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Message-Id: <fbef554ff1d05fa50312d91e61a0d63d3207076c.1237407249.git.monstr@monstr.eu>
Date: Wed, 18 Mar 2009 21:30:33 +0100
From: monstr@...str.eu
To: linux-kernel@...r.kernel.org
Cc: john.williams@...alogix.com, Michal Simek <monstr@...str.eu>
Subject: [PATCH 06/57] microblaze_v7: exception handling
From: Michal Simek <monstr@...str.eu>
Signed-off-by: Michal Simek <monstr@...str.eu>
---
arch/microblaze/include/asm/exceptions.h | 65 ++++
arch/microblaze/kernel/exceptions.c | 157 ++++++++
arch/microblaze/kernel/hw_exception_handler.S | 470 +++++++++++++++++++++++++
3 files changed, 692 insertions(+), 0 deletions(-)
create mode 100644 arch/microblaze/include/asm/exceptions.h
create mode 100644 arch/microblaze/kernel/exceptions.c
create mode 100644 arch/microblaze/kernel/hw_exception_handler.S
diff --git a/arch/microblaze/include/asm/exceptions.h b/arch/microblaze/include/asm/exceptions.h
new file mode 100644
index 0000000..cd41f6c
--- /dev/null
+++ b/arch/microblaze/include/asm/exceptions.h
@@ -0,0 +1,65 @@
+/*
+ * Preliminary support for HW exception handing for Microblaze
+ *
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2008 PetaLogix
+ * Copyright (C) 2005 John Williams <jwilliams@...e.uq.edu.au>
+ *
+ * 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.
+ */
+
+#ifndef _ASM_MICROBLAZE_EXCEPTIONS_H
+#define _ASM_MICROBLAZE_EXCEPTIONS_H
+
+#ifdef __KERNEL__
+#ifndef __ASSEMBLY__
+
+/* Macros to enable and disable HW exceptions in the MSR */
+/* Define MSR enable bit for HW exceptions */
+#define HWEX_MSR_BIT (1 << 8)
+
+#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
+#define __enable_hw_exceptions() \
+ __asm__ __volatile__ (" msrset r0, %0; \
+ nop;" \
+ : \
+ : "i" (HWEX_MSR_BIT) \
+ : "memory")
+
+#define __disable_hw_exceptions() \
+ __asm__ __volatile__ (" msrclr r0, %0; \
+ nop;" \
+ : \
+ : "i" (HWEX_MSR_BIT) \
+ : "memory")
+#else /* !CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR */
+#define __enable_hw_exceptions() \
+ __asm__ __volatile__ (" \
+ mfs r12, rmsr; \
+ nop; \
+ ori r12, r12, %0; \
+ mts rmsr, r12; \
+ nop;" \
+ : \
+ : "i" (HWEX_MSR_BIT) \
+ : "memory", "r12")
+
+#define __disable_hw_exceptions() \
+ __asm__ __volatile__ (" \
+ mfs r12, rmsr; \
+ nop; \
+ andi r12, r12, ~%0; \
+ mts rmsr, r12; \
+ nop;" \
+ : \
+ : "i" (HWEX_MSR_BIT) \
+ : "memory", "r12")
+#endif /* CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR */
+
+asmlinkage void full_exception(struct pt_regs *regs, unsigned int type, int fsr, int addr);
+
+#endif /*__ASSEMBLY__ */
+#endif /* __KERNEL__ */
+#endif /* _ASM_MICROBLAZE_EXCEPTIONS_H */
diff --git a/arch/microblaze/kernel/exceptions.c b/arch/microblaze/kernel/exceptions.c
new file mode 100644
index 0000000..223ce19
--- /dev/null
+++ b/arch/microblaze/kernel/exceptions.c
@@ -0,0 +1,157 @@
+/*
+ * arch/microblaze/kernel/exceptions.c - HW exception handling
+ *
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2008 PetaLogix
+ *
+ * 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.
