diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/sparc/kernel/wuf.S')
| -rw-r--r-- | ANDROID_3.4.5/arch/sparc/kernel/wuf.S | 359 |
1 files changed, 0 insertions, 359 deletions
diff --git a/ANDROID_3.4.5/arch/sparc/kernel/wuf.S b/ANDROID_3.4.5/arch/sparc/kernel/wuf.S deleted file mode 100644 index 779ff750..00000000 --- a/ANDROID_3.4.5/arch/sparc/kernel/wuf.S +++ /dev/null @@ -1,359 +0,0 @@ -/* - * wuf.S: Window underflow trap handler for the Sparc. - * - * Copyright (C) 1995 David S. Miller - */ - -#include <asm/contregs.h> -#include <asm/page.h> -#include <asm/ptrace.h> -#include <asm/psr.h> -#include <asm/smp.h> -#include <asm/asi.h> -#include <asm/winmacro.h> -#include <asm/asmmacro.h> -#include <asm/thread_info.h> - -/* Just like the overflow handler we define macros for registers - * with fixed meanings in this routine. - */ -#define t_psr l0 -#define t_pc l1 -#define t_npc l2 -#define t_wim l3 -/* Don't touch the above registers or else you die horribly... */ - -/* Now macros for the available scratch registers in this routine. */ -#define twin_tmp1 l4 -#define twin_tmp2 l5 - -#define curptr g6 - - .text - .align 4 - - /* The trap entry point has executed the following: - * - * rd %psr, %l0 - * rd %wim, %l3 - * b fill_window_entry - * andcc %l0, PSR_PS, %g0 - */ - - /* Datum current_thread_info->uwinmask contains at all times a bitmask - * where if any user windows are active, at least one bit will - * be set in to mask. If no user windows are active, the bitmask - * will be all zeroes. - */ - - /* To get an idea of what has just happened to cause this - * trap take a look at this diagram: - * - * 1 2 3 4 <-- Window number - * ---------- - * T O W I <-- Symbolic name - * - * O == the window that execution was in when - * the restore was attempted - * - * T == the trap itself has save'd us into this - * window - * - * W == this window is the one which is now invalid - * and must be made valid plus loaded from the - * stack - * - * I == this window will be the invalid one when we - * are done and return from trap if successful - */ - - /* BEGINNING OF PATCH INSTRUCTIONS */ - - /* On 7-window Sparc the boot code patches fnwin_patch1 - * with the following instruction. - */ - .globl fnwin_patch1_7win, fnwin_patch2_7win -fnwin_patch1_7win: srl %t_wim, 6, %twin_tmp2 -fnwin_patch2_7win: and %twin_tmp1, 0x7f, %twin_tmp1 - /* END OF PATCH INSTRUCTIONS */ - - .globl fill_window_entry, fnwin_patch1, fnwin_patch2 -fill_window_entry: - /* LOCATION: Window 'T' */ - - /* Compute what the new %wim is going to be if we retrieve - * the proper window off of the stack. - */ - sll %t_wim, 1, %twin_tmp1 -fnwin_patch1: srl %t_wim, 7, %twin_tmp2 - or %twin_tmp1, %twin_tmp2, %twin_tmp1 -fnwin_patch2: and %twin_tmp1, 0xff, %twin_tmp1 - - wr %twin_tmp1, 0x0, %wim /* Make window 'I' invalid */ - - andcc %t_psr, PSR_PS, %g0 - be fwin_from_user - restore %g0, %g0, %g0 /* Restore to window 'O' */ - - /* Trapped from kernel, we trust that the kernel does not - * 'over restore' sorta speak and just grab the window - * from the stack and return. Easy enough. - */ -fwin_from_kernel: - /* LOCATION: Window 'O' */ - - restore %g0, %g0, %g0 - - /* LOCATION: Window 'W' */ - - LOAD_WINDOW(sp) /* Load