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#include "psr.h"
#include "asm/asi.h"
#define ASI_BP ASI_M_BYPASS
#define REGWIN_SZ 0x40
.globl __switch_context, __switch_context_nosave, __exit_context, halt
.text
.align 4
#define STACKFRAME_SZ 0x60
/* These are just handy. */
#define _SV save %sp, -STACKFRAME_SZ, %sp
#define _RS restore
#define FLUSH_ALL_KERNEL_WINDOWS \
_SV; _SV; _SV; _SV; _SV; _SV; _SV; \
_RS; _RS; _RS; _RS; _RS; _RS; _RS;
/*
* Switch execution context
* This saves registers in the stack, then
* switches the stack, and restores everything from the new stack.
* This function takes no argument. New stack pointer is
* taken from global variable __context, and old stack pointer
* is also saved to __context. This way we can just jump to
* this routine to get back to the original context.
*/
__switch_context:
FLUSH_ALL_KERNEL_WINDOWS
/* Save everything in stack */
st %fp, [%fp + 120 -144]
add %fp, -144, %fp
st %g1, [%fp + 4]
st %g2, [%fp + 8]
st %g3, [%fp + 12]
st %g4, [%fp + 16]
st %g5, [%fp + 20]
st %g6, [%fp + 24]
st %g7, [%fp + 28]
st %o0, [%fp + 32]
st %o1, [%fp + 36]
st %o2, [%fp + 40]
st %o3, [%fp + 44]
st %o4, [%fp + 48]
st %o5, [%fp + 52]
st %sp, [%fp + 56]
st %o7, [%fp + 60]
st %l0, [%fp + 64]
st %l1, [%fp + 68]
st %l2, [%fp + 72]
st %l3, [%fp + 76]
st %l4, [%fp + 80]
st %l5, [%fp + 84]
st %l6, [%fp + 88]
st %l7, [%fp + 92]
st %i0, [%fp + 96]
st %i1, [%fp + 100]
st %i2, [%fp + 104]
st %i3, [%fp + 108]
st %i4, [%fp + 112]
st %i5, [%fp + 116]
st %i7, [%fp + 124]
/* ctx->return_address: Return to caller */
st %o7, [%fp + 128]
/* Interrupts are not allowed... */
/* Turn on Supervisor, EnableFloating, and all the PIL bits.
* Also puts us in register window zero with traps off.
*/
#if 0
set (PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
wr %g2, 0x0, %psr
#endif
set __context, %g1
/* Swap ctx pointer with %fp and jump*/
ba __set_context
swap [%g1], %fp
__switch_context_nosave:
set __context, %g1
/* load %fp from ctx pointer */
ld [%g1], %fp
__set_context:
/* Load all registers */
/* offset 0: %g0, no need to load */
ld [%fp + 4], %g1
ld [%fp + 8], %g2
ld [%fp + 12], %g3
ld [%fp + 16], %g4
ld [%fp + 20], %g5
ld [%fp + 24], %g6
ld [%fp + 28], %g7
/* offset 32: %o0, loaded from ctx->param */
ld [%fp + 36], %o1
ld [%fp + 40], %o2
ld [%fp + 44], %o3
ld [%fp + 48], %o4
ld [%fp + 52], %o5
ld [%fp + 56], %sp
/* offset 60: %o7, loaded from ctx->return_addr */
ld [%fp + 64], %l0
ld [%fp + 68], %l1
ld [%fp + 72], %l2
ld [%fp + 76], %l3
ld [%fp + 80], %l4
ld [%fp + 84], %l5
ld [%fp + 88], %l6
ld [%fp + 92], %l7
ld [%fp + 96], %i0
ld [%fp + 100], %i1
ld [%fp + 104], %i2
ld [%fp + 108], %i3
ld [%fp + 112], %i4
ld [%fp + 116], %i5
ld [%fp + 124], %i7
/* ctx->return_addr */
ld [%fp + 136], %o7
/* ctx->param */
ld [%fp + 140], %o0
/* ctx->pc, save %g1 to %y and load to %g1 */
mov %g1, %y
ld [%fp + 128], %g1
/* %fp last */
ld [%fp + 120], %fp
/* Finally, get the new %pc from %g1 and restore %g1*/
jmp %g1
mov %y, %g1
FLUSH_ALL_KERNEL_WINDOWS
__exit_context:
/* Get back to the original context */
call __switch_context
nop
/* We get here if the other context attempt to switch to this
* dead context. This should not happen. */
halt:
b halt
nop
|
