blob: 4e09a9e74d57ccb081aacdac50bfab6f8c913009 [file] [log] [blame]
/* Copyright (c) 2008-2009, 2011-2013 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/err.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/system.h>
#include <mach/msm_iomap.h>
#include <mach/remote_spinlock.h>
#include <mach/dal.h>
#include "smd_private.h"
#define SPINLOCK_PID_APPS 1
#define AUTO_MODE -1
#define DEKKERS_MODE 1
#define SWP_MODE 2
#define LDREX_MODE 3
#define SFPB_MODE 4
#if defined(CONFIG_MSM_REMOTE_SPINLOCK_DEKKERS) ||\
defined(CONFIG_MSM_REMOTE_SPINLOCK_SWP) ||\
defined(CONFIG_MSM_REMOTE_SPINLOCK_LDREX) ||\
defined(CONFIG_MSM_REMOTE_SPINLOCK_SFPB)
#ifdef CONFIG_MSM_REMOTE_SPINLOCK_DEKKERS
/*
* Use Dekker's algorithm when LDREX/STREX and SWP are unavailable for
* shared memory
*/
#define CURRENT_MODE_INIT DEKKERS_MODE;
#endif
#ifdef CONFIG_MSM_REMOTE_SPINLOCK_SWP
/* Use SWP-based locks when LDREX/STREX are unavailable for shared memory. */
#define CURRENT_MODE_INIT SWP_MODE;
#endif
#ifdef CONFIG_MSM_REMOTE_SPINLOCK_LDREX
/* Use LDREX/STREX for shared memory locking, when available */
#define CURRENT_MODE_INIT LDREX_MODE;
#endif
#ifdef CONFIG_MSM_REMOTE_SPINLOCK_SFPB
/* Use SFPB Hardware Mutex Registers */
#define CURRENT_MODE_INIT SFPB_MODE;
#endif
#else
/* Use DT info to configure with a fallback to LDREX if DT is missing */
#define CURRENT_MODE_INIT AUTO_MODE;
#endif
static int current_mode = CURRENT_MODE_INIT;
static int is_hw_lock_type;
static DEFINE_MUTEX(ops_init_lock);
struct spinlock_ops {
void (*lock)(raw_remote_spinlock_t *lock);
void (*unlock)(raw_remote_spinlock_t *lock);
int (*trylock)(raw_remote_spinlock_t *lock);
int (*release)(raw_remote_spinlock_t *lock, uint32_t pid);
int (*owner)(raw_remote_spinlock_t *lock);
};
static struct spinlock_ops current_ops;
static int remote_spinlock_init_address(int id, _remote_spinlock_t *lock);
/* dekkers implementation --------------------------------------------------- */
#define DEK_LOCK_REQUEST 1
#define DEK_LOCK_YIELD (!DEK_LOCK_REQUEST)
#define DEK_YIELD_TURN_SELF 0
static void __raw_remote_dek_spin_lock(raw_remote_spinlock_t *lock)
{
lock->dek.self_lock = DEK_LOCK_REQUEST;
while (lock->dek.other_lock) {
if (lock->dek.next_yield == DEK_YIELD_TURN_SELF)
lock->dek.self_lock = DEK_LOCK_YIELD;
while (lock->dek.other_lock)
;
lock->dek.self_lock = DEK_LOCK_REQUEST;
}
lock->dek.next_yield = DEK_YIELD_TURN_SELF;
smp_mb();
}
static int __raw_remote_dek_spin_trylock(raw_remote_spinlock_t *lock)
{
lock->dek.self_lock = DEK_LOCK_REQUEST;
if (lock->dek.other_lock) {
lock->dek.self_lock = DEK_LOCK_YIELD;
return 0;
}
lock->dek.next_yield = DEK_YIELD_TURN_SELF;
smp_mb();
return 1;
}
static void __raw_remote_dek_spin_unlock(raw_remote_spinlock_t *lock)
{
smp_mb();
lock->dek.self_lock = DEK_LOCK_YIELD;
}
static int __raw_remote_dek_spin_release(raw_remote_spinlock_t *lock,
uint32_t pid)
{
return -EPERM;
}
static int __raw_remote_dek_spin_owner(raw_remote_spinlock_t *lock)
{
return -EPERM;
}
/* end dekkers implementation ----------------------------------------------- */
/* swp implementation ------------------------------------------------------- */
static void __raw_remote_swp_spin_lock(raw_remote_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
"1: swp %0, %2, [%1]\n"
" teq %0, #0\n"
" bne 1b"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (1)
: "cc");
smp_mb();
}