+ *
+ */
+
+/*
+ * This file handles the architecture-dependent parts of hardware exceptions
+ */
+
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+
+#include <asm/exceptions.h>
+#include <asm/entry.h> /* For KM CPU var */
+#include <asm/uaccess.h>
+#include <asm/errno.h>
+#include <asm/ptrace.h>
+#include <asm/current.h>
+
+#ifdef CONFIG_XMON
+extern void xmon(struct pt_regs *regs);
+extern int xmon_bpt(struct pt_regs *regs);
+extern int xmon_sstep(struct pt_regs *regs);
+extern int xmon_iabr_match(struct pt_regs *regs);
+extern int xmon_dabr_match(struct pt_regs *regs);
+extern void (*xmon_fault_handler)(struct pt_regs *regs);
+#endif
+
+#ifdef CONFIG_XMON
+void (*debugger)(struct pt_regs *regs) = xmon;
+int (*debugger_bpt)(struct pt_regs *regs) = xmon_bpt;
+int (*debugger_sstep)(struct pt_regs *regs) = xmon_sstep;
+int (*debugger_iabr_match)(struct pt_regs *regs) = xmon_iabr_match;
+int (*debugger_dabr_match)(struct pt_regs *regs) = xmon_dabr_match;
+void (*debugger_fault_handler)(struct pt_regs *regs);
+#else
+#ifdef CONFIG_KGDB
+void (*debugger)(struct pt_regs *regs);
+int (*debugger_bpt)(struct pt_regs *regs);
+int (*debugger_sstep)(struct pt_regs *regs);
+int (*debugger_iabr_match)(struct pt_regs *regs);
+int (*debugger_dabr_match)(struct pt_regs *regs);
+void (*debugger_fault_handler)(struct pt_regs *regs);
+#else
+#define debugger(regs) do { } while (0)
+#define debugger_bpt(regs) 0
+#define debugger_sstep(regs) 0
+#define debugger_iabr_match(regs) 0
+#define debugger_dabr_match(regs) 0
+#define debugger_fault_handler ((void (*)(struct pt_regs *))0)
+#endif
+#endif
+
+#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
+#define MICROBLAZE_IBUS_EXCEPTION 0x03
+#define MICROBLAZE_DBUS_EXCEPTION 0x04
+#define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
+#define MICROBLAZE_FPU_EXCEPTION 0x06
+#define MICROBLAZE_PRIVILEG_EXCEPTION 0x07
+
+static spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
+
+void die(const char* str, struct pt_regs* fp, long err)
+{
+ console_verbose();
+ spin_lock_irq(&die_lock);
+ printk("Oops: %s, sig: %ld\n", str, err);
+ show_regs(fp);
+ spin_unlock_irq(&die_lock);
+ /* do_exit() should take care of panic'ing from an interrupt
+ * context so we don't handle it here
+ */
+ do_exit(err);
+}
+
+void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
+{
+ siginfo_t info;
+
+ if (kernel_mode(regs)) {
+ debugger(regs);
+ die("Exception in kernel mode", regs, signr);
+ }
+ info.si_signo = signr;
+ info.si_errno = 0;
+ info.si_code = code;
+ info.si_addr = (void __user *) addr;
+ force_sig_info(signr, &info, current);
+}
+
+asmlinkage void full_exception(struct pt_regs *regs, unsigned int type, int fsr, int addr)
+{
+#if 0
+ printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
+ type, user_mode(regs) ? "user" : "kernel", fsr,
+ (unsigned int) regs->pc, (unsigned int) regs->esr);
+#endif
+
+ switch (type & 0x1F) {
+ case MICROBLAZE_ILL_OPCODE_EXCEPTION:
+ _exception(SIGILL, regs, ILL_ILLOPC, addr);
+ break;
+ case MICROBLAZE_IBUS_EXCEPTION:
+ if (user_mode(regs)) {
+ printk("Instruction bus error exception in user mode.\n");
+ _exception(SIGBUS, regs, BUS_ADRERR, addr);
+ return;
+ }
+ printk("Instruction bus error exception in kernel mode.\n");
