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Re: [PATCH] Enable hw watchpoint with longer ranges using DAWR on Power
- From: Edjunior Barbosa Machado <emachado at linux dot vnet dot ibm dot com>
- To: gdb-patches at sourceware dot org
- Cc: Edjunior Barbosa Machado <emachado at linux dot vnet dot ibm dot com>, Ulrich dot Weigand at de dot ibm dot com, eliz at gnu dot org, lgustavo at codesourcery dot com
- Date: Tue, 16 Jul 2013 11:13:40 -0300
- Subject: Re: [PATCH] Enable hw watchpoint with longer ranges using DAWR on Power
Resending the patch rebased on current CVS head, with the latest updates on
gdb/ppc-linux-nat.c (thanks Ulrich for committing the patch renaming the
'booke' interface!).
Ok to commit?
Thanks,
--
Edjunior
gdb/ChangeLog
2013-07-16 Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>
* ppc-linux-nat.c (PPC_DEBUG_FEATURE_DATA_BP_DAWR): New define.
(ppc_linux_region_ok_for_hw_watchpoint): Add checking to use the new
DAWR interface for longer ranges hardware watchpoint (up to 512 bytes).
---
gdb/ppc-linux-nat.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/gdb/ppc-linux-nat.c b/gdb/ppc-linux-nat.c
index 4b3c78c..1f3f080 100644
--- a/gdb/ppc-linux-nat.c
+++ b/gdb/ppc-linux-nat.c
@@ -177,7 +177,11 @@ struct ppc_hw_breakpoint
(1<<((n)+PPC_BREAKPOINT_CONDITION_BE_SHIFT))
#endif /* PPC_PTRACE_GETHWDBGINFO */
-
+/* Feature defined on Linux kernel v3.9: DAWR interface, that enables wider
+ watchpoint (up to 512 bytes). */
+#ifndef PPC_DEBUG_FEATURE_DATA_BP_DAWR
+#define PPC_DEBUG_FEATURE_DATA_BP_DAWR 0x10
+#endif /* PPC_DEBUG_FEATURE_DATA_BP_DAWR */
/* Similarly for the general-purpose (gp0 -- gp31)
and floating-point registers (fp0 -- fp31). */
@@ -1504,6 +1508,7 @@ ppc_linux_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
watchpoints. */
if (have_ptrace_hwdebug_interface ())
{
+ int region_size;
/* Embedded DAC-based processors, like the PowerPC 440 have ranged
watchpoints and can watch any access within an arbitrary memory
region. This is useful to watch arrays and structs, for instance. It
@@ -1512,11 +1517,17 @@ ppc_linux_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
&& hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_RANGE
&& ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE)
return 2;
+ /* Check if the processor provides DAWR interface. */
+ if (hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_DAWR)
+ /* DAWR interface allows to watch up to 512 byte wide ranges which
+ can't cross a 512 byte boundary. */
+ region_size = 512;
+ else
+ region_size = hwdebug_info.data_bp_alignment;
/* Server processors provide one hardware watchpoint and addr+len should
fall in the watchable region provided by the ptrace interface. */
- if (hwdebug_info.data_bp_alignment
- && (addr + len > (addr & ~(hwdebug_info.data_bp_alignment - 1))
- + hwdebug_info.data_bp_alignment))
+ if (region_size
+ && (addr + len > (addr & ~(region_size - 1)) + region_size))
return 0;
}
/* addr+len must fall in the 8 byte watchable region for DABR-based
--
1.8.2.1