info();
115 int window;
117 flush_user_windows();
118 for(window = 0; window < tp->w_saved; window++) {
119 unsigned long sp = tp->rwbuf_stkptrs[window];
121 if ((sp & 7) ||
122 copy_to_user((char __user *) sp, &tp->reg_window[window],
123 sizeof(struct reg_window32)))
124 do_exit(SIGILL);
126 tp->w_saved = 0;