On Dec 10, 2009, at 9:57 AM, Dave Kleikamp wrote:

> powerpc: Add support for BookE Debug Reg. traps, exceptions and ptrace
> 
> From: Torez Smith <[email protected]>
> 
> This patch defines context switch and trap related functionality
> for BookE specific Debug Registers. It adds support to ptrace()
> for setting and getting BookE related Debug Registers
> 
> Signed-off-by: Torez Smith  <[email protected]>
> Signed-off-by: Dave Kleikamp <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Thiago Jung Bauermann <[email protected]>
> Cc: Sergio Durigan Junior <[email protected]>
> Cc: David Gibson <[email protected]>
> Cc: linuxppc-dev list <[email protected]>
> ---
> 
> arch/powerpc/include/asm/system.h |    2 
> arch/powerpc/kernel/process.c     |  109 ++++++++-
> arch/powerpc/kernel/ptrace.c      |  435 ++++++++++++++++++++++++++++++++++---
> arch/powerpc/kernel/signal.c      |    6 -
> arch/powerpc/kernel/signal_32.c   |    8 +
> arch/powerpc/kernel/traps.c       |   86 ++++++-
> 6 files changed, 564 insertions(+), 82 deletions(-)
> 
> 
> diff --git a/arch/powerpc/include/asm/system.h 
> b/arch/powerpc/include/asm/system.h
> index bb8e006..474bf23 100644
> --- a/arch/powerpc/include/asm/system.h
> +++ b/arch/powerpc/include/asm/system.h
> @@ -114,6 +114,8 @@ static inline int debugger_fault_handler(struct pt_regs 
> *regs) { return 0; }
> extern int set_dabr(unsigned long dabr);
> extern void do_dabr(struct pt_regs *regs, unsigned long address,
>                   unsigned long error_code);
> +extern void do_send_trap(struct pt_regs *regs, unsigned long address,
> +                      unsigned long error_code, int signal_code, int errno);
> extern void print_backtrace(unsigned long *);
> extern void show_regs(struct pt_regs * regs);
> extern void flush_instruction_cache(void);
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index c930ac3..a0dbb09 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -245,6 +245,24 @@ void discard_lazy_cpu_state(void)
> }
> #endif /* CONFIG_SMP */
> 
> +void do_send_trap(struct pt_regs *regs, unsigned long address,
> +               unsigned long error_code, int signal_code, int errno)
> +{
> +     siginfo_t info;
> +
> +     if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
> +                     11, SIGSEGV) == NOTIFY_STOP)
> +             return;
> +
> +     /* Deliver the signal to userspace */
> +     info.si_signo = SIGTRAP;
> +     info.si_errno = errno;
> +     info.si_code = signal_code;
> +     info.si_addr = (void __user *)address;
> +     force_sig_info(SIGTRAP, &info, current);
> +}
> +
> +#if !(defined(CONFIG_40x) || defined(CONFIG_BOOKE))
> void do_dabr(struct pt_regs *regs, unsigned long address,
>                   unsigned long error_code)
> {
> @@ -257,12 +275,6 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
>       if (debugger_dabr_match(regs))
>               return;
> 
> -     /* Clear the DAC and struct entries.  One shot trigger */
> -#if defined(CONFIG_BOOKE)
> -     mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W
> -                                                     | DBCR0_IDM));
> -#endif
> -
>       /* Clear the DABR */
>       set_dabr(0);
> 
> @@ -273,9 +285,71 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
>       info.si_addr = (void __user *)address;
>       force_sig_info(SIGTRAP, &info, current);
> }
> +#endif
> 
> static DEFINE_PER_CPU(unsigned long, current_dabr);
> 
> +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
> +/*
> + * Set the debug registers back to their default "safe" values.
> + */
> +static void set_debug_reg_defaults(struct thread_struct *thread)
> +{
> +     thread->iac1 = thread->iac2 = thread->iac3 = thread->iac4 = 0;
> +     thread->dac1 = thread->dac2 = 0;
> +     thread->dvc1 = thread->dvc2 = 0;
> +     /*
> +      * reset the DBCR0, DBCR1 and DBCR2 registers. All bits with
> +      * the exception of the reserved bits should be cleared out
> +      * and set to 0.
> +      *
> +      * For the DBCR0 register, the reserved bits are bits 17:30.
> +      * Reserved bits for DBCR1 are bits 10:14 and bits 26:30.
> +      * And, bits 10:11 for DBCR2.
> +      */
> +     thread->dbcr0 = DBCR0_BASE_REG_VALUE;

This seems to always be 0, why have a special #define for it.

