On Thu, Apr 06, 2017 at 09:30:59PM +0800, Leo Yan wrote: > Coresight includes debug module and usually the module connects with CPU > debug logic. ARMv8 architecture reference manual (ARM DDI 0487A.k) has > description for related info in "Part H: External Debug". > > Chapter H7 "The Sample-based Profiling Extension" introduces several > sampling registers, e.g. we can check program counter value with > combined CPU exception level, secure state, etc. So this is helpful for > analysis CPU lockup scenarios, e.g. if one CPU has run into infinite > loop with IRQ disabled. In this case the CPU cannot switch context and > handle any interrupt (including IPIs), as the result it cannot handle > SMP call for stack dump. > > This patch is to enable coresight debug module, so firstly this driver > is to bind apb clock for debug module and this is to ensure the debug > module can be accessed from program or external debugger. And the driver > uses sample-based registers for debug purpose, e.g. when system triggers > panic, the driver will dump program counter and combined context > registers (EDCIDSR, EDVIDSR); by parsing context registers so can > quickly get to know CPU secure state, exception level, etc. > > Some of the debug module registers are located in CPU power domain, so > this requires the CPU power domain stays on when access related debug > registers, but the power management for CPU power domain is quite > dependent on SoC integration for power management. For the platforms > which with sane power controller implementations, this driver follows > the method to set EDPRCR to try to pull the CPU out of low power state > and then set 'no power down request' bit so the CPU has no chance to > lose power. > > If the SoC has not followed up this design well for power management > controller, the user should use the command line parameter or sysfs > to constrain all or partial idle states to ensure the CPU power > domain is enabled and access coresight CPU debug component safely. > > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx> This is coming along well - a few comment below. In your next revision please add GKH to the 'To' list. Thanks, Mathieu > --- > drivers/hwtracing/coresight/Kconfig | 14 + > drivers/hwtracing/coresight/Makefile | 1 + > drivers/hwtracing/coresight/coresight-cpu-debug.c | 667 ++++++++++++++++++++++ > 3 files changed, 682 insertions(+) > create mode 100644 drivers/hwtracing/coresight/coresight-cpu-debug.c > > diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig > index 130cb21..8d55d6d 100644 > --- a/drivers/hwtracing/coresight/Kconfig > +++ b/drivers/hwtracing/coresight/Kconfig > @@ -89,4 +89,18 @@ config CORESIGHT_STM > logging useful software events or data coming from various entities > in the system, possibly running different OSs > > +config CORESIGHT_CPU_DEBUG > + tristate "CoreSight CPU Debug driver" > + depends on ARM || ARM64 > + depends on DEBUG_FS > + help > + This driver provides support for coresight debugging module. This > + is primarily used to dump sample-based profiling registers when > + system triggers panic, the driver will parse context registers so > + can quickly get to know program counter (PC), secure state, > + exception level, etc. Before use debugging functionality, platform > + needs to ensure the clock domain and power domain are enabled > + properly, please refer Documentation/trace/coresight-cpu-debug.txt > + for detailed description and the example for usage. > + > endif > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile > index af480d9..433d590 100644 > --- a/drivers/hwtracing/coresight/Makefile > +++ b/drivers/hwtracing/coresight/Makefile > @@ -16,3 +16,4 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \ > coresight-etm4x-sysfs.o > obj-$(CONFIG_CORESIGHT_QCOM_REPLICATOR) += coresight-replicator-qcom.o > obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o > +obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o > diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c > new file mode 100644 > index 0000000..8470e31 > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c > @@ -0,0 +1,667 @@ > +/* > + * Copyright (c) 2017 Linaro Limited. All rights reserved. > + * > + * Author: Leo Yan <leo.yan@xxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License version 2 as published by > + * the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + * > + */ > +#include <linux/amba/bus.h> > +#include <linux/coresight.h> > +#include <linux/cpu.h> > +#include <linux/debugfs.h> > +#include <linux/delay.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/iopoll.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/pm_qos.h> > +#include <linux/slab.h> > +#include <linux/smp.h> > +#include <linux/types.h> > +#include <linux/uaccess.h> > + > +#include "coresight-priv.h" > + > +#define EDPCSR 0x0A0 > +#define EDCIDSR 0x0A4 > +#define EDVIDSR 0x0A8 > +#define EDPCSR_HI 0x0AC > +#define EDOSLAR 0x300 > +#define EDPRCR 0x310 > +#define EDPRSR 0x314 > +#define EDDEVID1 0xFC4 > +#define EDDEVID 0xFC8 > + > +#define EDPCSR_PROHIBITED 0xFFFFFFFF > + > +/* bits definition for EDPCSR */ > +#define EDPCSR_THUMB BIT(0) > +#define EDPCSR_ARM_INST_MASK GENMASK(31, 2) > +#define EDPCSR_THUMB_INST_MASK GENMASK(31, 1) > + > +/* bits definition for EDPRCR */ > +#define EDPRCR_COREPURQ BIT(3) > +#define EDPRCR_CORENPDRQ BIT(0) > + > +/* bits definition for EDPRSR */ > +#define EDPRSR_DLK BIT(6) > +#define EDPRSR_PU BIT(0) > + > +/* bits definition for EDVIDSR */ > +#define EDVIDSR_NS BIT(31) > +#define EDVIDSR_E2 BIT(30) > +#define EDVIDSR_E3 BIT(29) > +#define EDVIDSR_HV BIT(28) > +#define EDVIDSR_VMID GENMASK(7, 0) > + > +/* > + * bits definition for EDDEVID1:PSCROffset > + * > + * NOTE: armv8 and armv7 have different definition for the register, > + * so consolidate the bits definition as below: > + * > + * 0b0000 - Sample offset applies based on the instruction state, we > + * rely on EDDEVID to check if EDPCSR is implemented or not > + * 0b0001 - No offset applies. > + * 0b0010 - No offset applies, but do not use in AArch32 mode > + * > + */ > +#define EDDEVID1_PCSR_OFFSET_MASK GENMASK(3, 0) > +#define EDDEVID1_PCSR_OFFSET_INS_SET (0x0) > +#define EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32 (0x2) > + > +/* bits definition for EDDEVID */ > +#define EDDEVID_PCSAMPLE_MODE GENMASK(3, 0) > +#define EDDEVID_IMPL_EDPCSR (0x1) > +#define EDDEVID_IMPL_EDPCSR_EDCIDSR (0x2) > +#define EDDEVID_IMPL_FULL (0x3) > + > +#define DEBUG_WAIT_SLEEP 1000 > +#define DEBUG_WAIT_TIMEOUT 32000 > + > +struct debug_drvdata { > + void __iomem *base; > e struct device *dev; > + int cpu; > + > + bool edpcsr_present; > + bool edcidsr_present; > + bool edvidsr_present; > + bool pc_has_offset; > + > + u32 edpcsr; > + u32 edpcsr_hi; > + u32 edprsr; > + u32 edvidsr; > + u32 edcidsr; > +}; > + > +static DEFINE_MUTEX(debug_lock); > +static DEFINE_PER_CPU(struct debug_drvdata *, debug_drvdata); > +static int debug_count; > +static struct dentry *debug_debugfs_dir; > + > +static bool debug_enable; > +module_param_named(enable, debug_enable, bool, 0600); > +MODULE_PARM_DESC(enable, "Knob to enable debug functionality " > + "(default is 0, which means is disabled by default)"); For this driver we have a debugFS interface so I question the validity of a kernel module parameter. Other than adding complexity to the code it offers no real added value. If a user is to insmod a module, it is just as easy to switch on the functionality using debugFS in a second step. > + > +static void debug_os_unlock(struct debug_drvdata *drvdata) > +{ > + /* Unlocks the debug registers */ > + writel_relaxed(0x0, drvdata->base + EDOSLAR); Here the wmb is to make sure reordering (either at compile time or in the CPU) doesn't happend. You need a comment here otherwise checkpatch will complain. Speaking of which, did you run this through checkpatch? > + wmb(); > +} > + > +/* > + * According to ARM DDI 0487A.k, before access external debug > + * registers should firstly check the access permission; if any > + * below condition has been met then cannot access debug > + * registers to avoid lockup issue: > + * > + * - CPU power domain is powered off; > + * - The OS Double Lock is locked; > + * > + * By checking EDPRSR can get to know if meet these conditions. > + */ > +static bool debug_access_permitted(struct debug_drvdata *drvdata) > +{ > + /* CPU is powered off */ > + if (!(drvdata->edprsr & EDPRSR_PU)) > + return false; > + > + /* The OS Double Lock is locked */ > + if (drvdata->edprsr & EDPRSR_DLK) > + return false; > + > + return true; > +} > + > +static void debug_force_cpu_powered_up(struct debug_drvdata *drvdata) > +{ > + bool retried = false; > + u32 edprcr; > + > +try_again: > + > + /* > + * Send request to power management controller and assert > + * DBGPWRUPREQ signal; if power management controller has > + * sane implementation, it should enable CPU power domain > + * in case CPU is in low power state. > + */ > + edprcr = readl_relaxed(drvdata->base + EDPRCR); > + edprcr |= EDPRCR_COREPURQ; > + writel_relaxed(edprcr, drvdata->base + EDPRCR); > + > + /* Wait for CPU to be powered up (timeout~=32ms) */ > + if (readx_poll_timeout_atomic(readl_relaxed, drvdata->base + EDPRSR, > + drvdata->edprsr, (drvdata->edprsr & EDPRSR_PU), > + DEBUG_WAIT_SLEEP, DEBUG_WAIT_TIMEOUT)) { > + /* > + * Unfortunately the CPU cannot be powered up, so return > + * back and later has no permission to access other > + * registers. For this case, should disable CPU low power > + * states to ensure CPU power domain is enabled! > + */ > + pr_err("%s: power up request for CPU%d failed\n", > + __func__, drvdata->cpu); > + return; > + } > + > + /* > + * At this point the CPU is powered up, so set the no powerdown > + * request bit so we don't lose power and emulate power down. > + */ > + edprcr = readl_relaxed(drvdata->base + EDPRCR); > + edprcr |= EDPRCR_COREPURQ | EDPRCR_CORENPDRQ; > + writel_relaxed(edprcr, drvdata->base + EDPRCR); > + > + drvdata->edprsr = readl_relaxed(drvdata->base + EDPRSR); > + > + /* Bail out if CPU is powered up */ > + if (likely(drvdata->edprsr & EDPRSR_PU)) > + return; /* The core power domain got switched off on use, try again */ if (unlikely(!drvdata->edprsr & EDPRSR_PU)) goto try_again; I understand you don't want to introduce a infinite loop but if that happens here, something else has gone very wrong. The above readx_poll_timeout_atomic loop should take care of bailing out in case of problems. That way you also get to rid of the retried variable and the code is more simple. > + > + /* > + * Handle race condition if CPU has been waken up but it sleeps > + * again if EDPRCR_CORENPDRQ has been flipped, so try to run > + * waken flow one more time. > + */ > + if (!retried) { > + retried = true; > + goto try_again; > + } > +} > + > +static void debug_read_regs(struct debug_drvdata *drvdata) > +{ > + u32 save_edprcr; > + > + CS_UNLOCK(drvdata->base); > + > + /* Unlock os lock */ > + debug_os_unlock(drvdata); > + > + /* Save EDPRCR register */ > + save_edprcr = readl_relaxed(drvdata->base + EDPRCR); > + > + /* > + * Ensure CPU power domain is enabled to let registers > + * are accessiable. > + */ > + debug_force_cpu_powered_up(drvdata); > + > + if (!debug_access_permitted(drvdata)) > + goto out; > + > + drvdata->edpcsr = readl_relaxed(drvdata->base + EDPCSR); > + > + /* > + * As described in ARM DDI 0487A.k, if the processing > + * element (PE) is in debug state, or sample-based > + * profiling is prohibited, EDPCSR reads as 0xFFFFFFFF; > + * EDCIDSR, EDVIDSR and EDPCSR_HI registers also become > + * UNKNOWN state. So directly bail out for this case. > + */ > + if (drvdata->edpcsr == EDPCSR_PROHIBITED) > + goto out; > + > + /* > + * A read of the EDPCSR normally has the side-effect of > + * indirectly writing to EDCIDSR, EDVIDSR and EDPCSR_HI; > + * at this point it's safe to read value from them. > + */ > + if (IS_ENABLED(CONFIG_64BIT)) > + drvdata->edpcsr_hi = readl_relaxed(drvdata->base + EDPCSR_HI); > + > + if (drvdata->edcidsr_present) > + drvdata->edcidsr = readl_relaxed(drvdata->base + EDCIDSR); > + > + if (drvdata->edvidsr_present) > + drvdata->edvidsr = readl_relaxed(drvdata->base + EDVIDSR); > + > +out: > + /* Restore EDPRCR register */ > + writel_relaxed(save_edprcr, drvdata->base + EDPRCR); > + > + CS_LOCK(drvdata->base); > +} > + > +static unsigned long debug_adjust_pc(struct debug_drvdata *drvdata) > +{ > + unsigned long arm_inst_offset = 0, thumb_inst_offset = 0; > + unsigned long pc; > + > + if (IS_ENABLED(CONFIG_64BIT)) > + return (unsigned long)drvdata->edpcsr_hi << 32 | > + (unsigned long)drvdata->edpcsr; > + > + pc = (unsigned long)drvdata->edpcsr; > + > + if (drvdata->pc_has_offset) { > + arm_inst_offset = 8; > + thumb_inst_offset = 4; > + } > + > + /* Handle thumb instruction */ > + if (pc & EDPCSR_THUMB) { > + pc = (pc & EDPCSR_THUMB_INST_MASK) - thumb_inst_offset; > + return pc; > + } > + > + /* > + * Handle arm instruction offset, if the arm instruction > + * is not 4 byte alignment then it's possible the case > + * for implementation defined; keep original value for this > + * case and print info for notice. > + */ > + if (pc & BIT(1)) > + pr_emerg("Instruction offset is implementation defined\n"); > + else > + pc = (pc & EDPCSR_ARM_INST_MASK) - arm_inst_offset; > + > + return pc; > +} > + > +static void debug_dump_regs(struct debug_drvdata *drvdata) > +{ > + unsigned long pc; > + > + pr_emerg("\tEDPRSR: %08x (Power:%s DLK:%s)\n", drvdata->edprsr, > + drvdata->edprsr & EDPRSR_PU ? "On" : "Off", > + drvdata->edprsr & EDPRSR_DLK ? "Lock" : "Unlock"); > + > + if (!debug_access_permitted(drvdata)) { > + pr_emerg("No permission to access debug registers!\n"); > + return; > + } > + > + if (drvdata->edpcsr == EDPCSR_PROHIBITED) { > + pr_emerg("CPU is in Debug state or profiling is prohibited!\n"); > + return; > + } > + > + pc = debug_adjust_pc(drvdata); > + pr_emerg("\tEDPCSR: [<%p>] %pS\n", (void *)pc, (void *)pc); > + > + if (drvdata->edcidsr_present) > + pr_emerg("\tEDCIDSR: %08x\n", drvdata->edcidsr); > + > + if (drvdata->edvidsr_present) > + pr_emerg("\tEDVIDSR: %08x (State:%s Mode:%s Width:%dbits VMID:%x)\n", > + drvdata->edvidsr, > + drvdata->edvidsr & EDVIDSR_NS ? "Non-secure" : "Secure", > + drvdata->edvidsr & EDVIDSR_E3 ? "EL3" : > + (drvdata->edvidsr & EDVIDSR_E2 ? "EL2" : "EL1/0"), > + drvdata->edvidsr & EDVIDSR_HV ? 64 : 32, > + drvdata->edvidsr & (u32)EDVIDSR_VMID); > +} > + > +static void debug_init_arch_data(void *info) > +{ > + struct debug_drvdata *drvdata = info; > + u32 mode, pcsr_offset; > + u32 eddevid, eddevid1; > + > + CS_UNLOCK(drvdata->base); > + > + /* Read device info */ > + eddevid = readl_relaxed(drvdata->base + EDDEVID); > + eddevid1 = readl_relaxed(drvdata->base + EDDEVID1); > + > + CS_LOCK(drvdata->base); > + > + /* Parse implementation feature */ > + mode = eddevid & EDDEVID_PCSAMPLE_MODE; > + pcsr_offset = eddevid1 & EDDEVID1_PCSR_OFFSET_MASK; > + > + drvdata->edpcsr_present = false; > + drvdata->edcidsr_present = false; > + drvdata->edvidsr_present = false; > + drvdata->pc_has_offset = false; > + > + switch (mode) { > + case EDDEVID_IMPL_FULL: > + drvdata->edvidsr_present = true; > + /* Fall through */ > + case