diff options
| -rw-r--r-- | include/linux/msm_rtb.h | 84 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 17 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 1 | ||||
| -rw-r--r-- | kernel/trace/msm_rtb.c | 320 |
4 files changed, 422 insertions, 0 deletions
diff --git a/include/linux/msm_rtb.h b/include/linux/msm_rtb.h new file mode 100644 index 000000000000..228094294b31 --- /dev/null +++ b/include/linux/msm_rtb.h @@ -0,0 +1,84 @@ +/* + * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only 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. + */ +#ifndef __MSM_RTB_H__ +#define __MSM_RTB_H__ + +/* + * These numbers are used from the kernel command line and sysfs + * to control filtering. Remove items from here with extreme caution. + */ +enum logk_event_type { + LOGK_NONE = 0, + LOGK_READL = 1, + LOGK_WRITEL = 2, + LOGK_LOGBUF = 3, + LOGK_HOTPLUG = 4, + LOGK_CTXID = 5, + LOGK_TIMESTAMP = 6, + LOGK_L2CPREAD = 7, + LOGK_L2CPWRITE = 8, + LOGK_IRQ = 9, +}; + +#define LOGTYPE_NOPC 0x80 + +struct msm_rtb_platform_data { + unsigned int size; +}; + +#if defined(CONFIG_QCOM_RTB) +/* + * returns 1 if data was logged, 0 otherwise + */ +int uncached_logk_pc(enum logk_event_type log_type, void *caller, + void *data); + +/* + * returns 1 if data was logged, 0 otherwise + */ +int uncached_logk(enum logk_event_type log_type, void *data); + +#define ETB_WAYPOINT do { \ + BRANCH_TO_NEXT_ISTR; \ + nop(); \ + BRANCH_TO_NEXT_ISTR; \ + nop(); \ + } while (0) + +#define BRANCH_TO_NEXT_ISTR asm volatile("b .+4\n" : : : "memory") +/* + * both the mb and the isb are needed to ensure enough waypoints for + * etb tracing + */ +#define LOG_BARRIER do { \ + mb(); \ + isb();\ + } while (0) +#else + +static inline int uncached_logk_pc(enum logk_event_type log_type, + void *caller, + void *data) { return 0; } + +static inline int uncached_logk(enum logk_event_type log_type, + void *data) { return 0; } + +#define ETB_WAYPOINT +#define BRANCH_TO_NEXT_ISTR +/* + * Due to a GCC bug, we need to have a nop here in order to prevent an extra + * read from being generated after the write. + */ +#define LOG_BARRIER nop() +#endif +#endif diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5f5b66a2f156..fd8b1a2de934 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -89,6 +89,23 @@ config RING_BUFFER_ALLOW_SWAP Allow the use of ring_buffer_swap_cpu. Adds a very slight overhead to tracing when enabled. +config QCOM_RTB + bool "Register tracing" + help + Add support for logging different events to a small uncached + region. This is designed to aid in debugging reset cases where the + caches may not be flushed before the target resets. + +config QCOM_RTB_SEPARATE_CPUS + bool "Separate entries for each cpu" + depends on QCOM_RTB + depends on SMP + help + Under some circumstances, it may be beneficial to give dedicated space + for each cpu to log accesses. Selecting this option will log each cpu + separately. This will guarantee that the last acesses for each cpu + will be logged but there will be fewer entries per cpu + # All tracer options should select GENERIC_TRACER. For those options that are # enabled by all tracers (context switch and event tracer) they select TRACING. # This allows those options to appear when no other tracer is selected. But the diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index ba04bf0c2653..9f2c8d0672c7 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -65,6 +65,7 @@ endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o obj-$(CONFIG_GPU_TRACEPOINTS) += gpu-traces.o +obj-$(CONFIG_QCOM_RTB) += msm_rtb.o obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o diff --git a/kernel/trace/msm_rtb.c b/kernel/trace/msm_rtb.c new file mode 100644 index 000000000000..2bbb909a20d5 --- /dev/null +++ b/kernel/trace/msm_rtb.c @@ -0,0 +1,320 @@ +/* + * Copyright (c) 2013, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only 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. + */ + +#include <linux/atomic.h> +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/dma-mapping.