From: "Suzuki K. Poulose" <suzuki.poul...@arm.com>
Use the system wide value of ID_AA64DFR0 to make safer decisions
Signed-off-by: Suzuki K. Poulose <suzuki.poul...@arm.com>
---
arch/arm64/include/asm/hw_breakpoint.h | 14 ++------------
arch/arm64/kernel/debug-monitors.c | 6 ++++--
arch/arm64/kernel/hw_breakpoint.c | 19 ++++++++++++++++++-
3 files changed, 24 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/include/asm/hw_breakpoint.h
b/arch/arm64/include/asm/hw_breakpoint.h
index 4c47cb2..0251768 100644
--- a/arch/arm64/include/asm/hw_breakpoint.h
+++ b/arch/arm64/include/asm/hw_breakpoint.h
@@ -119,6 +119,8 @@ extern int arch_install_hw_breakpoint(struct perf_event
*bp);
extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
extern void hw_breakpoint_pmu_read(struct perf_event *bp);
extern int hw_breakpoint_slots(int type);
+extern int get_num_brps(void);
+extern int get_num_wrps(void);
#ifdef CONFIG_HAVE_HW_BREAKPOINT
extern void hw_breakpoint_thread_switch(struct task_struct *next);
@@ -134,17 +136,5 @@ static inline void ptrace_hw_copy_thread(struct
task_struct *task)
extern struct pmu perf_ops_bp;
-/* Determine number of BRP registers available. */
-static inline int get_num_brps(void)
-{
- return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1;
-}
-
-/* Determine number of WRP registers available. */
-static inline int get_num_wrps(void)
-{
- return ((read_cpuid(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1;
-}
-
#endif /* __KERNEL__ */
#endif /* __ASM_BREAKPOINT_H */
diff --git a/arch/arm64/kernel/debug-monitors.c
b/arch/arm64/kernel/debug-monitors.c
index 9b3b62a..9ca5f77 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -26,14 +26,16 @@
#include <linux/stat.h>
#include <linux/uaccess.h>
-#include <asm/debug-monitors.h>
+#include <asm/cpufeature.h>
#include <asm/cputype.h>
+#include <asm/debug-monitors.h>
#include <asm/system_misc.h>
/* Determine debug architecture. */
u8 debug_monitors_arch(void)
{
- return read_cpuid(ID_AA64DFR0_EL1) & 0xf;
+ return cpuid_feature_extract_field(read_system_reg(SYS_ID_AA64DFR0_EL1),
+ ID_AA64DFR0_DEBUGVER_SHIFT);
}
/*
diff --git a/arch/arm64/kernel/hw_breakpoint.c
b/arch/arm64/kernel/hw_breakpoint.c
index c97040e..1fa0476 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -28,11 +28,12 @@
#include <linux/ptrace.h>
#include <linux/smp.h>
+#include <asm/cpufeature.h>
+#include <asm/cputype.h>
#include <asm/current.h>
#include <asm/debug-monitors.h>
#include <asm/hw_breakpoint.h>
#include <asm/traps.h>
-#include <asm/cputype.h>
#include <asm/system_misc.h>
/* Breakpoint currently in use for each BRP. */
@@ -48,6 +49,22 @@ static DEFINE_PER_CPU(int, stepping_kernel_bp);
static int core_num_brps;
static int core_num_wrps;
+/* Determine number of BRP registers available. */
+int get_num_brps(void)
+{
+ return 1 +
+
cpuid_feature_extract_field(read_system_reg(SYS_ID_AA64DFR0_EL1),
+ ID_AA64DFR0_BRPS_SHIFT);
+}
+
+/* Determine number of WRP registers available. */
+int get_num_wrps(void)
+{
+ return 1 +
+
cpuid_feature_extract_field(read_system_reg(SYS_ID_AA64DFR0_EL1),
+ ID_AA64DFR0_WRPS_SHIFT);
+}
+
int hw_breakpoint_slots(int type)
{
/*
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