> +     /*
> +      * First clear all "non reserved" bits from DBCR1 then initialize reg
> +      * to force User/Supervisor bits to b11 (user-only MSR[PR]=1) and
> +      * Effective/Real * bits to b10 (trap only if IS==0)
> +      */
> +     thread->dbcr1 = DBCR1_BASE_REG_VALUE;
> +     /*
> +      * Force Data Address Compare User/Supervisor bits to be User-only
> +      * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
> +      * This sets the Data Address Compare Effective/Real bits to be 0b00
> +      * (Effective, MSR[DS]=don't care).
> +      */
> +     thread->dbcr2 = DBCR2_BASE_REG_VALUE;
> +}
> +
> +static void prime_debug_regs(struct thread_struct *thread)
> +{
> +     mtspr(SPRN_IAC1, thread->iac1);
> +     mtspr(SPRN_IAC2, thread->iac2);
> +     mtspr(SPRN_IAC3, thread->iac3);
> +     mtspr(SPRN_IAC4, thread->iac4);
> +     mtspr(SPRN_DAC1, thread->dac1);
> +     mtspr(SPRN_DAC2, thread->dac2);
> +     mtspr(SPRN_DVC1, thread->dvc1);
> +     mtspr(SPRN_DVC2, thread->dvc2);
> +     mtspr(SPRN_DBCR0, thread->dbcr0);
> +     mtspr(SPRN_DBCR1, thread->dbcr1);
> +     mtspr(SPRN_DBCR2, thread->dbcr2);

We should probably look at dbginfo.num_condition_regs, 
dbginfo.num_instruction_bps, & dbginfo.num_data_bps and set these accordingly.

> +}
> +/*
> + * Unless neither the old or new thread are making use of the
> + * debug registers, set the debug registers from the values
> + * stored in the new thread.
> + */
> +static void switch_booke_debug_regs(struct thread_struct *new_thread)
> +{
> +     if ((current->thread.dbcr0 & DBCR0_IDM)
> +             || (new_thread->dbcr0 & DBCR0_IDM))
> +                     prime_debug_regs(new_thread);
> +}
> +#endif
> +
> int set_dabr(unsigned long dabr)
> {
>       __get_cpu_var(current_dabr) = dabr;
> @@ -284,7 +358,7 @@ int set_dabr(unsigned long dabr)
>               return ppc_md.set_dabr(dabr);
> 
>       /* XXX should we have a CPU_FTR_HAS_DABR ? */
> -#if defined(CONFIG_BOOKE)
> +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
>       mtspr(SPRN_DAC1, dabr);
> #elif defined(CONFIG_PPC_BOOK3S)
>       mtspr(SPRN_DABR, dabr);
> @@ -371,10 +445,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
> 
> #endif /* CONFIG_SMP */
> 
> -#if defined(CONFIG_BOOKE)
> -     /* If new thread DAC (HW breakpoint) is the same then leave it */
> -     if (new->thread.dabr)
> -             set_dabr(new->thread.dabr);
> +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
> +     switch_booke_debug_regs(&new->thread);
> #else
>       if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
>               set_dabr(new->thread.dabr);
> @@ -514,7 +586,7 @@ void show_regs(struct pt_regs * regs)
>       printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
>       trap = TRAP(regs);
>       if (trap == 0x300 || trap == 0x600)
> -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
> +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
>               printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
> #else
>               printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
> @@ -568,14 +640,19 @@ void flush_thread(void)
> 
>       discard_lazy_cpu_state();
> 
> +#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
> +     /*
> +      * flush_thread() is called on exec() to reset the
> +      * thread's status. Set all debug regs back to their
> +      * default values....Torez
> +      */
> +     set_debug_reg_defaults(&current->thread);
> +#else
>       if (current->thread.dabr) {
>               current->thread.dabr = 0;
>               set_dabr(0);
> -
> -#if defined(CONFIG_BOOKE)
> -             current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W);
> -#endif
>       }
> +#endif
> }
> 
> void
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index 6be2ce0..6710a69 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -737,17 +737,25 @@ void user_disable_single_step(struct task_struct *task)
>       struct pt_regs *regs = task->thread.regs;
> 
>       if (regs != NULL) {
> -#if defined(CONFIG_BOOKE)
> -             /* If DAC don't clear DBCRO_IDM or MSR_DE */
> -             if (task->thread.dabr)
> -                     task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT);
> -             else {
> -                     task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | 
> DBCR0_IDM);
> +#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +             /*
> +              * The logic to disable single stepping should be as
> +              * simple as turning off the Instruction Complete flag.