+ die("bus exception", regs, SIGBUS);
+ break;
+ case MICROBLAZE_DBUS_EXCEPTION:
+ if (user_mode(regs)) {
+ printk("Data bus error exception in user mode.\n");
+ _exception(SIGBUS, regs, BUS_ADRERR, addr);
+ return;
+ }
+ printk("Data bus error exception in kernel mode.\n");
+ die("bus exception", regs, SIGBUS);
+ break;
+ case MICROBLAZE_DIV_ZERO_EXCEPTION:
+ printk("Divide by zero exception\n");
+ _exception(SIGILL, regs, ILL_ILLOPC, addr);
+ break;
+
+ case MICROBLAZE_FPU_EXCEPTION:
+ /* IEEE FP exception */
+ /* I removed fsr variable and use code var for storing fsr */
+ if (fsr & FSR_IO)
+ fsr = FPE_FLTINV;
+ else if (fsr & FSR_OF)
+ fsr = FPE_FLTOVF;
+ else if (fsr & FSR_UF)
+ fsr = FPE_FLTUND;
+ else if (fsr & FSR_DZ)
+ fsr = FPE_FLTDIV;
+ else if (fsr & FSR_DO)
+ fsr = FPE_FLTRES;
+ _exception(SIGFPE, regs, fsr, addr);
+ break;
+
+ default:
+ printk(KERN_WARNING "Unexpected exception %02x in %s mode, PC=%08x\n",
+ type, kernel_mode(regs) ? "kernel" : "user",(unsigned int) addr);
+ }
+ return;
+}
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S
new file mode 100644
index 0000000..b6dd3ae
--- /dev/null
+++ b/arch/microblaze/kernel/hw_exception_handler.S
@@ -0,0 +1,470 @@
+/*
+ * arch/microblaze/kernel/hw_exception_handler.S
+ *
+ * Exception handling for Microblaze
+ *
+ * Rewriten interrupt handling
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2008 PetaLogix
+ *
+ * uClinux customisation (C) 2005 John Williams
+ *
+ * MMU code derived from arch/ppc/kernel/head_4xx.S:
+ * Copyright (C) 1995-1996 Gary Thomas <gdt@...uxppc.org>
+ * Initial PowerPC version.
+ * Copyright (C) 1996 Cort Dougan <cort@...nmt.edu>
+ * Rewritten for PReP
+ * Copyright (C) 1996 Paul Mackerras <paulus@...anu.edu.au>
+ * Low-level exception handers, MMU support, and rewrite.
+ * Copyright (C) 1997 Dan Malek <dmalek@....net>
+ * PowerPC 8xx modifications.
+ * Copyright (C) 1998-1999 TiVo, Inc.
+ * PowerPC 403GCX modifications.
+ * Copyright (C) 1999 Grant Erickson <grant@...e.umn.edu>
+ * PowerPC 403GCX/405GP modifications.
+ * Copyright 2000 MontaVista Software Inc.
+ * PPC405 modifications
+ * PowerPC 403GCX/405GP modifications.
+ * Author: MontaVista Software, Inc.
+ * frank_rowand@...sta.com or source@...sta.com
+ * debbie_chu@...sta.com
+ *
+ * Original code
+ * Copyright (C) 2004 Xilinx, Inc. All rights reserved.
+ *
+ * Xilinx, Inc.
+ * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
+ * COURTESY TO YOU. BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
+ * ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
+ * STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
+ * IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
+ * FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
+ * XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
+ * THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
+ * ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
+ * FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * $Id: hw_exception_handler.S,v 1.1.2.9 2007/12/07 10:41:28 vvlasov Exp $
+ *
+ *
+ * Here are the handlers which don't require enabling translation and calling other kernel code
+ * thus we can keep their design very simple and do all processing in real mode.
