c4df4bc155
Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com> Acked-by: John Linn <john.linn@xilinx.com> Acked-by: John Williams <john.williams@petalogix.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
459 lines
12 KiB
ArmAsm
459 lines
12 KiB
ArmAsm
/*
|
|
* Exception handling for Microblaze
|
|
*
|
|
* Rewriten interrupt handling
|
|
*
|
|
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
|
|
* Copyright (C) 2008-2009 PetaLogix
|
|
*
|
|
* uClinux customisation (C) 2005 John Williams
|
|
*
|
|
* MMU code derived from arch/ppc/kernel/head_4xx.S:
|
|
* Copyright (C) 1995-1996 Gary Thomas <gdt@linuxppc.org>
|
|
* Initial PowerPC version.
|
|
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
|
|
* Rewritten for PReP
|
|
* Copyright (C) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
|
|
* Low-level exception handers, MMU support, and rewrite.
|
|
* Copyright (C) 1997 Dan Malek <dmalek@jlc.net>
|
|
* PowerPC 8xx modifications.
|
|
* Copyright (C) 1998-1999 TiVo, Inc.
|
|
* PowerPC 403GCX modifications.
|
|
* Copyright (C) 1999 Grant Erickson <grant@lcse.umn.edu>
|
|
* PowerPC 403GCX/405GP modifications.
|
|
* Copyright 2000 MontaVista Software Inc.
|
|
* PPC405 modifications
|
|
* PowerPC 403GCX/405GP modifications.
|
|
* Author: MontaVista Software, Inc.
|
|
* frank_rowand@mvista.com or source@mvista.com
|
|
* debbie_chu@mvista.com
|
|
*
|
|
* Original code
|
|
* Copyright (C) 2004 Xilinx, Inc.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* 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, TOPHYS(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;
|
|
/* Get the word - delay slot */
|
|
swi r3, r0, TOPHYS(ex_tmp_data_loc_0);
|
|
/* 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 - dump register */
|
|
bri 0
|
|
|
|
.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
|