--- /dev/null
+/*
+ * 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
Code Review / kvmfornfv.git / blobdiff