android_kernel_cmhtcleo/arch/arm/mach-msm/remote_spinlock.c

/* Copyright (c) 2008-2009, Code Aurora Forum. All rights reserved.
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#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/string.h>

#include <asm/system.h>

#include <mach/remote_spinlock.h>
#include <mach/dal.h>
#include "smd_private.h"

#define SMEM_SPINLOCK_COUNT 8
#define SMEM_SPINLOCK_ARRAY_SIZE (SMEM_SPINLOCK_COUNT * sizeof(uint32_t))

#if defined(CONFIG_ARCH_MSM7X30)
static int remote_spinlock_smem_init(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;

	return 0;
}

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_item(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 DEK_LOCK_REQUEST		1
#define DEK_LOCK_YIELD			(!DEK_LOCK_REQUEST)
#define DEK_YIELD_TURN_SELF		0
static inline 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 inline 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 inline void __raw_remote_dek_spin_unlock(raw_remote_spinlock_t *lock)
{
	smp_mb();

	lock->dek.self_lock = DEK_LOCK_YIELD;
}
#endif

int _remote_spin_lock_init(remote_spin_lock_id_t id, _remote_spinlock_t *lock)
{
#if defined(CONFIG_ARCH_MSM7X30)
	BUG_ON(id == NULL);

	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 SMEM lock ID follows "S:" */
		BUG_ON(id[3] != '\0');
		return remote_spinlock_smem_init((((uint8_t)id[2])-'0'), lock);
	} else
		return -EINVAL;
#else
	_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;

	return 0;
#endif
}

#if defined(CONFIG_ARCH_MSM7X30)
void _remote_spin_lock(_remote_spinlock_t *lock)
{
	__raw_remote_dek_spin_lock((raw_remote_spinlock_t *) (*lock));
}

void _remote_spin_unlock(_remote_spinlock_t *lock)
{
	__raw_remote_dek_spin_unlock((raw_remote_spinlock_t *) (*lock));
}
#endif