ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/nios2/kernel/misaligned.c b/marvell/linux/arch/nios2/kernel/misaligned.c
new file mode 100644
index 0000000..23e0544
--- /dev/null
+++ b/marvell/linux/arch/nios2/kernel/misaligned.c
@@ -0,0 +1,238 @@
+/*
+ * linux/arch/nios2/kernel/misaligned.c
+ *
+ * basic emulation for mis-aligned accesses on the NIOS II cpu
+ * modelled after the version for arm in arm/alignment.c
+ *
+ * Brad Parker <brad@heeltoe.com>
+ * Copyright (C) 2010 Ambient Corporation
+ * Copyright (c) 2010 Altera Corporation, San Jose, California, USA.
+ * Copyright (c) 2010 Arrow Electronics, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+
+#include <asm/traps.h>
+#include <asm/unaligned.h>
+
+/* instructions we emulate */
+#define INST_LDHU 0x0b
+#define INST_STH 0x0d
+#define INST_LDH 0x0f
+#define INST_STW 0x15
+#define INST_LDW 0x17
+
+static unsigned int ma_usermode;
+#define UM_WARN 0x01
+#define UM_FIXUP 0x02
+#define UM_SIGNAL 0x04
+#define KM_WARN 0x08
+
+/* see arch/nios2/include/asm/ptrace.h */
+static u8 sys_stack_frame_reg_offset[] = {
+ /* struct pt_regs */
+ 8, 9, 10, 11, 12, 13, 14, 15, 1, 2, 3, 4, 5, 6, 7, 0,
+ /* struct switch_stack */
+ 16, 17, 18, 19, 20, 21, 22, 23, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static int reg_offsets[32];
+
+static inline u32 get_reg_val(struct pt_regs *fp, int reg)
+{
+ u8 *p = ((u8 *)fp) + reg_offsets[reg];
+ return *(u32 *)p;
+}
+
+static inline void put_reg_val(struct pt_regs *fp, int reg, u32 val)
+{
+ u8 *p = ((u8 *)fp) + reg_offsets[reg];
+ *(u32 *)p = val;
+}
+
+/*
+ * (mis)alignment handler
+ */
+asmlinkage void handle_unaligned_c(struct pt_regs *fp, int cause)
+{
+ u32 isn, addr, val;
+ int in_kernel;
+ u8 a, b, d0, d1, d2, d3;
+ s16 imm16;
+ unsigned int fault;
+
+ /* back up one instruction */
+ fp->ea -= 4;
+
+ if (fixup_exception(fp)) {
+ return;
+ }
+
+ in_kernel = !user_mode(fp);
+
+ isn = *(unsigned long *)(fp->ea);
+
+ fault = 0;
+
+ /* do fixup if in kernel or mode turned on */
+ if (in_kernel || (ma_usermode & UM_FIXUP)) {
+ /* decompose instruction */
+ a = (isn >> 27) & 0x1f;
+ b = (isn >> 22) & 0x1f;
+ imm16 = (isn >> 6) & 0xffff;
+ addr = get_reg_val(fp, a) + imm16;
+
+ /* do fixup to saved registers */
+ switch (isn & 0x3f) {
+ case INST_LDHU:
+ fault |= __get_user(d0, (u8 *)(addr+0));
+ fault |= __get_user(d1, (u8 *)(addr+1));
+ val = (d1 << 8) | d0;
+ put_reg_val(fp, b, val);
+ break;
+ case INST_STH:
+ val = get_reg_val(fp, b);
+ d1 = val >> 8;
+ d0 = val >> 0;
+ if (in_kernel) {
+ *(u8 *)(addr+0) = d0;
+ *(u8 *)(addr+1) = d1;
+ } else {
+ fault |= __put_user(d0, (u8 *)(addr+0));
+ fault |= __put_user(d1, (u8 *)(addr+1));
+ }
+ break;
+ case INST_LDH:
