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v3.5.6
  1/* windows.c: Routines to deal with register window management
  2 *            at the C-code level.
  3 *
  4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  5 */
  6
  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>
 12
 
 13#include <asm/uaccess.h>
 
 
 14
 15/* Do save's until all user register windows are out of the cpu. */
 16void flush_user_windows(void)
 17{
 18	register int ctr asm("g5");
 19
 20	ctr = 0;
 21	__asm__ __volatile__(
 22		"\n1:\n\t"
 23		"ld	[%%g6 + %2], %%g4\n\t"
 24		"orcc	%%g0, %%g4, %%g0\n\t"
 25		"add	%0, 1, %0\n\t"
 26		"bne	1b\n\t"
 27		" save	%%sp, -64, %%sp\n"
 28		"2:\n\t"
 29		"subcc	%0, 1, %0\n\t"
 30		"bne	2b\n\t"
 31		" restore %%g0, %%g0, %%g0\n"
 32	: "=&r" (ctr)
 33	: "0" (ctr),
 34	  "i" ((const unsigned long)TI_UWINMASK)
 35	: "g4", "cc");
 36}
 37
 38static inline void shift_window_buffer(int first_win, int last_win, struct thread_info *tp)
 39{
 40	int i;
 41
 42	for(i = first_win; i < last_win; i++) {
 43		tp->rwbuf_stkptrs[i] = tp->rwbuf_stkptrs[i+1];
 44		memcpy(&tp->reg_window[i], &tp->reg_window[i+1], sizeof(struct reg_window32));
 45	}
 46}
 47
 48/* Place as many of the user's current register windows 
 49 * on the stack that we can.  Even if the %sp is unaligned
 50 * we still copy the window there, the only case that we don't
 51 * succeed is if the %sp points to a bum mapping altogether.
 52 * setup_frame() and do_sigreturn() use this before shifting
 53 * the user stack around.  Future instruction and hardware
 54 * bug workaround routines will need this functionality as
 55 * well.
 56 */
 57void synchronize_user_stack(void)
 58{
 59	struct thread_info *tp = current_thread_info();
 60	int window;
 61
 62	flush_user_windows();
 63	if(!tp->w_saved)
 64		return;
 65
 66	/* Ok, there is some dirty work to do. */
 67	for(window = tp->w_saved - 1; window >= 0; window--) {
 68		unsigned long sp = tp->rwbuf_stkptrs[window];
 69
 70		/* Ok, let it rip. */
 71		if (copy_to_user((char __user *) sp, &tp->reg_window[window],
 72				 sizeof(struct reg_window32)))
 73			continue;
 74
 75		shift_window_buffer(window, tp->w_saved - 1, tp);
 76		tp->w_saved--;
 77	}
 78}
 79
 80#if 0
 81/* An optimization. */
 82static inline void copy_aligned_window(void *dest, const void *src)
 83{
 84	__asm__ __volatile__("ldd [%1], %%g2\n\t"
 85			     "ldd [%1 + 0x8], %%g4\n\t"
 86			     "std %%g2, [%0]\n\t"
 87			     "std %%g4, [%0 + 0x8]\n\t"
 88			     "ldd [%1 + 0x10], %%g2\n\t"
 89			     "ldd [%1 + 0x18], %%g4\n\t"
 90			     "std %%g2, [%0 + 0x10]\n\t"
 91			     "std %%g4, [%0 + 0x18]\n\t"
 92			     "ldd [%1 + 0x20], %%g2\n\t"
 93			     "ldd [%1 + 0x28], %%g4\n\t"
 94			     "std %%g2, [%0 + 0x20]\n\t"
 95			     "std %%g4, [%0 + 0x28]\n\t"
 96			     "ldd [%1 + 0x30], %%g2\n\t"
 97			     "ldd [%1 + 0x38], %%g4\n\t"
 98			     "std %%g2, [%0 + 0x30]\n\t"
 99			     "std %%g4, [%0 + 0x38]\n\t" : :
100			     "r" (dest), "r" (src) :
101			     "g2", "g3", "g4", "g5");
102}
103#endif
104
105/* Try to push the windows in a threads window buffer to the
106 * user stack.  Unaligned %sp's are not allowed here.
107 */
108
109void try_to_clear_window_buffer(struct pt_regs *regs, int who)
110{
111	struct thread_info *tp = current_thread_info();
112	int window;
113
114	flush_user_windows();
115	for(window = 0; window < tp->w_saved; window++) {
116		unsigned long sp = tp->rwbuf_stkptrs[window];
117
118		if ((sp & 7) ||
119		    copy_to_user((char __user *) sp, &tp->reg_window[window],
120				 sizeof(struct reg_window32)))
121			do_exit(SIGILL);
122	}
123	tp->w_saved = 0;
124}
v4.6
  1/* windows.c: Routines to deal with register window management
  2 *            at the C-code level.
  3 *
  4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  5 */
  6
  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>
 12
 13#include <asm/cacheflush.h>
 14#include <asm/uaccess.h>
 15
 16#include "kernel.h"
 17
 18/* Do save's until all user register windows are out of the cpu. */
 19void flush_user_windows(void)
 20{
 21	register int ctr asm("g5");
 22
 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");
 39}
 40
 41static inline void shift_window_buffer(int first_win, int last_win, struct thread_info *tp)
 42{
 43	int i;
 44
 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));
 48	}
 49}
 50
 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.
 59 */
 60void synchronize_user_stack(void)
 61{
 62	struct thread_info *tp = current_thread_info();
 63	int window;
 64
 65	flush_user_windows();
 66	if(!tp->w_saved)
 67		return;
 68
 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];
 72
 73		/* Ok, let it rip. */
 74		if (copy_to_user((char __user *) sp, &tp->reg_window[window],
 75				 sizeof(struct reg_window32)))
 76			continue;
 77
 78		shift_window_buffer(window, tp->w_saved - 1, tp);
 79		tp->w_saved--;
 80	}
 81}
 82
 83#if 0
 84/* An optimization. */
 85static inline void copy_aligned_window(void *dest, const void *src)
 86{
 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");
105}
106#endif
107
108/* Try to push the windows in a threads window buffer to the
109 * user stack.  Unaligned %sp's are not allowed here.
110 */
111
112void try_to_clear_window_buffer(struct pt_regs *regs, int who)
113{
114	struct thread_info *tp = current_thread_info();
115	int window;
116
117	flush_user_windows();
118	for(window = 0; window < tp->w_saved; window++) {
119		unsigned long sp = tp->rwbuf_stkptrs[window];
120
121		if ((sp & 7) ||
122		    copy_to_user((char __user *) sp, &tp->reg_window[window],
123				 sizeof(struct reg_window32)))
124			do_exit(SIGILL);
125	}
126	tp->w_saved = 0;
127}