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Merge branch 'topic/univ_api' into for-linus

This commit is contained in:
Vinod Koul 2016-01-06 15:17:32 +05:30
parent 5eec94388d 020c62ae38
commit 7c7b680fa6
7 changed files with 190 additions and 75 deletions
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21
Documentation/dmaengine/client.txt
View File

@ -22,25 +22,14 @@ The slave DMA usage consists of following steps:
Channel allocation is slightly different in the slave DMA context,
client drivers typically need a channel from a particular DMA
controller only and even in some cases a specific channel is desired.
To request a channel dma_request_channel() API is used.
To request a channel dma_request_chan() API is used.
Interface:
struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
dma_filter_fn filter_fn,
void *filter_param);
where dma_filter_fn is defined as:
typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
struct dma_chan *dma_request_chan(struct device *dev, const char *name);
The 'filter_fn' parameter is optional, but highly recommended for
slave and cyclic channels as they typically need to obtain a specific
DMA channel.
When the optional 'filter_fn' parameter is NULL, dma_request_channel()
simply returns the first channel that satisfies the capability mask.
Otherwise, the 'filter_fn' routine will be called once for each free
channel which has a capability in 'mask'. 'filter_fn' is expected to
return 'true' when the desired DMA channel is found.
Which will find and return the 'name' DMA channel associated with the 'dev'
device. The association is done via DT, ACPI or board file based
dma_slave_map matching table.
A channel allocated via this interface is exclusive to the caller,
until dma_release_channel() is called.

