blob: 6752dddf8d97678209b6dcdf6984b801750b1dfc [file] [log] [blame]
/*
* Copyright (c) 2016 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <zephyr/kernel_structs.h>
#include <zephyr/toolchain.h>
#include <zephyr/linker/sections.h>
#include <zephyr/wait_q.h>
#include <zephyr/sys/dlist.h>
#include <ksched.h>
#include <zephyr/init.h>
#include <zephyr/sys/check.h>
/**
* @brief Initialize kernel memory slab subsystem.
*
* Perform any initialization of memory slabs that wasn't done at build time.
* Currently this just involves creating the list of free blocks for each slab.
*
* @retval 0 on success.
* @retval -EINVAL if @p slab contains invalid configuration and/or values.
*/
static int create_free_list(struct k_mem_slab *slab)
{
uint32_t j;
char *p;
/* blocks must be word aligned */
CHECKIF(((slab->block_size | (uintptr_t)slab->buffer) &
(sizeof(void *) - 1)) != 0U) {
return -EINVAL;
}
slab->free_list = NULL;
p = slab->buffer;
for (j = 0U; j < slab->num_blocks; j++) {
*(char **)p = slab->free_list;
slab->free_list = p;
p += slab->block_size;
}
return 0;
}
/**
* @brief Complete initialization of statically defined memory slabs.
*
* Perform any initialization that wasn't done at build time.
*
* @return 0 on success, fails otherwise.
*/
static int init_mem_slab_module(const struct device *dev)
{
int rc = 0;
ARG_UNUSED(dev);
STRUCT_SECTION_FOREACH(k_mem_slab, slab) {
rc = create_free_list(slab);
if (rc < 0) {
goto out;
}
z_object_init(slab);
}
out:
return rc;
}
SYS_INIT(init_mem_slab_module, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
int k_mem_slab_init(struct k_mem_slab *slab, void *buffer,
size_t block_size, uint32_t num_blocks)
{
int rc = 0;
slab->num_blocks = num_blocks;
slab->block_size = block_size;
slab->buffer = buffer;
slab->num_used = 0U;
slab->lock = (struct k_spinlock) {};
#ifdef CONFIG_MEM_SLAB_TRACE_MAX_UTILIZATION
slab->max_used = 0U;
#endif
rc = create_free_list(slab);
if (rc < 0) {
goto out;
}
z_waitq_init(&slab->wait_q);
z_object_init(slab);
out:
SYS_PORT_TRACING_OBJ_INIT(k_mem_slab, slab, rc);
return rc;
}
int k_mem_slab_alloc(struct k_mem_slab *slab, void **mem, k_timeout_t timeout)
{
k_spinlock_key_t key = k_spin_lock(&slab->lock);
int result;
SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_mem_slab, alloc, slab, timeout);
if (slab->free_list != NULL) {
/* take a free block */
*mem = slab->free_list;
slab->free_list = *(char **)(slab->free_list);
slab->num_used++;
#ifdef CONFIG_MEM_SLAB_TRACE_MAX_UTILIZATION
slab->max_used = MAX(slab->num_used, slab->max_used);
#endif
result = 0;
} else if (K_TIMEOUT_EQ(timeout, K_NO_WAIT) ||
!IS_ENABLED(CONFIG_MULTITHREADING)) {
/* don't wait for a free block to become available */
*mem = NULL;
result = -ENOMEM;
} else {
SYS_PORT_TRACING_OBJ_FUNC_BLOCKING(k_mem_slab, alloc, slab, timeout);
/* wait for a free block or timeout */
result = z_pend_curr(&slab->lock, key, &slab->wait_q, timeout);
if (result == 0) {
*mem = _current->base.swap_data;
}
SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_mem_slab, alloc, slab, timeout, result);
return result;
}
SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_mem_slab, alloc, slab, timeout, result);
k_spin_unlock(&slab->lock, key);
return result;
}
void k_mem_slab_free(struct k_mem_slab *slab, void **mem)
{
k_spinlock_key_t key = k_spin_lock(&slab->lock);
SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_mem_slab, free, slab);
if (slab->free_list == NULL && IS_ENABLED(CONFIG_MULTITHREADING)) {
struct k_thread *pending_thread = z_unpend_first_thread(&slab->wait_q);
if (pending_thread != NULL) {
SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_mem_slab, free, slab);
z_thread_return_value_set_with_data(pending_thread, 0, *mem);
z_ready_thread(pending_thread);
z_reschedule(&slab->lock, key);
return;
}
}
**(char ***) mem = slab->free_list;
slab->free_list = *(char **) mem;
slab->num_used--;
SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_mem_slab, free, slab);
k_spin_unlock(&slab->lock, key);
}