> +              * And, after doing so, if all debug flags are off, turn
> +              * off DBCR0(IDM) and MSR(DE) .... Torez
> +              */
> +             task->thread.dbcr0 &= ~DBCR0_IC;
> +             /*
> +              * Test to see if any of the DBCR_ACTIVE_EVENTS bits are set.
> +              */
> +             if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
> +                                     task->thread.dbcr1)) {
> +                     /*
> +                      * All debug events were off.....
> +                      */
> +                     task->thread.dbcr0 &= ~DBCR0_IDM;
>                       regs->msr &= ~MSR_DE;
>               }
> -#elif defined(CONFIG_40x)
> -             task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | DBCR0_IDM);
> -             regs->msr &= ~MSR_DE;
> #else
>               regs->msr &= ~(MSR_SE | MSR_BE);
> #endif
> @@ -769,8 +777,7 @@ int ptrace_set_debugreg(struct task_struct *task, 
> unsigned long addr,
>       if ((data & ~0x7UL) >= TASK_SIZE)
>               return -EIO;
> 
> -#ifndef CONFIG_BOOKE
> -
> +#if !(defined(CONFIG_40x) || defined(CONFIG_BOOKE))
>       /* For processors using DABR (i.e. 970), the bottom 3 bits are flags.
>        *  It was assumed, on previous implementations, that 3 bits were
>        *  passed together with the data address, fitting the design of the
> @@ -789,21 +796,22 @@ int ptrace_set_debugreg(struct task_struct *task, 
> unsigned long addr,
> 
>       /* Move contents to the DABR register */
>       task->thread.dabr = data;
> -
> -#endif
> -#if defined(CONFIG_BOOKE)
> -
> +#else
>       /* As described above, it was assumed 3 bits were passed with the data
>        *  address, but we will assume only the mode bits will be passed
>        *  as to not cause alignment restrictions for DAC-based processors.
>        */
> 
>       /* DAC's hold the whole address without any mode flags */
> -     task->thread.dabr = data & ~0x3UL;
> -
> -     if (task->thread.dabr == 0) {
> -             task->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
> -             task->thread.regs->msr &= ~MSR_DE;
> +     task->thread.dac1 = data & ~0x3UL;
> +
> +     if (task->thread.dac1 == 0) {
> +             dbcr_dac(task) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +             if (!DBCR_ACTIVE_EVENTS(task->thread.dbcr0,
> +                                     task->thread.dbcr1)) {
> +                     task->thread.regs->msr &= ~MSR_DE;
> +                     task->thread.dbcr0 &= ~DBCR0_IDM;
> +             }
>               return 0;
>       }
> 
> @@ -814,15 +822,15 @@ int ptrace_set_debugreg(struct task_struct *task, 
> unsigned long addr,
> 
>       /* Set the Internal Debugging flag (IDM bit 1) for the DBCR0
>          register */
> -     task->thread.dbcr0 = DBCR0_IDM;
> +     task->thread.dbcr0 |= DBCR0_IDM;
> 
>       /* Check for write and read flags and set DBCR0
>          accordingly */
> +     dbcr_dac(task) &= ~(DBCR_DAC1R|DBCR_DAC1W);
>       if (data & 0x1UL)
> -             task->thread.dbcr0 |= DBSR_DAC1R;
> +             dbcr_dac(task) |= DBCR_DAC1R;
>       if (data & 0x2UL)
> -             task->thread.dbcr0 |= DBSR_DAC1W;
> -
> +             dbcr_dac(task) |= DBCR_DAC1W;
>       task->thread.regs->msr |= MSR_DE;
> #endif
>       return 0;
> @@ -839,11 +847,324 @@ void ptrace_disable(struct task_struct *child)
>       user_disable_single_step(child);
> }
> 
> +#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +static long set_intruction_bp(struct task_struct *child,
> +                           struct ppc_hw_breakpoint *bp_info)
> +{
> +     int slots_needed;
> +     int slot;
> +     int free_slot = 0;
> +
> +     /*
> +      * Find an avalailable slot for the breakpoint.
> +      * If possible, reserve consecutive slots, 1 & 2, for a range
> +      * breakpoint.  (Can this be done simpler?)
