Implement hardware breakpoint address mask for AMD Family 16h (and
any other future) processors. CPUID feature bit indicates the hardware
support for DRn_ADDR_MASK MSRs.
Signed-off-by: Jacob Shin <jacob.s...@amd.com>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/cpufeature.h | 2 ++
arch/x86/include/asm/debugreg.h | 7 +++++++
arch/x86/include/asm/hw_breakpoint.h | 6 ++++++
arch/x86/include/uapi/asm/msr-index.h | 6 ++++++
arch/x86/kernel/cpu/amd.c | 19 +++++++++++++++++++
arch/x86/kernel/hw_breakpoint.c | 5 +++++
7 files changed, 46 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 70c0f3d..eee63f8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -65,6 +65,7 @@ config X86
select HAVE_KERNEL_XZ
select HAVE_KERNEL_LZO
select HAVE_HW_BREAKPOINT
+ select HAVE_HW_BREAKPOINT_ADDR_MASK
select HAVE_MIXED_BREAKPOINTS_REGS
select PERF_EVENTS
select HAVE_PERF_EVENTS_NMI
diff --git a/arch/x86/include/asm/cpufeature.h
b/arch/x86/include/asm/cpufeature.h
index 93fe929..eb4f3a7 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -168,6 +168,7 @@
#define X86_FEATURE_TOPOEXT (6*32+22) /* topology extensions CPUID leafs */
#define X86_FEATURE_PERFCTR_CORE (6*32+23) /* core performance counter
extensions */
#define X86_FEATURE_PERFCTR_NB (6*32+24) /* NB performance counter extensions
*/
+#define X86_FEATURE_BPEXT (6*32+26) /* data breakpoint extension */
/*
* Auxiliary flags: Linux defined - For features scattered in various
@@ -315,6 +316,7 @@ extern const char * const x86_power_flags[32];
#define cpu_has_cx16 boot_cpu_has(X86_FEATURE_CX16)
#define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU)
#define cpu_has_topoext boot_cpu_has(X86_FEATURE_TOPOEXT)
+#define cpu_has_bpext boot_cpu_has(X86_FEATURE_BPEXT)
#ifdef CONFIG_X86_64
diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
index 4b528a9..bb48949 100644
--- a/arch/x86/include/asm/debugreg.h
+++ b/arch/x86/include/asm/debugreg.h
@@ -114,5 +114,12 @@ static inline void debug_stack_usage_inc(void) { }
static inline void debug_stack_usage_dec(void) { }
#endif /* X86_64 */
+#ifdef CONFIG_CPU_SUP_AMD
+extern void set_dr_addr_mask(u32 mask, int dr);
+#else
+static inline void set_dr_addr_mask(u32 mask, int dr)
+{
+}
+#endif
#endif /* _ASM_X86_DEBUGREG_H */
diff --git a/arch/x86/include/asm/hw_breakpoint.h
b/arch/x86/include/asm/hw_breakpoint.h
index ef1c4d2..c939415 100644
--- a/arch/x86/include/asm/hw_breakpoint.h
+++ b/arch/x86/include/asm/hw_breakpoint.h
@@ -14,6 +14,7 @@ struct arch_hw_breakpoint {
unsigned long address;
u8 len;
u8 type;
+ u32 mask;
};
#include <linux/kdebug.h>
@@ -72,4 +73,9 @@ extern int arch_bp_generic_fields(int x86_len, int x86_type,
extern struct pmu perf_ops_bp;
+static inline int arch_has_hw_breakpoint_addr_mask(void)
+{
+ return cpu_has_bpext;
+}
+
#endif /* _I386_HW_BREAKPOINT_H */
diff --git a/arch/x86/include/uapi/asm/msr-index.h
b/arch/x86/include/uapi/asm/msr-index.h
index bf7bb68..b0b9335 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -196,6 +196,12 @@
#define MSR_AMD64_IBSBRTARGET 0xc001103b
#define MSR_AMD64_IBS_REG_COUNT_MAX 8 /* includes MSR_AMD64_IBSBRTARGET */
+/* Fam 16h MSRs */
+#define MSR_F16H_DR0_ADDR_MASK 0xc0011027
+#define MSR_F16H_DR1_ADDR_MASK 0xc0011019
+#define MSR_F16H_DR2_ADDR_MASK 0xc001101a
+#define MSR_F16H_DR3_ADDR_MASK 0xc001101b
+
/* Fam 15h MSRs */
#define MSR_F15H_PERF_CTL 0xc0010200
#define MSR_F15H_PERF_CTR 0xc0010201
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index fa96eb0..aadc499 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -910,3 +910,22 @@ bool cpu_has_amd_erratum(const int *erratum)
}
EXPORT_SYMBOL_GPL(cpu_has_amd_erratum);
+
+void set_dr_addr_mask(u32 mask, int dr)
+{
+ if (!cpu_has_bpext)
+ return;
+
+ switch (dr) {
+ case 0:
+ wrmsr(MSR_F16H_DR0_ADDR_MASK, mask, 0);
+ break;
+ case 1:
+ case 2:
+ case 3:
+ wrmsr(MSR_F16H_DR1_ADDR_MASK - 1 + dr, mask, 0);
+ break;
+ default:
+ break;
+ }
+}
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 02f0763..f8bf2df 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -121,6 +121,8 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot"))
return -EBUSY;
+ set_dr_addr_mask(info->mask, i);
+
set_debugreg(info->address, i);
__this_cpu_write(cpu_debugreg[i], info->address);
@@ -163,6 +165,8 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
*dr7 &= ~__encode_dr7(i, info->len, info->type);
set_debugreg(*dr7, 7);
+
+ set_dr_addr_mask(0, i);
}
static int get_hbp_len(u8 hbp_len)
@@ -254,6 +258,7 @@ static int arch_build_bp_info(struct perf_event *bp)
struct arch_hw_breakpoint *info = counter_arch_bp(bp);
info->address = bp->attr.bp_addr;
+ info->mask = bp->attr.bp_addr_mask;
/* Type */
switch (bp->attr.bp_type) {
--
1.7.9.5
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