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linux-next/arch/powerpc/kernel/head_booke.h
Bharat Bhushan fc2a6cfe05 powerpc: Fix interrupt range check on debug exception 
We do not want to take single step and branch-taken debug exception
in kernel exception code. But the address range check was not covering
all kernel exception handlers address range.

With this patch we defined the interrupt_end label which defines the
end on kernel exception code. So now we check interrupt_base to
interrupt_end range for not handling debug exception in kernel
exception entry.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-02 10:31:01 +10:00

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#ifndef __HEAD_BOOKE_H__
#define __HEAD_BOOKE_H__
#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
#include <asm/kvm_asm.h>
#include <asm/kvm_booke_hv_asm.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
#if (THREAD_SHIFT < 15)
#define ALLOC_STACK_FRAME(reg, val) \
addi reg,reg,val
#else
#define ALLOC_STACK_FRAME(reg, val) \
addis reg,reg,val@ha; \
addi reg,reg,val@l
#endif
/*
* Macro used to get to thread save registers.
* Note that entries 0-3 are used for the prolog code, and the remaining
* entries are available for specific exception use in the event a handler
* requires more than 4 scratch registers.
*/
#define THREAD_NORMSAVE(offset) (THREAD_NORMSAVES + (offset * 4))
#define NORMAL_EXCEPTION_PROLOG(intno) \
mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
mfspr r10, SPRN_SPRG_THREAD; \
stw r11, THREAD_NORMSAVE(0)(r10); \
stw r13, THREAD_NORMSAVE(2)(r10); \
mfcr r13; /* save CR in r13 for now */\
mfspr r11, SPRN_SRR1; \
DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1; \
andi. r11, r11, MSR_PR; /* check whether user or kernel */\
mr r11, r1; \
beq 1f; \
/* if from user, start at top of this thread's kernel stack */ \
lwz r11, THREAD_INFO-THREAD(r10); \
ALLOC_STACK_FRAME(r11, THREAD_SIZE); \
1 : subi r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */ \
stw r13, _CCR(r11); /* save various registers */ \
stw r12,GPR12(r11); \
stw r9,GPR9(r11); \
mfspr r13, SPRN_SPRG_RSCRATCH0; \
stw r13, GPR10(r11); \
lwz r12, THREAD_NORMSAVE(0)(r10); \
stw r12,GPR11(r11); \
lwz r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */ \
mflr r10; \
stw r10,_LINK(r11); \
mfspr r12,SPRN_SRR0; \
stw r1, GPR1(r11); \
mfspr r9,SPRN_SRR1; \
stw r1, 0(r11); \
mr r1, r11; \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
stw r0,GPR0(r11); \
lis r10, STACK_FRAME_REGS_MARKER@ha;/* exception frame marker */ \
addi r10, r10, STACK_FRAME_REGS_MARKER@l; \
stw r10, 8(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 stack per additional priority level.
*
* 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.
*/
#define MC_STACK_BASE mcheckirq_ctx
#define CRIT_STACK_BASE critirq_ctx
/* only on e500mc/e200 */
#define DBG_STACK_BASE dbgirq_ctx
#define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
slwi r8,r8,2; \
addis r8,r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
lis r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
#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, intno, exc_level_srr0, exc_level_srr1) \
mtspr SPRN_SPRG_WSCRATCH_##exc_level,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
stw r9,GPR9(r8); /* save various registers */\
mfcr r9; /* save CR in r9 for now */\
stw r10,GPR10(r8); \
stw r11,GPR11(r8); \
stw r9,_CCR(r8); /* save CR on stack */\
mfspr r11,exc_level_srr1; /* check whether user or kernel */\
DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
andi. r11,r11,MSR_PR; \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
beq 1f; \
/* COMING FROM USER MODE */ \
stw r9,_CCR(r11); /* save CR */\
lwz r10,GPR10(r8); /* copy regs from exception stack */\
lwz r9,GPR9(r8); \
stw r10,GPR10(r11); \
lwz r10,GPR11(r8); \
stw r9,GPR9(r11); \
stw r10,GPR11(r11); \
b 2f; \
/* COMING FROM PRIV MODE */ \
1: lwz r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11); \
lwz r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11); \
stw r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8); \
stw r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8); \
lwz r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11); \
stw r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8); \
mr r11,r8; \
2: mfspr r8,SPRN_SPRG_RSCRATCH_##exc_level; \
stw r12,GPR12(r11); /* save various registers */\
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(intno) \
EXC_LEVEL_EXCEPTION_PROLOG(CRIT, intno, SPRN_CSRR0, SPRN_CSRR1)
#define DEBUG_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(DBG, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
#define MCHECK_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(MC, MACHINE_CHECK, \
SPRN_MCSRR0, SPRN_MCSRR1)
/*
* Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
* being delivered to the host. This exception can only happen
* inside a KVM guest -- so we just handle up to the DO_KVM rather
* than try to fit this into one of the existing prolog macros.