> +      */
> +     if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> +             slots_needed = 1;
> +     else
> +             slots_needed = 2;
> +
> +     if ((child->thread.dbcr0 & DBCR0_IAC1) == 0) {
> +             if (slots_needed == 1) {
> +                     if (child->thread.dbcr0 & DBCR0_IAC2) {
> +                             slot = 1;
> +                             goto found;
> +                     }
> +                     /* Try to save slots 1 & 2 for range */
> +                     free_slot = 1;
> +             } else
> +                     if ((child->thread.dbcr0 & DBCR0_IAC2) == 0) {
> +                             slot = 1;
> +                             goto found;
> +                     }
> +     } else if ((slots_needed == 1) &&
> +                ((child->thread.dbcr0 & DBCR0_IAC2) == 0)) {
> +             slot = 2;
> +             goto found;
> +     }
> +     if ((child->thread.dbcr0 & DBCR0_IAC3) == 0) {
> +             if (slots_needed == 1) {
> +                     slot = 3;
> +                     goto found;
> +             }
> +             if ((child->thread.dbcr0 & DBCR0_IAC4) == 0) {
> +                     slot = 3;
> +                     goto found;
> +             }
> +             return -ENOSPC;
> +     } else if (slots_needed == 2)
> +             return -ENOSPC;
> +     if ((child->thread.dbcr0 & DBCR0_IAC4) == 0) {
> +             slot = 4;
> +     } else if (free_slot)
> +             slot = free_slot;
> +     else
> +             return -ENOSPC;

Need to factor in if # of IACs is only 2.

> +found:
> +     if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT) {
> +             switch (slot) {
> +                     case 1:
> +                             child->thread.iac1 = bp_info->addr;
> +                             child->thread.dbcr0 |= DBCR0_IAC1;
> +                             break;
> +                     case 2:
> +                             child->thread.iac2 = bp_info->addr;
> +                             child->thread.dbcr0 |= DBCR0_IAC2;
> +                             break;
> +                     case 3:
> +                             child->thread.iac3 = bp_info->addr;
> +                             child->thread.dbcr0 |= DBCR0_IAC3;
> +                             break;
> +                     case 4:
> +                             child->thread.iac4 = bp_info->addr;
> +                             child->thread.dbcr0 |= DBCR0_IAC4;
> +                             break;
> +             }
> +     } else if (slot == 1) {
> +             child->thread.iac1 = bp_info->addr;
> +             child->thread.iac2 = bp_info->addr2;
> +             child->thread.dbcr0 |= (DBCR0_IAC1 | DBCR0_IAC2);
> +             if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +                     dbcr_iac_range(child) |= DBCR_IAC12M_X;
> +             else
> +                     dbcr_iac_range(child) |= DBCR_IAC12M_I;
> +     } else { /* slot == 3 */
> +             child->thread.iac3 = bp_info->addr;
> +             child->thread.iac4 = bp_info->addr2;
> +             child->thread.dbcr0 |= (DBCR0_IAC3 | DBCR0_IAC4);
> +             if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +                     dbcr_iac_range(child) |= DBCR_IAC34M_X;
> +             else
> +                     dbcr_iac_range(child) |= DBCR_IAC34M_I;
> +     }
> +     child->thread.dbcr0 |= DBCR0_IDM;
> +     child->thread.regs->msr |= MSR_DE;
> +
> +     return slot;
> +}
> +
> +static int del_instruction_bp(struct task_struct *child, int slot)
> +{
> +     switch (slot) {
> +     case 1:
> +             if (dbcr_iac_range(child) & DBCR_IAC12M) {
> +                     /* address range - clear slots 1 & 2 */
> +                     child->thread.iac2 = 0;
> +                     child->thread.dbcr0 &= ~DBCR0_IAC2;
> +                     dbcr_iac_range(child) &= ~DBCR_IAC12M;
> +             }
> +             child->thread.iac1 = 0;
> +             child->thread.dbcr0 &= ~DBCR0_IAC1;
> +             break;
> +     case 2:
> +             if (dbcr_iac_range(child) & DBCR_IAC12M)
> +                     /* used in a range */
> +                     return -EINVAL;
> +             child->thread.iac2 = 0;
> +             child->thread.dbcr0 &= ~DBCR0_IAC2;