+ * All what they need is a valid current (that is an issue for the CONFIG_REGISTER_TASK_PTR case)
+ * This handlers use r3,r4,r5,r6 and optionally r[current] to work therefore these registers are saved/restored
+ * The handlers which require translation are in entry.S --KAA
+ *
+ * Microblaze HW Exception Handler
+ * - Non self-modifying exception handler for the following exception conditions
+ * - Unalignment
+ * - Instruction bus error
+ * - Data bus error
+ * - Illegal instruction opcode
+ * - Divide-by-zero
+ *
+ * Note we disable interrupts during exception handling, otherwise we will possibly
+ * get multiple re-entrancy if interrupt handles themselves cause exceptions. JW
+ */
+
+#include <asm/exceptions.h>
+#include <asm/unistd.h>
+#include <asm/page.h>
+
+#include <asm/entry.h>
+#include <asm/current.h>
+#include <linux/linkage.h>
+
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/asm-offsets.h>
+
+/* Helpful Macros */
+#define EX_HANDLER_STACK_SIZ (4*19)
+#define NUM_TO_REG(num) r ## num
+
+#define LWREG_NOP \
+ bri ex_handler_unhandled; \
+ nop;
+
+#define SWREG_NOP \
+ bri ex_handler_unhandled; \
+ nop;
+
+/* FIXME this is weird - for noMMU kernel is not possible to use brid
+ * instruction which can shorten executed time
+ */
+
+/* r3 is the source */
+#define R3_TO_LWREG_V(regnum) \
+ swi r3, r1, 4 * regnum; \
+ bri ex_handler_done;
+
+/* r3 is the source */
+#define R3_TO_LWREG(regnum) \
+ or NUM_TO_REG (regnum), r0, r3; \
+ bri ex_handler_done;
+
+/* r3 is the target */
+#define SWREG_TO_R3_V(regnum) \
+ lwi r3, r1, 4 * regnum; \
+ bri ex_sw_tail;
+
+/* r3 is the target */
+#define SWREG_TO_R3(regnum) \
+ or r3, r0, NUM_TO_REG (regnum); \
+ bri ex_sw_tail;
+
+.extern other_exception_handler /* Defined in exception.c */
+
+/*
+ * hw_exception_handler - Handler for exceptions
+ *
+ * Exception handler notes:
+ * - Handles all exceptions
+ * - Does not handle unaligned exceptions during load into r17, r1, r0.
+ * - Does not handle unaligned exceptions during store from r17 (cannot be
+ * done) and r1 (slows down common case)
+ *
+ * Relevant register structures
+ *
+ * EAR - |----|----|----|----|----|----|----|----|
+ * - < ## 32 bit faulting address ## >
+ *
+ * ESR - |----|----|----|----|----| - | - |-----|-----|
+ * - W S REG EXC
+ *
+ *
+ * STACK FRAME STRUCTURE (for NO_MMU)
+ * ---------------------------------
+ *
+ * +-------------+ + 0
+ * | MSR |
+ * +-------------+ + 4
+ * | r1 |
+ * | . |
+ * | . |
+ * | . |
+ * | . |
+ * | r18 |
+ * +-------------+ + 76
+ * | . |
+ * | . |
+ *
+ * NO_MMU kernel use the same r0_ram pointed space - look to vmlinux.lds.S
+ * which is used for storing register values - old style was, that value were
+ * stored in stack but in case of failure you lost information about register.
+ * Currently you can see register value in memory in specific place.
+ * In compare to with previous solution the speed should be the same.
+ *
+ * MMU exception handler has different handling compare to no MMU kernel.
+ * Exception handler use jump table for directing of what happen. For MMU kernel
+ * is this approach better because MMU relate exception are handled by asm code
+ * in this file. In compare to with MMU expect of unaligned exception is everything
+ * handled by C code.
