| Message ID | 20200717040958.70561-11-ravi.bangoria@linux.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc/watchpoint: Enable 2nd DAWR on baremetal and powervm | expand |
On Fri, Jul 17, 2020 at 2:11 PM Ravi Bangoria <ravi.bangoria@linux.ibm.com> wrote: > > Power10 has removed 512 bytes boundary from match criteria. i.e. The watch > range can cross 512 bytes boundary. It looks like this change is not mentioned in ISA v3.1 Book III 9.4 Data Address Watchpoint. It could be useful to mention that in the commit message. Also I wonder if could add a test for this to the ptrace-hwbreak selftest? > > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> > --- > arch/powerpc/kernel/hw_breakpoint.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c > index c55e67bab271..1f4a1efa0074 100644 > --- a/arch/powerpc/kernel/hw_breakpoint.c > +++ b/arch/powerpc/kernel/hw_breakpoint.c > @@ -418,8 +418,9 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw) > > if (dawr_enabled()) { > max_len = DAWR_MAX_LEN; > - /* DAWR region can't cross 512 bytes boundary */ > - if (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512)) > + /* DAWR region can't cross 512 bytes boundary on p10 predecessors */ > + if (!cpu_has_feature(CPU_FTR_ARCH_31) && > + (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512))) > return -EINVAL; > } else if (IS_ENABLED(CONFIG_PPC_8xx)) { > /* 8xx can setup a range without limitation */ > -- > 2.26.2 >
Hi Jordan, On 7/20/20 12:24 PM, Jordan Niethe wrote: > On Fri, Jul 17, 2020 at 2:11 PM Ravi Bangoria > <ravi.bangoria@linux.ibm.com> wrote: >> >> Power10 has removed 512 bytes boundary from match criteria. i.e. The watch >> range can cross 512 bytes boundary. > It looks like this change is not mentioned in ISA v3.1 Book III 9.4 > Data Address Watchpoint. It could be useful to mention that in the > commit message. Yes, ISA 3.1 Book III 9.4 has a documentation mistake and hopefully it will be fixed in the next version of ISA. Though, this is mentioned in ISA 3.1 change log: Multiple DEAW: Added a second Data Address Watchpoint. [H]DAR is set to the first byte of overlap. 512B boundary is removed. I'll mention this in the commit description. > Also I wonder if could add a test for this to the ptrace-hwbreak selftest? Yes, I already have a selftest for this in perf-hwbreak. Will send that soon. Thanks, Ravi
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index c55e67bab271..1f4a1efa0074 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -418,8 +418,9 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw) if (dawr_enabled()) { max_len = DAWR_MAX_LEN; - /* DAWR region can't cross 512 bytes boundary */ - if (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512)) + /* DAWR region can't cross 512 bytes boundary on p10 predecessors */ + if (!cpu_has_feature(CPU_FTR_ARCH_31) && + (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512))) return -EINVAL; } else if (IS_ENABLED(CONFIG_PPC_8xx)) { /* 8xx can setup a range without limitation */
Power10 has removed 512 bytes boundary from match criteria. i.e. The watch range can cross 512 bytes boundary. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> --- arch/powerpc/kernel/hw_breakpoint.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)