> +             break;
> +     case 3:
> +             if (dbcr_iac_range(child) & DBCR_IAC34M) {
> +                     /* address range - clear slots 3 & 4 */
> +                     child->thread.iac4 = 0;
> +                     child->thread.dbcr0 &= ~DBCR0_IAC4;
> +                     dbcr_iac_range(child) &= ~DBCR_IAC34M;
> +             }
> +             child->thread.iac3 = 0;
> +             child->thread.dbcr0 &= ~DBCR0_IAC3;
> +             break;
> +     case 4:
> +             if (dbcr_iac_range(child) & DBCR_IAC34M)
> +                     /* Used in a range */
> +                     return -EINVAL;
> +             child->thread.iac4 = 0;
> +             child->thread.dbcr0 &= ~DBCR0_IAC4;
> +             break;
> +     default:
> +             return -EINVAL;
> +     }
> +     return 0;
> +}
> +
> +static int set_dac(struct task_struct *child, struct ppc_hw_breakpoint 
> *bp_info)
> +{
> +     int byte_enable =
> +             (bp_info->condition_mode >> PPC_BREAKPOINT_CONDITION_BE_SHIFT)
> +             & 0xf;
> +     int condition_mode =
> +             bp_info->condition_mode & PPC_BREAKPOINT_CONDITION_AND_OR;
> +     int slot;
> +
> +     if (byte_enable && (condition_mode == 0))
> +             return -EINVAL;
> +
> +     if (bp_info->addr >= TASK_SIZE)
> +             return -EIO;
> +
> +     if ((dbcr_dac(child) & (DBCR_DAC1R | DBCR_DAC1W)) == 0) {
> +             if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +                     dbcr_dac(child) |= DBCR_DAC1R;
> +             if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +                     dbcr_dac(child) |= DBCR_DAC1W;
> +             child->thread.dac1 = (unsigned long)bp_info->addr;
> +#ifdef CONFIG_BOOKE
> +             if (byte_enable) {
> +                     child->thread.dvc1 =
> +                             (unsigned long)bp_info->condition_value;
> +                     child->thread.dbcr2 |=
> +                             ((byte_enable << DBCR2_DVC1BE_SHIFT) |
> +                              (condition_mode << DBCR2_DVC1M_SHIFT));
> +             }
> +#endif
> +             slot = 1;
> +     } else if ((dbcr_dac(child) & (DBCR_DAC2R | DBCR_DAC2W)) == 0) {
> +             if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +                     dbcr_dac(child) |= DBCR_DAC2R;
> +             if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +                     dbcr_dac(child) |= DBCR_DAC2W;
> +             child->thread.dac2 = (unsigned long)bp_info->addr;
> +#ifdef CONFIG_BOOKE
> +             if (byte_enable) {
> +                     child->thread.dvc2 =
> +                             (unsigned long)bp_info->condition_value;
> +                     child->thread.dbcr2 |=
> +                             ((byte_enable << DBCR2_DVC2BE_SHIFT) |
> +                              (condition_mode << DBCR2_DVC2M_SHIFT));
> +             }
> +#endif
> +             slot = 2;
> +     } else
> +             return -ENOSPC;
> +     child->thread.dbcr0 |= DBCR0_IDM;
> +     child->thread.regs->msr |= MSR_DE;
> +
> +     return slot + 4;
> +}
> +
> +static int del_dac(struct task_struct *child, int slot)
> +{
> +     if (slot == 1) {
> +#ifdef CONFIG_BOOKE
> +             if (child->thread.dbcr2 & DBCR2_DAC12MODE) {
> +                     child->thread.dac1 = 0;
> +                     child->thread.dac2 = 0;
> +                     child->thread.dbcr0 &= ~(DBCR0_DAC1R | DBCR0_DAC1W |
> +                                              DBCR0_DAC2R | DBCR0_DAC2W);
> +                     child->thread.dbcr2 &= ~DBCR2_DAC12MODE;
> +                     return 0;
> +             }
> +             child->thread.dbcr2 &= ~(DBCR2_DVC1M | DBCR2_DVC1BE);
> +             child->thread.dvc1 = 0;
> +#endif
> +             child->thread.dac1 = 0;
> +             dbcr_dac(child) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +     } else if (slot == 2) {
> +#ifdef CONFIG_BOOKE
> +             if (child->thread.dbcr2 & DBCR2_DAC12MODE)
> +                     /* Part of a range */
> +                     return -EINVAL;
> +             child->thread.dbcr2 &= ~(DBCR2_DVC2M | DBCR2_DVC2BE);
> +             child->thread.dvc2 = 0;
> +#endif
> +             child->thread.dac2 = 0;
> +             dbcr_dac(child) &= ~(DBCR_DAC2R | DBCR_DAC2W);
