OpenCloudOS-Kernel/drivers/misc/mei/dma-ring.c

120 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved.
*/
#include <linux/dma-mapping.h>
#include <linux/mei.h>
#include "mei_dev.h"
/**
* mei_dmam_dscr_alloc() - allocate a managed coherent buffer
* for the dma descriptor
* @dev: mei_device
* @dscr: dma descriptor
*
* Return:
* * 0 - on success or zero allocation request
* * -EINVAL - if size is not power of 2
* * -ENOMEM - of allocation has failed
*/
static int mei_dmam_dscr_alloc(struct mei_device *dev,
struct mei_dma_dscr *dscr)
{
if (!dscr->size)
return 0;
if (WARN_ON(!is_power_of_2(dscr->size)))
return -EINVAL;
if (dscr->vaddr)
return 0;
dscr->vaddr = dmam_alloc_coherent(dev->dev, dscr->size, &dscr->daddr,
GFP_KERNEL);
if (!dscr->vaddr)
return -ENOMEM;
return 0;
}
/**
* mei_dmam_dscr_free() - free a managed coherent buffer
* from the dma descriptor
* @dev: mei_device
* @dscr: dma descriptor
*/
static void mei_dmam_dscr_free(struct mei_device *dev,
struct mei_dma_dscr *dscr)
{
if (!dscr->vaddr)
return;
dmam_free_coherent(dev->dev, dscr->size, dscr->vaddr, dscr->daddr);
dscr->vaddr = NULL;
}
/**
* mei_dmam_ring_free() - free dma ring buffers
* @dev: mei device
*/
void mei_dmam_ring_free(struct mei_device *dev)
{
int i;
for (i = 0; i < DMA_DSCR_NUM; i++)
mei_dmam_dscr_free(dev, &dev->dr_dscr[i]);
}
/**
* mei_dmam_ring_alloc() - allocate dma ring buffers
* @dev: mei device
*
* Return: -ENOMEM on allocation failure 0 otherwise
*/
int mei_dmam_ring_alloc(struct mei_device *dev)
{
int i;
for (i = 0; i < DMA_DSCR_NUM; i++)
if (mei_dmam_dscr_alloc(dev, &dev->dr_dscr[i]))
goto err;
return 0;
err:
mei_dmam_ring_free(dev);
return -ENOMEM;
}
/**
* mei_dma_ring_is_allocated() - check if dma ring is allocated
* @dev: mei device
*
* Return: true if dma ring is allocated
*/
bool mei_dma_ring_is_allocated(struct mei_device *dev)
{
return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;
}
static inline
struct hbm_dma_ring_ctrl *mei_dma_ring_ctrl(struct mei_device *dev)
{
return (struct hbm_dma_ring_ctrl *)dev->dr_dscr[DMA_DSCR_CTRL].vaddr;
}
/**
* mei_dma_ring_reset() - reset the dma control block
* @dev: mei device
*/
void mei_dma_ring_reset(struct mei_device *dev)
{
struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
if (!ctrl)
return;
memset(ctrl, 0, sizeof(*ctrl));
}