| /* $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_SIGPENDING|_TIF_RESTORE_SIGMASK), %g0 |
| bz,a ret_trap_continue |
| ld [%sp + STACKFRAME_SZ + PT_PSR], %t_psr |
| |
| mov %l5, %o1 |
| mov %l6, %o2 |
| call do_signal |
| add %sp, STACKFRAME_SZ, %o0 ! 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 |