blob: d765f6a628277704854a2d21c22780fea1da61b7 [file] [log] [blame]
/*
* Copyright (c) 2012, Code Aurora Forum. 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/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <asm/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
/* Write
* 1) 3 bytes sentinel
* 2) 1 bytes of log type
* 3) 4 bytes of where the caller came from
* 4) 4 bytes index
* 4) 4 bytes extra data from the caller
*
* Total = 16 bytes.
*/
struct msm_rtb_layout {
unsigned char sentinel[3];
unsigned char log_type;
void *caller;
unsigned long idx;
void *data;
} __attribute__ ((__packed__));
struct msm_rtb_state {
struct msm_rtb_layout *rtb;
unsigned long phys;
int nentries;
int size;
int enabled;
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
struct msm_rtb_state msm_rtb = {
.size = SZ_1M,
};
module_param_named(filter, msm_rtb.filter, uint, 0644);
module_param_named(enable, msm_rtb.enabled, int, 0644);
int msm_rtb_event_should_log(enum logk_event_type log_type)
{
return msm_rtb.enabled &&
((1 << log_type) & 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(void *caller, struct msm_rtb_layout *start)
{
start->caller = caller;
}
static void msm_rtb_write_idx(unsigned long idx,
struct msm_rtb_layout *start)
{
start->idx = idx;
}
static void msm_rtb_write_data(void *data, struct msm_rtb_layout *start)
{
start->data = data;
}
static int __init msm_rtb_set_buffer_size(char *p)
{
int s;
s = memparse(p, NULL);
msm_rtb.size = ALIGN(s, SZ_4K);
return 0;
}
early_param("msm_rtb_size", msm_rtb_set_buffer_size);
#if defined(CONFIG_MSM_RTB_SEPARATE_CPUS)
static int msm_rtb_get_idx(void)
{
int cpu, i;
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;
return i;
}
#else
static int msm_rtb_get_idx(void)
{
int i;
i = atomic_inc_return(&msm_rtb_idx);
i--;
return i;
}
#endif
int uncached_logk_pc(enum logk_event_type log_type, void *caller,
void *data)
{
int i;
struct msm_rtb_layout *start;
if (!msm_rtb_event_should_log(log_type))
return 0;
i = msm_rtb_get_idx();
start = &msm_rtb.rtb[i & (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(i, start);
msm_rtb_write_data(data, start);
mb();
return 1;
}
EXPORT_SYMBOL(uncached_logk_pc);
noinline int 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);
int msm_rtb_init(void)
{
#if defined(CONFIG_MSM_RTB_SEPARATE_CPUS)
unsigned int cpu;
#endif
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
msm_rtb.enabled = 1;
return 0;
}
module_init(msm_rtb_init)