blob: 6a71e36c1c9b2895a00fc05b3105e425ec55ecd8 [file] [log] [blame]
/*
* Copyright (c) 2013-2014, 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.
*/
#include <linux/atomic.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/memory_alloc.h>
#include <linux/module.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/io.h>
#include <asm-generic/sizes.h>
#include <mach/memory.h>
#include <mach/msm_rtb.h>
#include <mach/system.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) 3 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
* 5) 8 bytes for timestamp
*
* Total = 32 bytes.
*/
struct msm_rtb_layout {
unsigned char sentinel[3];
unsigned char log_type;
uint32_t idx;
uint64_t caller;
uint64_t data;
uint64_t timestamp;
} __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_MSM_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 msm_rtb_write_timestamp(struct msm_rtb_layout *start)
{
start->timestamp = sched_clock();
}
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);
msm_rtb_write_timestamp(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_MSM_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_MSM_RTB_SEPARATE_CPUS)
unsigned int cpu;
#endif
int ret;
if (!pdev->dev.of_node) {
msm_rtb.size = d->size;
} else {
int size;
ret = of_property_read_u32((&pdev->dev)->of_node,
"qcom,memory-reservation-size",
&size);
if (ret < 0)
return ret;
msm_rtb.size = size;
}
if (msm_rtb.size <= 0 || msm_rtb.size > SZ_1M)
return -EINVAL;
/*
* The ioremap call is made separately to store the physical
* address of the buffer. This is necessary for cases where
* the only way to access the buffer is a physical address.
*/
msm_rtb.phys = allocate_contiguous_ebi_nomap(msm_rtb.size, SZ_4K);
if (!msm_rtb.phys)
return -ENOMEM;
msm_rtb.rtb = ioremap(msm_rtb.phys, msm_rtb.size);
if (!msm_rtb.rtb) {
free_contiguous_memory_by_paddr(msm_rtb.phys);
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_MSM_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)