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usb: musb: tusb6010_omap: Allocate DMA channels upfront
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Instead of requesting the DMA channel in tusb_omap_dma_allocate() do it
when the controller is created and in runtime work from the DMA channel
pool.

This change is needed for the DMAengine conversion of the driver since the
tusb_omap_dma_allocate() is called in interrupt context which might lead
to lock within the DMAengine API when requesting channel.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Peter Ujfalusi authored and Greg Kroah-Hartman committed Jun 20, 2017
1 parent 1df9d9e commit 4cadc71
Showing 1 changed file with 92 additions and 93 deletions.
185 changes: 92 additions & 93 deletions drivers/usb/musb/tusb6010_omap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@ struct tusb_omap_dma_ch {
u8 tx;
struct musb_hw_ep *hw_ep;

struct tusb_dma_data dma_data;
struct tusb_dma_data *dma_data;

struct tusb_omap_dma *tusb_dma;

Expand All @@ -62,7 +62,7 @@ struct tusb_omap_dma {
struct dma_controller controller;
void __iomem *tbase;

struct tusb_dma_data dma_data;
struct tusb_dma_data dma_pool[MAX_DMAREQ];
unsigned multichannel:1;
};

Expand Down Expand Up @@ -120,10 +120,7 @@ static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)

spin_lock_irqsave(&musb->lock, flags);

if (tusb_dma->multichannel)
ch = chdat->dma_data.ch;
else
ch = tusb_dma->dma_data.ch;
ch = chdat->dma_data->ch;

if (ch_status != OMAP_DMA_BLOCK_IRQ)
printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
Expand Down Expand Up @@ -248,7 +245,8 @@ static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
if (dma_remaining) {
dev_dbg(musb->controller, "Busy %s dma ch%i, not using: %08x\n",
chdat->tx ? "tx" : "rx", chdat->dma_data.ch,
chdat->tx ? "tx" : "rx",
chdat->dma_data ? chdat->dma_data->ch : -1,
dma_remaining);
return false;
}
Expand All @@ -260,11 +258,8 @@ static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
else
chdat->transfer_packet_sz = packet_sz;

if (tusb_dma->multichannel) {
dma_data = &chdat->dma_data;
} else {
dma_data = &tusb_dma->dma_data;

dma_data = chdat->dma_data;
if (!tusb_dma->multichannel) {
if (tusb_omap_use_shared_dmareq(chdat) != 0) {
dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
return false;
Expand All @@ -276,10 +271,10 @@ static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
WARN_ON(1);
return false;
}

omap_set_dma_callback(dma_data->ch, tusb_omap_dma_cb, channel);
}

omap_set_dma_callback(dma_data->ch, tusb_omap_dma_cb, channel);

chdat->packet_sz = packet_sz;
chdat->len = len;
channel->actual_len = 0;
Expand Down Expand Up @@ -410,19 +405,9 @@ static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
static int tusb_omap_dma_abort(struct dma_channel *channel)
{
struct tusb_omap_dma_ch *chdat = to_chdat(channel);
struct tusb_omap_dma *tusb_dma = chdat->tusb_dma;
struct tusb_dma_data *dma_data = &tusb_dma->dma_data;

if (!tusb_dma->multichannel) {
if (dma_data->ch >= 0) {
omap_stop_dma(dma_data->ch);
omap_free_dma(dma_data->ch);
dma_data->ch = -1;
}

dma_data->dmareq = -1;
dma_data->sync_dev = -1;
}
if (chdat->dma_data)
omap_stop_dma(chdat->dma_data->ch);

channel->status = MUSB_DMA_STATUS_FREE;