EDDEVID_IMPL_EDPCSR_EDCIDSR: > + drvdata->edcidsr_present = true; > + /* Fall through */ > + case EDDEVID_IMPL_EDPCSR: > + /* > + * In ARM DDI 0487A.k, the EDDEVID1.PCSROffset is used to > + * define if has the offset for PC sampling value; if read > + * back EDDEVID1.PCSROffset == 0x2, then this means the debug > + * module does not sample the instruction set state when > + * armv8 CPU in AArch32 state. > + */ > + drvdata->edpcsr_present = (IS_ENABLED(CONFIG_64BIT) || > + (pcsr_offset != EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32)); > + > + drvdata->pc_has_offset = > + (pcsr_offset == EDDEVID1_PCSR_OFFSET_INS_SET); > + break; > + default: > + break; > + } > +} > + > +/* > + * Dump out information on panic. > + */ > +static int debug_notifier_call(struct notifier_block *self, > + unsigned long v, void *p) > +{ > + int cpu; > + struct debug_drvdata *drvdata; > + > + pr_emerg("ARM external debug module:\n"); > + > + for_each_possible_cpu(cpu) { > + drvdata = per_cpu(debug_drvdata, cpu); > + if (!drvdata) > + continue; > + > + pr_emerg("CPU[%d]:\n", drvdata->cpu); > + > + debug_read_regs(drvdata); > + debug_dump_regs(drvdata); > + } > + > + return 0; > +} > + > +static struct notifier_block debug_notifier = { > + .notifier_call = debug_notifier_call, > +}; > + > +static int debug_enable_func(void) > +{ > + struct debug_drvdata *drvdata; > + int cpu; > + > + for_each_possible_cpu(cpu) { > + drvdata = per_cpu(debug_drvdata, cpu); > + if (!drvdata) > + continue; > + > + pm_runtime_get_sync(drvdata->dev); > + } > + > + return atomic_notifier_chain_register(&panic_notifier_list, > + &debug_notifier); > +} > + > +static int debug_disable_func(void) > +{ > + struct debug_drvdata *drvdata; > + int cpu; > + > + for_each_possible_cpu(cpu) { > + drvdata = per_cpu(debug_drvdata, cpu); > + if (!drvdata) > + continue; > + > + pm_runtime_put(drvdata->dev); > + } > + > + return atomic_notifier_chain_unregister(&panic_notifier_list, > + &debug_notifier); > +} > + > +static ssize_t debug_func_knob_write(struct file *f, > + const char __user *buf, size_t count, loff_t *ppos) > +{ > + u8 val; > + int ret; > + > + ret = kstrtou8_from_user(buf, count, 2, &val); > + if (ret) > + return ret; > + > + mutex_lock(&debug_lock); > + > + if (val == debug_enable) > + goto out; > + > + if (val) > + ret = debug_enable_func(); > + else > + ret = debug_disable_func(); I don't think you need to install the handler every time the functionality is switched on/off. I suggest to install the handler at boot time (or module insertion time) and in the notifier handler, check the debug_enable flag before moving on with the output. > + > + if (ret) { > + pr_err("%s: unable to %s debug function: %d\n", > + __func__, val ? "enable" : "disable", ret); > + goto err; > + } > + > + debug_enable = val; Using a true/false value is probably better here. That way you don't end up with miscellaneous values in debugFS. > +out: > + ret = count; > +err: > + mutex_unlock(&debug_lock); > + return ret; > +} > + > +static ssize_t debug_func_knob_read(struct file *f, > + char __user *ubuf, size_t count, loff_t *ppos) > +{ > + ssize_t ret; > + char buf[2]; > + > + mutex_lock(&debug_lock); > + > + buf[0] = '0' + debug_enable; > + buf[1] = '\n'; snprintf() > + ret = simple_read_from_buffer(ubuf, count, ppos, buf, sizeof(buf)); > + > + mutex_unlock(&debug_lock); > + return ret; > +} > + > +static const struct file_operations debug_func_knob_fops = { > + .open = simple_open, > + .read = debug_func_knob_read, > + .write = debug_func_knob_write, > +}; > + > +static int debug_func_init(void) > +{ > + struct dentry *file; > + int ret; > + > + /* Create debugfs node */ > + debug_debugfs_dir = debugfs_create_dir("coresight_cpu_debug", NULL); > + if (!debug_debugfs_dir) { > + pr_err("%s: unable to create debugfs