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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-11-19 12:23:08 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-11-19 12:23:08 +0100 |
commit | c71d4aa7e98f30d4011b44b168263abc72f676bd (patch) | |
tree | 3daa760c738a6e90f8af4b9ff163e608f10884e4 /arch | |
parent | Merge branch 'perf/updates' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff) | |
parent | ARM: cti: fix manipulation of debug lock registers (diff) | |
download | linux-c71d4aa7e98f30d4011b44b168263abc72f676bd.tar.xz linux-c71d4aa7e98f30d4011b44b168263abc72f676bd.zip |
Merge branch 'hw-breakpoint' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/include/asm/cti.h | 20 | ||||
-rw-r--r-- | arch/arm/include/asm/hw_breakpoint.h | 8 | ||||
-rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 154 |
3 files changed, 91 insertions, 91 deletions
diff --git a/arch/arm/include/asm/cti.h b/arch/arm/include/asm/cti.h index a0ada3ea4358..f2e5cad3f306 100644 --- a/arch/arm/include/asm/cti.h +++ b/arch/arm/include/asm/cti.h @@ -146,15 +146,7 @@ static inline void cti_irq_ack(struct cti *cti) */ static inline void cti_unlock(struct cti *cti) { - void __iomem *base = cti->base; - unsigned long val; - - val = __raw_readl(base + LOCKSTATUS); - - if (val & 1) { - val = LOCKCODE; - __raw_writel(val, base + LOCKACCESS); - } + __raw_writel(LOCKCODE, cti->base + LOCKACCESS); } /** @@ -166,14 +158,6 @@ static inline void cti_unlock(struct cti *cti) */ static inline void cti_lock(struct cti *cti) { - void __iomem *base = cti->base; - unsigned long val; - - val = __raw_readl(base + LOCKSTATUS); - - if (!(val & 1)) { - val = ~LOCKCODE; - __raw_writel(val, base + LOCKACCESS); - } + __raw_writel(~LOCKCODE, cti->base + LOCKACCESS); } #endif diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h index c190bc992f0e..01169dd723f1 100644 --- a/arch/arm/include/asm/hw_breakpoint.h +++ b/arch/arm/include/asm/hw_breakpoint.h @@ -98,12 +98,12 @@ static inline void decode_ctrl_reg(u32 reg, #define ARM_BASE_WCR 112 /* Accessor macros for the debug registers. */ -#define ARM_DBG_READ(M, OP2, VAL) do {\ - asm volatile("mrc p14, 0, %0, c0," #M ", " #OP2 : "=r" (VAL));\ +#define ARM_DBG_READ(N, M, OP2, VAL) do {\ + asm volatile("mrc p14, 0, %0, " #N "," #M ", " #OP2 : "=r" (VAL));\ } while (0) -#define ARM_DBG_WRITE(M, OP2, VAL) do {\ - asm volatile("mcr p14, 0, %0, c0," #M ", " #OP2 : : "r" (VAL));\ +#define ARM_DBG_WRITE(N, M, OP2, VAL) do {\ + asm volatile("mcr p14, 0, %0, " #N "," #M ", " #OP2 : : "r" (VAL));\ } while (0) struct notifier_block; diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 281bf3301241..5ff2e77782b1 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -52,14 +52,14 @@ static u8 debug_arch; /* Maximum supported watchpoint length. */ static u8 max_watchpoint_len; -#define READ_WB_REG_CASE(OP2, M, VAL) \ - case ((OP2 << 4) + M): \ - ARM_DBG_READ(c ## M, OP2, VAL); \ +#define READ_WB_REG_CASE(OP2, M, VAL) \ + case ((OP2 << 4) + M): \ + ARM_DBG_READ(c0, c ## M, OP2, VAL); \ break -#define WRITE_WB_REG_CASE(OP2, M, VAL) \ - case ((OP2 << 4) + M): \ - ARM_DBG_WRITE(c ## M, OP2, VAL);\ +#define WRITE_WB_REG_CASE(OP2, M, VAL) \ + case ((OP2 << 4) + M): \ + ARM_DBG_WRITE(c0, c ## M, OP2, VAL); \ break #define GEN_READ_WB_REG_CASES(OP2, VAL) \ @@ -136,12 +136,12 @@ static u8 get_debug_arch(void) /* Do we implement the extended CPUID interface? */ if (((read_cpuid_id() >> 16) & 0xf) != 0xf) { - pr_warning("CPUID feature registers not supported. " - "Assuming v6 debug is present.\n"); + pr_warn_once("CPUID feature registers not supported. " + "Assuming v6 debug is present.