#ifndef __HEAD_BOOKE_H__
#define __HEAD_BOOKE_H__
/*
* Macros used for common Book-e exception handling
*/
#define SET_IVOR(vector_number, vector_label) \
li r26,vector_label@l; \
mtspr SPRN_IVOR##vector_number,r26; \
sync
#define NORMAL_EXCEPTION_PROLOG \
mtspr SPRN_SPRG0,r10; /* save two registers to work with */\
mtspr SPRN_SPRG1,r11; \
mtspr SPRN_SPRG4W,r1; \
mfcr r10; /* save CR in r10 for now */\
mfspr r11,SPRN_SRR1; /* check whether user or kernel */\
andi. r11,r11,MSR_PR; \
beq 1f; \
mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\
lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\
addi r1,r1,THREAD_SIZE; \
1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\
mr r11,r1; \
stw r10,_CCR(r11); /* save various registers */\
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
mfspr r10,SPRN_SPRG0; \
stw r10,GPR10(r11); \
mfspr r12,SPRN_SPRG1; \
stw r12,GPR11(r11); \
mflr r10; \
stw r10,_LINK(r11); \
mfspr r10,SPRN_SPRG4R; \
mfspr r12,SPRN_SRR0; \
stw r10,GPR1(r11); \
mfspr r9,SPRN_SRR1; \
stw r10,0(r11); \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
stw r0,GPR0(r11); \
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)
/* To handle the additional exception priority levels on 40x and Book-E
* processors we allocate a 4k stack per additional priority level. The various
* head_xxx.S files allocate space (exception_stack_top) for each priority's
* stack times the number of CPUs
*
* On 40x critical is the only additional level
* On 44x/e500 we have critical and machine check
* On e200 we have critical and debug (machine check occurs via critical)
*
* Additionally we reserve a SPRG for each priority level so we can free up a
* GPR to use as the base for indirect access to the exception stacks. This
* is necessary since the MMU is always on, for Book-E parts, and the stacks
* are offset from KERNELBASE.
*
* There is some space optimization to be had here if desired. However
* to allow for a common kernel with support for debug exceptions either
* going to critical or their own debug level we aren't currently
* providing configurations that micro-optimize space usage.
*/
#ifdef CONFIG_44x
#define NUM_EXCEPTION_LVLS 2
#else
#define NUM_EXCEPTION_LVLS 3
#endif
#define BOOKE_EXCEPTION_STACK_SIZE (4096 * NUM_EXCEPTION_LVLS)
/* CRIT_SPRG only used in critical exception handling */
#define CRIT_SPRG SPRN_SPRG2
/* MCHECK_SPRG only used in machine check exception handling */
#define MCHECK_SPRG SPRN_SPRG6W
#define MCHECK_STACK_TOP (exception_stack_top - 4096)
#define CRIT_STACK_TOP (exception_stack_top)
/* only on e200 for now */
#define DEBUG_STACK_TOP (exception_stack_top - 8192)
#define DEBUG_SPRG SPRN_SPRG6W
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
mulli r8,r8,BOOKE_EXCEPTION_STACK_SIZE; \
neg r8,r8; \
addis r8,r8,level##_STACK_TOP@ha; \
addi r8,r8,level##_STACK_TOP@l
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
lis r8,level##_STACK_TOP@h; \
ori r8,r8,level##_STACK_TOP@l
#endif
/*
* Exception prolog for critical/machine check exceptions. This is a
* little different from the normal exception prolog above since a
* critical/machine check exception can potentially occur at any point
* during normal exception processing. Thus we cannot use the same SPRG
* registers as the normal prolog above. Instead we use a portion of the
* critical/machine check exception stack at low physical addresses.