> +     } else
> +             return -EINVAL;
> +
> +     return 0;
> +}
> +#endif /* CONFIG_40x || CONFIG_BOOKE */
> +
> +#ifdef CONFIG_BOOKE
> +static int set_dac_range(struct task_struct *child,
> +                      struct ppc_hw_breakpoint *bp_info)
> +{
> +     int mode = bp_info->addr_mode & PPC_BREAKPOINT_MODE_MASK;
> +
> +     /* We don't allow range watchpoints to be used with DVC */
> +     if (bp_info->condition_mode && PPC_BREAKPOINT_CONDITION_BE_ALL)
> +             return -EINVAL;
> +
> +     if (bp_info->addr >= TASK_SIZE)
> +             return -EIO;
> +
> +     if (child->thread.dbcr0 &
> +         (DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W))
> +             return -ENOSPC;
> +
> +     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> +             child->thread.dbcr0 |= (DBCR0_DAC1R | DBCR0_DAC2R | DBCR0_IDM);
> +     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> +             child->thread.dbcr0 |= (DBCR0_DAC1W | DBCR0_DAC2W | DBCR0_IDM);
> +     child->thread.dac1 = bp_info->addr;
> +     child->thread.dac2 = bp_info->addr2;
> +     if (mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE)
> +             child->thread.dbcr2  |= DBCR2_DAC12R;
> +     else if (mode == PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE)
> +             child->thread.dbcr2  |= DBCR2_DAC12RX;
> +     else    /* PPC_BREAKPOINT_MODE_MASK */
> +             child->thread.dbcr2  |= DBCR2_DAC12MASK;
> +     child->thread.regs->msr |= MSR_DE;
> +
> +     return 5;
> +}
> +#endif /* CONFIG_BOOKE */
> +
> static long ppc_set_hwdebug(struct task_struct *child,
>                    struct ppc_hw_breakpoint *bp_info)
> {
> +     if (bp_info->version != 1)
> +             return -ENOTSUPP;
> +
> +#ifdef CONFIG_BOOKE
> +     /*
> +      * Check for invalid flags and combinations
> +      */
> +     if ((bp_info->trigger_type == 0) ||
> +         (bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
> +                                    PPC_BREAKPOINT_TRIGGER_RW)) ||
> +         (bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
> +         (bp_info->condition_mode &
> +          ~(PPC_BREAKPOINT_CONDITION_AND_OR |
> +            PPC_BREAKPOINT_CONDITION_BE_ALL)))
> +             return -EINVAL;

We should add a sanity check for bp_info->condition_mode != 
PPC_BREAKPOINT_CONDITION_NONE if dbginfo.num_condition_regs = 0.

> +
> +     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
> +             if (bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE)
> +                     /* At least another bit was set */
> +                     return -EINVAL;
> +             return set_intruction_bp(child, bp_info);
> +     }
> +
> +     if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_EXACT)
> +             return set_dac(child, bp_info);
> +
> +     return set_dac_range(child, bp_info);
> +#elif defined(CONFIG_40x)
> +     /*
> +      * Check for invalid flags and combinations
> +      */
> +     if ((bp_info->trigger_type == 0) ||
> +         (bp_info->trigger_type & ~(PPC_BREAKPOINT_TRIGGER_EXECUTE |
> +                                    PPC_BREAKPOINT_TRIGGER_RW)) ||
> +         (bp_info->addr_mode & ~PPC_BREAKPOINT_MODE_MASK) ||
> +         (bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE))
> +             return -EINVAL;
> +
> +     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_EXECUTE) {
> +             if (bp_info->trigger_type != PPC_BREAKPOINT_TRIGGER_EXECUTE)
> +                     /* At least another bit was set */
> +                     return -EINVAL;
> +             return set_intruction_bp(child, bp_info);
> +     }
> +     if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
> +             return -EINVAL;
> +
> +     return set_dac(child, bp_info);
> +#else
>       /*
> -      * We currently support one data breakpoint
> +      * We only support one data breakpoint
>        */
>       if (((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0) ||
>           ((bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0) ||
> @@ -859,28 +1180,35 @@ static long ppc_set_hwdebug(struct task_struct *child,
>               return -EIO;
> 
>       child->thread.dabr = (unsigned long)bp_info->addr;
> -#ifdef CONFIG_BOOKE
> -     child->thread.dbcr0 = DBCR0_IDM;