\n"); return ARM_DEBUG_ARCH_V6; } - ARM_DBG_READ(c0, 0, didr); + ARM_DBG_READ(c0, c0, 0, didr); return (didr >> 16) & 0xf; } @@ -169,7 +169,7 @@ static int debug_exception_updates_fsr(void) static int get_num_wrp_resources(void) { u32 didr; - ARM_DBG_READ(c0, 0, didr); + ARM_DBG_READ(c0, c0, 0, didr); return ((didr >> 28) & 0xf) + 1; } @@ -177,7 +177,7 @@ static int get_num_wrp_resources(void) static int get_num_brp_resources(void) { u32 didr; - ARM_DBG_READ(c0, 0, didr); + ARM_DBG_READ(c0, c0, 0, didr); return ((didr >> 24) & 0xf) + 1; } @@ -228,19 +228,17 @@ static int get_num_brps(void) * be put into halting debug mode at any time by an external debugger * but there is nothing we can do to prevent that. */ -static int enable_monitor_mode(void) +static int monitor_mode_enabled(void) { u32 dscr; - int ret = 0; - - ARM_DBG_READ(c1, 0, dscr); + ARM_DBG_READ(c0, c1, 0, dscr); + return !!(dscr & ARM_DSCR_MDBGEN); +} - /* Ensure that halting mode is disabled. */ - if (WARN_ONCE(dscr & ARM_DSCR_HDBGEN, - "halting debug mode enabled. Unable to access hardware resources.\n")) { - ret = -EPERM; - goto out; - } +static int enable_monitor_mode(void) +{ + u32 dscr; + ARM_DBG_READ(c0, c1, 0, dscr); /* If monitor mode is already enabled, just return. */ if (dscr & ARM_DSCR_MDBGEN) @@ -250,24 +248,27 @@ static int enable_monitor_mode(void) switch (get_debug_arch()) { case ARM_DEBUG_ARCH_V6: case ARM_DEBUG_ARCH_V6_1: - ARM_DBG_WRITE(c1, 0, (dscr | ARM_DSCR_MDBGEN)); + ARM_DBG_WRITE(c0, c1, 0, (dscr | ARM_DSCR_MDBGEN)); break; case ARM_DEBUG_ARCH_V7_ECP14: case ARM_DEBUG_ARCH_V7_1: - ARM_DBG_WRITE(c2, 2, (dscr | ARM_DSCR_MDBGEN)); + ARM_DBG_WRITE(c0, c2, 2, (dscr | ARM_DSCR_MDBGEN)); + isb(); break; default: - ret = -ENODEV; - goto out; + return -ENODEV; } /* Check that the write made it through. */ - ARM_DBG_READ(c1, 0, dscr); - if (!(dscr & ARM_DSCR_MDBGEN)) - ret = -EPERM; + ARM_DBG_READ(c0, c1, 0, dscr); + if (!(dscr & ARM_DSCR_MDBGEN)) { + pr_warn_once("Failed to enable monitor mode on CPU %d.\n", + smp_processor_id()); + return -EPERM; + } out: - return ret; + return 0; } int hw_breakpoint_slots(int type) @@ -328,14 +329,9 @@ int arch_install_hw_breakpoint(struct perf_event *bp) { struct arch_hw_breakpoint *info = counter_arch_bp(bp); struct perf_event **slot, **slots; - int i, max_slots, ctrl_base, val_base, ret = 0; + int i, max_slots, ctrl_base, val_base; u32 addr, ctrl; - /* Ensure that we are in monitor mode and halting mode is disabled. */ - ret = enable_monitor_mode(); - if (ret) - goto out; - addr = info->address; ctrl = encode_ctrl_reg(info->ctrl) | 0x1; @@ -362,9 +358,9 @@ int arch_install_hw_breakpoint(struct perf_event *bp) } } - if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n")) { - ret = -EBUSY; - goto out; + if (i == max_slots) { + pr_warning("Can't find any breakpoint slot\n"); + return -EBUSY; } /* Override the breakpoint data with the step data. */ @@ -383,9 +379,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) /* Setup the control register. */ write_wb_reg(ctrl_base + i, ctrl); - -out: - return ret; + return 0; } void arch_uninstall_hw_breakpoint(struct perf_event *bp) @@ -416,8 +410,10 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp) } } - if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n")) + if (i == max_slots) { + pr_warning("Can't find any breakpoint slot\n"); return; + } /* Ensure that we disable the mismatch breakpoint. */ if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE && @@ -596,6 +592,10 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) int ret = 0; u32 offset, alignment_mask = 0x3; + /* Ensure that we are in monitor debug mode. */ + if (!monitor_mode_enabled()) + return -ENODEV; + /* Build the arch_hw_breakpoint. */ ret = arch_build_bp_info(bp); if (ret) @@ -858,7 +858,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr, local_irq_enable(); /* We only handle watchpoints and hardware breakpoints. */ - ARM_DBG_READ(c1, 0, dscr); + ARM_DBG_READ(c0, c1, 0, dscr); /* Perform