directory\n", __func__); > + return -ENOMEM; > + } > + > + file = debugfs_create_file("enable", S_IRUGO | S_IWUSR, > + debug_debugfs_dir, NULL, &debug_func_knob_fops); Please align this properly. > + if (!file) { > + pr_err("%s: unable to create enable knob file\n", __func__); > + ret = -ENOMEM; > + goto err; > + } > + > + /* Use sysfs node to enable functionality */ > + if (!debug_enable) > + return 0; > + > + /* Register function to be called for panic */ > + ret = atomic_notifier_chain_register(&panic_notifier_list, > + &debug_notifier); > + if (ret) { > + pr_err("%s: unable to register notifier: %d\n", > + __func__, ret); > + goto err; > + } > + > + return 0; > + > +err: > + debugfs_remove_recursive(debug_debugfs_dir); > + return ret; > +} > + > +static void debug_func_exit(void) > +{ > + debugfs_remove_recursive(debug_debugfs_dir); > + > + /* Unregister panic notifier callback */ > + if (debug_enable) > + atomic_notifier_chain_unregister(&panic_notifier_list, > + &debug_notifier); > +} > + > +static int debug_probe(struct amba_device *adev, const struct amba_id *id) > +{ > + void __iomem *base; > + struct device *dev = &adev->dev; > + struct debug_drvdata *drvdata; > + struct resource *res = &adev->res; > + struct device_node *np = adev->dev.of_node; > + int ret; > + > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); > + if (!drvdata) > + return -ENOMEM; > + > + drvdata->cpu = np ? of_coresight_get_cpu(np) : 0; > + if (per_cpu(debug_drvdata, drvdata->cpu)) { > + dev_err(dev, "CPU%d drvdata has been initialized\n", > + drvdata->cpu); > + return -EBUSY; > + } > + > + drvdata->dev = &adev->dev; > + amba_set_drvdata(adev, drvdata); > + > + /* Validity for the resource is already checked by the AMBA core */ > + base = devm_ioremap_resource(dev, res); > + if (IS_ERR(base)) > + return PTR_ERR(base); > + > + drvdata->base = base; > + > + get_online_cpus(); > + per_cpu(debug_drvdata, drvdata->cpu) = drvdata; > + ret = smp_call_function_single(drvdata->cpu, > + debug_init_arch_data, drvdata, 1); > + put_online_cpus(); > + > + if (ret) { > + dev_err(dev, "CPU%d debug arch init failed\n", drvdata->cpu); > + goto err; > + } > + > + if (!drvdata->edpcsr_present) { > + dev_err(dev, "CPU%d sample-based profiling isn't implemented\n", > + drvdata->cpu); > + ret = -ENXIO; > + goto err; > + } > + > + if (!debug_count++) { > + ret = debug_func_init(); > + if (ret) > + goto err_func_init; > + } > + > + if (!debug_enable) > + pm_runtime_put(dev); > + > + dev_info(dev, "Coresight debug-CPU%d initialized\n", drvdata->cpu); > + return 0; > + > +err_func_init: > + debug_count--; > +err: > + per_cpu(debug_drvdata, drvdata->cpu) = NULL; > + return ret; > +} > + > +static int debug_remove(struct amba_device *adev) > +{ > + struct device *dev = &adev->dev; > + struct debug_drvdata *drvdata = amba_get_drvdata(adev); > + > + per_cpu(debug_drvdata, drvdata->cpu) = NULL; > + > + if (debug_enable) > + pm_runtime_put(dev); > + > + if (!--debug_count) > + debug_func_exit(); > + > + return 0; > +} > + > +static struct amba_id debug_ids[] = { > + { /* Debug for Cortex-A53 */ > + .id = 0x000bbd03, > + .mask = 0x000fffff, > + }, > + { /* Debug for Cortex-A57 */ > + .id = 0x000bbd07, > + .mask = 0x000fffff, > + }, > + { /* Debug for Cortex-A72 */ > + .id = 0x000bbd08, > + .mask = 0x000fffff, > + }, > + { 0, 0 }, > +}; > + > +static struct amba_driver debug_driver = { > + .drv = { > + .name = "coresight-cpu-debug", > + .suppress_bind_attrs = true, > + }, > + .probe = debug_probe, > + .remove = debug_remove, > + .id_table = debug_ids, > +}; > + > +module_amba_driver(debug_driver); > + > +MODULE_AUTHOR("Leo Yan <leo.yan@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("ARM Coresight CPU Debug Driver"); > +MODULE_LICENSE("GPL"); > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
