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linux/drivers/usb/musb/ux500_dma.c
Per Forlin be18a25189 usb: musb: ux500: optimize DMA callback routine 
Skip the use of work queue and call musb_dma_completion() directly from
DMA callback context.

Here follows measurements on a Snowball board with ondemand governor active.

Performance using work queue:
(105 MB) copied, 6.23758 s, 16.8 MB/s
(105 MB) copied, 5.7151 s, 18.3 MB/s
(105 MB) copied, 5.83583 s, 18.0 MB/s
(105 MB) copied, 5.93611 s, 17.7 MB/s

Performance without work queue
(105 MB) copied, 5.62173 s, 18.7 MB/s
(105 MB) copied, 5.61811 s, 18.7 MB/s
(105 MB) copied, 5.57817 s, 18.8 MB/s
(105 MB) copied, 5.58549 s, 18.8 MB/s

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-12 11:51:39 +02:00

394 lines
11 KiB
C
Raw Blame History

/*
* drivers/usb/musb/ux500_dma.c
*
* U8500 and U5500 DMA support code
*
* Copyright (C) 2009 STMicroelectronics
* Copyright (C) 2011 ST-Ericsson SA
* Authors:
* Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
* Praveena Nadahally <praveen.nadahally@stericsson.com>
* Rajaram Regupathy <ragupathy.rajaram@stericsson.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/pfn.h>
#include <mach/usb.h>
#include "musb_core.h"
struct ux500_dma_channel {
struct dma_channel channel;
struct ux500_dma_controller *controller;
struct musb_hw_ep *hw_ep;
struct dma_chan *dma_chan;
unsigned int cur_len;
dma_cookie_t cookie;
u8 ch_num;
u8 is_tx;
u8 is_allocated;
};
struct ux500_dma_controller {
struct dma_controller controller;
struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_CHANNELS];
struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_TX_CHANNELS];
u32 num_rx_channels;
u32 num_tx_channels;
void *private_data;
dma_addr_t phy_base;
};
/* Work function invoked from DMA callback to handle rx transfers. */
void ux500_dma_callback(void *private_data)
{
struct dma_channel *channel = private_data;
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
struct musb *musb = hw_ep->musb;
unsigned long flags;
dev_dbg(musb->controller, "DMA rx transfer done on hw_ep=%d\n",
hw_ep->epnum);
spin_lock_irqsave(&musb->lock, flags);
ux500_channel->channel.actual_len = ux500_channel->cur_len;
ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
musb_dma_completion(musb, hw_ep->epnum,
ux500_channel->is_tx);
spin_unlock_irqrestore(&musb->lock, flags);
}
static bool ux500_configure_channel(struct dma_channel *channel,
u16 packet_sz, u8 mode,
dma_addr_t dma_addr, u32 len)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
struct dma_chan *dma_chan = ux500_channel->dma_chan;
struct dma_async_tx_descriptor *dma_desc;
enum dma_data_direction direction;
struct scatterlist sg;
struct dma_slave_config slave_conf;
enum dma_slave_buswidth addr_width;
dma_addr_t usb_fifo_addr = (MUSB_FIFO_OFFSET(hw_ep->epnum) +
ux500_channel->controller->phy_base);
struct musb *musb = ux500_channel->controller->private_data;
dev_dbg(musb->controller,
"packet_sz=%d, mode=%d, dma_addr=0x%x, len=%d is_tx=%d\n",
packet_sz, mode, dma_addr, len, ux500_channel->is_tx);
ux500_channel->cur_len = len;
sg_init_table(&sg, 1);
sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
offset_in_page(dma_addr));
sg_dma_address(&sg) = dma_addr;
sg_dma_len(&sg) = len;
direction = ux500_channel->is_tx ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
DMA_SLAVE_BUSWIDTH_4_BYTES;
slave_conf.direction = direction;
slave_conf.src_addr = usb_fifo_addr;
slave_conf.src_addr_width = addr_width;
slave_conf.src_maxburst = 16;
slave_conf.dst_addr = usb_fifo_addr;
slave_conf.dst_addr_width = addr_width;
slave_conf.dst_maxburst = 16;
dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
(unsigned long) &slave_conf);
dma_desc = dma_chan->device->
device_prep_slave_sg(dma_chan, &sg, 1, direction,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!dma_desc)
return false;
dma_desc->callback = ux500_dma_callback;
dma_desc->callback_param = channel;
ux500_channel->cookie = dma_desc->tx_submit(dma_desc);
dma_async_issue_pending(dma_chan);
return true;
}
static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
struct musb_hw_ep *hw_ep, u8 is_tx)
{
struct ux500_dma_controller *controller = container_of(c,
struct ux500_dma_controller, controller);
struct ux500_dma_channel *ux500_channel = NULL;
struct musb *musb = controller->private_data;
u8 ch_num = hw_ep->epnum - 1;
u32 max_ch;
/* Max 8 DMA channels (0 - 7). Each DMA channel can only be allocated
* to specified hw_ep. For example DMA channel 0 can only be allocated
* to hw_ep 1 and 9.
*/
if (ch_num > 7)
ch_num -= 8;
max_ch = is_tx ? controller->num_tx_channels :
controller->num_rx_channels;
if (ch_num >= max_ch)
return NULL;
ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
&(controller->rx_channel[ch_num]) ;
/* Check if channel is already used. */
if (ux500_channel->is_allocated)
return NULL;
ux500_channel->hw_ep = hw_ep;
ux500_channel->is_allocated = 1;
dev_dbg(musb->controller, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
hw_ep->epnum, is_tx, ch_num);
return &(ux500_channel->channel);
}
static void ux500_dma_channel_release(struct dma_channel *channel)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb *musb = ux500_channel->controller->private_data;
dev_dbg(musb->controller, "channel=%d\n", ux500_channel->ch_num);
if (ux500_channel->is_allocated) {
ux500_channel->is_allocated = 0;
channel->status = MUSB_DMA_STATUS_FREE;
channel->actual_len = 0;
}
}
static int ux500_dma_is_compatible(struct dma_channel *channel,
u16 maxpacket, void *buf, u32 length)
{
if ((maxpacket & 0x3) ||
((int)buf & 0x3) ||
(length < 512) ||
(length & 0x3))
return false;
else
return true;
}
static int ux500_dma_channel_program(struct dma_channel *channel,
u16 packet_sz, u8 mode,
dma_addr_t dma_addr, u32 len)
{
int ret;
BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
channel->status == MUSB_DMA_STATUS_BUSY);
if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
return false;
channel->status = MUSB_DMA_STATUS_BUSY;
channel->actual_len = 0;
ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
if (!ret)
channel->status = MUSB_DMA_STATUS_FREE;
return ret;
}
static int ux500_dma_channel_abort(struct dma_channel *channel)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct ux500_dma_controller *controller = ux500_channel->controller;
struct musb *musb = controller->private_data;
void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
u16 csr;
dev_dbg(musb->controller, "channel=%d, is_tx=%d\n",
ux500_channel->ch_num, ux500_channel->is_tx);
if (channel->status == MUSB_DMA_STATUS_BUSY) {
if (ux500_channel->is_tx) {
csr = musb_readw(epio, MUSB_TXCSR);
csr &= ~(MUSB_TXCSR_AUTOSET |
MUSB_TXCSR_DMAENAB |
MUSB_TXCSR_DMAMODE);
musb_writew(epio, MUSB_TXCSR, csr);
} else {
csr = musb_readw(epio, MUSB_RXCSR);
csr &= ~(MUSB_RXCSR_AUTOCLEAR |
MUSB_RXCSR_DMAENAB |
MUSB_RXCSR_DMAMODE);
musb_writew(epio, MUSB_RXCSR, csr);
}
ux500_channel->dma_chan->device->
device_control(ux500_channel->dma_chan,
DMA_TERMINATE_ALL, 0);
channel->status = MUSB_DMA_STATUS_FREE;
}
return 0;
}
static int ux500_dma_controller_stop(struct dma_controller *c)
{
struct ux500_dma_controller *controller = container_of(c,
struct ux500_dma_controller, controller);
struct ux500_dma_channel *ux500_channel;
struct dma_channel *channel;