+ */
+
+/* every of these handlers is entered having R3/4/5/6/11/current saved on stack and clobbered
+ * so care should be taken to restore them if someone is going to return from exception */
+
+/* wrappers to restore state before coming to entry.S */
+
+.global _hw_exception_handler
+.section .text
+.align 4
+.ent _hw_exception_handler
+_hw_exception_handler:
+ addik r1, r1, -(EX_HANDLER_STACK_SIZ); /* Create stack frame */
+ swi r3, r1, PT_R3
+ swi r4, r1, PT_R4
+ swi r5, r1, PT_R5
+ swi r6, r1, PT_R6
+
+ mfs r5, rmsr;
+ nop
+ swi r5, r1, 0;
+ mfs r4, rbtr /* Save BTR before jumping to handler */
+ nop
+ mfs r3, resr
+ nop
+
+ andi r5, r3, 0x1000; /* Check ESR[DS] */
+ beqi r5, not_in_delay_slot; /* Branch if ESR[DS] not set */
+ mfs r17, rbtr; /* ESR[DS] set - return address in BTR */
+ nop
+not_in_delay_slot:
+ swi r17, r1, PT_R17
+
+ andi r5, r3, 0x1F; /* Extract ESR[EXC] */
+
+ /* Exceptions enabled here. This will allow nested exceptions */
+ mfs r6, rmsr;
+ nop
+ swi r6, r1, 0; /* RMSR_OFFSET */
+ ori r6, r6, 0x100; /* Turn ON the EE bit */
+ andi r6, r6, ~2; /* Disable interrupts */
+ mts rmsr, r6;
+ nop
+
+ xori r6, r5, 1; /* 00001 = Unaligned Exception */
+ /* Jump to unalignment exception handler */
+ beqi r6, handle_unaligned_ex;
+
+handle_other_ex: /* Handle Other exceptions here */
+ /* Save other volatiles before we make procedure calls below */
+ swi r7, r1, PT_R7
+ swi r8, r1, PT_R8
+ swi r9, r1, PT_R9
+ swi r10, r1, PT_R10
+ swi r11, r1, PT_R11
+ swi r12, r1, PT_R12
+ swi r14, r1, PT_R14
+ swi r15, r1, PT_R15
+ swi r18, r1, PT_R18
+
+ or r5, r1, r0
+ andi r6, r3, 0x1F; /* Load ESR[EC] */
+ lwi r7, r0, PER_CPU(KM) /* MS: saving current kernel mode to regs */
+ swi r7, r1, PT_MODE
+ mfs r7, rfsr
+ nop
+ addk r8, r17, r0; /* Load exception address */
+ bralid r15, full_exception; /* Branch to the handler */
+ nop;
+
+ /*
+ * Trigger execution of the signal handler by enabling
+ * interrupts and calling an invalid syscall.
+ */
+ mfs r5, rmsr;
+ nop
+ ori r5, r5, 2;
+ mts rmsr, r5; /* enable interrupt */
+ nop
+ addi r12, r0, __NR_syscalls;
+ brki r14, 0x08;
+ mfs r5, rmsr; /* disable interrupt */
+ nop
+ andi r5, r5, ~2;
+ mts rmsr, r5;
+ nop
+
+ lwi r7, r1, PT_R7
+ lwi r8, r1, PT_R8
+ lwi r9, r1, PT_R9
+ lwi r10, r1, PT_R10
+ lwi r11, r1, PT_R11
+ lwi r12, r1, PT_R12
+ lwi r14, r1, PT_R14
+ lwi r15, r1, PT_R15
+ lwi r18, r1, PT_R18
+
+ bri ex_handler_done; /* Complete exception handling */
+
+/* 0x01 - Unaligned data access exception
+ * This occurs when a word access is not aligned on a word boundary,
+ * or when a 16-bit access is not aligned on a 16-bit boundary.
+ * This handler perform the access, and returns, except for MMU when
+ * the unaligned address is last on a 4k page or the physical address is
+ * not found in the page table, in which case unaligned_data_trap is called.