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/atomic.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/io.h> +#include <asm-generic/sizes.h> +#include <linux/msm_rtb.h> + +#define SENTINEL_BYTE_1 0xFF +#define SENTINEL_BYTE_2 0xAA +#define SENTINEL_BYTE_3 0xFF + +#define RTB_COMPAT_STR "qcom,msm-rtb" + +/* Write + * 1) 11 bytes sentinel + * 2) 1 bytes of log type + * 3) 8 bytes of where the caller came from + * 4) 4 bytes index + * 4) 8 bytes extra data from the caller + * + * Total = 32 bytes. + */ +struct msm_rtb_layout { + unsigned char sentinel[11]; + unsigned char log_type; + uint32_t idx; + uint64_t caller; + uint64_t data; +} __attribute__ ((__packed__)); + + +struct msm_rtb_state { + struct msm_rtb_layout *rtb; + phys_addr_t phys; + int nentries; + int size; + int enabled; + int initialized; + uint32_t filter; + int step_size; +}; + +#if defined(CONFIG_QCOM_RTB_SEPARATE_CPUS) +DEFINE_PER_CPU(atomic_t, msm_rtb_idx_cpu); +#else +static atomic_t msm_rtb_idx; +#endif + +static struct msm_rtb_state msm_rtb = { + .filter = 1 << LOGK_LOGBUF, + .enabled = 1, +}; + +module_param_named(filter, msm_rtb.filter, uint, 0644); +module_param_named(enable, msm_rtb.enabled, int, 0644); + +static int msm_rtb_panic_notifier(struct notifier_block *this, + unsigned long event, void *ptr) +{ + msm_rtb.enabled = 0; + return NOTIFY_DONE; +} + +static struct notifier_block msm_rtb_panic_blk = { + .notifier_call = msm_rtb_panic_notifier, +}; + +int notrace msm_rtb_event_should_log(enum logk_event_type log_type) +{ + return msm_rtb.initialized && msm_rtb.enabled && + ((1 << (log_type & ~LOGTYPE_NOPC)) & msm_rtb.filter); +} +EXPORT_SYMBOL(msm_rtb_event_should_log); + +static void msm_rtb_emit_sentinel(struct msm_rtb_layout *start) +{ + start->sentinel[0] = SENTINEL_BYTE_1; + start->sentinel[1] = SENTINEL_BYTE_2; + start->sentinel[2] = SENTINEL_BYTE_3; +} + +static void msm_rtb_write_type(enum logk_event_type log_type, + struct msm_rtb_layout *start) +{ + start->log_type = (char)log_type; +} + +static void msm_rtb_write_caller(uint64_t caller, struct msm_rtb_layout *start) +{ + start->caller = caller; +} + +static void msm_rtb_write_idx(uint32_t idx, + struct msm_rtb_layout *start) +{ + start->idx = idx; +} + +static void msm_rtb_write_data(uint64_t data, struct msm_rtb_layout *start) +{ + start->data = data; +} + +static void uncached_logk_pc_idx(enum logk_event_type log_type, uint64_t caller, + uint64_t data, int idx) +{ + struct msm_rtb_layout *start; + + start = &msm_rtb.rtb[idx & (msm_rtb.nentries - 1)]; + + msm_rtb_emit_sentinel(start); + msm_rtb_write_type(log_type, start); + msm_rtb_write_caller(caller, start); + msm_rtb_write_idx(idx, start); + msm_rtb_write_data(data, start); + mb(); + + return; +} + +static void uncached_logk_timestamp(int idx) +{ + unsigned long long timestamp; + + timestamp = sched_clock(); + uncached_logk_pc_idx(LOGK_TIMESTAMP|LOGTYPE_NOPC, + (uint64_t)lower_32_bits(timestamp), + (uint64_t)upper_32_bits(timestamp), idx); +} + +#if defined(CONFIG_QCOM_RTB_SEPARATE_CPUS) +static int