> -     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
> -             child->thread.dbcr0 |= DBSR_DAC1R;
> -     if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
> -             child->thread.dbcr0 |= DBSR_DAC1W;
> -     child->thread.regs->msr |= MSR_DE;
> -#endif
>       return 1;
> +#endif
> }
> 
> static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
> {
> +#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +     int rc;
> +
> +     if (data <= 4)
> +             rc = del_instruction_bp(child, (int)data);
> +     else
> +             rc = del_dac(child, (int)data - 4);
> +
> +     if (!rc) {
> +             if (!DBCR_ACTIVE_EVENTS(child->thread.dbcr0,
> +                                     child->thread.dbcr1)) {
> +                     child->thread.dbcr0 &= ~DBCR0_IDM;
> +                     child->thread.regs->msr &= ~MSR_DE;
> +             }
> +     }
> +     return rc;
> +#else
>       if ((data != 1) || (child->thread.dabr == 0))
>               return -EINVAL;
> 
>       child->thread.dabr = 0;
> -#ifdef CONFIG_BOOKE
> -     child->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W | DBCR0_IDM);
> -     child->thread.regs->msr &= ~MSR_DE;
> -#endif
>       return 0;
> +#endif
> }
> 
> /*
> @@ -980,16 +1308,36 @@ long arch_ptrace(struct task_struct *child, long 
> request, long addr, long data)
>               struct ppc_debug_info dbginfo;
> 
>               dbginfo.version = 1;
> +#ifdef CONFIG_BOOKE
> +             dbginfo.num_instruction_bps = 4;
> +             dbginfo.num_data_bps = 2;
> +             dbginfo.num_condition_regs = 2;
> +             dbginfo.data_bp_alignment = 0;
> +             dbginfo.sizeof_condition = 4;
> +             dbginfo.features = PPC_DEBUG_FEATURE_INSN_BP_RANGE |
> +                                PPC_DEBUG_FEATURE_INSN_BP_MASK |
> +                                PPC_DEBUG_FEATURE_DATA_BP_RANGE |
> +                                PPC_DEBUG_FEATURE_DATA_BP_MASK;
> +#elif defined(CONFIG_40x)
> +             /*
> +              * I don't know how the DVCs work on 40x, I'm not going
> +              * to support it now. -- Shaggy
> +              */
> +             dbginfo.num_instruction_bps = 4;
> +             dbginfo.num_data_bps = 2;
> +             dbginfo.num_condition_regs = 0;
> +             dbginfo.data_bp_alignment = 0;
> +             dbginfo.sizeof_condition = 0;
> +             dbginfo.features = PPC_DEBUG_FEATURE_INSN_BP_RANGE |
> +                                PPC_DEBUG_FEATURE_INSN_BP_MASK;
> +#else
>               dbginfo.num_instruction_bps = 0;
>               dbginfo.num_data_bps = 1;
>               dbginfo.num_condition_regs = 0;
> -#ifdef CONFIG_PPC64
>               dbginfo.data_bp_alignment = 8;
> -#else
> -             dbginfo.data_bp_alignment = 0;
> -#endif
>               dbginfo.sizeof_condition = 0;
>               dbginfo.features = 0;
> +#endif

This is a bit ugly and BOOKE 64 parts probably don't have the 8 byte alignment.

Should we push some of this into cputable?

> 
>               if (!access_ok(VERIFY_WRITE, data,
>                              sizeof(struct ppc_debug_info)))
> @@ -1025,8 +1373,13 @@ long arch_ptrace(struct task_struct *child, long 
> request, long addr, long data)
>               /* We only support one DABR and no IABRS at the moment */
>               if (addr > 0)
>                       break;
> +#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +             ret = put_user(child->thread.dac1,
> +                            (unsigned long __user *)data);
> +#else
>               ret = put_user(child->thread.dabr,
>                              (unsigned long __user *)data);
> +#endif
>               break;
>       }
> 
> diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
> index 00b5078..94df779 100644
> --- a/arch/powerpc/kernel/signal.c
> +++ b/arch/powerpc/kernel/signal.c
> @@ -140,17 +140,15 @@ static int do_signal_pending(sigset_t *oldset, struct 
> pt_regs *regs)
>               return 0;               /* no signals delivered */
>       }
> 
> +#if !(defined(CONFIG_BOOKE) || defined(CONFIG_40x))
>         /*
>        * Reenable the DABR before delivering the signal to
>        * user space. The DABR will have been cleared if it
>        * triggered inside the kernel.