172
drivers/dma/dmaengine.c
View File

@ -43,6 +43,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/module.h>
@ -512,7 +513,7 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
{
struct dma_chan *chan;
if (!__dma_device_satisfies_mask(dev, mask)) {
if (mask && !__dma_device_satisfies_mask(dev, mask)) {
pr_debug("%s: wrong capabilities\n", __func__);
return NULL;
}
@ -543,6 +544,42 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
return NULL;
}
static struct dma_chan *find_candidate(struct dma_device *device,
const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param)
{
struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
int err;
if (chan) {
/* Found a suitable channel, try to grab, prep, and return it.
* We first set DMA_PRIVATE to disable balance_ref_count as this
* channel will not be published in the general-purpose
* allocator
*/
dma_cap_set(DMA_PRIVATE, device->cap_mask);
device->privatecnt++;
err = dma_chan_get(chan);
if (err) {
if (err == -ENODEV) {
pr_debug("%s: %s module removed\n", __func__,
dma_chan_name(chan));
list_del_rcu(&device->global_node);
} else
pr_debug("%s: failed to get %s: (%d)\n",
__func__, dma_chan_name(chan), err);
if (--device->privatecnt == 0)
dma_cap_clear(DMA_PRIVATE, device->cap_mask);
chan = ERR_PTR(err);
}
}
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
}
/**
* dma_get_slave_channel - try to get specific channel exclusively
* @chan: target channel
@ -581,7 +618,6 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
int err;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
@ -589,23 +625,11 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
/* lock against __dma_request_channel */
mutex_lock(&dma_list_mutex);
chan = private_candidate(&mask, device, NULL, NULL);
if (chan) {
dma_cap_set(DMA_PRIVATE, device->cap_mask);
device->privatecnt++;
err = dma_chan_get(chan);
if (err) {
pr_debug("%s: failed to get %s: (%d)\n",
__func__, dma_chan_name(chan), err);
chan = NULL;
if (--device->privatecnt == 0)
dma_cap_clear(DMA_PRIVATE, device->cap_mask);
}
}
chan = find_candidate(device, &mask, NULL, NULL);
mutex_unlock(&dma_list_mutex);
return chan;
return IS_ERR(chan) ? NULL : chan;
}
EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
@ -622,35 +646,15 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
{
struct dma_device *device, *_d;
struct dma_chan *chan = NULL;
int err;
/* Find a channel */
mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
chan = private_candidate(mask, device, fn, fn_param);
if (chan) {
/* Found a suitable channel, try to grab, prep, and
* return it. We first set DMA_PRIVATE to disable
* balance_ref_count as this channel will not be
* published in the general-purpose allocator
*/
dma_cap_set(DMA_PRIVATE, device->cap_mask);
device->privatecnt++;
err = dma_chan_get(chan);
chan = find_candidate(device, mask, fn, fn_param);
if (!IS_ERR(chan))
break;
if (err == -ENODEV) {
pr_debug("%s: %s module removed\n",
__func__, dma_chan_name(chan));
list_del_rcu(&device->global_node);
} else if (err)
pr_debug("%s: failed to get %s: (%d)\n",
__func__, dma_chan_name(chan), err);
else
break;
if (--device->privatecnt == 0)
dma_cap_clear(DMA_PRIVATE, device->cap_mask);
chan = NULL;
}
chan = NULL;
}
mutex_unlock(&dma_list_mutex);
@ -663,27 +667,73 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
}
EXPORT_SYMBOL_GPL(__dma_request_channel);
static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
const char *name,
struct device *dev)
{
int i;
if (!device->filter.mapcnt)
return NULL;
for (i = 0; i < device->filter.mapcnt; i++) {
const struct dma_slave_map *map = &device->filter.map[i];
if (!strcmp(map->devname, dev_name(dev)) &&
!strcmp(map->slave, name))
return map;
}
return NULL;
}
/**
* dma_request_slave_channel_reason - try to allocate an exclusive slave channel
* dma_request_chan - try to allocate an exclusive slave channel
* @dev: pointer to client device structure
* @name: slave channel name
*
* Returns pointer to appropriate DMA channel on success or an error pointer.
*/
struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
const char *name)
struct dma_chan *dma_request_chan(struct device *dev, const char *name)
{
struct dma_device *d, *_d;
struct dma_chan *chan = NULL;
/* If device-tree is present get slave info from here */
if (dev->of_node)
return of_dma_request_slave_channel(dev->of_node, name);
chan = of_dma_request_slave_channel(dev->of_node, name);
/* If device was enumerated by ACPI get slave info from here */
if (ACPI_HANDLE(dev))
return acpi_dma_request_slave_chan_by_name(dev, name);
if (has_acpi_companion(dev) && !chan)
chan = acpi_dma_request_slave_chan_by_name(dev, name);
return ERR_PTR(-ENODEV);
if (chan) {
/* Valid channel found or requester need to be deferred */
if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
return chan;
}
/* Try to find the channel via the DMA filter map(s) */
mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
dma_cap_mask_t mask;
const struct dma_slave_map *map = dma_filter_match(d, name, dev);
if (!map)
continue;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = find_candidate(d, &mask, d->filter.fn, map->param);
if (!IS_ERR(chan))
break;
}
mutex_unlock(&dma_list_mutex);
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
}
EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
EXPORT_SYMBOL_GPL(dma_request_chan);
/**
* dma_request_slave_channel - try to allocate an exclusive slave channel
@ -695,17 +745,35 @@ EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
struct dma_chan *dma_request_slave_channel(struct device *dev,
const char *name)
{
struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
struct dma_chan *ch = dma_request_chan(dev, name);
if (IS_ERR(ch))
return NULL;
dma_cap_set(DMA_PRIVATE, ch->device->cap_mask);
ch->device->privatecnt++;
return ch;
}
EXPORT_SYMBOL_GPL(dma_request_slave_channel);
/**
* dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
* @mask: capabilities that the channel must satisfy
*
* Returns pointer to appropriate DMA channel on success or an error pointer.
*/
struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
{
struct dma_chan *chan;
if (!mask)
return ERR_PTR(-ENODEV);
chan = __dma_request_channel(mask, NULL, NULL);
if (!chan)
chan = ERR_PTR(-ENODEV);
return chan;
}
EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
void dma_release_channel(struct dma_chan *chan)
{
mutex_lock(&dma_list_mutex);

4
drivers/dma/edma.c
View File

@ -2297,6 +2297,10 @@ static int edma_probe(struct platform_device *pdev)
edma_set_chmap(&ecc->slave_chans[i], ecc->dummy_slot);
}
ecc->dma_slave.filter.map = info->slave_map;
ecc->dma_slave.filter.mapcnt = info->slavecnt;
ecc->dma_slave.filter.fn = edma_filter_fn;
ret = dma_async_device_register(&ecc->dma_slave);
if (ret) {
dev_err(dev, "slave ddev registration failed (%d)\n", ret);

4
drivers/dma/omap-dma.c
View File

@ -1203,6 +1203,10 @@ static int omap_dma_probe(struct platform_device *pdev)
return rc;
}
od->ddev.filter.map = od->plat->slave_map;
od->ddev.filter.mapcnt = od->plat->slavecnt;
od->ddev.filter.fn = omap_dma_filter_fn;
rc = dma_async_device_register(&od->ddev);
if (rc) {
pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",