static int __raw_remote_swp_spin_trylock(raw_remote_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
" swp %0, %2, [%1]\n"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (1)
: "cc");
if (tmp == 0) {
smp_mb();
return 1;
}
return 0;
}
static void __raw_remote_swp_spin_unlock(raw_remote_spinlock_t *lock)
{
int lock_owner;
smp_mb();
lock_owner = readl_relaxed(&lock->lock);
if (lock_owner != SPINLOCK_PID_APPS) {
pr_err("%s: spinlock not owned by Apps (actual owner is %d)\n",
__func__, lock_owner);
}
__asm__ __volatile__(
" str %1, [%0]"
:
: "r" (&lock->lock), "r" (0)
: "cc");
}
/* end swp implementation --------------------------------------------------- */
/* ldrex implementation ----------------------------------------------------- */
static void __raw_remote_ex_spin_lock(raw_remote_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
"1: ldrex %0, [%1]\n"
" teq %0, #0\n"
" strexeq %0, %2, [%1]\n"
" teqeq %0, #0\n"
" bne 1b"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (SPINLOCK_PID_APPS)
: "cc");
smp_mb();
}
static int __raw_remote_ex_spin_trylock(raw_remote_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
" ldrex %0, [%1]\n"
" teq %0, #0\n"
" strexeq %0, %2, [%1]\n"
: "=&r" (tmp)
: "r" (&lock->lock), "r" (SPINLOCK_PID_APPS)
: "cc");
if (tmp == 0) {
smp_mb();
return 1;
}
return 0;
}
static void __raw_remote_ex_spin_unlock(raw_remote_spinlock_t *lock)
{
int lock_owner;
smp_mb();
lock_owner = readl_relaxed(&lock->lock);
if (lock_owner != SPINLOCK_PID_APPS) {
pr_err("%s: spinlock not owned by Apps (actual owner is %d)\n",
__func__, lock_owner);
}
__asm__ __volatile__(
" str %1, [%0]\n"
:
: "r" (&lock->lock), "r" (0)
: "cc");
}
/* end ldrex implementation ------------------------------------------------- */
/* sfpb implementation ------------------------------------------------------ */
#define SFPB_SPINLOCK_COUNT 8
#define MSM_SFPB_MUTEX_REG_BASE 0x01200600
#define MSM_SFPB_MUTEX_REG_SIZE (33 * 4)
#define SFPB_SPINLOCK_OFFSET 4
#define SFPB_SPINLOCK_SIZE 4
static uint32_t lock_count;
static phys_addr_t reg_base;
static uint32_t reg_size;
static uint32_t lock_offset; /* offset into the hardware block before lock 0 */
static uint32_t lock_size;
static void *hw_mutex_reg_base;
static DEFINE_MUTEX(hw_map_init_lock);
static char *compatible_string = "qcom,ipc-spinlock";
static int init_hw_mutex(struct device_node *node)
{
struct resource r;
int rc;
rc = of_address_to_resource(node, 0, &r);
if (rc)
BUG();
rc = of_property_read_u32(node, "qcom,num-locks", &lock_count);
if (rc)
BUG();
reg_base = r.start;
reg_size = (uint32_t)(resource_size(&r));
lock_offset = 0;
lock_size = reg_size / lock_count;
return 0;
}
static void find_and_init_hw_mutex(void)
{
struct device_node *node;
node = of_find_compatible_node(NULL, NULL, compatible_string);
if (node) {
init_hw_mutex(node);
} else {
lock_count = SFPB_SPINLOCK_COUNT;
reg_base = MSM_SFPB_MUTEX_REG_BASE;
reg_size = MSM_SFPB_MUTEX_REG_SIZE;
lock_offset = SFPB_SPINLOCK_OFFSET;
lock_size = SFPB_SPINLOCK_SIZE;
}
hw_mutex_reg_base = ioremap(reg_base, reg_size);
BUG_ON(hw_mutex_reg_base == NULL);
}
static int remote_spinlock_init_address_hw(int id, _remote_spinlock_t *lock)
{
/*
* Optimistic locking. Init only needs to be done once by the first
* caller. After that, serializing inits between different callers
* is unnecessary. The second check after the lock ensures init
* wasn't previously completed by someone else before the lock could
* be grabbed.