+ */
+handle_unaligned_ex:
+ /* Working registers already saved: R3, R4, R5, R6
+ * R3 = ESR
+ * R4 = BTR
+ */
+ mfs r4, rear;
+ nop
+
+ andi r6, r3, 0x3E0; /* Mask and extract the register operand */
+ srl r6, r6; /* r6 >> 5 */
+ srl r6, r6;
+ srl r6, r6;
+ srl r6, r6;
+ srl r6, r6;
+ /* Store the register operand in a temporary location */
+ sbi r6, r0, ex_reg_op;
+
+ andi r6, r3, 0x400; /* Extract ESR[S] */
+ bnei r6, ex_sw;
+ex_lw:
+ andi r6, r3, 0x800; /* Extract ESR[W] */
+ beqi r6, ex_lhw;
+ lbui r5, r4, 0; /* Exception address in r4 */
+ /* Load a word, byte-by-byte from destination address
+ and save it in tmp space */
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_0);
+ lbui r5, r4, 1;
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_1);
+ lbui r5, r4, 2;
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_2);
+ lbui r5, r4, 3;
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_3);
+ /* Get the destination register value into r3 */
+ lwi r3, r0, TOPHYS(ex_tmp_data_loc_0);
+ bri ex_lw_tail;
+ex_lhw:
+ lbui r5, r4, 0; /* Exception address in r4 */
+ /* Load a half-word, byte-by-byte from destination
+ address and save it in tmp space */
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_0);
+ lbui r5, r4, 1;
+ sbi r5, r0, TOPHYS(ex_tmp_data_loc_1);
+ /* Get the destination register value into r3 */
+ lhui r3, r0, TOPHYS(ex_tmp_data_loc_0);
+ex_lw_tail:
+ /* Get the destination register number into r5 */
+ lbui r5, r0, TOPHYS(ex_reg_op);
+ /* Form load_word jump table offset (lw_table + (8 * regnum)) */
+ la r6, r0, TOPHYS(lw_table);
+ addk r5, r5, r5;
+ addk r5, r5, r5;
+ addk r5, r5, r5;
+ addk r5, r5, r6;
+ bra r5;
+ex_lw_end: /* Exception handling of load word, ends */
+ex_sw:
+ /* Get the destination register number into r5 */
+ lbui r5, r0, TOPHYS(ex_reg_op);
+ /* Form store_word jump table offset (sw_table + (8 * regnum)) */
+ la r6, r0, TOPHYS(sw_table);
+ add r5, r5, r5;
+ add r5, r5, r5;
+ add r5, r5, r5;
+ add r5, r5, r6;
+ bra r5;
+ex_sw_tail:
+ mfs r6, resr;
+ nop
+ andi r6, r6, 0x800; /* Extract ESR[W] */
+ beqi r6, ex_shw;
+ swi r3, r0, TOPHYS(ex_tmp_data_loc_0); /* Get the word - delay slot */
+ /* Store the word, byte-by-byte into destination address */
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_0);
+ sbi r3, r4, 0;
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_1);
+ sbi r3, r4, 1;
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_2);
+ sbi r3, r4, 2;
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_3);
+ sbi r3, r4, 3;
+ bri ex_handler_done;
+
+ex_shw:
+ /* Store the lower half-word, byte-by-byte into destination address */
+ swi r3, r0, TOPHYS(ex_tmp_data_loc_0);
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_2);
+ sbi r3, r4, 0;
+ lbui r3, r0, TOPHYS(ex_tmp_data_loc_3);
+ sbi r3, r4, 1;
+ex_sw_end: /* Exception handling of store word, ends. */
+
+ex_handler_done:
+ lwi r5, r1, 0 /* RMSR */
+ mts rmsr, r5
+ nop
+ lwi r3, r1, PT_R3
+ lwi r4, r1, PT_R4
+ lwi r5, r1, PT_R5
+ lwi r6, r1, PT_R6
+ lwi r17, r1, PT_R17
+
+ rted r17, 0
+ addik r1, r1, (EX_HANDLER_STACK_SIZ); /* Restore stack frame */
+
+.end _hw_exception_handler
+
+ex_handler_unhandled:
+/* FIXME add handle function for unhandled exception - for example dump register */
+ bri 0
+
+/*
+ * hw_exception_handler Jump Table
+ * - Contains code snippets for each register that caused the unaligned exception
+ * - Hence exception handler is NOT self-modifying
+ * - Separate table for load exceptions and store exceptions.
