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m68k: adjustments to stack frame for ColdFire with MMU enabled

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The exception return stack adjustment required by ColdFire when running
with the MMU enabled is not completely identical to 680x0 processors.
Specifically the format type 4 stack frame doesn't need any stack
adjustment on exception return. And the ColdFire always must return with
a frame type of 4, not 0.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
This commit is contained in:
Greg Ungerer 2011-10-19 13:58:55 +10:00
parent ed865e31a8
commit e9fcffa493
1 changed files with 15 additions and 2 deletions
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17
arch/m68k/kernel/signal_mm.c
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@ -56,7 +56,11 @@ static const int frame_extra_sizes[16] = {
[1] = -1, /* sizeof(((struct frame *)0)->un.fmt1), */
[2] = sizeof(((struct frame *)0)->un.fmt2),
[3] = sizeof(((struct frame *)0)->un.fmt3),
#ifdef CONFIG_COLDFIRE
[4] = 0,
#else
[4] = sizeof(((struct frame *)0)->un.fmt4),
#endif
[5] = -1, /* sizeof(((struct frame *)0)->un.fmt5), */
[6] = -1, /* sizeof(((struct frame *)0)->un.fmt6), */
[7] = sizeof(((struct frame *)0)->un.fmt7),
@ -84,7 +88,11 @@ int handle_kernel_fault(struct pt_regs *regs)
regs->stkadj = frame_extra_sizes[regs->format];
tregs = (struct pt_regs *)((long)regs + regs->stkadj);
tregs->vector = regs->vector;
#ifdef CONFIG_COLDFIRE
tregs->format = 4;
#else
tregs->format = 0;
#endif
tregs->pc = fixup->fixup;
tregs->sr = regs->sr;
@ -336,8 +344,12 @@ static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
regs->format = formatvec >> 12;
regs->vector = formatvec & 0xfff;
#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
__asm__ __volatile__
(" movel %0,%/a0\n\t"
__asm__ __volatile__ (
#ifdef CONFIG_COLDFIRE
" movel %0,%/sp\n\t"
" bra ret_from_signal\n"
#else
" movel %0,%/a0\n\t"
" subl %1,%/a0\n\t" /* make room on stack */
" movel %/a0,%/sp\n\t" /* set stack pointer */
/* move switch_stack and pt_regs */
@ -350,6 +362,7 @@ static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
"2: movel %4@+,%/a0@+\n\t"
" dbra %1,2b\n\t"
" bral ret_from_signal\n"
#endif
: /* no outputs, it doesn't ever return */
: "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
"n" (frame_offset), "a" (buf + fsize/4)