*/
if (!hw_mutex_reg_base) {
mutex_lock(&hw_map_init_lock);
if (!hw_mutex_reg_base)
find_and_init_hw_mutex();
mutex_unlock(&hw_map_init_lock);
}
if (id >= lock_count)
return -EINVAL;
*lock = hw_mutex_reg_base + lock_offset + id * lock_size;
return 0;
}
static void __raw_remote_sfpb_spin_lock(raw_remote_spinlock_t *lock)
{
do {
writel_relaxed(SPINLOCK_PID_APPS, lock);
smp_mb();
} while (readl_relaxed(lock) != SPINLOCK_PID_APPS);
}
static int __raw_remote_sfpb_spin_trylock(raw_remote_spinlock_t *lock)
{
return 1;
}
static void __raw_remote_sfpb_spin_unlock(raw_remote_spinlock_t *lock)
{
int lock_owner;
lock_owner = readl_relaxed(lock);
if (lock_owner != SPINLOCK_PID_APPS) {
pr_err("%s: spinlock not owned by Apps (actual owner is %d)\n",
__func__, lock_owner);
}
writel_relaxed(0, lock);
smp_mb();
}
/* end sfpb implementation -------------------------------------------------- */
/* common spinlock API ------------------------------------------------------ */
/**
* Release spinlock if it is owned by @pid.
*
* This is only to be used for situations where the processor owning
* the spinlock has crashed and the spinlock must be released.
*
* @lock: lock structure
* @pid: processor ID of processor to release
*/
static int __raw_remote_gen_spin_release(raw_remote_spinlock_t *lock,
uint32_t pid)
{
int ret = 1;
if (readl_relaxed(&lock->lock) == pid) {
writel_relaxed(0, &lock->lock);
wmb();
ret = 0;
}
return ret;
}
/**
* Return owner of the spinlock.
*
* @lock: pointer to lock structure
* @returns: >= 0 owned PID; < 0 for error case
*
* Used for testing. PID's are assumed to be 31 bits or less.
*/
static int __raw_remote_gen_spin_owner(raw_remote_spinlock_t *lock)
{
rmb();
return readl_relaxed(&lock->lock);
}
static void initialize_ops(void)
{
struct device_node *node;
switch (current_mode) {
case DEKKERS_MODE:
current_ops.lock = __raw_remote_dek_spin_lock;
current_ops.unlock = __raw_remote_dek_spin_unlock;
current_ops.trylock = __raw_remote_dek_spin_trylock;
current_ops.release = __raw_remote_dek_spin_release;
current_ops.owner = __raw_remote_dek_spin_owner;
is_hw_lock_type = 0;
break;
case SWP_MODE:
current_ops.lock = __raw_remote_swp_spin_lock;
current_ops.unlock = __raw_remote_swp_spin_unlock;
current_ops.trylock = __raw_remote_swp_spin_trylock;
current_ops.release = __raw_remote_gen_spin_release;
current_ops.owner = __raw_remote_gen_spin_owner;
is_hw_lock_type = 0;
break;
case LDREX_MODE:
current_ops.lock = __raw_remote_ex_spin_lock;
current_ops.unlock = __raw_remote_ex_spin_unlock;
current_ops.trylock = __raw_remote_ex_spin_trylock;
current_ops.release = __raw_remote_gen_spin_release;
current_ops.owner = __raw_remote_gen_spin_owner;
is_hw_lock_type = 0;
break;
case SFPB_MODE:
current_ops.lock = __raw_remote_sfpb_spin_lock;
current_ops.unlock = __raw_remote_sfpb_spin_unlock;
current_ops.trylock = __raw_remote_sfpb_spin_trylock;
current_ops.release = __raw_remote_gen_spin_release;
current_ops.owner = __raw_remote_gen_spin_owner;
is_hw_lock_type = 1;
break;
case AUTO_MODE:
node = of_find_compatible_node(NULL, NULL, compatible_string);
if (node) {
