Commit 50437bff authored by Russell King's avatar Russell King

dmaengine: split out virtual channel DMA support from sa11x0 driver

Split the virtual slave channel DMA support from the sa11x0 driver so
this code can be shared with other slave DMA engine drivers.
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 6887a413
...@@ -255,6 +255,7 @@ config DMA_SA11X0 ...@@ -255,6 +255,7 @@ config DMA_SA11X0
tristate "SA-11x0 DMA support" tristate "SA-11x0 DMA support"
depends on ARCH_SA1100 depends on ARCH_SA1100
select DMA_ENGINE select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
help help
Support the DMA engine found on Intel StrongARM SA-1100 and Support the DMA engine found on Intel StrongARM SA-1100 and
SA-1110 SoCs. This DMA engine can only be used with on-chip SA-1110 SoCs. This DMA engine can only be used with on-chip
...@@ -263,6 +264,9 @@ config DMA_SA11X0 ...@@ -263,6 +264,9 @@ config DMA_SA11X0
config DMA_ENGINE config DMA_ENGINE
bool bool
config DMA_VIRTUAL_CHANNELS
tristate
comment "DMA Clients" comment "DMA Clients"
depends on DMA_ENGINE depends on DMA_ENGINE
......
...@@ -2,6 +2,7 @@ ccflags-$(CONFIG_DMADEVICES_DEBUG) := -DDEBUG ...@@ -2,6 +2,7 @@ ccflags-$(CONFIG_DMADEVICES_DEBUG) := -DDEBUG
ccflags-$(CONFIG_DMADEVICES_VDEBUG) += -DVERBOSE_DEBUG ccflags-$(CONFIG_DMADEVICES_VDEBUG) += -DVERBOSE_DEBUG
obj-$(CONFIG_DMA_ENGINE) += dmaengine.o obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
obj-$(CONFIG_DMA_VIRTUAL_CHANNELS) += virt-dma.o
obj-$(CONFIG_NET_DMA) += iovlock.o obj-$(CONFIG_NET_DMA) += iovlock.o
obj-$(CONFIG_INTEL_MID_DMAC) += intel_mid_dma.o obj-$(CONFIG_INTEL_MID_DMAC) += intel_mid_dma.o
obj-$(CONFIG_DMATEST) += dmatest.o obj-$(CONFIG_DMATEST) += dmatest.o
......
This diff is collapsed.
/*
* Virtual DMA channel support for DMAengine
*
* Copyright (C) 2012 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include "virt-dma.h"
static struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx)
{
return container_of(tx, struct virt_dma_desc, tx);
}
dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct virt_dma_chan *vc = to_virt_chan(tx->chan);
struct virt_dma_desc *vd = to_virt_desc(tx);
unsigned long flags;
dma_cookie_t cookie;
spin_lock_irqsave(&vc->lock, flags);
cookie = dma_cookie_assign(tx);
list_add_tail(&vd->node, &vc->desc_submitted);
spin_unlock_irqrestore(&vc->lock, flags);
dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n",
vc, vd, cookie);
return cookie;
}
EXPORT_SYMBOL_GPL(vchan_tx_submit);
/*
* This tasklet handles the completion of a DMA descriptor by
* calling its callback and freeing it.
*/
static void vchan_complete(unsigned long arg)
{
struct virt_dma_chan *vc = (struct virt_dma_chan *)arg;
LIST_HEAD(head);
spin_lock_irq(&vc->lock);
list_splice_tail_init(&vc->desc_completed, &head);
spin_unlock_irq(&vc->lock);
while (!list_empty(&head)) {
struct virt_dma_desc *vd = list_first_entry(&head,
struct virt_dma_desc, node);
dma_async_tx_callback cb = vd->tx.callback;
void *cb_data = vd->tx.callback_param;
list_del(&vd->node);
vc->desc_free(vd);
if (cb)
cb(cb_data);
}
}
void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head)
{
while (!list_empty(head)) {
struct virt_dma_desc *vd = list_first_entry(head,
struct virt_dma_desc, node);
list_del(&vd->node);
dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd);
vc->desc_free(vd);
}
}
EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list);
void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
{
dma_cookie_init(&vc->chan);
spin_lock_init(&vc->lock);
INIT_LIST_HEAD(&vc->desc_submitted);
INIT_LIST_HEAD(&vc->desc_issued);
INIT_LIST_HEAD(&vc->desc_completed);
tasklet_init(&vc->task, vchan_complete, (unsigned long)vc);
vc->chan.device = dmadev;
list_add_tail(&vc->chan.device_node, &dmadev->channels);
}
EXPORT_SYMBOL_GPL(vchan_init);
MODULE_AUTHOR("Russell King");
MODULE_LICENSE("GPL");
/*
* Virtual DMA channel support for DMAengine
*
* Copyright (C) 2012 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef VIRT_DMA_H
#define VIRT_DMA_H
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include "dmaengine.h"
struct virt_dma_desc {
struct dma_async_tx_descriptor tx;
/* protected by vc.lock */
struct list_head node;
};
struct virt_dma_chan {
struct dma_chan chan;
struct tasklet_struct task;
void (*desc_free)(struct virt_dma_desc *);
spinlock_t lock;
/* protected by vc.lock */
struct list_head desc_submitted;
struct list_head desc_issued;
struct list_head desc_completed;
};
static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
{
return container_of(chan, struct virt_dma_chan, chan);
}
void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head);
void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev);
/**
* vchan_tx_prep - prepare a descriptor
* vc: virtual channel allocating this descriptor
* vd: virtual descriptor to prepare
* tx_flags: flags argument passed in to prepare function
*/
static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan *vc,
struct virt_dma_desc *vd, unsigned long tx_flags)
{
extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
vd->tx.flags = tx_flags;
vd->tx.tx_submit = vchan_tx_submit;
return &vd->tx;
}
/**
* vchan_issue_pending - move submitted descriptors to issued list
* vc: virtual channel to update
*
* vc.lock must be held by caller
*/
static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
{
list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
return !list_empty(&vc->desc_issued);
}
/**
* vchan_cookie_complete - report completion of a descriptor
* vd: virtual descriptor to update
*
* vc.lock must be held by caller
*/
static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
{
struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
dma_cookie_complete(&vd->tx);
dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
vd, vd->tx.cookie);
list_add_tail(&vd->node, &vc->desc_completed);
tasklet_schedule(&vc->task);
}
/**
* vchan_next_desc - peek at the next descriptor to be processed
* vc: virtual channel to obtain descriptor from
*
* vc.lock must be held by caller
*/
static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc)
{
if (list_empty(&vc->desc_issued))
return NULL;
return list_first_entry(&vc->desc_issued, struct virt_dma_desc, node);
}
/**
* vchan_get_all_descriptors - obtain all submitted and issued descriptors
* vc: virtual channel to get descriptors from
* head: list of descriptors found
*
* vc.lock must be held by caller
*
* Removes all submitted and issued descriptors from internal lists, and
* provides a list of all descriptors found
*/
static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
struct list_head *head)
{
list_splice_tail_init(&vc->desc_submitted, head);
list_splice_tail_init(&vc->desc_issued, head);
list_splice_tail_init(&vc->desc_completed, head);
}
static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
{
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&vc->lock, flags);
vchan_get_all_descriptors(vc, &head);
spin_unlock_irqrestore(&vc->lock, flags);
vchan_dma_desc_free_list(vc, &head);
}
#endif
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