*/
#define GUEST_DOORBELL_EXCEPTION \
START_EXCEPTION(GuestDoorbell); \
mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
mfspr r10, SPRN_SPRG_THREAD; \
stw r11, THREAD_NORMSAVE(0)(r10); \
mfspr r11, SPRN_SRR1; \
stw r13, THREAD_NORMSAVE(2)(r10); \
mfcr r13; /* save CR in r13 for now */\
DO_KVM BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1; \
trap
/*
* Exception vectors.
*/
#define START_EXCEPTION(label) \
.align 5; \
label:
#define EXCEPTION(n, intno, label, hdlr, xfer) \
START_EXCEPTION(label); \
NORMAL_EXCEPTION_PROLOG(intno); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
xfer(n, hdlr)
#define CRITICAL_EXCEPTION(n, intno, label, hdlr) \
START_EXCEPTION(label); \
CRITICAL_EXCEPTION_PROLOG(intno); \
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 DSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,interrupt_base@h; /* check if exception in vectors */ \
ori r10,r10,interrupt_base@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,interrupt_end@h; \
ori r10,r10,interrupt_end@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|DBSR_BT)@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 SPRN_SPRG_WSCRATCH_DBG,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
lwz r10,GPR10(r8); \
lwz r11,GPR11(r8); \
mfspr r8,SPRN_SPRG_RSCRATCH_DBG; \
\
PPC_RFDI; \
b .; \
\
/* continue normal handling for a debug 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(DEBUG); \
\
/* \
* 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|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,interrupt_base@h; /* check if exception in vectors */ \
ori r10,r10,interrupt_base@l; \
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
lis r10,interrupt_end@h; \
ori r10,r10,interrupt_end@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|DBSR_BT)@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 SPRN_SPRG_WSCRATCH_CRIT,r8; \
BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
lwz r10,GPR10(r8); \
lwz r11,GPR11(r8); \
mfspr r8,SPRN_SPRG_RSCRATCH_CRIT; \
\
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 DATA_STORAGE_EXCEPTION \
START_EXCEPTION(DataStorage) \
NORMAL_EXCEPTION_PROLOG(DATA_STORAGE); \
mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
stw r5,_ESR(r11); \
mfspr r4,SPRN_DEAR; /* Grab the DEAR */ \
EXC_XFER_LITE(0x0300, handle_page_fault)
#define INSTRUCTION_STORAGE_EXCEPTION \
START_EXCEPTION(InstructionStorage) \
NORMAL_EXCEPTION_PROLOG(INST_STORAGE); \
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_LITE(0x0400, handle_page_fault)
#define ALIGNMENT_EXCEPTION \
START_EXCEPTION(Alignment) \
NORMAL_EXCEPTION_PROLOG(ALIGNMENT); \
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(PROGRAM); \
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(DECREMENTER); \
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(FP_UNAVAIL); \
beq 1f; \
bl load_up_fpu; /* if from user, just load it up */ \
b fast_exception_return; \
1: addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
#ifndef __ASSEMBLY__
struct exception_regs {
unsigned long mas0;
unsigned long mas1;
unsigned long mas2;
unsigned long mas3;
unsigned long mas6;
unsigned long mas7;
unsigned long srr0;
unsigned long srr1;
unsigned long csrr0;
unsigned long csrr1;
unsigned long dsrr0;
unsigned long dsrr1;
unsigned long saved_ksp_limit;
};
/* ensure this structure is always sized to a multiple of the stack alignment */
#define STACK_EXC_LVL_FRAME_SIZE _ALIGN_UP(sizeof (struct exception_regs), 16)
#endif /* __ASSEMBLY__ */
#endif /* __HEAD_BOOKE_H__ */
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