+ * - Each table is of size: (8 * 32) = 256 bytes
+ */
+
+.section .text
+.align 4
+lw_table:
+lw_r0: R3_TO_LWREG (0);
+lw_r1: LWREG_NOP;
+lw_r2: R3_TO_LWREG (2);
+lw_r3: R3_TO_LWREG_V (3);
+lw_r4: R3_TO_LWREG_V (4);
+lw_r5: R3_TO_LWREG_V (5);
+lw_r6: R3_TO_LWREG_V (6);
+lw_r7: R3_TO_LWREG (7);
+lw_r8: R3_TO_LWREG (8);
+lw_r9: R3_TO_LWREG (9);
+lw_r10: R3_TO_LWREG (10);
+lw_r11: R3_TO_LWREG (11);
+lw_r12: R3_TO_LWREG (12);
+lw_r13: R3_TO_LWREG (13);
+lw_r14: R3_TO_LWREG (14);
+lw_r15: R3_TO_LWREG (15);
+lw_r16: R3_TO_LWREG (16);
+lw_r17: LWREG_NOP;
+lw_r18: R3_TO_LWREG (18);
+lw_r19: R3_TO_LWREG (19);
+lw_r20: R3_TO_LWREG (20);
+lw_r21: R3_TO_LWREG (21);
+lw_r22: R3_TO_LWREG (22);
+lw_r23: R3_TO_LWREG (23);
+lw_r24: R3_TO_LWREG (24);
+lw_r25: R3_TO_LWREG (25);
+lw_r26: R3_TO_LWREG (26);
+lw_r27: R3_TO_LWREG (27);
+lw_r28: R3_TO_LWREG (28);
+lw_r29: R3_TO_LWREG (29);
+lw_r30: R3_TO_LWREG (30);
+lw_r31: R3_TO_LWREG (31);
+
+sw_table:
+sw_r0: SWREG_TO_R3 (0);
+sw_r1: SWREG_NOP;
+sw_r2: SWREG_TO_R3 (2);
+sw_r3: SWREG_TO_R3_V (3);
+sw_r4: SWREG_TO_R3_V (4);
+sw_r5: SWREG_TO_R3_V (5);
+sw_r6: SWREG_TO_R3_V (6);
+sw_r7: SWREG_TO_R3 (7);
+sw_r8: SWREG_TO_R3 (8);
+sw_r9: SWREG_TO_R3 (9);
+sw_r10: SWREG_TO_R3 (10);
+sw_r11: SWREG_TO_R3 (11);
+sw_r12: SWREG_TO_R3 (12);
+sw_r13: SWREG_TO_R3 (13);
+sw_r14: SWREG_TO_R3 (14);
+sw_r15: SWREG_TO_R3 (15);
+sw_r16: SWREG_TO_R3 (16);
+sw_r17: SWREG_NOP;
+sw_r18: SWREG_TO_R3 (18);
+sw_r19: SWREG_TO_R3 (19);
+sw_r20: SWREG_TO_R3 (20);
+sw_r21: SWREG_TO_R3 (21);
+sw_r22: SWREG_TO_R3 (22);
+sw_r23: SWREG_TO_R3 (23);
+sw_r24: SWREG_TO_R3 (24);
+sw_r25: SWREG_TO_R3 (25);
+sw_r26: SWREG_TO_R3 (26);
+sw_r27: SWREG_TO_R3 (27);
+sw_r28: SWREG_TO_R3 (28);
+sw_r29: SWREG_TO_R3 (29);
+sw_r30: SWREG_TO_R3 (30);
+sw_r31: SWREG_TO_R3 (31);
+
+/* Temporary data structures used in the handler */
+.section .data
+.align 4
+ex_tmp_data_loc_0:
+ .byte 0
+ex_tmp_data_loc_1:
+ .byte 0
+ex_tmp_data_loc_2:
+ .byte 0
+ex_tmp_data_loc_3:
+ .byte 0
+ex_reg_op:
+ .byte 0
--
1.5.5.1
--
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