diff options
Diffstat (limited to 'arch/sparc/kernel/rtrap.S')
| -rw-r--r-- | arch/sparc/kernel/rtrap.S | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/arch/sparc/kernel/rtrap.S b/arch/sparc/kernel/rtrap.S new file mode 100644 index 00000000000..f7460d897e7 --- /dev/null +++ b/arch/sparc/kernel/rtrap.S @@ -0,0 +1,319 @@ +/* $Id: rtrap.S,v 1.58 2002/01/31 03:30:05 davem Exp $ + * rtrap.S: Return from Sparc trap low-level code. + * + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + */ + +#include <asm/page.h> +#include <asm/ptrace.h> +#include <asm/psr.h> +#include <asm/asi.h> +#include <asm/smp.h> +#include <asm/contregs.h> +#include <asm/winmacro.h> +#include <asm/asmmacro.h> +#include <asm/thread_info.h> + +#define t_psr l0 +#define t_pc l1 +#define t_npc l2 +#define t_wim l3 +#define twin_tmp1 l4 +#define glob_tmp g4 +#define curptr g6 + + /* 7 WINDOW SPARC PATCH INSTRUCTIONS */ + .globl rtrap_7win_patch1, rtrap_7win_patch2, rtrap_7win_patch3 + .globl rtrap_7win_patch4, rtrap_7win_patch5 +rtrap_7win_patch1: srl %t_wim, 0x6, %glob_tmp +rtrap_7win_patch2: and %glob_tmp, 0x7f, %glob_tmp +rtrap_7win_patch3: srl %g1, 7, %g2 +rtrap_7win_patch4: srl %g2, 6, %g2 +rtrap_7win_patch5: and %g1, 0x7f, %g1 + /* END OF PATCH INSTRUCTIONS */ + + /* We need to check for a few things which are: + * 1) The need to call schedule() because this + * processes quantum is up. + * 2) Pending signals for this process, if any + * exist we need to call do_signal() to do + * the needy. + * + * Else we just check if the rett would land us + * in an invalid window, if so we need to grab + * it off the user/kernel stack first. + */ + + .globl ret_trap_entry, rtrap_patch1, rtrap_patch2 + .globl rtrap_patch3, rtrap_patch4, rtrap_patch5 + .globl ret_trap_lockless_ipi +ret_trap_entry: +ret_trap_lockless_ipi: + andcc %t_psr, PSR_PS, %g0 + be 1f + nop + + wr %t_psr, 0x0, %psr + b ret_trap_kernel + nop + +1: + ld [%curptr + TI_FLAGS], %g2 + andcc %g2, (_TIF_NEED_RESCHED), %g0 + be signal_p + nop + + call schedule + nop + + ld [%curptr + TI_FLAGS], %g2 +signal_p: + andcc %g2, (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING), %g0 + bz,a ret_trap_continue + ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr + + clr %o0 + mov %l5, %o2 + mov %l6, %o3 + call do_signal + add %sp, STACKFRAME_SZ, %o1 ! pt_regs ptr + + /* Fall through. */ + ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr + clr %l6 +ret_trap_continue: + wr %t_psr, 0x0, %psr + WRITE_PAUSE + + ld [%curptr + TI_W_SAVED], %twin_tmp1 + orcc %g0, %twin_tmp1, %g0 + be ret_trap_nobufwins + nop + + wr %t_psr, PSR_ET, %psr + WRITE_PAUSE + + mov 1, %o1 + call try_to_clear_window_buffer + add %sp, STACKFRAME_SZ, %o0 + + b signal_p + ld [%curptr + TI_FLAGS], %g2 + +ret_trap_nobufwins: + /* Load up the user's out registers so we can pull + * a window from the stack, if necessary. + */ + LOAD_PT_INS(sp) + + /* If there are already live user windows in the + * set we can return from trap safely. + */ + ld [%curptr + TI_UWINMASK], %twin_tmp1 + orcc %g0, %twin_tmp1, %g0 + bne ret_trap_userwins_ok + nop + + /* Calculate new %wim, we have to pull a register + * window from the users stack. + */ +ret_trap_pull_one_window: + rd %wim, %t_wim + sll %t_wim, 0x1, %twin_tmp1 +rtrap_patch1: srl %t_wim, 0x7, %glob_tmp + or %glob_tmp, %twin_tmp1, %glob_tmp +rtrap_patch2: and %glob_tmp, 0xff, %glob_tmp + + wr %glob_tmp, 0x0, %wim + + /* Here comes the architecture specific + * branch to the user stack checking routine + * for return from traps. + */ + .globl rtrap_mmu_patchme +rtrap_mmu_patchme: b sun4c_rett_stackchk + andcc %fp, 0x7, %g0 + +ret_trap_userwins_ok: + LOAD_PT_PRIV(sp, t_psr, t_pc, t_npc) + or %t_pc, %t_npc, %g2 + andcc %g2, 0x3, %g0 + be 1f + nop + + b ret_trap_unaligned_pc + add %sp, STACKFRAME_SZ, %o0 + +1: + LOAD_PT_YREG(sp, g1) + LOAD_PT_GLOBALS(sp) + + wr %t_psr, 0x0, %psr + WRITE_PAUSE + + jmp %t_pc + rett %t_npc + +ret_trap_unaligned_pc: + ld [%sp + STACKFRAME_SZ + PT_PC], %o1 + ld [%sp + STACKFRAME_SZ + PT_NPC], %o2 + ld [%sp + STACKFRAME_SZ + PT_PSR], %o3 + + wr %t_wim, 0x0, %wim ! or else... + + wr %t_psr, PSR_ET, %psr + WRITE_PAUSE + + call do_memaccess_unaligned + nop + + b signal_p + ld [%curptr + TI_FLAGS], %g2 + +ret_trap_kernel: + /* Will the rett land us in the invalid window? */ + mov 2, %g1 + sll %g1, %t_psr, %g1 +rtrap_patch3: srl %g1, 8, %g2 + or %g1, %g2, %g1 + rd %wim, %g2 + andcc %g2, %g1, %g0 + be 1f ! Nope, just return from the trap + sll %g2, 0x1, %g1 + + /* We have to grab a window before returning. */ +rtrap_patch4: srl %g2, 7, %g2 + or %g1, %g2, %g1 +rtrap_patch5: and %g1, 0xff, %g1 + + wr %g1, 0x0, %wim + + /* Grrr, make sure we load from the right %sp... */ + LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) + + restore %g0, %g0, %g0 + LOAD_WINDOW(sp) + b 2f + save %g0, %g0, %g0 + + /* Reload the entire frame in case this is from a + * kernel system call or whatever... + */ +1: + LOAD_PT_ALL(sp, t_psr, t_pc, t_npc, g1) +2: + wr %t_psr, 0x0, %psr + WRITE_PAUSE + + jmp %t_pc + rett %t_npc + +ret_trap_user_stack_is_bolixed: + wr %t_wim, 0x0, %wim + + wr %t_psr, PSR_ET, %psr + WRITE_PAUSE + + call window_ret_fault + add %sp, STACKFRAME_SZ, %o0 + + b signal_p + ld [%curptr + TI_FLAGS], %g2 + + + .globl sun4c_rett_stackchk +sun4c_rett_stackchk: + be 1f + and %fp, 0xfff, %g1 ! delay slot + + b ret_trap_user_stack_is_bolixed + 0x4 + wr %t_wim, 0x0, %wim + + /* See if we have to check the sanity of one page or two */ +1: + add %g1, 0x38, %g1 + sra %fp, 29, %g2 + add %g2, 0x1, %g2 + andncc %g2, 0x1, %g0 + be 1f + andncc %g1, 0xff8, %g0 + + /* %sp is in vma hole, yuck */ + b ret_trap_user_stack_is_bolixed + 0x4 + wr %t_wim, 0x0, %wim + +1: + be sun4c_rett_onepage /* Only one page to check */ + lda [%fp] ASI_PTE, %g2 + +sun4c_rett_twopages: + add %fp, 0x38, %g1 + sra %g1, 29, %g2 + add %g2, 0x1, %g2 + andncc %g2, 0x1, %g0 + be 1f + lda [%g1] ASI_PTE, %g2 + + /* Second page is in vma hole */ + b ret_trap_user_stack_is_bolixed + 0x4 + wr %t_wim, 0x0, %wim + +1: + srl %g2, 29, %g2 + andcc %g2, 0x4, %g0 + bne sun4c_rett_onepage + lda [%fp] ASI_PTE, %g2 + + /* Second page has bad perms */ + b ret_trap_user_stack_is_bolixed + 0x4 + wr %t_wim, 0x0, %wim + +sun4c_rett_onepage: + srl %g2, 29, %g2 + andcc %g2, 0x4, %g0 + bne,a 1f + restore %g0, %g0, %g0 + + /* A page had bad page permissions, losing... */ + b ret_trap_user_stack_is_bolixed + 0x4 + wr %t_wim, 0x0, %wim + + /* Whee, things are ok, load the window and continue. */ +1: + LOAD_WINDOW(sp) + + b ret_trap_userwins_ok + save %g0, %g0, %g0 + + .globl srmmu_rett_stackchk +srmmu_rett_stackchk: + bne ret_trap_user_stack_is_bolixed + sethi %hi(PAGE_OFFSET), %g1 + cmp %g1, %fp + bleu ret_trap_user_stack_is_bolixed + mov AC_M_SFSR, %g1 + lda [%g1] ASI_M_MMUREGS, %g0 + + lda [%g0] ASI_M_MMUREGS, %g1 + or %g1, 0x2, %g1 + sta %g1, [%g0] ASI_M_MMUREGS + + restore %g0, %g0, %g0 + + LOAD_WINDOW(sp) + + save %g0, %g0, %g0 + + andn %g1, 0x2, %g1 + sta %g1, [%g0] ASI_M_MMUREGS + + mov AC_M_SFAR, %g2 + lda [%g2] ASI_M_MMUREGS, %g2 + + mov AC_M_SFSR, %g1 + lda [%g1] ASI_M_MMUREGS, %g1 + andcc %g1, 0x2, %g0 + be ret_trap_userwins_ok + nop + + b,a ret_trap_user_stack_is_bolixed |