*/
#define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, exc_level_srr0, exc_level_srr1) \
mtspr exc_level##_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
stw r10,GPR10-INT_FRAME_SIZE(r8); \
stw r11,GPR11-INT_FRAME_SIZE(r8); \
mfcr r10; /* save CR in r10 for now */\
mfspr r11,exc_level_srr1; /* check whether user or kernel */\
andi. r11,r11,MSR_PR; \
mr r11,r8; \
mfspr r8,exc_level##_SPRG; \
beq 1f; \
/* COMING FROM USER MODE */ \
mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\
lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,THREAD_SIZE; \
1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\
stw r10,_CCR(r11); /* save various registers */\
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
stw r12,_DEAR(r11); /* since they may have had stuff */\
mfspr r9,SPRN_ESR; /* in them at the point where the */\
stw r9,_ESR(r11); /* exception was taken */\
mfspr r12,exc_level_srr0; \
stw r1,GPR1(r11); \
mfspr r9,exc_level_srr1; \
stw r1,0(r11); \
mr r1,r11; \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
stw r0,GPR0(r11); \
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)
#define CRITICAL_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(CRIT, SPRN_CSRR0, SPRN_CSRR1)
#define DEBUG_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(DEBUG, SPRN_DSRR0, SPRN_DSRR1)
#define MCHECK_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(MCHECK, SPRN_MCSRR0, SPRN_MCSRR1)
/*
* Exception vectors.
*/
#define START_EXCEPTION(label) \
.align 5; \
label:
#define FINISH_EXCEPTION(func) \
bl transfer_to_handler_full; \
.long func; \
.long ret_from_except_full
#define EXCEPTION(n, label, hdlr, xfer) \
START_EXCEPTION(label); \
NORMAL_EXCEPTION_PROLOG; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
xfer(n, hdlr)
#define CRITICAL_EXCEPTION(n, label, hdlr) \
START_EXCEPTION(label); \
CRITICAL_EXCEPTION_PROLOG; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
NOCOPY, crit_transfer_to_handler, \
ret_from_crit_exc)
#define MCHECK_EXCEPTION(n, label, hdlr) \
START_EXCEPTION(label); \
MCHECK_EXCEPTION_PROLOG; \
mfspr r5,SPRN_ESR; \
stw r5,_ESR(r11); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
NOCOPY, mcheck_transfer_to_handler, \
ret_from_mcheck_exc)
#define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret) \
li r10,trap; \
stw r10,_TRAP(r11); \
lis r10,msr@h; \
ori r10,r10,msr@l; \
copyee(r10, r9); \
bl tfer; \
.long hdlr; \
.long ret
#define COPY_EE(d, s) rlwimi d,s,0,16,16
#define NOCOPY(d, s)
#define EXC_XFER_STD(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
ret_from_except_full)
#define EXC_XFER_LITE(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
ret_from_except)
#define EXC_XFER_EE(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
ret_from_except_full)
#define EXC_XFER_EE_LITE(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
ret_from_except)
/* Check for a single step debug exception while in an exception
* handler before state has been saved. This is to catch the case
* where an instruction that we are trying to single step causes
* an exception (eg ITLB/DTLB miss) and thus the first instruction of
* the exception handler generates a single step debug exception.
*
* If we get a debug trap on the first instruction of an exception handler,
* we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
* a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
* The exception handler was handling a non-critical interrupt, so it will
* save (and later restore) the MSR via SPRN_CSRR1, which will still have
* the MSR_DE bit set.