msm_rtb_get_idx(void) +{ + int cpu, i, offset; + atomic_t *index; + + /* + * ideally we would use get_cpu but this is a close enough + * approximation for our purposes. + */ + cpu = raw_smp_processor_id(); + + index = &per_cpu(msm_rtb_idx_cpu, cpu); + + i = atomic_add_return(msm_rtb.step_size, index); + i -= msm_rtb.step_size; + + /* Check if index has wrapped around */ + offset = (i & (msm_rtb.nentries - 1)) - + ((i - msm_rtb.step_size) & (msm_rtb.nentries - 1)); + if (offset < 0) { + uncached_logk_timestamp(i); + i = atomic_add_return(msm_rtb.step_size, index); + i -= msm_rtb.step_size; + } + + return i; +} +#else +static int msm_rtb_get_idx(void) +{ + int i, offset; + + i = atomic_inc_return(&msm_rtb_idx); + i--; + + /* Check if index has wrapped around */ + offset = (i & (msm_rtb.nentries - 1)) - + ((i - 1) & (msm_rtb.nentries - 1)); + if (offset < 0) { + uncached_logk_timestamp(i); + i = atomic_inc_return(&msm_rtb_idx); + i--; + } + + return i; +} +#endif + +int notrace uncached_logk_pc(enum logk_event_type log_type, void *caller, + void *data) +{ + int i; + + if (!msm_rtb_event_should_log(log_type)) + return 0; + + i = msm_rtb_get_idx(); + uncached_logk_pc_idx(log_type, (uint64_t)((unsigned long) caller), + (uint64_t)((unsigned long) data), i); + + return 1; +} +EXPORT_SYMBOL(uncached_logk_pc); + +noinline int notrace uncached_logk(enum logk_event_type log_type, void *data) +{ + return uncached_logk_pc(log_type, __builtin_return_address(0), data); +} +EXPORT_SYMBOL(uncached_logk); + +static int msm_rtb_probe(struct platform_device *pdev) +{ + struct msm_rtb_platform_data *d = pdev->dev.platform_data; +#if defined(CONFIG_QCOM_RTB_SEPARATE_CPUS) + unsigned int cpu; +#endif + int ret; + + if (!pdev->dev.of_node) { + msm_rtb.size = d->size; + } else { + u64 size; + struct device_node *pnode; + + pnode = of_parse_phandle(pdev->dev.of_node, + "linux,contiguous-region", 0); + if (pnode != NULL) { + const u32 *addr; + + addr = of_get_address(pnode, 0, &size, NULL); + if (!addr) { + of_node_put(pnode); + return -EINVAL; + } + of_node_put(pnode); + } else { + ret = of_property_read_u32(pdev->dev.of_node, + "qcom,rtb-size", + (u32 *)&size); + if (ret < 0) + return ret; + + } + + msm_rtb.size = size; + } + + if (msm_rtb.size <= 0 || msm_rtb.size > SZ_1M) + return -EINVAL; + + msm_rtb.rtb = dma_alloc_coherent(&pdev->dev, msm_rtb.size, + &msm_rtb.phys, + GFP_KERNEL); + + if (!msm_rtb.rtb) + return -ENOMEM; + + msm_rtb.nentries = msm_rtb.size / sizeof(struct msm_rtb_layout); + + /* Round this down to a power of 2 */ + msm_rtb.nentries = __rounddown_pow_of_two(msm_rtb.nentries); + + memset(msm_rtb.rtb, 0, msm_rtb.size); + + +#if defined(CONFIG_QCOM_RTB_SEPARATE_CPUS) + for_each_possible_cpu(cpu) { + atomic_t *a = &per_cpu(msm_rtb_idx_cpu, cpu); + atomic_set(a, cpu); + } + msm_rtb.step_size = num_possible_cpus(); +#else + atomic_set(&msm_rtb_idx, 0); + msm_rtb.step_size = 1; +#endif + + atomic_notifier_chain_register(&panic_notifier_list, + &msm_rtb_panic_blk); + msm_rtb.initialized = 1; + return 0; +} + +static struct of_device_id msm_match_table[] = { + {.compatible = RTB_COMPAT_STR}, + {}, +}; + +static struct platform_driver msm_rtb_driver = { + .driver = { + .name = "msm_rtb", + .owner = THIS_MODULE, + .of_match_table = msm_match_table + }, +}; + +static int __init msm_rtb_init(void) +{ + return platform_driver_probe(&msm_rtb_driver, msm_rtb_probe); +} + +static void __exit msm_rtb_exit(void) +{ + platform_driver_unregister(&msm_rtb_driver); +} +module_init(msm_rtb_init) +module_exit(msm_rtb_exit) |