diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-11-26 17:43:29 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-01-23 21:31:14 +1100 |
| commit | 39413ae009674c6ba745850515b551bbb9d6374b (patch) | |
| tree | b743c9950361f2d2246166aac9ad2554be1dc28d /arch/powerpc/kernel/hw_breakpoint.c | |
| parent | 991d656d722dbc783481f408d6e4cbcce2e8bb78 (diff) | |
powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.
Unlike standard powerpc, Powerpc 8xx doesn't have SPRN_DABR, but
it has a breakpoint support based on a set of comparators which
allow more flexibility.
Commit 4ad8622dc548 ("powerpc/8xx: Implement hw_breakpoint")
implemented breakpoints by emulating the DABR behaviour. It did
this by setting one comparator the match 4 bytes at breakpoint address
and the other comparator to match 4 bytes at breakpoint address + 4.
Rewrite 8xx hw_breakpoint to make breakpoints match all addresses
defined by the breakpoint address and length by making full use of
comparators.
Now, comparator E is set to match any address greater than breakpoint
address minus one. Comparator F is set to match any address lower than
breakpoint address plus breakpoint length. Addresses are aligned
to 32 bits.
When the breakpoint range starts at address 0, the breakpoint is set
to match comparator F only. When the breakpoint range end at address
0xffffffff, the breakpoint is set to match comparator E only.
Otherwise the breakpoint is set to match comparator E and F.
At the same time, use registers bit names instead of hardcoded values.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/05105deeaf63bc02151aea2cdeaf525534e0e9d4.1574790198.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/powerpc/kernel/hw_breakpoint.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 58ce3d37c2a3..2462cd7c565c 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -160,6 +160,9 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw) /* DAWR region can't cross 512 bytes boundary */ if ((start_addr >> 9) != (end_addr >> 9)) return -EINVAL; + } else if (IS_ENABLED(CONFIG_PPC_8xx)) { + /* 8xx can setup a range without limitation */ + max_len = U16_MAX; } if (hw_len > max_len) @@ -328,13 +331,11 @@ int hw_breakpoint_handler(struct die_args *args) } info->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ; - if (IS_ENABLED(CONFIG_PPC_8xx)) { - if (!dar_within_range(regs->dar, info)) - info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ; - } else { - if (!stepping_handler(regs, bp, info)) - goto out; - } + if (!dar_within_range(regs->dar, info)) + info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ; + + if (!IS_ENABLED(CONFIG_PPC_8xx) && !stepping_handler(regs, bp, info)) + goto out; /* * As a policy, the callback is invoked in a 'trigger-after-execute' |