Expand All @@ -434,15 +419,6 @@ static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
u32 reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
int i, dmareq_nr = -1;

const int sync_dev[6] = {
OMAP24XX_DMA_EXT_DMAREQ0,
OMAP24XX_DMA_EXT_DMAREQ1,
OMAP242X_DMA_EXT_DMAREQ2,
OMAP242X_DMA_EXT_DMAREQ3,
OMAP242X_DMA_EXT_DMAREQ4,
OMAP242X_DMA_EXT_DMAREQ5,
};

for (i = 0; i < MAX_DMAREQ; i++) {
int cur = (reg & (0xf << (i * 5))) >> (i * 5);
if (cur == 0) {
Expand All @@ -459,8 +435,7 @@ static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
reg |= ((1 << 4) << (dmareq_nr * 5));
musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);

chdat->dma_data.dmareq = dmareq_nr;
chdat->dma_data.sync_dev = sync_dev[chdat->dma_data.dmareq];
chdat->dma_data = &chdat->tusb_dma->dma_pool[dmareq_nr];

return 0;
}
Expand All @@ -469,15 +444,14 @@ static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
{
u32 reg;

if (!chdat || chdat->dma_data.dmareq < 0)
if (!chdat || !chdat->dma_data || chdat->dma_data->dmareq < 0)
return;

reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
reg &= ~(0x1f << (chdat->dma_data.dmareq * 5));
reg &= ~(0x1f << (chdat->dma_data->dmareq * 5));
musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);

chdat->dma_data.dmareq = -1;
chdat->dma_data.sync_dev = -1;
chdat->dma_data = NULL;
}

static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
Expand All @@ -488,8 +462,6 @@ tusb_omap_dma_allocate(struct dma_controller *c,
u8 tx)
{
int ret, i;
const char *dev_name;
void *cb_data;
struct tusb_omap_dma *tusb_dma;
struct musb *musb;
void __iomem *tbase;
Expand Down Expand Up @@ -543,46 +515,22 @@ tusb_omap_dma_allocate(struct dma_controller *c,
channel->desired_mode = 0;
channel->actual_len = 0;

if (tusb_dma->multichannel) {
dma_data = &chdat->dma_data;
ret = tusb_omap_dma_allocate_dmareq(chdat);
if (ret != 0)
goto free_dmareq;

if (chdat->tx)
dev_name = "TUSB transmit";
else
dev_name = "TUSB receive";
cb_data = channel;
} else if (tusb_dma->dma_data.ch == -1) {
dma_data = &tusb_dma->dma_data;
dma_data->dmareq = 0;
dma_data->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;

dev_name = "TUSB shared";
/* Callback data gets set later in the shared dmareq case */
cb_data = NULL;

chdat->dma_data.dmareq = -1;
chdat->dma_data.ch = -1;
chdat->dma_data.sync_dev = -1;
if (!chdat->dma_data) {
if (tusb_dma->multichannel) {
ret = tusb_omap_dma_allocate_dmareq(chdat);
if (ret != 0)
goto free_dmareq;
} else {
chdat->dma_data = &tusb_dma->dma_pool[0];
}
}

if (dma_data) {
ret = omap_request_dma(dma_data->sync_dev, dev_name,
tusb_omap_dma_cb, cb_data,
&dma_data->ch);
if (ret != 0)
goto free_dmareq;
} else {
/* Already allocated shared, single DMA channel. */
dma_data = &tusb_dma->dma_data;
}
dma_data = chdat->dma_data;

dev_dbg(musb->controller, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
chdat->epnum,
chdat->tx ? "tx" : "rx",
chdat->dma_data.ch >= 0 ? "dedicated" : "shared",
tusb_dma->multichannel ? "shared" : "dedicated",
dma_data->ch, dma_data->dmareq, dma_data->sync_dev);

return channel;
Expand All @@ -604,7 +552,7 @@ static void tusb_omap_dma_release(struct dma_channel *channel)
u32 reg;

dev_dbg(musb->controller, "ep%i ch%i\n", chdat->epnum,
chdat->dma_data.ch);
chdat->dma_data->ch);

reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
if (chdat->tx)
Expand All @@ -622,14 +570,8 @@ static void tusb_omap_dma_release(struct dma_channel *channel)

