/**
* dcdbas_exit: perform driver cleanup
*/
static void __exit dcdbas_exit(void)
{
/*
* make sure functions that use dcdbas_pdev are called
* before platform_device_unregister
*/
unregister_reboot_notifier(&dcdbas_reboot_nb);
smi_data_buf_free();
platform_device_unregister(dcdbas_pdev);
platform_driver_unregister(&dcdbas_driver);
/*
* We have to free the buffer here instead of dcdbas_remove
* because only in module exit function we can be sure that
* all sysfs attributes belonging to this module have been
* released.
*/
smi_data_buf_free();
}
/**
* smi_data_buf_realloc: grow SMI data buffer if needed
*/
static int smi_data_buf_realloc(unsigned long size)
{
void *buf;
dma_addr_t handle;
if (smi_data_buf_size >= size)
return 0;
if (size > MAX_SMI_DATA_BUF_SIZE)
return -EINVAL;
/* new buffer is needed */
buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
if (!buf) {
dev_dbg(&dcdbas_pdev->dev,
"%s: failed to allocate memory size %lu\n",
__func__, size);
return -ENOMEM;
}
/* memory zeroed by dma_alloc_coherent */
if (smi_data_buf)
memcpy(buf, smi_data_buf, smi_data_buf_size);
/* free any existing buffer */
smi_data_buf_free();
/* set up new buffer for use */
smi_data_buf = buf;
smi_data_buf_handle = handle;
smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
smi_data_buf_size = size;
dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
__func__, smi_data_buf_phys_addr, smi_data_buf_size);
return 0;
}