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Subject[PATCH 2/5] Powerpc/hw-breakpoint: Refactor hw_breakpoint_arch_parse()
Date
Move feature availability check at the start of the function.
Rearrange comment to it's associated code. Use hw->address and
hw->len in the 512 bytes boundary check(to write if statement
in a single line). Add spacing between code blocks.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
arch/powerpc/kernel/hw_breakpoint.c | 34 +++++++++++++++--------------
1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 1908e4fcc132..36bcf705df65 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -133,10 +133,13 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
const struct perf_event_attr *attr,
struct arch_hw_breakpoint *hw)
{
- int ret = -EINVAL, length_max;
+ int length_max;
+
+ if (!ppc_breakpoint_available())
+ return -ENODEV;

if (!bp)
- return ret;
+ return -EINVAL;

hw->type = HW_BRK_TYPE_TRANSLATE;
if (attr->bp_type & HW_BREAKPOINT_R)
@@ -145,34 +148,33 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
hw->type |= HW_BRK_TYPE_WRITE;
if (hw->type == HW_BRK_TYPE_TRANSLATE)
/* must set alteast read or write */
- return ret;
+ return -EINVAL;
+
if (!attr->exclude_user)
hw->type |= HW_BRK_TYPE_USER;
if (!attr->exclude_kernel)
hw->type |= HW_BRK_TYPE_KERNEL;
if (!attr->exclude_hv)
hw->type |= HW_BRK_TYPE_HYP;
+
hw->address = attr->bp_addr;
hw->len = attr->bp_len;

- /*
- * Since breakpoint length can be a maximum of HW_BREAKPOINT_LEN(8)
- * and breakpoint addresses are aligned to nearest double-word
- * HW_BREAKPOINT_ALIGN by rounding off to the lower address, the
- * 'symbolsize' should satisfy the check below.
- */
- if (!ppc_breakpoint_available())
- return -ENODEV;
length_max = 8; /* DABR */
if (dawr_enabled()) {
length_max = 512 ; /* 64 doublewords */
- /* DAWR region can't cross 512 boundary */
- if ((attr->bp_addr >> 9) !=
- ((attr->bp_addr + attr->bp_len - 1) >> 9))
+ /* DAWR region can't cross 512 bytes boundary */
+ if ((hw->address >> 9) != ((hw->address + hw->len - 1) >> 9))
return -EINVAL;
}
- if (hw->len >
- (length_max - (hw->address & HW_BREAKPOINT_ALIGN)))
+
+ /*
+ * Since breakpoint length can be a maximum of length_max and
+ * breakpoint addresses are aligned to nearest double-word
+ * HW_BREAKPOINT_ALIGN by rounding off to the lower address,
+ * the 'symbolsize' should satisfy the check below.
+ */
+ if (hw->len > (length_max - (hw->address & HW_BREAKPOINT_ALIGN)))
return -EINVAL;
return 0;
}
--
2.20.1
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