perf callbacks. */ switch (ARM_DSCR_MOE(dscr)) { @@ -906,7 +906,7 @@ static struct undef_hook debug_reg_hook = { static void reset_ctrl_regs(void *unused) { int i, raw_num_brps, err = 0, cpu = smp_processor_id(); - u32 dbg_power; + u32 val; /* * v7 debug contains save and restore registers so that debug state @@ -919,23 +919,30 @@ static void reset_ctrl_regs(void *unused) switch (debug_arch) { case ARM_DEBUG_ARCH_V6: case ARM_DEBUG_ARCH_V6_1: - /* ARMv6 cores just need to reset the registers. */ - goto reset_regs; + /* ARMv6 cores clear the registers out of reset. */ + goto out_mdbgen; case ARM_DEBUG_ARCH_V7_ECP14: /* * Ensure sticky power-down is clear (i.e. debug logic is * powered up). */ - asm volatile("mrc p14, 0, %0, c1, c5, 4" : "=r" (dbg_power)); - if ((dbg_power & 0x1) == 0) + ARM_DBG_READ(c1, c5, 4, val); + if ((val & 0x1) == 0) err = -EPERM; + + /* + * Check whether we implement OS save and restore. + */ + ARM_DBG_READ(c1, c1, 4, val); + if ((val & 0x9) == 0) + goto clear_vcr; break; case ARM_DEBUG_ARCH_V7_1: /* * Ensure the OS double lock is clear. */ - asm volatile("mrc p14, 0, %0, c1, c3, 4" : "=r" (dbg_power)); - if ((dbg_power & 0x1) == 1) + ARM_DBG_READ(c1, c3, 4, val); + if ((val & 0x1) == 1) err = -EPERM; break; } @@ -947,24 +954,29 @@ static void reset_ctrl_regs(void *unused) } /* - * Unconditionally clear the lock by writing a value + * Unconditionally clear the OS lock by writing a value * other than 0xC5ACCE55 to the access register. */ - asm volatile("mcr p14, 0, %0, c1, c0, 4" : : "r" (0)); + ARM_DBG_WRITE(c1, c0, 4, 0); isb(); /* * Clear any configured vector-catch events before * enabling monitor mode. */ - asm volatile("mcr p14, 0, %0, c0, c7, 0" : : "r" (0)); +clear_vcr: + ARM_DBG_WRITE(c0, c7, 0, 0); isb(); -reset_regs: - if (enable_monitor_mode()) + if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) { + pr_warning("CPU %d failed to disable vector catch\n", cpu); return; + } - /* We must also reset any reserved registers. */ + /* + * The control/value register pairs are UNKNOWN out of reset so + * clear them to avoid spurious debug events. + */ raw_num_brps = get_num_brp_resources(); for (i = 0; i < raw_num_brps; ++i) { write_wb_reg(ARM_BASE_BCR + i, 0UL); @@ -975,6 +987,19 @@ reset_regs: write_wb_reg(ARM_BASE_WCR + i, 0UL); write_wb_reg(ARM_BASE_WVR + i, 0UL); } + + if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) { + pr_warning("CPU %d failed to clear debug register pairs\n", cpu); + return; + } + + /* + * Have a crack at enabling monitor mode. We don't actually need + * it yet, but reporting an error early is useful if it fails. + */ +out_mdbgen: + if (enable_monitor_mode()) + cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu)); } static int __cpuinit dbg_reset_notify(struct notifier_block *self, @@ -992,8 +1017,6 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = { static int __init arch_hw_breakpoint_init(void) { - u32 dscr; - debug_arch = get_debug_arch(); if (!debug_arch_supported()) { @@ -1028,17 +1051,10 @@ static int __init arch_hw_breakpoint_init(void) core_num_brps, core_has_mismatch_brps() ? "(+1 reserved) " : "", core_num_wrps); - ARM_DBG_READ(c1, 0, dscr); - if (dscr & ARM_DSCR_HDBGEN) { - max_watchpoint_len = 4; - pr_warning("halting debug mode enabled. Assuming maximum watchpoint size of %u bytes.\n", - max_watchpoint_len); - } else { - /* Work out the maximum supported watchpoint length. */ - max_watchpoint_len = get_max_wp_len(); - pr_info("maximum watchpoint size is %u bytes.\n", - max_watchpoint_len); - } + /* Work out the maximum supported watchpoint length. */ + max_watchpoint_len = get_max_wp_len(); + pr_info("maximum watchpoint size is %u bytes.\n", + max_watchpoint_len); /* Register debug fault handler. */ hook_fault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP, |