| /* |
| * Proll takes this from Sparclinux kernel, ruthlessly truncated |
| * because we have no user windows. |
| * |
| * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| * MA 02110-1301, USA. |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License V2 |
| * as published by the Free Software Foundation |
| */ |
| |
| // #include <asm/winmacro.h> |
| // #include <asm/asmmacro.h> |
| |
| /* Reg_window offsets */ |
| #define RW_L0 0x00 |
| #define RW_L1 0x04 |
| #define RW_L2 0x08 |
| #define RW_L3 0x0c |
| #define RW_L4 0x10 |
| #define RW_L5 0x14 |
| #define RW_L6 0x18 |
| #define RW_L7 0x1c |
| #define RW_I0 0x20 |
| #define RW_I1 0x24 |
| #define RW_I2 0x28 |
| #define RW_I3 0x2c |
| #define RW_I4 0x30 |
| #define RW_I5 0x34 |
| #define RW_I6 0x38 |
| #define RW_I7 0x3c |
| |
| /* Store the register window onto the 8-byte aligned area starting |
| * at %reg. It might be %sp, it might not, we don't care. |
| */ |
| #define STORE_WINDOW(reg) \ |
| std %l0, [%reg + RW_L0]; \ |
| std %l2, [%reg + RW_L2]; \ |
| std %l4, [%reg + RW_L4]; \ |
| std %l6, [%reg + RW_L6]; \ |
| std %i0, [%reg + RW_I0]; \ |
| std %i2, [%reg + RW_I2]; \ |
| std %i4, [%reg + RW_I4]; \ |
| std %i6, [%reg + RW_I6]; |
| |
| /* We define macro's for registers which have a fixed |
| * meaning throughout this entire routine. The 'T' in |
| * the comments mean that the register can only be |
| * accessed when in the 'trap' window, 'G' means |
| * accessible in any window. Do not change these registers |
| * after they have been set, until you are ready to return |
| * from the trap. |
| */ |
| #define t_psr l0 /* %psr at trap time T */ |
| #define t_pc l1 /* PC for trap return T */ |
| #define t_npc l2 /* NPC for trap return T */ |
| #define t_wim l3 /* %wim at trap time T */ |
| #define saved_g5 l5 /* Global save register T */ |
| #define saved_g6 l6 /* Global save register T */ |
| |
| /* Now registers whose values can change within the handler. */ |
| #define twin_tmp l4 /* Temp reg, only usable in trap window T */ |
| #define glob_tmp g5 /* Global temporary reg, usable anywhere G */ |
| |
| .text |
| .align 4 |
| |
| /* BEGINNING OF PATCH INSTRUCTIONS */ |
| /* On a 7-window Sparc the boot code patches spnwin_* |
| * instructions with the following ones. |
| */ |
| .globl spnwin_patch1_7win, spnwin_patch2_7win, spnwin_patch3_7win |
| spnwin_patch1_7win: sll %t_wim, 6, %glob_tmp |
| spnwin_patch2_7win: and %glob_tmp, 0x7f, %glob_tmp |
| spnwin_patch3_7win: and %twin_tmp, 0x7f, %twin_tmp |
| /* END OF PATCH INSTRUCTIONS */ |
| |
| /* The trap entry point has done the following: |
| * |
| * rd %psr, %l0 |
| * rd %wim, %l3 |
| * b spill_window_entry |
| * nop |
| */ |
| |
| .globl spill_window_entry |
| .globl spnwin_patch1, spnwin_patch2 |
| spill_window_entry: |
| /* LOCATION: Trap Window */ |
| |
| mov %g5, %saved_g5 ! save away global temp register |
| mov %g6, %saved_g6 ! save away 'current' ptr register |
| |
| /* Compute what the new %wim will be if we save the |
| * window properly in this trap handler. |
| * |
| * newwim = ((%wim>>1) | (%wim<<(nwindows - 1))); |
| */ |
| srl %t_wim, 0x1, %twin_tmp |
| spnwin_patch1: sll %t_wim, 7, %glob_tmp |
| or %glob_tmp, %twin_tmp, %glob_tmp |
| spnwin_patch2: and %glob_tmp, 0xff, %glob_tmp |
| |
| /* Save into the window which must be saved and do it. |
| */ |
| save %g0, %g0, %g0 ! save into the window to stash away |
| wr %glob_tmp, 0x0, %wim ! set new %wim, this is safe now |
| |
| /* LOCATION: Window to be saved */ |
| |
| STORE_WINDOW(sp) ! stash the window |
| restore %g0, %g0, %g0 ! go back into trap window |
| |
| /* LOCATION: Trap window */ |
| mov %saved_g5, %g5 ! restore %glob_tmp |
| mov %saved_g6, %g6 ! restore %curptr |
| wr %t_psr, 0x0, %psr ! restore condition codes in %psr |
| nop; nop; nop ! waste some time |
| jmp %t_pc ! Return from trap |
| rett %t_npc ! we are done |
