powerpc: BookE hardware watchpoint support

This patch implements support for HW based watchpoint via the
DBSR_DAC (Data Address Compare) facility of the BookE processors.

It does so by interfacing with the existing DABR breakpoint code
and adding the necessary bits and pieces for the new bits to
be properly set or cleared

Signed-off-by: Luis Machado <luisgpm@br.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Luis Machado
2008-07-24 02:10:41 +10:00
committed by Benjamin Herrenschmidt
parent 00bf6e9061
commit d6a61bfc06
7 changed files with 138 additions and 35 deletions

View File

@@ -1067,6 +1067,22 @@ void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
}
_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));
}
/* Setup and send the trap to the handler */
do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
}
}
#endif /* CONFIG_4xx || CONFIG_BOOKE */