>        */
> -     if (current->thread.dabr) {
> +     if (current->thread.dabr)
>               set_dabr(current->thread.dabr);
> -#if defined(CONFIG_BOOKE)
> -             mtspr(SPRN_DBCR0, current->thread.dbcr0);
> #endif
> -     }
> 
>       if (is32) {
>               if (ka.sa.sa_flags & SA_SIGINFO)
> diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
> index d670429..6cc6e81 100644
> --- a/arch/powerpc/kernel/signal_32.c
> +++ b/arch/powerpc/kernel/signal_32.c
> @@ -1092,8 +1092,12 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
>                               new_msr |= MSR_DE;
>                               new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
>                       } else {
> -                             new_msr &= ~MSR_DE;
> -                             new_dbcr0 &= ~(DBCR0_IDM | DBCR0_IC);
> +                             new_dbcr0 &= ~DBCR0_IC;
> +                             if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
> +                                             current->thread.dbcr1)) {
> +                                     new_msr &= ~MSR_DE;
> +                                     new_dbcr0 &= ~DBCR0_IDM;
> +                             }
>                       }
> #else
>                       if (op.dbg_value)
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index a81c743..d919571 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -1016,9 +1016,63 @@ void SoftwareEmulation(struct pt_regs *regs)
> #endif /* CONFIG_8xx */
> 
> #if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
> +{
> +     int changed = 0;
> +     /*
> +      * Determine the cause of the debug event, clear the
> +      * event flags and send a trap to the handler. Torez
> +      */
> +     if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
> +             dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
> +             do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
> +                          5);
> +             changed |= 0x01;
> +     }  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
> +             dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
> +             do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
> +                          6);
> +             changed |= 0x01;
> +     }  else if (debug_status & DBSR_IAC1) {
> +             current->thread.dbcr0 &= ~DBCR0_IAC1;
> +             do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
> +                          1);
> +             changed |= 0x01;
> +     }  else if (debug_status & DBSR_IAC2) {
> +             current->thread.dbcr0 &= ~DBCR0_IAC2;
> +             do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
> +                          2);
> +             changed |= 0x01;
> +     }  else if (debug_status & DBSR_IAC3) {
> +             current->thread.dbcr0 &= ~DBCR0_IAC3;
> +             do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
> +                          3);
> +             changed |= 0x01;
> +     }  else if (debug_status & DBSR_IAC4) {
> +             current->thread.dbcr0 &= ~DBCR0_IAC4;
> +             do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
> +                          4);
> +             changed |= 0x01;
> +     }
> +     /*
> +      * At the point this routine was called, the MSR(DE) was turned off.
> +      * Check all other debug flags and see if that bit needs to be turned
> +      * back on or not.
> +      */
> +     if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0, current->thread.dbcr1))
> +             regs->msr |= MSR_DE;
> +     else
> +             /* Make sure the IDM flag is off */
> +             current->thread.dbcr0 &= ~DBCR0_IDM;
> +
> +     if (changed & 0x01)
> +             mtspr(SPRN_DBCR0, current->thread.dbcr0);
> +}
> 
> void __kprobes DebugException(struct pt_regs *regs, unsigned long 
> debug_status)
> {
> +     current->thread.dbsr = debug_status;
> +
>       /* Hack alert: On BookE, Branch Taken stops on the branch itself, while
>        * on server, it stops on the target of the branch. In order to simulate
>        * the server behaviour, we thus restart right away with a single step
> @@ -1062,27 +1116,21 @@ void __kprobes DebugException(struct pt_regs *regs, 
> unsigned long debug_status)
>               if (debugger_sstep(regs))
>                       return;
> 
> -             if (user_mode(regs))
> -                     current->thread.dbcr0 &= ~(DBCR0_IC);
> -
> -             _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
> -     } else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
> -             regs->msr &= ~MSR_DE;
> -
>               if (user_mode(regs)) {
> -                     current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W |
> -                                                             DBCR0_IDM);
> -             } else {
> -                     /* Disable DAC interupts */
> -                     mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R |
> -                                             DBSR_DAC1W | DBCR0_IDM));
> -
> -                     /* Clear the DAC event */
> -                     mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W));
> +                     current->thread.dbcr0 &= ~DBCR0_IC;
> +#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
> +                     if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0,
> +                                            current->thread.dbcr1))
> +                             regs->msr |= MSR_DE;
> +                     else
> +                             /* Make sure the IDM bit is off */
> +                             current->thread.dbcr0 &= ~DBCR0_IDM;
> +#endif
>               }
> -             /* Setup and send the trap to the handler */
> -             do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
> -     }
> +
> +             _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
> +     } else
> +             handle_debug(regs, debug_status);
> }
> #endif /* CONFIG_4xx || CONFIG_BOOKE */
> 
> 
> -- 
> Dave Kleikamp
> IBM Linux Technology Center
> _______________________________________________
> Linuxppc-dev mailing list
> [email protected]
> https://lists.ozlabs.org/listinfo/linuxppc-dev

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