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The DMA ring control block contains write and read indices for host and device circular buffers. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
120 lines
2.4 KiB
C
120 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved.
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*/
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#include <linux/dma-mapping.h>
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#include <linux/mei.h>
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#include "mei_dev.h"
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/**
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* mei_dmam_dscr_alloc() - allocate a managed coherent buffer
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* for the dma descriptor
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* @dev: mei_device
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* @dscr: dma descriptor
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*
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* Return:
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* * 0 - on success or zero allocation request
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* * -EINVAL - if size is not power of 2
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* * -ENOMEM - of allocation has failed
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*/
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static int mei_dmam_dscr_alloc(struct mei_device *dev,
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struct mei_dma_dscr *dscr)
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{
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if (!dscr->size)
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return 0;
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if (WARN_ON(!is_power_of_2(dscr->size)))
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return -EINVAL;
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if (dscr->vaddr)
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return 0;
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dscr->vaddr = dmam_alloc_coherent(dev->dev, dscr->size, &dscr->daddr,
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GFP_KERNEL);
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if (!dscr->vaddr)
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return -ENOMEM;
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return 0;
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}
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/**
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* mei_dmam_dscr_free() - free a managed coherent buffer
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* from the dma descriptor
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* @dev: mei_device
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* @dscr: dma descriptor
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*/
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static void mei_dmam_dscr_free(struct mei_device *dev,
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struct mei_dma_dscr *dscr)
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{
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if (!dscr->vaddr)
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return;
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dmam_free_coherent(dev->dev, dscr->size, dscr->vaddr, dscr->daddr);
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dscr->vaddr = NULL;
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}
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/**
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* mei_dmam_ring_free() - free dma ring buffers
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* @dev: mei device
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*/
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void mei_dmam_ring_free(struct mei_device *dev)
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{
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int i;
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for (i = 0; i < DMA_DSCR_NUM; i++)
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mei_dmam_dscr_free(dev, &dev->dr_dscr[i]);
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}
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/**
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* mei_dmam_ring_alloc() - allocate dma ring buffers
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* @dev: mei device
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*
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* Return: -ENOMEM on allocation failure 0 otherwise
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*/
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int mei_dmam_ring_alloc(struct mei_device *dev)
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{
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int i;
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for (i = 0; i < DMA_DSCR_NUM; i++)
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if (mei_dmam_dscr_alloc(dev, &dev->dr_dscr[i]))
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goto err;
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return 0;
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err:
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mei_dmam_ring_free(dev);
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return -ENOMEM;
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}
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/**
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* mei_dma_ring_is_allocated() - check if dma ring is allocated
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* @dev: mei device
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*
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* Return: true if dma ring is allocated
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*/
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bool mei_dma_ring_is_allocated(struct mei_device *dev)
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{
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return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;
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}
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static inline
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struct hbm_dma_ring_ctrl *mei_dma_ring_ctrl(struct mei_device *dev)
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{
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return (struct hbm_dma_ring_ctrl *)dev->dr_dscr[DMA_DSCR_CTRL].vaddr;
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}
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/**
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* mei_dma_ring_reset() - reset the dma control block
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* @dev: mei device
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*/
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void mei_dma_ring_reset(struct mei_device *dev)
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{
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struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
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if (!ctrl)
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return;
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memset(ctrl, 0, sizeof(*ctrl));
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}
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