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Date: Wed, 16 Sep 2015 15:21:14 +0100 From: "Suzuki K. Poulose" <suzuki.poulose@....com> To: linux-arm-kernel@...ts.infradead.org Cc: Catalin.Marinas@....com, Will.Deacon@....com, Mark.Rutland@....com, edward.nevill@...aro.org, aph@...hat.com, linux-kernel@...r.kernel.org, andre.przywara@....com, ard.biesheuvel@...aro.org, dave.martin@....com, marc.zyngier@....com, "Suzuki K. Poulose" <suzuki.poulose@....com> Subject: [PATCH 16/22] arm64/debug: Make use of the system wide safe value From: "Suzuki K. Poulose" <suzuki.poulose@....com> Use the system wide value of ID_AA64DFR0 to make safer decisions Signed-off-by: Suzuki K. Poulose <suzuki.poulose@....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 majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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