it up */ - - /* Spin the wheel... */ - save %g0, %g0, %g0 - save %g0, %g0, %g0 - /* I'd like to buy a vowel please... */ - - /* LOCATION: Window 'T' */ - - /* Now preserve the condition codes in %psr, pause, and - * return from trap. This is the simplest case of all. - */ - wr %t_psr, 0x0, %psr - WRITE_PAUSE - - jmp %t_pc - rett %t_npc - -fwin_from_user: - /* LOCATION: Window 'O' */ - - restore %g0, %g0, %g0 /* Restore to window 'W' */ - - /* LOCATION: Window 'W' */ - - /* Branch to the architecture specific stack validation - * routine. They can be found below... - */ - .globl fwin_mmu_patchme -fwin_mmu_patchme: b sun4c_fwin_stackchk - andcc %sp, 0x7, %g0 - -#define STACK_OFFSET (THREAD_SIZE - TRACEREG_SZ - STACKFRAME_SZ) - -fwin_user_stack_is_bolixed: - /* LOCATION: Window 'W' */ - - /* Place a pt_regs frame on the kernel stack, save back - * to the trap window and call c-code to deal with this. - */ - LOAD_CURRENT(l4, l5) - - sethi %hi(STACK_OFFSET), %l5 - or %l5, %lo(STACK_OFFSET), %l5 - add %l4, %l5, %l5 - - /* Store globals into pt_regs frame. */ - STORE_PT_GLOBALS(l5) - STORE_PT_YREG(l5, g3) - - /* Save current in a global while we change windows. */ - mov %l4, %curptr - - save %g0, %g0, %g0 - - /* LOCATION: Window 'O' */ - - rd %psr, %g3 /* Read %psr in live user window */ - mov %fp, %g4 /* Save bogus frame pointer. */ - - save %g0, %g0, %g0 - - /* LOCATION: Window 'T' */ - - sethi %hi(STACK_OFFSET), %l5 - or %l5, %lo(STACK_OFFSET), %l5 - add %curptr, %l5, %sp - - /* Build rest of pt_regs. */ - STORE_PT_INS(sp) - STORE_PT_PRIV(sp, t_psr, t_pc, t_npc) - - /* re-set trap time %wim value */ - wr %t_wim, 0x0, %wim - - /* Fix users window mask and buffer save count. */ - mov 0x1, %g5 - sll %g5, %g3, %g5 - st %g5, [%curptr + TI_UWINMASK] ! one live user window still - st %g0, [%curptr + TI_W_SAVED] ! no windows in the buffer - - wr %t_psr, PSR_ET, %psr ! enable traps - nop - call window_underflow_fault - mov %g4, %o0 - - b ret_trap_entry - clr %l6 - -fwin_user_stack_is_ok: - /* LOCATION: Window 'W' */ - - /* The users stack area is kosher and mapped, load the - * window and fall through to the finish up routine. - */ - LOAD_WINDOW(sp) - - /* Round and round she goes... */ - save %g0, %g0, %g0 /* Save to window 'O' */ - save %g0, %g0, %g0 /* Save to window 'T' */ - /* Where she'll trap nobody knows... */ - - /* LOCATION: Window 'T' */ - -fwin_user_finish_up: - /* LOCATION: Window 'T' */ - - wr %t_psr, 0x0, %psr - WRITE_PAUSE - - jmp %t_pc - rett %t_npc - - /* Here come the architecture specific checks for stack. - * mappings. Note that unlike the window overflow handler - * we only need to check whether the user can read from - * the appropriate addresses. Also note that we are in - * an invalid window which will be loaded, and this means - * that until we actually load the window up we are free - * to use any of the local registers contained within. - * - * On success these routine branch to fwin_user_stack_is_ok - * if the area at %sp is user readable and the window still - * needs to be loaded, else fwin_user_finish_up if the - * routine has done the loading itself. On failure (bogus - * user stack) the routine shall branch to the label called - * fwin_user_stack_is_bolixed. - * - * Contrary to the arch-specific window overflow stack - * check routines in wof.S, these routines are free to use - * any of the local registers they want to as this window - * does not belong to anyone at this point, however the - * outs and ins are still verboten as they are part of - * 'someone elses' window possibly. - */ - - .align 4 -sun4c_fwin_stackchk: - /* LOCATION: Window 'W' */ - - /* Caller did 'andcc %sp, 0x7, %g0' */ - be 1f - and %sp, 0xfff, %l0 ! delay slot - - b,a fwin_user_stack_is_bolixed - - /* See if we have to check the sanity of one page or two */ -1: - add %l0, 0x38, %l0 - sra %sp, 29, %l5 - add %l5, 0x1, %l5 - andncc %l5, 0x1, %g0 - be 1f - andncc %l0, 0xff8, %g0 - - b,a fwin_user_stack_is_bolixed /* %sp is in vma hole, yuck */ - -1: - be sun4c_fwin_onepage /* Only one page to check */ - lda [%sp] ASI_PTE, %l1 -sun4c_fwin_twopages: - add %sp, 0x38, %l0 - sra %l0, 29, %l5 - add %l5, 0x1, %l5 - andncc %l5, 0x1, %g0 - be 1f - lda [%l0] ASI_PTE, %l1 - - b,a fwin_user_stack_is_bolixed /* Second page in vma hole */ - -1: - srl %l1, 29, %l1 - andcc %l1, 0x4, %g0 - bne sun4c_fwin_onepage - lda [%sp] ASI_PTE, %l1 - - b,a fwin_user_stack_is_bolixed /* Second page has bad perms */ - -sun4c_fwin_onepage: - srl %l1, 29, %l1 - andcc %l1, 0x4, %g0 - bne fwin_user_stack_is_ok - nop - - /* A page had bad page permissions, losing... */ - b,a fwin_user_stack_is_bolixed - - .globl srmmu_fwin_stackchk -srmmu_fwin_stackchk: - /* LOCATION: Window 'W' */ - - /* Caller did 'andcc %sp, 0x7, %g0' */ - bne fwin_user_stack_is_bolixed - sethi %hi(PAGE_OFFSET), %l5 - - /* Check if the users stack is in kernel vma, then our - * trial and error technique below would succeed for - * the 'wrong' reason. - */ - mov AC_M_SFSR, %l4 - cmp %l5, %sp - bleu fwin_user_stack_is_bolixed - lda [%l4] ASI_M_MMUREGS, %g0 ! clear fault status - - /* The technique is, turn off faults on this processor, - * just let the load rip, then check the sfsr to see if - * a fault did occur. Then we turn on fault traps again - * and branch conditionally based upon what happened. - */ - lda [%g0] ASI_M_MMUREGS, %l5 ! read mmu-ctrl reg - or %l5, 0x2, %l5 ! turn on no-fault bit - sta %l5, [%g0] ASI_M_MMUREGS ! store it - - /* Cross fingers and go for it. */ - LOAD_WINDOW(sp) - - /* A penny 'saved'... */ - save %g0, %g0, %g0 - save %g0, %g0, %g0 - /* Is a BADTRAP earned... */ - - /* LOCATION: Window 'T' */ - - lda [%g0] ASI_M_MMUREGS, %twin_tmp1 ! load mmu-ctrl again - andn %twin_tmp1, 0x2, %twin_tmp1 ! clear no-fault bit - sta %twin_tmp1, [%g0] ASI_M_MMUREGS ! store it - - mov AC_M_SFAR, %twin_tmp2 - lda [%twin_tmp2] ASI_M_MMUREGS, %g0 ! read fault address - - mov AC_M_SFSR, %twin_tmp2 - lda [%twin_tmp2] ASI_M_MMUREGS, %twin_tmp2 ! read fault status - andcc %twin_tmp2, 0x2, %g0 ! did fault occur? - - bne 1f ! yep, cleanup - nop - - wr %t_psr, 0x0, %psr - nop - b fwin_user_finish_up + 0x4 - nop - - /* Did I ever tell you about my window lobotomy? - * anyways... fwin_user_stack_is_bolixed expects - * to be in window 'W' so make it happy or else - * we watchdog badly. - */ -1: - restore %g0, %g0, %g0 - b fwin_user_stack_is_bolixed ! oh well - restore %g0, %g0, %g0 |