channel->status = MUSB_DMA_STATUS_UNKNOWN;

if (chdat->dma_data.ch >= 0) {
omap_stop_dma(chdat->dma_data.ch);
omap_free_dma(chdat->dma_data.ch);
chdat->dma_data.ch = -1;
}

if (chdat->dma_data.dmareq >= 0)
tusb_omap_dma_free_dmareq(chdat);
omap_stop_dma(chdat->dma_data->ch);
tusb_omap_dma_free_dmareq(chdat);

channel = NULL;
}
Expand All @@ -646,15 +588,73 @@ void tusb_dma_controller_destroy(struct dma_controller *c)
kfree(ch->private_data);
kfree(ch);
}
}

if (tusb_dma && !tusb_dma->multichannel && tusb_dma->dma_data.ch >= 0)
omap_free_dma(tusb_dma->dma_data.ch);
/* Free up the DMA channels */
if (tusb_dma && tusb_dma->dma_pool[i].ch >= 0)
omap_free_dma(tusb_dma->dma_pool[i].ch);
}

kfree(tusb_dma);
}
EXPORT_SYMBOL_GPL(tusb_dma_controller_destroy);

static int tusb_omap_allocate_dma_pool(struct tusb_omap_dma *tusb_dma)
{
int i;
int ret = 0;
const int sync_dev[6] = {
OMAP24XX_DMA_EXT_DMAREQ0,
OMAP24XX_DMA_EXT_DMAREQ1,
OMAP242X_DMA_EXT_DMAREQ2,
OMAP242X_DMA_EXT_DMAREQ3,
OMAP242X_DMA_EXT_DMAREQ4,
OMAP242X_DMA_EXT_DMAREQ5,
};

for (i = 0; i < MAX_DMAREQ; i++) {
struct tusb_dma_data *dma_data = &tusb_dma->dma_pool[i];

/*
* Request DMA channels:
* - one channel in case of non multichannel mode
* - MAX_DMAREQ number of channels in multichannel mode
*/
if (i == 0 || tusb_dma->multichannel) {
char ch_name[8];

sprintf(ch_name, "dmareq%d", i);
dma_data->sync_dev = sync_dev[i];
dma_data->ch = -1;
/* callback data is ngoing to be set later */
ret = omap_request_dma(dma_data->sync_dev, ch_name,
tusb_omap_dma_cb, NULL, &dma_data->ch);
if (ret != 0) {
dev_err(tusb_dma->controller.musb->controller,
"Failed to request %s\n", ch_name);
goto dma_error;
}

dma_data->dmareq = i;
} else {
dma_data->dmareq = -1;
dma_data->sync_dev = -1;
dma_data->ch = -1;
}
}

return 0;

dma_error:
for (; i >= 0; i--) {
struct tusb_dma_data *dma_data = &tusb_dma->dma_pool[i];

if (dma_data->ch >= 0)
omap_free_dma(dma_data->ch);
}

return ret;
}

struct dma_controller *
tusb_dma_controller_create(struct musb *musb, void __iomem *base)
{
Expand All @@ -679,10 +679,6 @@ tusb_dma_controller_create(struct musb *musb, void __iomem *base)
tusb_dma->controller.musb = musb;
tusb_dma->tbase = musb->ctrl_base;

tusb_dma->dma_data.ch = -1;
tusb_dma->dma_data.dmareq = -1;
tusb_dma->dma_data.sync_dev = -1;

tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
tusb_dma->controller.channel_release = tusb_omap_dma_release;
tusb_dma->controller.channel_program = tusb_omap_dma_program;
Expand All @@ -709,6 +705,9 @@ tusb_dma_controller_create(struct musb *musb, void __iomem *base)
ch->private_data = chdat;
}

if (tusb_omap_allocate_dma_pool(tusb_dma))
goto cleanup;

return &tusb_dma->controller;

cleanup:
Expand Down

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