+ fault |= __get_user(d0, (u8 *)(addr+0));
+ fault |= __get_user(d1, (u8 *)(addr+1));
+ val = (short)((d1 << 8) | d0);
+ put_reg_val(fp, b, val);
+ break;
+ case INST_STW:
+ val = get_reg_val(fp, b);
+ d3 = val >> 24;
+ d2 = val >> 16;
+ d1 = val >> 8;
+ d0 = val >> 0;
+ if (in_kernel) {
+ *(u8 *)(addr+0) = d0;
+ *(u8 *)(addr+1) = d1;
+ *(u8 *)(addr+2) = d2;
+ *(u8 *)(addr+3) = d3;
+ } else {
+ fault |= __put_user(d0, (u8 *)(addr+0));
+ fault |= __put_user(d1, (u8 *)(addr+1));
+ fault |= __put_user(d2, (u8 *)(addr+2));
+ fault |= __put_user(d3, (u8 *)(addr+3));
+ }
+ break;
+ case INST_LDW:
+ fault |= __get_user(d0, (u8 *)(addr+0));
+ fault |= __get_user(d1, (u8 *)(addr+1));
+ fault |= __get_user(d2, (u8 *)(addr+2));
+ fault |= __get_user(d3, (u8 *)(addr+3));
+ val = (d3 << 24) | (d2 << 16) | (d1 << 8) | d0;
+ put_reg_val(fp, b, val);
+ break;
+ }
+ }
+
+ addr = RDCTL(CTL_BADADDR);
+ cause >>= 2;
+
+ if (fault) {
+ if (in_kernel) {
+ pr_err("fault during kernel misaligned fixup @ %#lx; addr 0x%08x; isn=0x%08x\n",
+ fp->ea, (unsigned int)addr,
+ (unsigned int)isn);
+ } else {
+ pr_err("fault during user misaligned fixup @ %#lx; isn=%08x addr=0x%08x sp=0x%08lx pid=%d\n",
+ fp->ea,
+ (unsigned int)isn, addr, fp->sp,
+ current->pid);
+
+ _exception(SIGSEGV, fp, SEGV_MAPERR, fp->ea);
+ return;
+ }
+ }
+
+ /*
+ * kernel mode -
+ * note exception and skip bad instruction (return)
+ */
+ if (in_kernel) {
+ fp->ea += 4;
+
+ if (ma_usermode & KM_WARN) {
+ pr_err("kernel unaligned access @ %#lx; BADADDR 0x%08x; cause=%d, isn=0x%08x\n",
+ fp->ea,
+ (unsigned int)addr, cause,
+ (unsigned int)isn);
+ /* show_regs(fp); */
+ }
+
+ return;
+ }
+
+ /*
+ * user mode -
+ * possibly warn,
+ * possibly send SIGBUS signal to process
+ */
+ if (ma_usermode & UM_WARN) {
+ pr_err("user unaligned access @ %#lx; isn=0x%08lx ea=0x%08lx ra=0x%08lx sp=0x%08lx\n",
+ (unsigned long)addr, (unsigned long)isn,
+ fp->ea, fp->ra, fp->sp);
+ }
+
+ if (ma_usermode & UM_SIGNAL)
+ _exception(SIGBUS, fp, BUS_ADRALN, fp->ea);
+ else
+ fp->ea += 4; /* else advance */
+}
+
+static void __init misaligned_calc_reg_offsets(void)
+{
+ int i, r, offset;
+
+ /* pre-calc offsets of registers on sys call stack frame */
+ offset = 0;
+
+ /* struct pt_regs */
+ for (i = 0; i < 16; i++) {
+ r = sys_stack_frame_reg_offset[i];
+ reg_offsets[r] = offset;
+ offset += 4;
+ }
+
+ /* struct switch_stack */
+ offset = -sizeof(struct switch_stack);
+ for (i = 16; i < 32; i++) {
+ r = sys_stack_frame_reg_offset[i];
+ reg_offsets[r] = offset;
+ offset += 4;
+ }
+}
+
+
+static int __init misaligned_init(void)
+{
+ /* default mode - silent fix */
+ ma_usermode = UM_FIXUP | KM_WARN;
+
+ misaligned_calc_reg_offsets();
+
+ return 0;
+}
+
+fs_initcall(misaligned_init);