current_ops.lock = __raw_remote_sfpb_spin_lock;
current_ops.unlock = __raw_remote_sfpb_spin_unlock;
current_ops.trylock = __raw_remote_sfpb_spin_trylock;
current_ops.release = __raw_remote_gen_spin_release;
current_ops.owner = __raw_remote_gen_spin_owner;
is_hw_lock_type = 1;
} else {
current_ops.lock = __raw_remote_ex_spin_lock;
current_ops.unlock = __raw_remote_ex_spin_unlock;
current_ops.trylock = __raw_remote_ex_spin_trylock;
current_ops.release = __raw_remote_gen_spin_release;
current_ops.owner = __raw_remote_gen_spin_owner;
is_hw_lock_type = 0;
pr_warn("Falling back to LDREX remote spinlock implementation");
}
break;
default:
BUG();
break;
}
}
/**
* Release all spinlocks owned by @pid.
*
* This is only to be used for situations where the processor owning
* spinlocks has crashed and the spinlocks must be released.
*
* @pid - processor ID of processor to release
*/
static void remote_spin_release_all_locks(uint32_t pid, int count)
{
int n;
_remote_spinlock_t lock;
for (n = 0; n < count; ++n) {
if (remote_spinlock_init_address(n, &lock) == 0)
_remote_spin_release(&lock, pid);
}
}
void _remote_spin_release_all(uint32_t pid)
{
remote_spin_release_all_locks(pid, lock_count);
}
static int
remote_spinlock_dal_init(const char *chunk_name, _remote_spinlock_t *lock)
{
void *dal_smem_start, *dal_smem_end;
uint32_t dal_smem_size;
struct dal_chunk_header *cur_header;
if (!chunk_name)
return -EINVAL;
dal_smem_start = smem_get_entry(SMEM_DAL_AREA, &dal_smem_size);
if (!dal_smem_start)
return -ENXIO;
dal_smem_end = dal_smem_start + dal_smem_size;
/* Find first chunk header */
cur_header = (struct dal_chunk_header *)
(((uint32_t)dal_smem_start + (4095)) & ~4095);
*lock = NULL;
while (cur_header->size != 0
&& ((uint32_t)(cur_header + 1) < (uint32_t)dal_smem_end)) {
/* Check if chunk name matches */
if (!strncmp(cur_header->name, chunk_name,
DAL_CHUNK_NAME_LENGTH)) {
*lock = (_remote_spinlock_t)&cur_header->lock;
return 0;
}
cur_header = (void *)cur_header + cur_header->size;
}
pr_err("%s: DAL remote lock \"%s\" not found.\n", __func__,
chunk_name);
return -EINVAL;
}
#define SMEM_SPINLOCK_COUNT 8
#define SMEM_SPINLOCK_ARRAY_SIZE (SMEM_SPINLOCK_COUNT * sizeof(uint32_t))
static int remote_spinlock_init_address_smem(int id, _remote_spinlock_t *lock)
{
_remote_spinlock_t spinlock_start;
if (id >= SMEM_SPINLOCK_COUNT)
return -EINVAL;
spinlock_start = smem_alloc(SMEM_SPINLOCK_ARRAY,
SMEM_SPINLOCK_ARRAY_SIZE);
if (spinlock_start == NULL)
return -ENXIO;
*lock = spinlock_start + id;
lock_count = SMEM_SPINLOCK_COUNT;
return 0;
}
static int remote_spinlock_init_address(int id, _remote_spinlock_t *lock)
{
if (is_hw_lock_type)
return remote_spinlock_init_address_hw(id, lock);
else
return remote_spinlock_init_address_smem(id, lock);
}
int _remote_spin_lock_init(remote_spinlock_id_t id, _remote_spinlock_t *lock)
{
BUG_ON(id == NULL);
/*
* Optimistic locking. Init only needs to be done once by the first
* caller. After that, serializing inits between different callers
* is unnecessary. The second check after the lock ensures init
* wasn't previously completed by someone else before the lock could
* be grabbed.
