diff mbox series

[v5,10/10] powerpc/watchpoint: Remove 512 byte boundary

Message ID 20200723090813.303838-11-ravi.bangoria@linux.ibm.com (mailing list archive)
State Accepted
Commit 3f31e49dc4588d396023028791e36c23235e1334
Headers show
Series powerpc/watchpoint: Enable 2nd DAWR on baremetal and powervm | expand

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snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (d6c13d397d6988ec3e6029cae9e80501364cf9cb)
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Commit Message

Ravi Bangoria July 23, 2020, 9:08 a.m. UTC
Power10 has removed 512 bytes boundary from match criteria i.e. the watch
range can cross 512 bytes boundary.

Note: ISA 3.1 Book III 9.4 match criteria includes 512 byte limit but that
is a documentation mistake and hopefully will be fixed in the next version
of ISA. Though, ISA 3.1 change log mentions about removal of 512B boundary:

  Multiple DEAW:
  Added a second Data Address Watchpoint. [H]DAR is
  set to the first byte of overlap. 512B boundary is
  removed.

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 mbox series

Patch

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 */