u8 ch_num;
for (ch_num = 0; ch_num < controller->num_rx_channels; ch_num++) {
channel = &controller->rx_channel[ch_num].channel;
ux500_channel = channel->private_data;
ux500_dma_channel_release(channel);
if (ux500_channel->dma_chan)
dma_release_channel(ux500_channel->dma_chan);
}
for (ch_num = 0; ch_num < controller->num_tx_channels; ch_num++) {
channel = &controller->tx_channel[ch_num].channel;
ux500_channel = channel->private_data;
ux500_dma_channel_release(channel);
if (ux500_channel->dma_chan)
dma_release_channel(ux500_channel->dma_chan);
}
return 0;
}
static int ux500_dma_controller_start(struct dma_controller *c)
{
struct ux500_dma_controller *controller = container_of(c,
struct ux500_dma_controller, controller);
struct ux500_dma_channel *ux500_channel = NULL;
struct musb *musb = controller->private_data;
struct device *dev = musb->controller;
struct musb_hdrc_platform_data *plat = dev->platform_data;
struct ux500_musb_board_data *data = plat->board_data;
struct dma_channel *dma_channel = NULL;
u32 ch_num;
u8 dir;
u8 is_tx = 0;
void **param_array;
struct ux500_dma_channel *channel_array;
u32 ch_count;
dma_cap_mask_t mask;
if ((data->num_rx_channels > UX500_MUSB_DMA_NUM_RX_CHANNELS) ||
(data->num_tx_channels > UX500_MUSB_DMA_NUM_TX_CHANNELS))
return -EINVAL;
controller->num_rx_channels = data->num_rx_channels;
controller->num_tx_channels = data->num_tx_channels;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
/* Prepare the loop for RX channels */
channel_array = controller->rx_channel;
ch_count = data->num_rx_channels;
param_array = data->dma_rx_param_array;
for (dir = 0; dir < 2; dir++) {
for (ch_num = 0; ch_num < ch_count; ch_num++) {
ux500_channel = &channel_array[ch_num];
ux500_channel->controller = controller;
ux500_channel->ch_num = ch_num;
ux500_channel->is_tx = is_tx;
dma_channel = &(ux500_channel->channel);
dma_channel->private_data = ux500_channel;
dma_channel->status = MUSB_DMA_STATUS_FREE;
dma_channel->max_len = SZ_16M;
ux500_channel->dma_chan = dma_request_channel(mask,
data->dma_filter,
param_array[ch_num]);
if (!ux500_channel->dma_chan) {
ERR("Dma pipe allocation error dir=%d ch=%d\n",
dir, ch_num);
/* Release already allocated channels */
ux500_dma_controller_stop(c);
return -EBUSY;
}
}
/* Prepare the loop for TX channels */
channel_array = controller->tx_channel;
ch_count = data->num_tx_channels;
param_array = data->dma_tx_param_array;
is_tx = 1;
}
return 0;
}
void dma_controller_destroy(struct dma_controller *c)
{
struct ux500_dma_controller *controller = container_of(c,
struct ux500_dma_controller, controller);
kfree(controller);
}
struct dma_controller *__init
dma_controller_create(struct musb *musb, void __iomem *base)
{
struct ux500_dma_controller *controller;
struct platform_device *pdev = to_platform_device(musb->controller);
struct resource *iomem;
controller = kzalloc(sizeof(*controller), GFP_KERNEL);
if (!controller)
return NULL;
controller->private_data = musb;
/* Save physical address for DMA controller. */
iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
controller->phy_base = (dma_addr_t) iomem->start;
controller->controller.start = ux500_dma_controller_start;
controller->controller.stop = ux500_dma_controller_stop;
controller->controller.channel_alloc = ux500_dma_channel_allocate;
controller->controller.channel_release = ux500_dma_channel_release;
controller->controller.channel_program = ux500_dma_channel_program;
controller->controller.channel_abort = ux500_dma_channel_abort;
controller->controller.is_compatible = ux500_dma_is_compatible;
return &controller->controller;
}
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