*/
if (!current_ops.lock) {
mutex_lock(&ops_init_lock);
if (!current_ops.lock)
initialize_ops();
mutex_unlock(&ops_init_lock);
}
if (id[0] == 'D' && id[1] == ':') {
/* DAL chunk name starts after "D:" */
return remote_spinlock_dal_init(&id[2], lock);
} else if (id[0] == 'S' && id[1] == ':') {
/* Single-digit lock ID follows "S:" */
BUG_ON(id[3] != '\0');
return remote_spinlock_init_address((((uint8_t)id[2])-'0'),
lock);
} else {
return -EINVAL;
}
}
/*
* lock comes in as a pointer to a pointer to the lock location, so it must
* be dereferenced and casted to the right type for the actual lock
* implementation functions
*/
void _remote_spin_lock(_remote_spinlock_t *lock)
{
if (unlikely(!current_ops.lock))
BUG();
current_ops.lock((raw_remote_spinlock_t *)(*lock));
}
EXPORT_SYMBOL(_remote_spin_lock);
void _remote_spin_unlock(_remote_spinlock_t *lock)
{
if (unlikely(!current_ops.unlock))
BUG();
current_ops.unlock((raw_remote_spinlock_t *)(*lock));
}
EXPORT_SYMBOL(_remote_spin_unlock);
int _remote_spin_trylock(_remote_spinlock_t *lock)
{
if (unlikely(!current_ops.trylock))
BUG();
return current_ops.trylock((raw_remote_spinlock_t *)(*lock));
}
EXPORT_SYMBOL(_remote_spin_trylock);
int _remote_spin_release(_remote_spinlock_t *lock, uint32_t pid)
{
if (unlikely(!current_ops.release))
BUG();
return current_ops.release((raw_remote_spinlock_t *)(*lock), pid);
}
EXPORT_SYMBOL(_remote_spin_release);
int _remote_spin_owner(_remote_spinlock_t *lock)
{
if (unlikely(!current_ops.owner))
BUG();
return current_ops.owner((raw_remote_spinlock_t *)(*lock));
}
EXPORT_SYMBOL(_remote_spin_owner);
/* end common spinlock API -------------------------------------------------- */
/* remote mutex implementation ---------------------------------------------- */
int _remote_mutex_init(struct remote_mutex_id *id, _remote_mutex_t *lock)
{
BUG_ON(id == NULL);
lock->delay_us = id->delay_us;
return _remote_spin_lock_init(id->r_spinlock_id, &(lock->r_spinlock));
}
EXPORT_SYMBOL(_remote_mutex_init);
void _remote_mutex_lock(_remote_mutex_t *lock)
{
while (!_remote_spin_trylock(&(lock->r_spinlock))) {
if (lock->delay_us >= 1000)
msleep(lock->delay_us/1000);
else
udelay(lock->delay_us);
}
}
EXPORT_SYMBOL(_remote_mutex_lock);
void _remote_mutex_unlock(_remote_mutex_t *lock)
{
_remote_spin_unlock(&(lock->r_spinlock));
}
EXPORT_SYMBOL(_remote_mutex_unlock);
int _remote_mutex_trylock(_remote_mutex_t *lock)
{
return _remote_spin_trylock(&(lock->r_spinlock));
}
EXPORT_SYMBOL(_remote_mutex_trylock);
/* end remote mutex implementation ------------------------------------------ */