51
include/linux/dmaengine.h
View File

@ -606,12 +606,39 @@ enum dmaengine_alignment {
DMAENGINE_ALIGN_64_BYTES = 6,
};
/**
* struct dma_slave_map - associates slave device and it's slave channel with
* parameter to be used by a filter function
* @devname: name of the device
* @slave: slave channel name
* @param: opaque parameter to pass to struct dma_filter.fn
*/
struct dma_slave_map {
const char *devname;
const char *slave;
void *param;
};
/**
* struct dma_filter - information for slave device/channel to filter_fn/param
* mapping
* @fn: filter function callback
* @mapcnt: number of slave device/channel in the map
* @map: array of channel to filter mapping data
*/
struct dma_filter {
dma_filter_fn fn;
int mapcnt;
const struct dma_slave_map *map;
};
/**
* struct dma_device - info on the entity supplying DMA services
* @chancnt: how many DMA channels are supported
* @privatecnt: how many DMA channels are requested by dma_request_channel
* @channels: the list of struct dma_chan
* @global_node: list_head for global dma_device_list
* @filter: information for device/slave to filter function/param mapping
* @cap_mask: one or more dma_capability flags
* @max_xor: maximum number of xor sources, 0 if no capability
* @max_pq: maximum number of PQ sources and PQ-continue capability
@ -667,6 +694,7 @@ struct dma_device {
unsigned int privatecnt;
struct list_head channels;
struct list_head global_node;
struct dma_filter filter;
dma_cap_mask_t cap_mask;
unsigned short max_xor;
unsigned short max_pq;
@ -1142,9 +1170,11 @@ enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
void dma_issue_pending_all(void);
struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param);
struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
const char *name);
struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
struct dma_chan *dma_request_chan(struct device *dev, const char *name);
struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);
void dma_release_channel(struct dma_chan *chan);
int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps);
#else
@ -1168,16 +1198,21 @@ static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
{
return NULL;
}
static inline struct dma_chan *dma_request_slave_channel_reason(
struct device *dev, const char *name)
{
return ERR_PTR(-ENODEV);
}
static inline struct dma_chan *dma_request_slave_channel(struct device *dev,
const char *name)
{
return NULL;
}
static inline struct dma_chan *dma_request_chan(struct device *dev,
const char *name)
{
return ERR_PTR(-ENODEV);
}
static inline struct dma_chan *dma_request_chan_by_mask(
const dma_cap_mask_t *mask)
{
return ERR_PTR(-ENODEV);
}
static inline void dma_release_channel(struct dma_chan *chan)
{
}
@ -1188,6 +1223,8 @@ static inline int dma_get_slave_caps(struct dma_chan *chan,
}
#endif
#define dma_request_slave_channel_reason(dev, name) dma_request_chan(dev, name)
static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx)
{
struct dma_slave_caps caps;

6
include/linux/omap-dma.h
View File

@ -267,6 +267,9 @@ struct omap_dma_reg {
u8 type;
};
#define SDMA_FILTER_PARAM(hw_req) ((int[]) { (hw_req) })
struct dma_slave_map;
/* System DMA platform data structure */
struct omap_system_dma_plat_info {
const struct omap_dma_reg *reg_map;
@ -278,6 +281,9 @@ struct omap_system_dma_plat_info {
void (*clear_dma)(int lch);
void (*dma_write)(u32 val, int reg, int lch);
u32 (*dma_read)(int reg, int lch);
const struct dma_slave_map *slave_map;
int slavecnt;
};
#ifdef CONFIG_ARCH_OMAP2PLUS

7
include/linux/platform_data/edma.h
View File

@ -53,12 +53,16 @@ enum dma_event_q {
#define EDMA_CTLR(i) ((i) >> 16)
#define EDMA_CHAN_SLOT(i) ((i) & 0xffff)
#define EDMA_FILTER_PARAM(ctlr, chan) ((int[]) { EDMA_CTLR_CHAN(ctlr, chan) })
struct edma_rsv_info {
const s16 (*rsv_chans)[2];
const s16 (*rsv_slots)[2];
};
struct dma_slave_map;
/* platform_data for EDMA driver */
struct edma_soc_info {
/*
@ -76,6 +80,9 @@ struct edma_soc_info {
s8 (*queue_priority_mapping)[2];
const s16 (*xbar_chans)[2];
const struct dma_slave_map *slave_map;
int slavecnt;
};
#endif