*/
#define DEBUG_DEBUG_EXCEPTION \
START_EXCEPTION(DebugDebug); \
DEBUG_EXCEPTION_PROLOG; \
\
/* \
* If there is a single step or branch-taken exception in an \
* exception entry sequence, it was probably meant to apply to \
* the code where the exception occurred (since exception entry \
* doesn't turn off DE automatically). We simulate the effect \
* of turning off DE on entry to an exception handler by turning \
* off DE in the CSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
andis. r10,r10,DBSR_IC@h; \
beq+ 2f; \
\
lis r10,KERNELBASE@h; /* check if exception in vectors */ \
ori r10,r10,KERNELBASE@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,DebugDebug@h; \
ori r10,r10,DebugDebug@l; \
cmplw r12,r10; \
bgt+ 2f; /* addr above exception vectors */ \
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CDRR1 value */ \
lis r10,DBSR_IC@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
lwz r0,GPR0(r11); \
lwz r1,GPR1(r11); \
mtcrf 0x80,r10; \
mtspr SPRN_DSRR0,r12; \
mtspr SPRN_DSRR1,r9; \
lwz r9,GPR9(r11); \
lwz r12,GPR12(r11); \
mtspr DEBUG_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(DEBUG); /* r8 points to the debug stack */ \
lwz r10,GPR10-INT_FRAME_SIZE(r8); \
lwz r11,GPR11-INT_FRAME_SIZE(r8); \
mfspr r8,DEBUG_SPRG; \
\
RFDI; \
b .; \
\
/* continue normal handling for a critical exception... */ \
2: mfspr r4,SPRN_DBSR; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(DebugException, 0x2008, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, debug_transfer_to_handler, ret_from_debug_exc)
#define DEBUG_CRIT_EXCEPTION \
START_EXCEPTION(DebugCrit); \
CRITICAL_EXCEPTION_PROLOG; \
\
/* \
* If there is a single step or branch-taken exception in an \
* exception entry sequence, it was probably meant to apply to \
* the code where the exception occurred (since exception entry \
* doesn't turn off DE automatically). We simulate the effect \
* of turning off DE on entry to an exception handler by turning \
* off DE in the CSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
andis. r10,r10,DBSR_IC@h; \
beq+ 2f; \
\
lis r10,KERNELBASE@h; /* check if exception in vectors */ \
ori r10,r10,KERNELBASE@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,DebugCrit@h; \
ori r10,r10,DebugCrit@l; \
cmplw r12,r10; \
bgt+ 2f; /* addr above exception vectors */ \
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CSRR1 value */ \
lis r10,DBSR_IC@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
lwz r0,GPR0(r11); \
lwz r1,GPR1(r11); \
mtcrf 0x80,r10; \
mtspr SPRN_CSRR0,r12; \
mtspr SPRN_CSRR1,r9; \
lwz r9,GPR9(r11); \
lwz r12,GPR12(r11); \
mtspr CRIT_SPRG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
lwz r10,GPR10-INT_FRAME_SIZE(r8); \
lwz r11,GPR11-INT_FRAME_SIZE(r8); \
mfspr r8,CRIT_SPRG; \
\
rfci; \
b .; \
\
/* continue normal handling for a critical exception... */ \
2: mfspr r4,SPRN_DBSR; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
#define INSTRUCTION_STORAGE_EXCEPTION \
START_EXCEPTION(InstructionStorage) \
NORMAL_EXCEPTION_PROLOG; \
mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
stw r5,_ESR(r11); \
mr r4,r12; /* Pass SRR0 as arg2 */ \
li r5,0; /* Pass zero as arg3 */ \
EXC_XFER_EE_LITE(0x0400, handle_page_fault)
#define ALIGNMENT_EXCEPTION \
START_EXCEPTION(Alignment) \
NORMAL_EXCEPTION_PROLOG; \
mfspr r4,SPRN_DEAR; /* Grab the DEAR and save it */ \
stw r4,_DEAR(r11); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_EE(0x0600, alignment_exception)
#define PROGRAM_EXCEPTION \
START_EXCEPTION(Program) \
NORMAL_EXCEPTION_PROLOG; \
mfspr r4,SPRN_ESR; /* Grab the ESR and save it */ \
stw r4,_ESR(r11); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_STD(0x0700, program_check_exception)
#define DECREMENTER_EXCEPTION \
START_EXCEPTION(Decrementer) \
NORMAL_EXCEPTION_PROLOG; \
lis r0,TSR_DIS@h; /* Setup the DEC interrupt mask */ \
mtspr SPRN_TSR,r0; /* Clear the DEC interrupt */ \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_LITE(0x0900, timer_interrupt)
#define FP_UNAVAILABLE_EXCEPTION \
START_EXCEPTION(FloatingPointUnavailable) \
NORMAL_EXCEPTION_PROLOG; \
bne load_up_fpu; /* if from user, just load it up */ \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
#endif /* __HEAD_BOOKE_H__ */
