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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 11:30:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 11:30:02 -0800
commitb1286f4e9ac14c8973140b338b4d3c5691264d3b (patch)
tree5a67788bb2276cd67230d24b5a6994ddafb10707 /arch/arm/kernel/hw_breakpoint.c
parent6facac1ab68fbf9cbad31a9d521f3a0d6aa9470e (diff)
parent0fa5d3996dbda1ee9653c43d39b7ef159fb57ee7 (diff)
downloadtalos-op-linux-b1286f4e9ac14c8973140b338b4d3c5691264d3b.tar.gz
talos-op-linux-b1286f4e9ac14c8973140b338b4d3c5691264d3b.zip
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King: "Here's the updates for ARM for this merge window, which cover quite a variety of areas. There's a bunch of patch series from Will tackling various bugs like the PROT_NONE handling, ASID allocation, cluster boot protocol and ASID TLB tagging updates. We move to a build-time sorted exception table rather than doing the sorting at run-time, add support for the secure computing filter, and some updates to the perf code. We also have sorted out the placement of some headers, fixed some build warnings, fixed some hotplug problems with the per-cpu TWD code." * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (73 commits) ARM: 7594/1: Add .smp entry for REALVIEW_EB ARM: 7599/1: head: Remove boot-time HYP mode check for v5 and below ARM: 7598/1: net: bpf_jit_32: fix sp-relative load/stores offsets. ARM: 7595/1: syscall: rework ordering in syscall_trace_exit ARM: 7596/1: mmci: replace readsl/writesl with ioread32_rep/iowrite32_rep ARM: 7597/1: net: bpf_jit_32: fix kzalloc gfp/size mismatch. ARM: 7593/1: nommu: do not enable DCACHE_WORD_ACCESS when !CONFIG_MMU ARM: 7592/1: nommu: prevent generation of kernel unaligned memory accesses ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6 ARM: 7590/1: /proc/interrupts: limit the display of IPIs to online CPUs only ARM: 7587/1: implement optimized percpu variable access ARM: 7589/1: integrator: pass the lm resource to amba ARM: 7588/1: amba: create a resource parent registrator ARM: 7582/2: rename kvm_seq to vmalloc_seq so to avoid confusion with KVM ARM: 7585/1: kernel: fix nr_cpu_ids check in DT logical map init ARM: 7584/1: perf: fix link error when CONFIG_HW_PERF_EVENTS is not selected ARM: gic: use a private mapping for CPU target interfaces ARM: kernel: add logical mappings look-up ARM: kernel: add cpu logical map DT init in setup_arch ARM: kernel: add device tree init map function ...
Diffstat (limited to 'arch/arm/kernel/hw_breakpoint.c')
-rw-r--r--arch/arm/kernel/hw_breakpoint.c154
1 files changed, 85 insertions, 69 deletions
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,
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